AP-42
Supplement A
October 1986
SUPPLEMENT A
TO
COMPILATION
OF
AIR POLLUTANT
EMISSION FACTORS
Volume I:
Stationary Point
9
And Area Sources
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office Of Air And Radiation
Office Of Air Quality Planning And Standards
Research Triangle Park. North Carolina 27711
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INSTRUCTIONS FOR INSERTING SUPPLEMENT A
INTO AP-42
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Add Appendix C.I. New Information.
Add Appendix C.2. New Information.
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PUBLICATI-ONS IN SERIES
Issue
COMPILATION OF AIR POLLUTANT EMISSION FACTORS (Fourth Edition)
9/85
SUPPLEMENT A
Introduction
Section 1.1
1.2
1.3
1.4
1.6
1.7
5.16
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.10
7.11
8.1
8.3
8.6
8.10
- 8.13
8.15
8.19.2
8.22
8.24
10.1
11.2.6
Appendix C.1
Appendix C.2
10/86
Bituminous And Subbiturn!nous Coal Combustion
Anthracite Coal Combustion
Fuel Oil Combustion
Natural Gas Combustion
Wood Waste Combustion In Boilers
Lignite Combustion
Sodium Carbonate
Primary Aluminum Production
Coke Production
Primary Copper Smelting
Ferroalloy Production
Iron And Steel Production
Primary Lead Smelting
Zinc Smelting
Secondary Aluminum Operations
Gray Iron Foundries
Secondary Lead Smelting
Asphaltic Concrete Plants
Bricks And Related Clay Products
Portland Cement Manufacturing
Concrete Batching
Glass Manufacturing
Lime Manufacturing
Crushed Stone Processing
Taconite Ore Processing
Western Surface Coal Mining
Chemical Wood Pulping
Industrial Paved Roads
Particle Size Distribution Data And Sized Emission Factors
For Selected Sources
Generalized Particle Size Distributions
iii
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CONTENTS
Page
INTRODUCTION 1
1. EXTERNAL COMBUSTION SOURCES 1.1-1
1.1 Bituminous Coal Combustion 1.1-1
1.2 Anthracite Coal Combustion 1.2-1
1.3 Fuel Oil Combustion 1.3-1
1.4 Natural Gas Combustion 1.4-1
1.5 Liquified Petroleum Gas Combustion 1.5-1
1.6 Wood Waste Combustion In Boilers 1.6-1
1.7 Lignite Combustion 1.7-1
1.8 Bagasse Combustion In Sugar Mills 1.8-1
1.9 Residential Fireplaces 1.9-1
1.10 Wood Stoves , 1.10-1
1.11 Waste Oil Disposal 1.11-1
2. SOLID WASTE DISPOSAL 2.0-1
2.1 Refuse Incineration 2.1-1
2.2 Automobile Body Incineration 2.2-1
2.3 Conical Burners 2.3-1
2.4 Open Burning 2.4-1
2.5 Sewage Sludge Incineration 2.5-1
3. STATIONARY INTERNAL COMBUSTION SOURCES 3.0-1
Glossary Of Terms Vol. II
3.1 Highway Vehicles Vol. II
3.2 Off Highway Mobile Sources "... Vol. II
3.3 Off Highway Stationary Sources 3.3-1
4. EVAPORATION LOSS SOURCES 4.1-1
4.1 Dry Cleaning 4.1-1
4.2 Surface Coating 4.2-1
4.3 Storage Of Organic Liquids 4.3-1
4.4 Transportation And Marketing Of Petroleum Liquids 4.4-1
4.5 Cutback Asphalt, Emulsified Asphalt And Asphalt Cement .. 4.5-1
4.6 Solvent Degreasing 4.6-1
4.7 Waste Solvent Reclamation 4.7-1
4.8 Tank And Drum jCl«eaning 4.8-1
4.9 Graphic Arts 4.9-1
4.10 Commercial/Consumer Solvent Use 4.10-1
4.11 Textile Fabric Printing 4.11-1
5. CHEMICAL PROCESS INDUSTRY 5.1-1
5.1 Adipic Acid 5.1-1
5.2 Synthetic Ammonia 5.2-1
5.3 Carbon Bl ack 5.3-1
5.4 Charcoal 5.4-1
5.5 Chlor-Alkali 5.5-1
5.6 Explosives 5.6-1
5.7 Hydrochloric Acid 5.7-1
5.8 Hydrofluoric Acid 5.8-1
5.9 Nitric Acid .. .• 5.9-1
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Page
6.
7 .
5.10
5.11
5.12
5.13
5.14
5.15
5.16
5.17
5.18
5.19
5.20
5.21
5.22
5.23
5.24
FOOD
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
6.12
6.13
6.14
6.15
6.16
6.17
6.18
Sulf uric Acid
Synthetic Fibers
Lead Alkyl ,
AND AGRICULTURAL INDUSTRY ,
Feed And Grain Mills And Elevators
METALLURGICAL INDUSTRY
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
7.11
7.12
7.13
7.14
7.15
5.10-1
5.11-1
5.12-1
5.13-1
5.14-1
5.15-1
5.16-1
5.17-1
5.18-1
5.19-1
5.20-1
5.21-1
5.22-1
5.23-1
5.24-1
6.1-1
6.1-1
6.2-1
6.3-1
6.4-1
6.5-1
6.6^-1
6.7-1
6.8-1
6.9-1
6.10-1
6.11-1
6.12-1
6.13-1
6.14-1
6.15-1
6.16-1
6.17-1
...... 6.18-1
7.1-1
7.1-1
7.2-1
7.3-1
7.4-1
7.5-1
7.6-1
7.7-1
7.8-1
7.9-1
7.10-1
7.11-1
7.12-1
7.13-1
7.14-1
7.15-1
vi
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Page
7.16 Lead "Oxide And Pigment Production 7.16-1
7.17 Miscellaneous Lead Products 7.17-1
7.18 Leadbearing Ore Crushing And Grinding ;.'. .7.18-1
8. MINERAL PRODUCTS INDUSTRY V^S.l-l
8.1 Asphaltic Concrete Plants 8.1-1
8.2 Asphalt Roofing 8.2-1
8.3 Bricks And Related Clay Products 8.3-1
8.4 Calcium Carbide Manufacturing 8.4-1
8.5 Gastable Refractories 8.S-1
8.6 Portland Cement Manufacturing .8.6-1
8.7 Ceramic Clay Manufacturing 8.7-1
8.8 Clay And Fly Ash Sintering 8.8-1
8.9 Coal Cleaning ... 8.9-1
8.10 Concrete Batching 8.10-1
8.11 Glass Fiber Manufacturing 8.11-1
8.12 Frit Manufacturing 8.12-1
8.13 Glass Manufacturing 8.13-1
8.14 Gypsum Manufacturing 8.14-1
8 .15 Lime Manufacturing 8.15-1
8.16 Mineral Wool Manufacturing * 8.16-1
8.17 Perlite Manufacturing 8.17-1
8.18 Phosphate Rock Processing 8.18-1
8.19 Construction Aggregate Processing 8.19-1
8.20 [Reserved] 8.20-1
8.21 Coal Conversion 8.21-1
8.22 Taconite. Ore Processing 8.22-1
8.23. Metallic Minerals Processing 8.23-1
8.24 Western Surface Coal Mining 8.24-1
9. . • PETROLEUM INDUSTRY 9.1-1
9.1 Petroleum Refining 9.1-1
9.2 Natural Gas Processing 9.2-1
10. WOOD PRODUCTS INDUSTRY 10.1-1
10.1 Chemical Wood Pulping 10.1-1
10.2 Pulpboard 10.2-1
10.3 Plywood Veneer And Layout Operations 10.3-1
10.4 Woodworking Waste Collection Operations 10.4-1
11. MISCELLANEOUS SOURCES 11.1-1
11.1 Forest Wildfires ' 11.1-1
11.2 Fugitive Dust Sources 11.2-1
11.3 Explosives Detonation 11.3-1
APPENDIX A Miscellaneous Data And Conversion Factors A-l
APPENDIX B (Reserved For Future Use)
APPENDIX C.I Particle Size Distribution Data And Sized Emission
Factors For Selected Sources C.l-1
APPENDIX C.2 Generalized Particle Size Distributions C.2-1
vii
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COMPILATION OF AIR POLLUTANT EMISSION FACTORS
VOLUME I:
STATIONARY POINT AND AREA SOURCES
Introduction
What is an emission factor?
An emission factor is an average value which relates the quantity of a
pollutant released to the atmosphere with the activity associated with the
release of that pollutant. It is usually expressed as the weight of pollutant
divided by a unit weight, volume, distance or duration of the activity that
emits the pollutant (e. g., kilograms of particulate emitted per raegagram of
coal combusted). Using such factors permits the estimation of emissions from
various sources of air pollution. In most cases, these factors are simply
averages of all available data of acceptable quality, generally without consid-
eration for the influence of various process parameters such as temperature,
reactant concentrations, etc. For a few cases, however, such as in the estima-
tion of volatile organic emissions from petroleum storage tanks, this document
contains empirical formulae which can relate emissions to such variables as
tank diameter, .liquid temperature and wind velocity. Emission factors corre-
lated with such variables tend to yield more precise estimates than-would
factors derived from broader statistical averages.
Recommended uses of emission factors
Emission factors are very useful tools for estimating emissions of air pol-
lutants. However, because such factors are averages obtained from data of wide
range and varying degrees of accuracy, emissions calculated this way for a given
facility are likely to differ from that facility's actual emissions. Because
they are averages, factors will indicate higher emission estimates than are ac-
tual for some sources, and lower for others. Only specific source measurement
can determine the actual pollutant contribution from a source, under conditions
existing at the time of the test. For the most accurate emissions estimate, it
is recommended that source specific data be obtained whenever possible. Emis-
sion factors are more appropriately used to estimate the collective emissions
of a number of sources, such as is done in emissions inventory efforts for a
particular geographic area.
If factors are used to predict emissions from new or proposed sources, users
should review the latest literature and technology to determine if such sources
would likely exhibit emissions characteristics different from those of typical
existing sources.
In a few AP-42 Sections, emission factors are presented for facilities
having air pollution control equipment in place. These factors are not intend-
ed to be used as regulatory standards. They do not represent best" available
control technology (BACT), such as may be reflected in New Source Performance
Standards (NSPS), or reasonably available control technology (RACT) for exist-
ing sources . Rather, they relate to the average level of controls found on
existing facilities for which data are available. The usefulness of this
information should be considered carefully, in light' of changes in air pollution
control technology. In using this information with respect to any specific
1 10/86
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source, the user should consider Che age, level of maintenance and other aspects
which may influence equipment efficacy.
Examples of various factor applications
Calculating carbon monoxide (CO) emissions from distillate oil combustion
serves as an example of the simplest use of emission factors. Consider an
industrial boiler which burns 90,000 liters of distillate oil per day. In
Section 1.3 of AP-42, the CO emission factor for industrial boilers burning
distillate oil is 0.6 kg CO per 103 liters of oil burned.
Then CO emissions
= CO emission factor x distillate oil burned/day
=• 0.6 x 90
- 54 kg/day
In a somewhat more complex case, suppose a sulfuric acid (H2S04) plant
produces 200 Mg of 100% H2S04 Per da? bv converting sulfur dioxide (S02) into
sulfur trioxide (803) at 97.5% efficiency. In Section 5.17, the S02 emission
factors are listed according to S02 to SO-j conversion efficiencies, in whole
numbers. The reader is directed to Footnote b, an interpolation formula which
may be used to obtain the emission factor for 97.5% S02 to SOj conversion.
Emission factor for kg S02/Mg 100% H2S04
= 682 - [(6.82)(% S02 to 50^ conversion)]
- 682 - [(6.82X97.5)]
= 682 - 665
° 17
For production of 200 Mg of 100% H2S04 per day, SO-j emissions are calculated as
S02 emissions
= 17 kg S02 emissions/Mg 100% H2S04 x 200 Mg 100% H2S04/day
=- 3400 kg/day
Emission Factor Ratings
To help users understand Che reliability and accuracy of AP-42 emission
factors, each Table (and sometimes individual factors within a Table) is given
a rating (A through E, with A being the best) which reflects the quality and
the amount of data on which the factors.are based. In general, factors based
on many observations or on more widely accepted test procedures are assigned
higher rankings. For instance, an emission factor based on ten or more source
tests on different plants would likely get an A rating, if all tests were
conducted using a single valid reference measurement method or equivalent
techniques. Conversely, a factor based on a single observation of questionable
quality, or one extrapolated from another factor for a similar process, would
probably be labeled D or E. Several subjective schemes have been used in the
past to assign these ratings, depending upon data availability, source charac-
teristics, etc. Because these ratings are subjective and take no account of
the inherent scatter among the data used to calculate factors, they should be
used only as approximations, to infer error bounds or confidence intervals
about each emission factor. At most, a rating- should be considered an indi-
cator of the accuracy and precision of a given factor used to estimate emis-
sions from a large number of sources. This indicator will largely reflect the
professional judgment of the authors and reviewers of AP-42 Sections concerning
the reliability of any estimates derived with these factors.
10/86 2
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1.1 BITUMINOUS AND SUBBITUMINOUS COAL COMBUSTION
1.1.1 General1
Coal is a complex combination of organic matter and inorganic ash formed
over eons from successive layers of fallen vegetation. Coal types are broadly
classified as anthracite, bituminous, subbituminous or lignite, and classifica-
tion is made by heating values and amounts of fixed carbon, volatile matter,
ash, sulfur and moisture. Formulas for differentiating, coals based on these
properties are given in Reference 1. See Sections 1.2 and 1.7 for discussions
of anthracite and lignite, respectively.
There are two major coal combustion techniques, suspension firing and
grate firing. Suspension firing is the primary combustion mechanism in pulver-
ized coal and cyclone systems. Grate firing is the primary mechanism in under-
feed and overfeed stokers. Both mechanisms are employed in spreader stokers.
Pulverized coal furnaces are used primarily in utility and large industrial
boilers. In these systems, the coal is pulverized in a mill to the consistency
of talcum powder (i. e., at least 70 percent of the particles will pass through
a 200 mesh sieve). The pulverized coal is generally entrained in primary air
before being fed through the burners to the combustion chamber, where it is
fired in suspension. Pulverized coal furnaces are classified as either dry or
wet bottom, depending on the ash removal technique. Dry bottom furnaces.fire
coals with high ash fusion temperatures, and dry ash removal techniques are
used. In wet bottom (slag tap) furnaces, coals with low ash fusion tempera-
tures are used, and molten ash is drained from the bottom of Che furnace.
Pulverized coal furnaces are further classified by the firing position of the
burners, i. e., single (front or rear) wall, horizontally opposed, vertical,
tangential (corner fired), turbo or arch fired.
Cyclone furnaces burn low ash fusion temperature coal crushed to a 4 mesh
size. The .coal is fed tangentially, with primary air, to a horizontal cylin-
drical combustion- chamber. In this chamber, small coal particles are burned
in suspension, while the larger particles are forced against the outer wall.
Because of the high temperatures developed in the relatively small furnace
volume, and because of the low fusion temperature of the coal ash, much of the
ash forms a liquid slag which is drained from the bottom of the furnace through
a slag tap opening. Cyclone furnaces are used mostly in utility and large
Industrial applications.
In spreader stokers, a flipping mechanism throws the coal Into the furnace
and onto a moving fuel bed. Combustion occurs partly in suspension and partly
on the grate. Because of significant carbon in the particulate, flyash rein-
jection from mechanical collectors is commonly employed to improve boiler
efficiency. Ash residife in the fuel bed is deposited in a receiving pit at the
end of the grate.
10/86 External Combustion Sources 1.1-1
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TABLE i.1-1. EMISSION FACTORS FOR EXTERNAL BITUMINOUS AND SUBBITUMINOUS COAL COMBUSTION8
I
N)
n
CO
CO
o
z
fc
H
o
po
CO
•trine. Coof Ifurelloo
Dry bottom
Vet bolloM
Cyclone furnece
Uncontrolled
Alter Multiple cyclone
fro* Multiple, cyclone
Mo lly eek rolnjecllon
frcej Multiple cyclone
Overfeed •loner*
Uncontrolled
Alter Multiple cyclone
Underfeed ecaker
Uncontrolled
After Multiple cyclone
Hindi Iced unite
fertlculele*
->»/»n
1A
l.l»h
V U»
10)
i.J
t
«•
4.1"
;.ip
i.j"
;.s
Ib/tan
IOA
)«h
U»
6UJ
i;
12
16*
»"
IIP
II"
IS
Sulfur Oildee'
•4/Kl
H.IS(II.U)
I».SS(I).JS)
l».5S(U.iS)
I».1S(1).>S)
1» iS(ll.5S)
IV.)S(I7 iS)
IV.)S(l).iS)
H.>S(I'.)S)
15. IS
Ib IS
H.1S
Ib/IOM
JHOJS)
)»(JJS)
)»S(J1S)
1«S()»I)
»S()S1)
)«S()SS)
KS(lll)
1>S(»S)
IIS
)IS
IIS
• Uroten Oeldee'
•1/N.
I0.5(' i)«
11
II. >
1
1
I
).M
).)•>
».M
».;j
i.i
U/ton
ll(l»l
J»
11
14
14
14
7.1
;.»
i .1
9.5
1
Cerboe Moaoilde*
•i/M.'
0.1
0.)
0.1
I.i
l.S
I.i
1
1
l.S
S.5
4)
IWtoe
0.4
0.4
0.4
)
S
1
i
t
11
II
10
laoMMlheoe VOC*,'
M/«d
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
O.t*
0.4)
S
•fector* repreeent uncontrolled cMleelone unleee otherwise epectfled end ehould be epplled to coel coneuMplloi
preceding the "A". For eeeopli
would be i • 1. or 40 kg/Ng (DC
-------
o
00
TABLE 1.1-2. EMISSION FACTOR RATINGS AND REFERENCES FOR BITUMINOUS AND SUBBITUMINOUS COAL COMBUSTION
en
X
r»
a>
n
0)
n
§
i>no>lde Nunaclheie VOC Hvllidne
RalhiM Htt . lUtlng
A 16.18-19,21 A
47.57
A " A
A " A
A 17.19,11-W. A
16.47.51
A " A
A " A
1 (7.41-42.45. A
47.51
1 A
1 19,47-48 A
B A
D 50 [)
«e
-------
In overfeed stokers, coal Is fed onto a traveling or vibrating grate, and
it burns on the fuel bed as i t progresses through the furnace. Ash particles
fall Into an ash pit at the rear of the stoker. The term "overfeed" applies
because the coal is fed onto the moving grate under an adjustable gate. Con-
versely, in "underfeed" stokers, coal is fed into the firing zone from under-
neath by mechanical rams or screw conveyers. The coal moves in a channel,
known as a retort, from which it is forced upward, spilling over the top of
each side to form and to feed the fuel bed. Combustion Is completed by the
time the bed reaches the side dump grates from which the ash is discharged to
shallow pits. Underfeed stokers include single retort units and multiple
retort units, the latter having several retorts side by side.
1.1.2 Emissions And Controls
The major pollutants of concern from external coal combustion are partic-
ulate, sulfur oxides and nitrogen oxides. Some unburnt combustibles, including
numerous organic compounds and carbon monoxide, are generally emitted even
under proper boiler operating conditions.
_ particulate composition and emission levels are a complex
function of firing configuration, boiler operation and coal properties. In
pulverized coal systems, combustion is almost complete, and thus particulate
largely comprises inorganic ash residue. In wet bottom pulverized coal units
and cyclones, the quantity of ash leaving the boiler is less than in dry bottom
units, since some of the ash liquifies, collects on the furnace walls, and
drains from the furnace bottom as molten slag. To Increase the fraction of ash
drawn off as wet slag, and thus to reduce the flyash disposal problem, flyash
may be reinjected from collection equipment into slag tap systems. Dry bottom
unit ash may also be reinjected into wet bottom boilers for the same purpose.
Because a mixture of fine and coarse coal particles is fired in spreader
stokers, significant unburnt carbon can be present in the particulate. To
improve boiler efficiency, flyash from collection devices (typically multiple
cyclones) is sometimes reinjected Into spreader stoker furnaces. This prac-
tice can dramatically increase the particulate loading at the boiler outlet
and, to a lesser extent, at the mechanical collector outlet. Flyash can also
be reinjected from the boiler, air heater and economizer dust hoppers. Flyash
reinjection from these hoppers does not increase particulate loadings nearly so
much as from multiple cyclones. 5
Uncontrolled overfeed and underfeed stokers emit considerably less particu-
late than do pulverized coal, units and spreader stokers, since combustion takes
place in a relatively quiescent fuel bed. Flyash reinjection is not practiced
In these kinds of stokers.
Other variables than firing configuration and flyash reinjection can
affect emissions from stokers. Particulate loadings will often increase as
load increases (especially as full load is approached) and with sudden load
changes. Similarly, particulate can increase as the ash and fines contents
increase. ("Fines", in this context, are coal particles smaller than about 1.6
millimeters, or one sixteenth inch, in diameter.) Conversely, particulate can
be reduced significantly when overftre air pressures are increased. 5
1.1-4 EMISSION FACTORS 10/86
-------
The primary kinds of particulate control devices used for coal combustion
include multiple cyclones, electrostatic precipitators, fabric filters (bag-
houses) and scrubbers. Some measure of control will even result from ash
settling in boiler/air heater/economizer dust hoppers, large breeches and chim-
ney bases. To the extent possible from the existing data base, the effects of
such settling are reflected in the emission factors in Table 1.1-1.
Electrostatic precipitators (ESP) are the most common high efficiency
control device used on pulverized coal and cyclone units, and they are being
used increasingly on stokers. Generally, ESP collection efficiencies are a
function of collection plate area per volumetric flow rate of flue gas through
the device. Particulate control efficiencies of 99.9 weight percent are
obtainable with ESPs. Fabric filters have recently seen increased use in both
utility and Industrial applications, generally effecting about 99.8 percent
efficiency. An advantage of fabric filters is that they are unaffected by high
flyash resistivities associated with low sulfur coals. ESPs located after air
preheaters (i. e., cold side precipitators) may operate at significantly reduced
efficiencies when low sulfur coal is fired. Scrubbers are also used to control
particulate, although their primary use is to control sulfur oxides. One draw-
back of scrubbers is the high energy requirement to achieve control efficiencies
comparable to those of ESPs and baghouses.2
Mechanical collectors, generally multiple cyclones, are the primary means
of control on many stokers and are sometimes installed upsteam of high effi-
ciency control devices in order to reduce the ash collection burden. Depending
on application and design,, multiple cyclone efficiencies can vary tremendously.
Where cyclone design flow rates are not attained (which is common with under-
feed and overfeed stokers), these devices may be only marginally effective and
may prove little better in reducing particulate than large breeching. Con-
versely, well designed multiple cyclones, operating at the required flow rates,
can achieve collection efficiencies on spreader stokers and overfeed stokers
of 90 to 95 percent. Even higher collection efficiencies are obtainable on
spreader stokers with reinjected flyash, because of the larger particle sizes
and increased particulate loading reaching the controls.5~6
Sulfur Oxides7~9 - Gaseous sulfur oxides from external coal combustion
are largely sulfur dioxide (802) and much less quantity of sulfur trioxide
(303) and gaseous sulfates. These compounds form as the organic and pyritic
sulfur in the coal is oxidized during the combustion process. On average, 98
percent of the sulfur present in bituminous coal will be emitted as gaseous
sulfur oxides, whereas somewhat less will be emitted when subbituminous coal
is fired. The more alkaline nature of the ash in some subbituminous coal
causes some of the sulfur to react to form various sulfate salts that are
retained in the boiler or in the flyash. Generally, boiler size, firing con-
figuration and boiler operations have little effect on the percent conversion
of fuel sulfur to sulfur oxides.
Several techniques are used to reduce sulfur oxides from coal combustion.
One way is to switch to lower sulfur coals, since sulfur oxide emissions are
proportional to the sulfur content of the coal. This alternative may not be
possible where lower sulfur coal is not readily available or where a different
grade of coal can not be satisfactorily fired. In some cases, various cleaning
processes may be employed to reduce the fuel sulfur content. Physical coal
cleaning removes mineral sulfur such as pyrite but is not effective in removing
10/86 External Combustion Sources 1.1-5
-------
organic sulfur. Chemical .cleaning and solvent refining processes are being
developed to remove organic sulfur.
Many flue gas desulfurization techniques can remove sulfur oxides formed
during combustion. Flue gases can be treated through wet, semidry or dry
desulfurization processes of either the throwaway type, in which all waste
streams are discarded, or the recovery (regenerable) type, in which the 50%
absorbent is regenerated and reused. To date, wet systems are the most com-
monly applied. Wet systems generally use alkali slurries as the 50^ absorbent
medium and can be designed to remove well in excess of 90 percent of the in-
coming SO^. Particulate reduction of up to 99 percent is also possible with
wet scrubbers, but flyash Is often collected by upsteam ESPs or baghouses, to
avoid erosion of the desulfurization equipment and possible interference with
the process reactions. ^ Also, the volume of scrubber sludge is reduced with
separate flyash removal, and- contamination of the reagents and byproducts is
prevented. References 7 and 8 give more details on scrubbing and other SOX
removal techniques.
Nitrogen Oxides 1U~11 - Nitrogen oxides (NOL) emissions from coal
combustion are primarily nitrogen oxide (NO). Only a few volume percent are
nitrogen dioxide (N02). NO results from thermal fixation of atmospheric nitro-
gen in the combustion flame and from oxidation of nitrogen bound in the coal.
Typically, only 20 to 60 percent of the fuel nitrogen is converted to nitrogen
oxides. Bituminous and subbi turn! nous coals usually contain from 0.5 to 2
weight percent nitrogen, present mainly in aromatic ring structures. Fuel
nitrogen can account for up to 80 percent of total NOjj from coal combustion.
A number of combustion modifications can.be made to reduce NOX emissions
from boilers. Low excess air (LEA) flring'is the most widespread control
modification, because It can be practiced in both old and new units and In all
sizes of boilers. LEA firing is easy to implement and has the added advantage
of increasing fuel use efficiency. LEA firing is generally effective only
above 20 percent excess air for pulverized coal units and above 30 percent
excess air for stokers. Below these levels, the NOx reduction from decreased 62
availability is offset by Increased NOX because of increased flame temperature.
Another NOX reduction technique is simply to switch to a coal having a lower
nitrogen content, although many boilers may not properly fire coals of different
properties.
_ »
Of f-stoichioraetric (staged) combustion is also an effective means of
controlling NOX from coal fired equipment. This can be achieved by using
overflre air or low NOjj burners designed to stage combustion in the flame zone.
Other NOx reduction techniques include flue gas reel rculation, load reduction,
and steam or water injection'. However, these techniques are not very effective
for use on coal fired 'equipment because of the fuel nitrogen effect. Ammonia
injection is another technique which can be used, but it is costly. The net
reduction of NOX from any of these techniques or combinations thereof varies
considerably with boiler type, coal properties and existing operating practices.
Typical reductions will range from 10 to 60 percent. References 10 and 60
should be consulted for a detailed discussion of each of these NOjj reduction
techniques. To date, flue gas treatment is not used to reduce nitrogen oxide
emissions because of its higher cost.
1.1-6 EMISSION FACTORS 10/86
-------
Volatile Organic Compounds And Carbon Monoxide - Volatile organic compounds
(VOC) and carbon monoxide (CO) are unburnt gaseous combustibles which generally
are emitted In quite small amounts. However, during startups, temporary upsets
or other conditions preventing complete qombustion, unburnt combustible emis-
sions may Increase dramatically. VOC and CO emissions per unit of fuel fired
are normally lower from pulverized coal or cyclone furnaces than from smaller
stokers and handflred units where operating conditions are not so well con-
trolled. Measures used for NOX control can Increase CO emissions, so to reduce
the risk of explosion, such measures are applied only to the point at which CO
In the flue gas reaches a maximum of about 200 parts per million. Other than
maintaining proper combustion conditions, control measures are not applied to
control VOC and CO.
Emission Factors And References - Emission factors for several pollutants
are presented in Table 1.1-1, and factor ratings and references are presented
in Table 1.1-2. The factors for uncontrolled underfeed stokers and hand fired
units also may be applied to hot air furnaces. Tables 1.1-3 through 1.1-8
present cumulative size distribution data and size specific emission factors
for particulate emissions from the combustion sources discussed above. Uncon-
trolled and controlled size specific emission factors are presented in Figures
1.1-1 through 1.1-6.
1-0/86 External Combustion Sources 1.1-7
-------
TABLE 1.1-3. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR DRY BOTTOM BOILERS BURNING PULVERIZED BITUMINOUS COALa
EMISSION FACTOR RATING:
C (uncontrolled)
D (scrubber and ESP controlled
E (multiple cyclone and baghouse)
nrtlcle .tie*
U
10
6
2.)
1.2)
1.00
0.625
TOTAL
Cuemlecive eteee X < tceted else
Uncontrolled
12
2]
17
6
2
2
I
100
Controlled
Multiple
cyclone
54
29
14
J
1
1
1
10O
Scrubber
81
71
62
SI
"
31
20
100
esr
7»
67
50
29
17
'»
12
100
.M^e
97
92
77
JJ
31
25
14
100
Oewl.tlT. emlteloa (actor* (kf/Nf do/ton) coel, ee fired)
Uncontrolled
I.6A
O.:A>
LISA
(2.3A)
0.85A
(1.7A)
O.MA
(0.6A)
0.10A
(0.2A)
0.10A
(0.2A)
O.OiA
(0.10)
JA
(IDA)
Controlled*1
Multiple
cyclone
0.54A
(1.08A)
0.29A
(0.58*)
0.14A
(0.2SA)
O.OJA
(0.06A)
O.OIA
(0.02A)
O.OIA
(0.02A)
O.OIA
(0.02A)
IA
(2A)
Scrubber
0.24A
(0.48A)
0.21A
(0.42A)
0.19A
(0.38A)
0.15*
(0.3A)
0.11*
(0.22A)
0.09*
(0.18A)
0.06A
(0.12A)
0.3A
(0.6A)
tsr
O.OJ2A
(0.06A)
0.027A
(0.05A)
0.020A
(0.04A)
0.012A
(0.02A)
0.007A
(O.OIA)
0.006*
(O.OIA)
O.OO5A
(O.OIA)
0.04*
(0.08*)
.M^oue.
0.010A
(0.02A)
0.009A
(0.02A)
0.008 A
(0.02A)
0.005A
(O.OIA)
0.001*
(0.006A)
0.003*
(0.006A)
0.001A
(0.002A)
O.OIA
(0.02A)
CA - coal ul> »«l|hc I, t» (lr«i.
dt«t!.«t»d control .fftcl.aer for (ulclpl. cyclon*. 801; •erukb.r. 941;
Sir. 99.22: bM»ou>*. 99.81.
2.0A
l.SA
1.6A
t.4A
1.2A
l.QA
0.8A
0.6A
0.4A
0.2A
0
ScruoDer
Baqhouse
Uncontrolled
Multiple cyclone
.2 .4 .6 1 2 4 6 10
Particle diameter (urn)
40 60 100
l.CA -3
0.6A 1^
0.4A i'C
0.2A ^^ —
a. o
o.w =-5.
£ ^
0.06A '"g
0.04A o a
^ o
c V
o -|
0.02A ^i
•A u
— o
6 •*
O.OIA —'
0. 1A _
0.06 A 1
U
0.04A
0.02A
O.OIA
0.006A
0.004A
Q.002A
0.001A
Figure 1.1-1. Cumulative size specific emission factors for dry bottom
boilers burning pulverized bituminous coal.
1.1-8
EMISSION FACTORS
10/86
-------
TABLE 1.1-4.
CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR WET BOTTOM BOILERS BURNING PULVERIZED BITUMINOUS COAL3
EMISSION FACTOR RATING: E
Particle slzeb
(u«>
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative aaaa X < stated alze
Uncontrolled
40
37
33
21
6
t,
2
100
Controlled
Multiple
cyclone
99
93
8A
61
31
19
e
100
ESP
83
75
63
40
17
8
e
100
Cumulative emlaalon factor* [kg/Hg (lb/ton) coal, aa fired)
Uncontrolled
1.4A (2.8A)
1.30A (2.6A)
1.16A (2.32A)
0.74A (1.48A)
0.21A (0.42A)
0.14A (0.28A)
0.07A (0.14A)
3.5A (7.0A)
Controlled"1
0.69A (1.38A)
0.65A (1.3A)
0.59A (I. ISA)
. 0.43A (0.86A)
0.22A (0.44A)
0.13A (0.26A)
e
0.7A (1.4A)
ESP
0.023A (0.046A)
0.021A (0.042A)
0.018A (0.036A)
0.011A (0.022A)
0.005A (0.01A)
0.002A C0.004A)
e
0.028A (0.056A)
Reference 61. ESP - electrostatic preclplcator.
^Expressed aa aerodynamic equivalent dlaaeter.
CA - coal a»h weight X, aa fired.
dEatluted control efficiency for multiple cyclone, SOX; ESP, 99.21.
'Insufficient data.
J.bA
.2*, 2.1A -
1.4A -
0.70A ~
.1
.4 .6
1 246 10
Particle diameter (urn)
40 60 100
iA
Q6A
o.
04A _2
02A §.
0.01A
•o —
OJ
— o
.006A o "
-i
0.
0.004A o 5.
Q.002A
0.001A
Figure 1.1-2. Cumulative size specific emission factors for wet bottom
boilers burning pulverized bituminous coal
10/86
External Combustion Sources
1.1-9
-------
TABLE 1.1-5.
CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR CYCLONE FURNACES BURNING BITUMINOUS COAL3
EMISSION FACTOR RATING: E
Particle alzc°
(urn)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass Z £ seated size
Uncontrolled
33
13
a
0
0
0
0
too
Controlled
Scrubber
95
94
93
92
85
82
d
100
ESP
90
68
56
36
22
17
d
100
Cuaulatlve emission factor* (kg/Mg (Ib/ton) coal, aa fired)
Uncontrolled
0.33A (0.66A)
O.I3A (0.26A)
0.08A (O.I6A)
0 (0)
0 (0)
0 (0)
0 (0)
U (2A)
Controlled'
Scrubber
0.057A (O.I14A)
0.056A (0.1 12A)
0.056A (0.1 12A)
0.055A (0.1 1A)
0.051A (0.10A)
0.049A (O.IOA)
d
0.06A (0.12A)
ESP
0.0064A (0.013A)
0.0054A (O.OI1A)
0.0045A (0.009A)
0.0029A (0.006A)
O.OOI8A (0.004A)
0.0014A (0.003A)
d
0.008A (0.016A)
^Reference 61. ESP • electrostatic preclpl tator.
^Expressed as aerodynaalc equivalent diameter.
CA - coal ash weight I, as fired.
^Insufficient data.
eEatluted control efficiency for scrubber, 94Z; ESP, 99. 2Z.
8"
1.0ft
0.9A
O.SA
0.7A
0.6A
O.SA
0.4A
0.3A
0.2A
0.1A
0
ESP-
.1 ,2 .4 .6 1 2 4 6 10
Particle diameter
Uncontrolled
0.1CW
0.06A ,
0.04A -_.
•— -u
0.02A S£
O.OW i_-
C -O
o o
o-00" ^!«
*s* X
0.004A 1^™
e •*--
w
-------
TABLE 1.1-6. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR SPREADER STOKERS BURNING BITUMINOUS COAL3
EMISSION FACTOR RATING:
C (uncontrolled and controlled for
multiple cyclone without flyash
relnjectlon, and with baghouse)
E (multiple cyclone controlled with
flyash reinjection, and ESP
controlled)
Porttelo •!••*
1)
10
6
2.)
1.2)
1.00
0.62)
TOTAL
Cuouletlve wee 1 £ eeetod efte
Uncontrolled
28
20
14
7
)
)
4
100
Coot rolled
Multiple
96
73
51
8
2
2
'
100
Multiple
74
6)
52
27
16
14
'
100
1ST
»7
•0
92
61
46
41
'
IOO
„.,«..
72
60
46
26
18
1)
7
too
Uncontrolled
9.4
(16.8)
6.0
(12.0) "
4.2
(8.4)
2.1
(4.2)
1.)
(3.0)
1.)
(3.0)
1.2
(2.4)
30.0
(60.0)
t» UWt«-> eonl. M Hrne|
ControllW
HnltlpI*
7.3
(14.6)
6.2
(12.4)
4.3
(8.6)
0.7
(1.4)
0.2
(0.4)
0.2
(0.4)
0.1
(0.2)
9.)
(17.0)
NnltlpU
4.4
(8.8)
3.*
(7.8)
3.1
(6.2)
1.6
(3.2)
1.0
(2.0)
O.I
(1.4)
0.3
(1.0)
6.0
(12.0)
ESP
0.23
(0.46)
0.22
(0.44)
0.2O
(0.40)
O.I)
(O.JO)'
0.11
(0.22)
0.10
(0.20)
'
0.24
(0.46)
•.(houee
0.043
(0.086)
0.036
(0.072)
0.028
(0.0)6)
0.016
(0.032)
0.011
(0.022)
o.oot
(0.018)
0.004
(0.008)
0.06
(0.12)
•t«f.r««e. 61. ESP - «l*clro>c
-------
TABLE 1.1-7. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR OVERFEED STOKERS BURNING BITUMINOUS COALa
EMISSION FACTOR RATING: C (uncontrolled)
E (multiple cyclone controlled)
Particle »lzeb
(un)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
emulative mass I £ stated alze
Uncontrolled
49
37
24
14
13
12
c
100
Multiple cyclone
controlled
60
55
49
43
39
39
16
100
emulative emission factor
Ik«/Hg (Ib/ton) coal, »• flredj
Uncontrolled
3.9 (7.8)
3.0 (6.0)
1.9 (3.«)
I.I (2.2)
1.0 (2.0)
1.0 (2.0)
c
8.0 (16.0)
Multiple cyclone
controlled''
2.7 (5.4)
2.5 (5.0)
2.2 (4.4)
1.9 (3.8)
1.8 (3.6)
1.8 (3.6)
0.7 (1.4)
4.5 (9.0)
"Reference 61.
^Expreiaed aa aerodynanlc equivalent diameter.
cln«ufficlent data.
dEatlB«ted control efficiency for multiple cyclone, 80Z.
a
. 7.
!._ 6.
!= 5
; • 4
,"I 4
J U
- "01
:l 3
j~ 2
3
1
0
Figure 1.1-5.
Multiple
cyclone
10
6.0
4.0
2.0
1.0
0.6.
0.4
0.1
.4 .6 1 2 4 6 10 20 40 60 100
Particle diameter
52
.2
0.2 -5
Cumulative size specific emission factors for
stokers burning bituminous coal
overfeed
1.1-12
EMISSION FACTORS
10/86
-------
TABLE 1.1-8.
CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR UNDERFEED STOKERS BURNING BITUMINOUS COALa •
EMISSION FACTOR RATING: C
Particle slreb
(urn)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass Z < stated size
50
41
32
25
22
21
18
100
Uncontrolled cumulative emission factor0
[kg/Mg (Ib/ton) coal, as fired)
3.8 (7.6)
3.1 (6.2)
2.4 (4.8)
1.9 (3.8)
1.7 (3.4)
1.6 (3.2)
1.4 (2.7)
7.5 (15.0)
Reference 61.
^Expressed as aerodynamic equivalent diameter.
cMay also be used for uncontrolled hand fired units.
10
9
8
7
€ 3
CM
£• 2
1
0
Uncontrolled
.1 .2 .4 .6 1 2 46 10
Particle diameter (uu)
20
40 60 100
Figure 1.1-6. Cumulative size specific emission factors for underfeed
stokers burning bituminous coal.
10/86
External Combustion Sources
1.1-13
-------
References for Section 1.1
1. Steam, 38th Edition, Babcock and Wilcox, New York, 1975.
2. Control Techniques for Particulate Emissions from Stationary Sources,
Volume I, EPA-450/3-8l-005a, U. S. Environmental Protection Agency,
Research Triangle Park, NC, April 1981.
3. ibidem, Volume II, EPA-450/3-81-0005b.
4. Electric Utility Steam Generating Units; Background Information for
Proposed Particulate Matter Emission Standard, EPA-450/2-78-006a, U. S.
Environmental Protection Agency, Research Triangle Park, NC, July 1978.
5. W. Axtman and M. A. Eleniewski, "Field Test Results of Eighteen Industrial
Coal Stoker Fired Boilers for Emission Control and Improved Efficiency",
Presented at the 74th Annual Meeting of the Air Pollution Control Asso-
ciation, Philadelphia, PA, June 1981.
6. Field Tests of Industrial Stoker Coal Fired Boilers for Emission Control
and Efficiency Improvement - Sites Ll-17, EPA-600/7-81-020a, U. S. Environ-
mental Protection Agency, Washington, DC, February 1981.
7. Control Techniques for Sulfur Dioxide Emissions from Stationary Sources,
2nd Edition, EPA-450/3-81-004, U. S. Environmental Protection Agency,
Research Triangle Park, NC, April 1981.
8. Electric Utility Steam Generating Units; Background Information for
Proposed SO? Emission Standards, EPA-450/2-78-007a, U. S. Environmental
Protection Agency, Research Triangle Park, NC, July 1978.
Environmental Protection Agency, Washington, DC, February 1981.
9. Carlo Castaldini and Meredith Angwtn, Boiler Design and Operating Vari-
ables Affecting Uncontrolled Sulfur Emissions from Pulverized Coal Fired
Steam Generators, EPA-450/3-77-047, U. S. Environmental Protection Agency,
Research Triangle Park, NC, December 1977.
10. Control Techniques for Nitrogen Oxides Emissions from Stationary Sources,
2nd Edition, EPA-450/1-78-001, U. S. Environmental Protection Agency,
Research Triangle Park, NC, January 1978.
11. Review of NCy Emission Factors for Stationary Fossil Fuel Combustion
Sources, EPA-450/4-79-021, U. S. Environmental Protection Agency,
Research Triangle Park, NC, September 1979.
12. Standards of Performance for New Stationary Sources, 36 FR 24876, December
23, 1971.
13. L. Scinto, Primary Sulfate Emissions from Coal and Oil Combustion, EPA
Contract Number 68-02-3138, TRW Inc., Redondo Beach, CA, February 1980.
14. S. T. Cuffe and R. W. Gerstele, Emissions from Coal Fired Power Plants:
A Comprehensive Summary, 999-AP-35, U. S. Environmental Protection Agency,
Research Triangle Park, NC, 1967.
1.1-14 EMISSION FACTORS 10/86
-------
15. Field Testing; Application of Combustion Modifications To Control
Emissions from Utility Boilers, EPA-650/2-74-066, U. S. Environmental
Protection Agency, Washington, DC, June 1974.
16. Control of Utility Boiler and Gas Turbine Pollutant Emissions by Combus-
tion Modification - Phase I, EPA-6QO/7-78-036a, U. S. Environmental
Protection Agency, Washington, DC, March 1978.
17. Low-sulfur Western Coal Use in Existing Small and Intermediate Size
Boilers, EPA-600/7-78-153a, U. S. Environmental Protection Agency,
Washington, DC, July 1978.
18. Hazardous Emission Characterization of Utility Boilers, EPA-650/2-75-066,
U. S. Environmental Protection Agency, Washington, DC, July 1975.
19. Application of Combustion Modifications To Control Pollutant Emissions
from Industrial Boilers - Phase I, EPA-650/2-74-078a, U. S. Environmental
Protection Agency, Washington, DC, October 1974.
20. Field Study To Obtain Trace Element Mass Balances at a Coal Fired Utility
Boiler, EPA-600/7-80-171, U. S. Environmental Protection Agency, Washing-
ton, DC, October 1980.
21. Environmental Assessment of Coal and Oil Firing in a Controlled Industrial
Boiler, Volume II, EPA-600/7-78-164b, U. S. Environmental Protection
Agency, Washington, DC, August 1978.
22. Coal Fired Power Plant Trace Element Study, U. S. Environmental Protection
Agency, Denver, CO, September 1975.
23. Source Testing of Duke Power Company, Pl'ezer, SC, EMB-71-CI-01 , Q. S.
Environmental Protection Agency, Research Triangle Park., NC, February 1971.
24. J. W. Kaakinen, et al., "Trace Element Behavior in Coal-fired Power Plants",
Environmental Science and Technology, ^.O):862-869, September 1975.
25. Five Field Performance Tests on Koppers Company Precipitators, Docket No.
OAQPS-78-1, Office Of Air Quality Planning And Standards, U. S. Environ-.
mental Protection Agency, Research Triangle Park, NC, February-March 1974.
26. H. M. Rayne and L. P. Copian, Slag Tap Boiler Performance Associated with
Power Plant Flyash Disposal, Western Electric Company, Hawthorne Works,
Chicago, IL, undated.
27. A. B. Walker, "Emission Characteristics for Industrial Boilers", Air
Engineering, £(8):17-19, August 1967.
28. Environmental Assessment of Coal-fired Controlled Utility Boiler, EPA-600/
7-80-086, U. S. Environmental Protection Agency, Washington, DC, April
1980.
29. Steam, 37th Edition, Babcock and Wilcox, New York, 1963.
10/86 External Combustion Sources 1.1-15
-------
30. Industrial Boiler; Emission Tesc Report, Formica Corporation, Cincinnati,
Ohio, EMB-80-IBR-7, U. S. Environmental Protection Agency, Research Triangle
Park, NC, October 1980.
31. Field Tests of Industrial Stoker Coal-fired Boilers for Emissions Control
and Efficiency Improvement - Site A, EPA-600/7-78-l35a, U. S. Environ-
mental Protection Agency, Washington, DC, July 1978.
32. ibidem-Site C, EPA-600/7-79-130a, May 1979.
33. Ibidem-Site E, EPA-600/7-80-064a, March 1980.
34. ibidem-Site F, EPA-600/7-80-065a, March 1980.
35. ibidem-Site G, EPA-600/7-80-082a, April 1980.
36. ibidem-Site B, EPA-600/7-79-041a, February 1979.
37. Industrial Boilers: Emission Test Report, General Motors Corporation,
Parma, Ohio, Volume I, EMB-80-IBR-4, U. S. Environmental Protection Agency,
Research Triangle Park, NC, March 1980.
38. A Field Test Using Coal: dRDF Blends in Spreader Stoker-fired Boilers,
EPA-600/2-80-095, U. S. Environmental Protection Agency, Cincinnati, OH,
August 1980.
39. Industrial Boilers: Emission Test Report, Rlckenbacker Air Force Base,
Columbus, Ohio, EMB-80-IBR-6, U. S. Environmental Protection Agency,
Research Triangle Park, NC, March 1980.
40. Thirty-day Field Tests of Industrial Boilers; Site 1, EPA-600/7-80-085a,
U. S. Environmental Protection Agency, Washington, DC, April 1980.
41. Field Tests of Industrial Stoker Coal-fired Boilers for Emissions Control
and Efficiency Improvement - Site D, EPA-600/7-79-237a, U. S. Environmental
Protection Agency, Washington, DC, November 1979.
42. Ibidem-Site H, EPA-600/7-80-112a, May'1980.
43. ibidem-Site I, EPA-600/7-80-136a, May 1980.
44. ibidem-Site J, EPA-600/7-80-137a, May 1980.
45. ibidem-Site K. EPA-600/7-80-138a, May 1980.
46. Regional Air Pollution Study; Point Source Emission Inventory, EPA-600/4-
77-014, U. S. Environmental Protection Agency, Research Triangle Park, NC,
March 1977.
47. R. P. Hangebrauck, et al., "Emissions of Polynuclear Hydrocarbons and
Other Pollutants from Heat Generation and Incineration Process", Journal
of the Air Pollution Control Association, 14(7):267-278, July 1964.
1.1-16 EMISSION FACTORS 10/86
-------
48. Source Assessment; Coal-fired Industrial Combustion Equipment Field Test,
EPA-600/ 2-78-004o, U. S. Environmental Protection Agency, Washington, DC,
June 1978.
49. Source Sampling Residential Fireplaces for Emission Factor Development,
EPA-450/3-76-010, U. S. Environmental Protection Agency, Research Triangle
Park, NC, November 1975.
50. Atmospheric Emissions from Coal Combustion: An Inventory Guide, 999-AP-24,
U. S. Environmental Protection Agency, Washington, DC, April 1966.
51 . Application of Combustion Modification To Control Pollutant Emissions from
Industrial Boilers - Phase II, EPA-600/ 2-76-086a, U. S. Environmental
Protection Agency ,. Washington, DC, April 1976.
52. Continuous Emission Monitoring for Industrial Boiler, General Motors Cor-
poration, St. Louis, Missouri, Volume I, EPA Contract Number 68-02-2687,
GCA Corporation, Bedford, MA, June 1980.
53. Survey of Flue Gas Desulf urization Systems; Cholla Station, Arizona
Public Service Company, EPA-600/7-78-048a, U. S. Environmental Protection
Agency, Washington, DC, March 1978.
54. ibidem; La Cygne Station, Kansas City Power and Light, EPA-600/ 7-78-048d ,
March 1978.
55 . Source Assessment: Dry Bottom Utility Boilers Firing Pulverized Bituminous
Coal, EPA-600/ 2-79-019, U. S. Environmental Protection Agency, Washington,
DC, August 1980. . .
56. Thirty-day Field Tests of Industrial Boilers; Site 3 - Pulverized - Coal
Fired Boiler, EPA-600/ 7-80-085c, U. S. Environmental Protection Agency,
Washington, DC, April 1980.
57 . Systematic Field Study of Nitrogen Oxide Emission Control Methods for
Utility Boilers, APTD-1163, U. S. Environmental Protection Agency, Research
Triangle Park, NC, December 1971.
58. Emissions of Reactive Volatile Organic Compounds from Utility Boilers,
EPA-600/ 7-80-11 1 , U. S. Environmental Protection Agency, Washington, DC,
May 1980.
59. Industrial Boilers; Emission Test Report, DuPont Corporation, Parkers-
burg, West Virginia, EMB-80-IBR-12, U. S. Environmental Protection Agency,
Research Triangle Park, NC, February 1982.
60. Technology Assessment Report for Industrial Boiler Applications;
Combustion Modification, EPA-600/ 7-79- 178f, U. S. Environmental Protection
Agency, Washington, DC, December 1979.
61 . Inhalable Particulate Source Category Report for External Combustion
Sources, EPA Contract No. 68-02-3156, Acurex Corporation, Mountain View,
CA, January 1985.
10/86 External Combustion Sources 1.1-17 '
-------
1.2 ANTHRACITE COAL COMBUSTION
1.2.1 General1'2
Anthracite coal is a high rank coal with more fixed carbon and less vola-
tile matter than either bituminous coal or lignite, and it has higher ignition
and ash fusion temperatures. Because of its low volatile matter content and
slight cllnkering, anthracite is most commonly fired in medium sized traveling
grate stokers and small hand fired units. Some anthracite (occasionally with
petroleum coke) is used in pulverized coal fired boilers. It is also blended
with bituminous coal. None is fired in spreader stokers. For its low sulfur
content (typically less than 0.8 weight percent) and minimal smoking tendencies,
anthracite is considered a desirable fuel where readily available.
In the United States, all anthracite is mined in northeastern Pennsylvania
and is consumed mostly in Pennsylvania and several surrounding states. The
largest use of anthracite is for space heating. Lesser amounts are employed
for steam/electric production; coke manufacturing, sintering and pelletizing;
and other industrial uses. Anthracite currently is only a small fraction of
the total quantity of coal combusted in the United States.
1.2.2 Emissions And Controls2~14
Particulate emissions from anthracite combustion are.a function of furnace
firing configuration, firing practices (boiler load, quantity and location of
underfire air, sootblowing, flyash reinjection, etc.), and the ash content of
the coal. Pulverized coal fired boilers emit the highest quantity of partic-
ulate per unit of fuel because they fire the anthracite in suspension, which
results in a high percentage of ash carryover into, exhaust gases. Pulverized
anthracite fired boilers operate in the dry tap or dry bottom mode, because of
anthracite's characteristically high ash fusion temperature. Traveling grate
stokers and hand fired units produce much less particulate per unit of fuel
fired, because combustion .takes place in a quiescent fuel bed without signifi-
cant ash carryover into the exhaust gases. In general, particulate emissions
from traveling grate stokers will increase during sootblowing and flyash rein-
jection and with higher fuel bed underfeed air from forced draft fans. Smoking
is rarely a problem, because of anthracite's low volatile matter content.
Limited data are available on the emission of gaseous pollutants from
anthracite combustion. It is assumed from bituminous coal combustion data that
a large fraction of the fuel sulfur is emitted as sulfur oxides. Also, because
combustion equipment, excess air rates, combustion temperatures, etc., are
similar between anthracite and bituminous coal combustion, nitrogen oxide and
carbon monoxide emissions are assumed to be similar, too. Volatile organic
compound (VOC) emissions, however, are expected to be considerably lower,
since the volatile matter content of anthracite is significantly less than that
of bituminous coal.
1Q/86 External Combustion Sources 1.2-1
-------
NJ
I
K>
TABLE 1.2-1. UNCONTROLLED EMISSION FACTORS FOR ANTHRACITE COMBUSTION*
m
CO
GO
M
O
O
H
O
73
CA
Boiler type
Pulverized coal fired
Traveling grate
stoker
Hand fed units
Partlculateb
kg/Mg
f
4.68
5"
Ib/ton
f
9.18
I0h
Sulfur uxldesc
kg/Mg
19. 5S
19. 5S
19. 5S
Ib/ton
39S
39S
39S
Nitrogen oxides'*
kg/Mg
9
5
1.5
Ib/ton
18
10
3
Carbon monoxide6
kg/Mg
f
0.3
f
Ib/ton
f
0.6
f
Volatile organlcs
Nonmethane
f
f
f
Methane
f
f
f
aFactors are for uncontrolled emissions and should be applied to coal consumption as fired.
bBased on EPA Method 5 (front half catch).
cAssumes, as .with bituminous coal combustion, most fuel sulfur Is emitted as SOX. Limited data In Reference 5
verify this for pulverized anthracite fired boilers. Emissions are mostly SC>2, with 1 - 3Z 803. S Indicates that
weight Z sulfur should be multiplied by the value given.
dpor pulverized anthracite fired boilers and hand fed units, assumed to be similar to bituminous coal combustion. For
traveling grate stokers, see References 8, II.
eMay increase by several orders of magnitude with boilers not properly operated or maintained. For traveling grate
stokers, based on limited information In Reference 8. For pulverized coal fired boilers, substantiated by additional
data in Reference 14.
^Factors in Table 1.1-1 may be used, based on similarity of anthracite and bituminous coal.
^References 12-13, 15-18. Accounts for limited fallout that may occur In fallout chambers and stack breeching. Factors
for Individual boilers may be 2.5 - 25 kg/Mg (5 - 50 Ib/ton), highest during soot blowing.
"Reference 2.
O
-»»
CD
-------
Controls on anthracite emissions mainly have been applied to particulate
matter. The most efficient particulate controls, fabric filters, scrubbers and
electrostatic precipitators, have been installed on large pulverized anthracite
fired boilers. Fabric filters and venturi scrubbers can effect collection
efficiencies exceeding 99 percent. Electrostatic precipitators typically are
only 90 to 97 percent efficient, because of the characteristic high resistivity
of low sulfur anthracite fly ash. It is reported that higher efficiencies can
be achieved using larger precipitators and flue gas conditioning. Mechanical
collectors are frequently employed upstream from these devices for large part-
icle removal.
Traveling grate stokers are often uncontrolled. Indeed, particulate
control has often been considered unnecessary, because of anthracite's low smok-
ing tendencies and of the fact that a significant fraction of large size flyash
from stokers is readily collected in flyash hoppers as well as in the breeching
and base of the stack. Cyclone collectors have been employed on traveling
grate stokers, and limited information suggests•these devices may be up to 75
percent efficient on particulate. Flyash reinjection, frequently used in
traveling grate stokers to enhance fuel use efficiency, tends to increase
particulate.emissions per unit of fuel combusted.
Emission factors for pollutants from anthracite coal combustion are given
in Table 1.2-1, and factor ratings in Table 1.2-2. Cumulative size distribution
data and size specific emission factors and ratings for particulate emissions
are in Tables 1.2-3 and 1.2-4. Uncontrolled and controlled size specific emis-
sion factors are presented in Figures 1.2-1 and 1.2-2. Size distribution data
for bituminous coal combustion may be used for uncontrolled emissions from-
pulverized anthracite fired furnaces, and data for anthracite fired traveling
grate stokers may be used for hand fired units.
TABLE 1.2-2. ANTHRACITE COAL EMISSION FACTOR RATINGS
Furnace type
Pulverized coal
Traveling grate
stoker
Hand fired units
Particulate
B
B
B
Sulfur
oxides
B
B
B
Nitrogen
oxides
B
B
B
Carbon
monoxide
B
B
B
Volatile organics
Nonmethane
C
C
D
Methane
C
C
D
10/86
External Combustion Sources
1.2-3
-------
TABLE 1.2-3. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR DRY BOTTOM BOILERS BURNING PULVERIZED
ANTHRACITE COAL3
EMISSION FACTOR RATING: D
Particle alia*
(»•)
1)
10
6
2.5
1.25
1.00
0.62$
TOTAL
Cuamlatlv* ataaa t £ stated alze
Uncontrolled
32
23
17
6
2
2
1
100
Controlled
Multiple cyclone
63
55
46
24
13
10
7
100
Baghouae
79
67
51
• 32
21
It
100
Cumulative eailaalon factor0
lkg/«g do/ton) bark, aa fired!
Uncontrolled
I.6A (3.2A)
I.2A (2.3A)
0.9A (1.7A)
0.3A (0.6A)
0.1A (0.2A)
0.1A (0.2A)
0.05A (0.1A)
5A ( IDA)
Controlled11
Multiple cyclone
0.63A (1.26A)
0.55A (1.IOA)
0.46A (0.92A)
0.24A (0.48A)
O.I3A (0.26A)
O.IOA (0.20A)
0.07A (0.14A)
IA (2A)
Baghouee
9.0079A (O.OI6A)
0.0067A (O.OI3A)
0.0051A (0.010A)
0.0032A (0.006A)
0.0021A (0.004A)
0.0018A (0.004A)
e
O.OIA (0.02A)
bExpr«aaed aa aerodynamic equivalent dla«ter.
CA - coal aeh Might, aa fired.
deatlMtad control efficiency for vultlple cyclone, 801; baghouae, 99.8Z.
•Insufficient data.
2.0A
1.8A
2 l'SA
2H 1.4A
l! I-*
w* <0
I -* 1. OA
•o o
41 W
= , 0-8*
s€
I£ °-6*
u
c
3 0.4A
0.2A
0
.1
Saghouse
Multiple
cyclone
Uncontrolled
i . . i
.6
10
20
i i i i i i i
40 60 103
l.OA
0.9A
0.8A
0.7A.
0.6A
0.5A
0.4A
0.3A
0.2A
0.1A
0
If
— CT
0.010A
0.009A
3
0.008A £
•<*_
0.007A °^
0.006A s""
£ *n
*
0.005A !_•
o o
0.004A i u
0.003A fs
i/l -w
0.002A I
en
0.001A ™
0
Particle diameter
Figure 1.2-1,
Cumulative size specific emission factors for dry bottom
boilers burning pulverized anthracite coal.
1.2.-4
EMISSION FACTORS
10/86
-------
TABLE 1.2-4. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR TRAVELING GRATE STOKERS BURNING ANTHRACITE COAL3
EMISSION FACTOR RATING: E
Particle sizeb
(urn)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass Z
< stated size
Uncontrolled0
64
52
42
27
24
23
d
100
Cumulative emission factor
[kg/Mg (Ib/ton) coal, as fired]
Controlled
2.9 (5.8)
2.4 (4.8)
1.9 (3.8)
1.2 (2.4)
1.1 (2.2)
1.1 (2.2)
d
4.6 (9.2)
aReference 19.
^Expressed as aerodynamic equivalent diameter.
cMay also be used for uncontrolled hand fired units.
Insufficient data.
S 2
I
I I i i
..1 .2 .4 .6 t 2 46 10 20 40 60 100
Particle diameter (urn)
Figure 1.2-2. Cumulative size specific emission factors for traveling
grate stokers burning anthracite coal.
10/86
External Combustion Sources
1.2-5
-------
References for Section 1.2
1. Minerals Yearbook, 1978-79, Bureau of Mines, U. S. Department of the
Interior, Washington, DC, 1981.
2. Air Pollutant Emission Factors, APTD-0923, U. S. Environmental Protection
Agency, Research Triangle Park, NC, April 1970.
3. Steam, 38th Edition, Babcock and Wilcox, New York, NY, 1975.
4. Fossil Fuel Fired Industrial Boilers - Background Information for Proposed
Standards, Draft, Office Of Air Quality Planning And Standards, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1980.
5. R. W. Cass and R. W. Bradway, Fractional Efficiency of a Utility Boiler
Baghouse; Sunbury Steam Electric Station, EPA-600/2-76-077a, U. S.
Environmental Protection Agency, Washington, DC* March 1976.
6. R. P. Janaso, "Baghouse Dust Collectors on a Low Sulfur Coal Fired Utility
Boiler", Presented at the 67th Annual Meeting of the Air Pollution Control
Association, Denver, CO, June 1974.
7. J. H. Phelan, et al., Design and Operation Experience with Baghouse'Dust
Collectors for Pulverized Coal Fired Utility Boilers - Sunbury Station,
Holtwood Station, Proceedings of the American Power Conference, Denver,
CO, 1976.
8. Source Test Data on Anthracite Fired Traveling Grate Stokers, Office Of
Air Quality Planning And Standards, U. S. Environmental Protection Agency,
Research Triangle Park, NC, 1975.
9. Source and Emissions informationT on Anthracite Fired Traveling Grate
Stokers, Office Of Air Quality Planning And Standards, U. S. Environmental
Protection Agency, Research Triangle Park, NC, 1975.
10. R. J. Mllligan, et al., Review of NOy Emission Factors for Stationary
Fossil Fuel Combustion Sources, EPA-450/4-79-021, U. S. Environmental
Protection Agency, Research Triangle Park, NC, September 1979.
11. N. F. Suprenant, et al., Emissions Assessment of Conventional Stationary
Combustion Systems, Volume IV; Commercial/Institutional Combustion
Sources, EPA Contract No. 68-02-2197, GCA Corporation, Bedford, MA, October
1980..
12. Source Sampling of Anthracite Coal Fired Boilers, RCA-Electronic Com-
ponents, Lancaster, Pennsylvania, Final Report, Scott Environmental
Technology, Inc., Plumsteadville, PA, April 1975.
13. Source Sampling of Anthracite Coal Fired Boilers, Shippensburg State
College, Shippensburg. Pennsylvania, Final Report, Scott Environmental
"Technology, Inc., Plurasteadville, PA, May 1975.
1-2-6 EMISSION FACTORS 10/86
-------
14. W. Bartok, et al., Systematic Field Study of NOy Emission Control Methods
for Utility Boilers, APTD-1163, U. S. Environmental Protection Agency,
Research Triangle Park, NC, December 1971.
15. Source Sampling of Anthracite Coal Fired Boilers, Ashland State General
Hospital, Ashland, Pennsylvania, Final Report, Pennsylvania Department of
Environmental Resources, Harrisburg, PA, March 16, 1977.
16. Source Sampling of Anthracite Coal Fired Boilers, Norristown State Hospi-
tal, Norristown, Pennsylvania, Final Repor:, Pennsylvania Department of
Environmental Resources, Harrisburg, PA, January 19, 1980.
17. Source Sampling of Anthracite Coal Fired Boilers, Pennhurst Center, Spring
City, Pennsylvania, Final Report, TRC Environmental Consultants, Inc.,
Wethersfield, CT, January 23, 1980.
18. Source Sampling of Anthracite Coal Fired Boilers, West Chester State, West
Chester, Pennsylvania, Final Report, Roy Weston, Inc., West Chester, PA,
April 4, 1977.
19. Inhalable Particulate Source Category Report for External Combustion
Sources, EPA Contract No. 68-02-3156, Acurex Corporation, Mountain View,
CA, January 1985.
10/86 External Combustion Sources 1.2-7
-------
1.3 FUEL OIL COMBUSTION
1.3.1 General 1-2,22
Fuel oils are broadly classified into two major types, distillate and
residual. Distillate oils (fuel oil grade Nos. 1 and 2) are used mainly in
domestic and small commercial applications in which easy fuel burning is
required. Distillates are more volatile and less viscous that residual oils,
having negligible ash and nitrogen contents and usually containing less than
0.3 weight percent sulfur. Residual oils (grade Nos. 4, 5 and 6), on the other
hand, are used mainly in utility, industrial and large commercial applications
with sophisticated combustion equipment. No. 4 oil is sometimes classified as
a distillate, and No. 6 is sometimes referred to as Bunker C. Being more vis-
cous and less volatile than distillate oils, the heavier residual oils (Nos. 5
and 6) must be heated to facilitate handling and proper atomization. Because
residual oils are produced from the residue after lighter fractions (gasoline,
kerosene and distillate oils) have been removed from the crude oil, they contain
significant quantities of. ash, nitrogen and sulfur. Properties of typical fuel
oils can be found in Appendix A.
1.3.2 Emissions
Emissions from fuel oil combustion depend on the grade and composition of
the fuel, the type and size of the boiler,, the firing and loading practices
used, and the level of equipment maintenance. Table 1.3-1 presents emission
factors for fuel oil combustion pollutants, and Tables 1.3-2 through 1.3-5 pre-
sent cumulative size distribution data and size specific emission factors for
partlculate emissions from fuel oil combustion. Uncontrolled and controlled
size specific emission factors are presented in Figures 1.3-1 through 1.3-4.
Distillate and residual oil categories are given separately, because their
combustion produces significantly different particulate, S02 and NOx emissions.
Particulate Matter^"?, 12-13,24,26-27 _ particulate emissions depend most on
the grade of fuel fired. The lighter distillate oils result in particulate
formation significantly lower than with heavier residual oils. Among residual
oils, Nos. 4 and 5 usually produce less particulate than does the heavier No. 6.
In boilers firing No. 6, particulate emissions can be described, on the
average, as a function of the sulfur content of the oil. As shown in Table
1.3-1), particulate emissions can be reduced considerably when low
sulfur No. 6 oil is fired. This is because low sulfur No. 6, either refined
from naturally low sulfur crude oil or desulfurized by one of several current
processes, exhibits substantially lower viscosity and reduced asphalt ene, ash
and sulfur, which results in better atomization and cleaner combustion.
Boiler load can also affect particulate emissions in units firing No. 6
oil. At low load conditions, particulate emissions may be lowered 30 to 40
percent from utility boilers and by as much as 60 percent from small industrial
and commercial units. No significant particulate reductions have been noted at
10/86 External Combustion Sources 1.3-1
-------
TABLE 1.3-1. UNCONTROLLED EMISSION FACTORS FOR FUEL OIL COMBUSTION
EMISSION FACTOR RATING: A
CO
V)
r->
O
Z
fc
H
O
90
W
Paniculate1*
Hatter
kg/101! Ib/I03gal
Utility Boiler*
Residual Oil
Industrial Bollara
Realdual Ull
Distillate Oil
Commercial Boiler*
Realdual Oil
Distillate Oil
Residential Furnace*
Distillate Oil
8 g
8 8
0.24 2
8 8
0.24 2
0.1 2.5
Sulfur Dioxide'
Sulfur
Trio, id*
kg/101! lb/103gal kg/101!
19S I57S
I9S I57S
I7S I42S
I9S I57S
175 I42S
17S I4JS
h
0.14S"
0.24S
0.24S
0.24S
0.24S
0.24S
Ib/t03g*l
k
2,9S"
2S
IS
2S
IS
2S
Carbon. . Nitrogen
Honoalde
kg/101!
0.6
0.6
0.6
0.6
0.6
0.6
Ib/I03gal kg/101!
5
1
5
5
5
5
5
8.0 ,
6.6J
2.4
6.6
2.4
2.2
0«lde*
Ib/I03gal
67 1
(IOSH42)*
55J
20
55
20
18
Volatile Organic*'
MonaMthaM • Methane
kg/101!
0.09
0.014
0.024
0.14
0.04
0.085
,b/,oV,
0.76
•
0.28
0.2
I.I)
0.14
0.71)
1 kg/101! I
0.0)
0.12
0.006
0.057
0.026
0.214
ib/.oV,
0.28
1.0
0.052
0.475
0.216
1.78
*Bullere can be approilmalaly claaatfled according to (heir groaa (higher) heat rate aa ahown. below:
Utility (power plant) bollera: >I06 » I09 J/hr OIOO > 10* Btu/hr)
Induatrlal boileral 10.6 I 10* to IU6 i IU* J/hr (10 » I06 to 100 > 106 llu/hr)
Conwrclal bollarai 0.5 a 10s to 10.6 • 10* J/hr (0.5 * 10* to 10 a I06 Itu/hr)
Residential furnaceei <0.5 >
J/hr (preaa«d aa NO,. Reference* 1-5, 8-11, 17 and 26. Teat result* Indicate that at leaat 951 by weight of HO, la NO for all boiler typee eicept residential
.furnacea, where about' 75S 1* NO.
References 18-21. Volatile organic coapuund ralsulune aie generally negligible. unlea* boiler la improperly opereted or not well maintained. In which caae
emissions may Increaaa by several orders of magnitude.
Paniculate emlaalon factora for realdual oil combustion ore, on average, a function of fuel oil grade and aulfur content!
Cride 6 oil: I.25(S) • 0.18 kg/101 liter |IO(S) • 1 lb/|0> gal | where S le the weight X of aulfur In the oil. Thia relationship le
b«iu.'il on 81 Individual leata and haa a correlation coefficient of 0.65.
Urade 5 olli 1.25 kg/10* liter (10 Ib/I0> gal)
trade 4 oil: 0.88 kg/10' liter (7 lb/101 gal)
"Reference 25.
Use 5 kg/10* liters (42 Ib/IU* gal) for^langent lal ly fired bollera, 12.6 kg/10' lltera (105 Ib/IO'gal) for vertical fired bollera, and 8.0 kg/10* liters
(67 lb/10* gal) for all othera, at full load and normal OI5X) eiceaa air. Several combuallon modifications can b* employed for NO, reduction: (I)
limited encese air can reduce NO, vmlmilona 5-20X, (2) ataged combuatlon 20-401, (!) ualng low NO, burner* 20-50Z, and (4) asiaonla Injection can reduce NO,
emlaalona 40-70Z but may Increaao emlaalona of ammonia. Combinations of the** modifications have been employed for further reduction* In certain bollera.
See Reference 2) for a discussion of these and other NO, reducing techniques and their operational and environmental Impact*.
Nitrogen oalde* amlaalona from realdual oil combustion In Induatrlal and commercial boiler* are atrongly related to fuel nitrogen content, estimated more
accurately by the empirical relationship:
kg NU,/IU* lllera - 2.75 « 50(N)* |lb NO,/|0'gal - 22 > 4UO(N)'| where N la the weight X of nitrogen In the oil. For realdual olla having high
(XJ.i weight X) nitrogen content, uae 15 kg N0,/I0' liter (120 Ib N0t/I0*gal) aa an emlaaion factor.
-------
low loads from boilers firing any of the lighter grades, however. At too low a
load condition, proper combustion conditions cannot be maintained, and parti~-
ulate emissions may increase drastically. It should be noted, in this regard,
that any condition that prevents proper boiler operation can result in excessive
particulate formation.
Sulfur Oxides 1~5>25,27 _ Total SO emissions are almost entirely dependent
on the sulfur content of the fuel and are not affected by boiler size, burner
design, or grade of fuel being fired. On the average, more than 95 percent of
the fuel sulfur is emitted as S02» about 1 to 5 percent as SOj and about 1 to 3
percent as sulfate particulate. 803 readily reacts with water vapor (in both
air and flue gases) to form a sulfuric acid mist.
Nitrogen Oxides 1~1 I .4,17 ,23,27 _ ^Q mechanlsras form NO , oxidation of
fuelbound nitrogen and thermal fixation of the nitrogen in combustion air.
Fuel NOy. is primarily a function of the nitrogen content of the fuel and the
available oxygen. On average, about 45 percent of the fuel nitrogen is con-
verted to NOX, but this may vary from 20 to 70 percent. Thermal NOx, rather,
is largely a function of peak flame temperature and available oxygen, factors
which depend on boiler size, firing configuration and operating practices.
Fuel nitrogen conversion is the more important NOX forming mechanism in
residual oil boilers. Except in certain large units having unusually high peak
flame temperatures, or in units firing a low nitrogen residual oil, fuel NO^
will generally account for over 50 percent of the total NOX generated. Thermal
fixation, on the other handj is the dominant NOX forming mechanism in units
firing distillate oils, primarily because of the negligible nitrogen content in
these lighter oils. Because distillate oil fired boilers usually have low heat
release rates, however, the quantity of thermal NOX formed in them is less than
that of larger units.
A number of variables influence how much NOjj is formed by these two
mechanisms. One important variable is firing configuration. Nitrogen oxide
emissions from tangentially (corner) fired boilers are, on the average, less
than those of horizontally opposed units. Also Important are the firing prac-
tices employed during boiler operation. Limited excess air firing, flue gas
recirculation, staged combustion, or some combination thereof may result in NOX
reductions of 5 to 60 percent. See Section 1.4 for a discussion of these
techniques. Load reduction can likewise decrease NOx production. Nitrogen
oxide emissions may be reduced from 0.5 to 1 percent for each percentage
reduction in load from full load operation. It should be noted that most of
these variables, with the exception of excess air, Infuence the NOX emissions
only of large oil fired boilers. Limited excess air firing is possible in many
small boilers, but the resulting NOjj reductions are not nearly so significant.
Other Pollutants^-21 - AS a rule, only minor amounts of volatile organic
compounds (VOC) and carbon monoxide will be emitted from the combustion of fuel
oil. The rate at which VOCs are emitted depends on combustion efficiency.
Emissions of trace elements from oil fired boilers are relative to the trace
element concentrations of the oil.
10/86 ' External Combustion Sources 1.3-3
-------
TABLE 1.3-2.
CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR UTILITY BOILERS FIRING RESIDUAL OIL3
EMISSION FACTOR RATING:
C (uncontrolled)
E (ESP controlled)
D (scrubber controlled)
Particle alzeb
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cusulatlve aaaa Z £ itated slxe
Dncont rolled
80
71
58
52
43
39
20
100
Controlled
ESP
75
63
52
41
31
28
10
100
Scrubber
ICO
100
' 100
97
91
34
64
100
Cumulative emission factor* [kg/103 1 (Ib/lCP gal)J
Uncontrolled
0.80A (6.7A)
0.71A (5.9A)
0.58A (4.8A)
0.52A (4.3A)
0.43A (3.6A)
0.39A (3.3A)
0.20A (1.7A)
1A (8.3A)
Control led**
ESP
0.0060A (0.05A)
0.0050A (0.042A)
0.0042A (0.035A)
0.0033A (0.028A)
0.002SA (0.021A)
0.0022A (0.018A)
0.0008A (0.007A)
0.008A (0.067A)
Scrubber
0.06A (0.50A)
0.06A (0.50A)
0.06A (0.50A)
0.058A (0.48A)
0.055A (0.46A)
0.050A (0.42A)
0.038A (0.32A)
0.06A (0.50A)
•Reference 29. ESP - electrostatic preclpltator.
Expressed as aerodynsalc equivalent diameter.
cPartlculate emission factors for residual oil coabuatlon without
of fuel oil grade and sulfur content:
Crade 6 Oil: A - 1.23(5) + 0.38
Where S Is the weight Z of sulfur In the oil.
Crade 5 Oil: A - 1.25
. Crade 4 Oil: A - 0.88
d£«tlasted control efficiency for scrubber, 94Z; ESP, 99.21.
enlaslon controls are, oo average, a function
l.QA
0.9A |_
0.8A
0.7A
0.6A
0.5A
0.4A
0.3A
Q.2A
0.1A
0
.1
Figure 1.3-1.
1.3-4
0.1QA
0.09* 3
\j
0.08A t
o
0.07A $
S
0.06A -g^
0.05A i| _
Si
0.04A g
0.03A |
0.02A 5
0.01A
i i i i i i
.4 .6 1 2 4 6 10
Particle diameter (vim)
20
40 60 100
0.01A
0.006A .
0.004A o
u
19
••>
O.OOZA g
^r
0.001A ,
41
0.0006A =
*J
0.0004A §
0.0002A ^
0.0001A
Cumulative size specific emission factors for utility
boilers firing residual oil.
EMISSION FACTORS
10/86
-------
TABLE 1.3-3. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR INDUSTRIAL BOILERS FIRING RESIDUAL OIL3
EMISSION FACTOR RATING: D (uncontrolled)
E (multiple cyclone controlled)
Particle •lxeb
(u»)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cuaulatlve mass Z <_ stated size
Uncontrolled
91
86
77
56
39
36
30
100
Multiple cyclone
controlled
100
95
72
22
21
21
d
100
Cumulative emission factor0
kg/103 1 (lb/103 gal)
Uncontrolled
0.91A (7.59A)
0.86A (7.17A)
0.77A (6.42A)
0.56A (4.67A)
0.39A (3.25A)
0.36A (3.00A)
0.30A (2.50A)
1A (8.34A)
Multiple cyclone
controlled"
0.20A (1.67A)
0.19A (1.58A)
0.14A (1.17A)
0.04A (0.33A)
0.04A (0.33A)
0.04A (0.33A)
d
0.2A (1.67A)
'Reference 29.
''Expressed as aerodynaalc equivalent diameter.
cPartlculate ealsslon factors for residual oil combustion without emission controls are, on
average, a function of fuel oil grade and sulfur content:
Grade 6 Oil: A -• 1.25(3) + 0.38
Where S is the weight Z of sulfur In the oil
Grade 5 Oil: A • 1.25
Grade 4 Oil: A - 0.88
^Insufficient data.
'Estimated control efficiency for multiple cyclone, 80Z.
Figure 1.3-2.
10/86
.4 .6
1 2 4 6 10
Particle diameter (urn)
20
40 60 100
Cumulative size specific emission factors for industrial
boilers firing residual oil.
External Combustion Sources
1.3-5
-------
TABLE 1.3-4. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR UNCONTROLLED INDUSTRIAL BOILERS FIRING DISTILLATE OIL3
EMISSION FACTOR RATING:
Particle sizeb
(urn)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass Z
£ stated size
Uncontrolled
68
50
30
12
9
8
2
100
Cumulative emission factor
kg/103 1 (lb/103 gal)
Uncontrolled
0.16 (1.33)
0.12 (1.00)
0.07 (0.58)
0.03 (0.25)
0.02 (0.17)
0.02 (0.17)
0.005 (0.04)
0.24 (2.00)
Reference 29.
^Expressed as aerodynamic equivalent diameter.
0.25
0.20
0.15
0.10
0.05
• I .2 .4 .6 1 2 4 6 10 20 40 60 100
Particle diameter (urn)
Figure 1.3-3.
Cumulative size specific emission factors for uncontrolled
industrial boilers firing distillate oil.
1.3-6
EMISSION FACTORS
10/86
-------
TABLE 1.3-5. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR UNCONTROLLED COMMERCIAL BOILERS BURNING RESIDUAL
AND DISTILLATE OIL3
EMISSION FACTOR RATING: D
Particle slzeb
(um)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass I < stated size
Uncontrolled with
residual oil
78
62
44
23
16
14
13
100
Uncontrolled with
distillate oll=
60
55
. 49
42
38
37
35
100
Cumulative emission factor
kg/103 1 (lb/103 gal)
Uncontrolled with
residual oil
0.78A (6.50A)
0.62A (5.17A)
0.44A (3.67A)
0.23A (1.92A)
0.16A (1.33A)
0.14A (1.17A)
0.13A (1.08A)
1A (8.34A)
Uncontrolled with
distillate oil
0.14 (1.17)
0.13 (1.08)
0.12 (1.00)
0.10 (0.83)
0.09 (0.75)
0.09 (0.75)
0.08 (0.67)
0.24 (2.00)
"Reference 29.
''Expressed as aerodynamic equivalent diameter.
cPartlculate emission factors for residual oil combustion without emission controls are, on average,
a function of fuel oil grade and aulfur content:
Grade 6 Oil: A - 1.25 (S) + 0.38
Where S Is the weight Z of sulfur in the oil . •
Grade 5 Oil': A - 1.25
Grade 4 Oil: A - 0.88
l.OOA
0.90A
0.30A
0.70A
0;60A
0.50A
•0.40A
O.JOA
0.20A
0.10A
0
Distil lace oi1
Residual oil
0.25
0-15
0.10
0.05
— o
1 „
• 1 .2 .4 .6 1 2 46 10 20 40 60 100
Particle diameter (urn)
Figure 1.3-4.
Cumulative size specific emission factors for uncontrolled
.commercial boilers burning residual and distillate oil.
10/86
External Combustion Sources
1.3-7
-------
Organic compounds present in the flue gas streams of boilers include
aliphatic and aromatic hydrocarbons, esters, ethers, alcohols, carbonyls,
carboxylic acids and polycylic organic matter. The last includes all organic
matter having two or more benzene rings*
Trace elements are also emitted from the combustion of fuel oil. The
quantity of trace elements emitted depends on combustion temperature, fuel
feed mechanism and the composition of the fuel. The temperature determines the
degree of volatilization of specific compounds contained In the fuel. The fuel
feed mechanism affects the separation of emissions into bottom ash and fly ash.
If a boiler unit is operated improperly or is poorly maintained, the
concentrations of carbon monoxide and VOCs may increase by several orders of
magnitude.
1.3.3 Controls
The various control devices and/or techniques employed on oil fired
boilers depend on the type of boiler and the pollutant being controlled. All
such controls may be classified into three categories, boiler modification,
fuel substitution and flue gas cleaning.
Boiler Modification 1-4.8-9,13-14,23_ Boiler modification includes any
physical change in the boiler apparatus itself or in its operation. Maintenance
of the burner system, for example, is important to assure proper atomlzatlon
and subsequent minimization of any unburned combustibles. Periodic tuning is
important in small units for maximum operating efficiency and emission control,
particularly of smoke and CO. Combustion modifications, such as limited excess
air firing, flue gas reclrculatlon, staged, combustion and reduced load opera- I
tibn, result in lowered NOx emissions in large facilities. See Table 1.3-1 for
specific reductions possible through these combustion modifications.
Fuel Substitution's, 12,28_ puei substitution, the firing of "cleaner" fuel
oils, can substantially reduce emissions of a number of pollutants. Lower
sulfur oils, for Instance, will reduce SOX emissions in all boilers, regardless
of size or type of unit or grade of oil fired. Particulates generally will be
reduced when a lighter grade of oil is fired. Nitrogen oxide emissions will be
reduced by switching to either a distillate oil or a residual oil with less
nitrogen. The practice of fuel substitution, however, may be limited, by the
ability of a given operation to fire a better grade of oil and by the cost and
availability thereof.
Flue Gas Cleaning15-I6,28 _ piue gas cleaning equipment generally is
employed only on large oil fired boilers. Mechanical collectors, a prevalent
type of control device, are primarily useful in controlling partlculates gen-
erated during soot blowing, during upset conditions, or when a very dirty heavy
oil Is fired. During these situations, high efficiency cyclonic collectors can
effect up to 85 percent control of particulate. Under normal firing conditions,
or when a clean oil is combusted, cyclonic collectors will not be nearly so
effective because of the high percentage of small particles (less than 3 micro-
meters diameter) emitted.
1-3-8 EMISSION FACTORS 10/86
-------
Electrostatic precipitators are commonly used in oil fired power plants.
Older precipitators, usually small, remove generally 40 to 60 percent of the
particulate matter. Because of the low ash content of the oil, greater
collection efficiency may not be required. Today, new or rebuilt electrostatic
precipitators have collection efficiencies of up to 90 percent.
Scrubbing systems have been installed on oil fired boilers, especially of
late, to control both sulfur oxides and particulate. These systems can achieve
S02 removal efficiencies of 90 to 95 percent and particulate control
efficiencies of 50 to 60 percent.
References for Section 1.3
1. W. S. Smith, Atmospheric Emissions from Fuel Oil Combustion: An Inventory
Guide, 999-AP-2, Q. S. Environmental Protection Agency, Washington, DC,
November 1962.
2. J. A. Danielson (ed.), Air Pollution Engineering Manual, Second Edition,
AP-40, U. S. Environmental Protection Agency, Research Triangle Park, NC,
1973. Out of Print.
3. A. Levy, et al., A Field Investigation of Emissions from Fuel Oil Combus-
tion for Space Heating, API Bulletin 4099, Battelle Columbus Laboratories,
Columbia, OH, November 1971.
4. R. E. Barrett, et al., Field Investigation of Emissions from Combustion
Equipment for Space Heating, EPA-R2-73-084a, U. S. Environmental Protec-
tion Agency, Research Triangle Park, NC,. June 1973.
5. G. A. Cato, et al., Fiel'd Testing: Application of Combustion Modifications
To Control Pollutant Emissions from Industrial Boilers - Phase I, EPA-650/
2-74-078a, U. S. Environmental Protection Agency, Washington, DC, October
1974.
6. G. A. Cato, et al., Field Testing: Application of Combustion Modifications
To Control Pollutant Emissions from Industrial Boilers - Phase II, EPA-600/
2-76-086a, U. S. Environmental Protection Agency, Washington, DC," April"
1976.
7. Particulate Emission Control Systems for Oil Fired Boilers, EPA-450/3-74-
063, U. S. Environmental Protection Agency, Research Triangle Park, NC,
December 1974.
8. W. Bartok, et al., Systematic Field Study of NOy Emission Control Methods
for Utility Boilers, APTD-1163, U. S. Environmental Protection Agency,
Research Triangle Park, NC, December 1971.
9. A. R. Crawford, et al., Field Testing: Application of Combustion Modi-
fications To Control NO, Emissions from Utility Boilers, EPA-650/2-74-066,
U. S. Environmental Protection Agency, Washington, DC, June 1974.
1Q/86 External Combustion Sources 1.3-9
-------
1Q. J. F. Deffner, et al . , Evaluation of Gulf Econoj et Equipment with Respect
to Air Conservation, Report No. 731RC044, Gulf Research and Development
Company, Pittsburgh, PA, December 18, 1972.
11. C. E. Blakeslee and H. E. Burbach, "Controlling NOx Emissions from Steam
Generators", Journal of the Air Pollution Control Association, 23; 37-42,
January 1973.
12. C. W. Siegmund, "Will Desulfurized Fuel Oils Help?", American Society of
Heating, Refrigerating and Air Conditioning Engineers Journal, 11; 29-33,
April 1969.
13. F. A. Govan, et al . , "Relationships of Particulate Emissions Versus
Partial to Full Load Operations for Utility-sized Boilers", Proceedings
of Third Annual Industrial Air Pollution Control Conference, Knoxville,
TN, March 29-30, 1973.
14. R. E. Hall, et al . , A Study of Air Pollutant Emissions from Residential
Heating Systems, EPA-650/ 2-74-003, U. S. Environmental Protection Agency,
Washington, DC, January 1974.
15. Flue Gas Desulf urization: Installations and Operations, PB 257721,
National Technical Information Service, Springfield, VA, September 1974.
16. Proceedings; Flue Gas Desulf urization Symposium - 1973, EP A-650/ 2-7 3-038 ,
U. S. Environmental Protection Agency, Washington, DC, December 1973.
17. R. J. Milligan, et al . , Review of. NOy Emission Factors for Stationary
Fossil Fuel Combustion Sources, EPA-450/4-79-021, U. S. Environmental
Protection Agency, Research Triangle Park, NC, September 1979.
18. N. F. Suprenant, et al . , Emissions Assessment of Conventional Stationary
Combustion Systems, Volume I; Gas and Oil Fired Residential Heating
Sources, EPA-600/7-79-029b, U. S. Environmental Protection Agency,
Washington, DC, May 1979;
19. C. C. Shih, et al . , Emissions Assessment of Conventional Stationary Com-
bustion Systems, Volume III; External Combustion 'Sources- 'for Electricity
Generation, EPA Contract No. 68-02-2197, TRW, Inc., Redondo Beach, CA,
November 1980.
20. N. F. Suprenant, et al . , Emissions Assessment of Conventional Stationary
Combustion System, Volume IV; Commercial Institutional Combustion Sources,
EPA Contract No. 68-02-2197, GCA Corporation, Bedford, MA, October 1980.
21. N. F. Suprenant, et al . , Emissions Assessment of Conventional Stationary
Combustion Systems, Volume V; Industrial Combustion Sources, EPA Contract
No. 68-02-2197, GCA Corporation, Bedford, MA, October 1980.
22. Fossil Fuel Fired Industrial Boilers - Background Information for Proposed
Standards (Draft EIS), Office Of Air Quality Planning And Standards, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1980.
1.3-10 EMISSION FACTORS 10/86
-------
23. K. J. Lim, et al., Technology Assessment Report for Industrial Boiler
Applications; NCy Combustion Modification, EPA-600/7-79-178f, U. S.
Environmental Protection Agency, Washington, DC, December 1979.
24. Emission Test Reports, Docket No. OAQPS-78-1, Category II-I-257 through
265, Office Of Air Quality Planning And Standards, U. S. Environmental
Protection Agency, Research Triangle Park, NC, 1972 through 1974.
25. Primary Sulfate Emissions from Coal and Oil Combustion, EPA Contract No.
68-02-3138, TRW, Inc., Redondo Beach, CA, February 1980.
26. C. Leavitt, et al., Environmental Assessment of an Oil Fired Controlled
Utility Boiler, EPA-600/7-80-087, U. S. Environmental Protection Agency,
Washington, DC, April 1980.
27. W. A. Carter and R. J. Tidona, Thirty-day Field Tests of Industrial
Boilers; Site 2 - Residual-oil-fired Boiler, EPA-600/7-80-085b, U. S.
Environmental Protection Agency, Washington, DC, April 1980.
28. G. R. Offen, et al., Control of Particulate Matter from Oil Burners and
Boilers, EPA-450/3-76-005, U. S. Environmental Protection Agency, Research
Triangle Park, NC, April 1976.
29. Inhalable Particulate Source Category Report for External Combustion
Sources, EPA Contract No. 68-02-3156a, Acurex Corporation,. Mountain View,
CA, January 1985.
10/86 External Combustion Sources 1.3-11
-------
1.4 NATURAL GAS COMBUSTION
1.4.1 General1"2
Natural gas Is one of the major fuels used throughout the country. It is
used mainly for power generation, for Industrial process steam and heat produc-
tion, and for domestic and commercial space heating. The primary component of
natural gas Is methane, • although varying amounts of ethane and smaller amounts
of nitrogen, helium and carbon dioxide are also present. Gas processing plants
are required for recovery of llqueflable constltutents and removal of hydrogen
sulflde (H2S) before the gas Is used (see Natural Gas Processing, Section 9.2).
The average gross heating value of natural gas Is approximately 9350 kilo-
calories per standard cubic meter (1050 British thermal units/standard cubic
foot), usually varying from 8900 to 9800 kcal/scm (1000 to 1100 Btu/scf).
1.4.2 Emission And Controls3"26
Even though natural gas is considered to be a relatively clean fuel, some
emissions can occur from the combustion reaction. For example, Improper oper-
ating conditions, Including poor mixing, insufficient air, etc., may cause
large amounts of smoke, carbon monoxide and hydrocarbons. Moreover, because a
sulfur containing raercaptan is added to natural gas to permit detection, small
amounts of sulfur oxides will also be produced in the combustion process.
Nitrogen oxides are the major pollutants of concern when burning natural
gas. Nitrogen oxide emissions are functions of combustion . chamber' temperature
and combustion product cooling rate. Emission levels vary considerably with
the type and. size of unit and with operating conditions.
In some large boilers, several operating modifications may be used for
control. Staged combustion, for example, including of f-stoichiometric firing
and/or two stage combustion, can reduce emissions by 5 to 50 percent.26 In off-
stoichiometric firing, also called "biased firing", some burners ar.e operated
fuel rich, some fuel lean, and others may supply air only. In two stage combus-
tion, the burners are operated fuel rich (by introducing only 70 to 90 percent
stoichiometric air), with combustion being completed by air injected above the
flame zone through second stage "NO ports". In staged combustion, NOX emissions
are reduced because the bulk of combustion occurs under fuel rich conditions.
Other NOjj reducing modifications include low excess air firing and flue
gas reclrculation. In low excess air firing, excess air levels are kept as
low as possible without producing unacceptable levels of unburned combustibles
(carbon monoxide, volatile organic compounds and smoke) and/or other operating
problems. This technique can reduce NOX emissions 5 to 35 percent, primarily
because of lack of oxygen during combustion. Flue gas recirculation Into the
primary combustion zone, because the flue gas is relatively cool and oxygen
deficient, can also lower NOX emissions 4 to 85 percent, depending on the
amount of gas reel rculated. Flue gas recirculation is best suited for new
boilers. Retrofit application would require extensive burner modifications.
10/86 External Combustion Sources 1.4-1
-------
I
N)
TABLE 1.4-1. UNCONTROLLED EMISSION FACTORS FOR NATURAL GAS COMBUSTION3
in
M
§
"3
to
furnace ill* 4 type
(10* Itu/hr heat Input)
Utility bolUri (> 100)
Industrial bollere (10 - 100)
Doaeetlc and conerclal
boll.r. « 10)
Particular"
kg/IO'.J
16 - 8U
16 - ao
16 - ao
Ib/IO4 111
1 - 5
1 - i
1 - 5
Sulfur dlu«ld«c
kg/10*!!1
9.6
9.6
9.6
Ib/IO* It'
0.6
0.6
0.6
Nitrogen oildeed
k«/IO'.)
aaoob
2240
1600
Ib/IO6 (t1
5 SO"
UO
100
Carbon •onoilde*
•n/io*.'
. 640
560
120
Ib/IO6 «t'
40
IS
20
Volitll* oriciilc*
NotiH«thanc
M/IO6*1
2)
44
84
Ib/IO* «t>
1.4
2. 8
5.)
Htthan*
kj/IO*.'
4.B
48
4)
Ib/IO* li>
0.)
)
2.7
*Eiprlefe»nc« t, 7-8. 16. 18. 22-25.
IRcftrtncM 16. It. H«y Incrtai* 10 - 100 !!•<• Kith Imfioftt oo.r.tlon or ••Int.cunci.
hPor tengencUllf flr«4 «•!(•. u§« 4400 kg/lfl' •' (27i Ib/IU* ft'). At'reduced lo*de. aultlply
factor by load reduction coefficient la figure 1.4-1. For potentl.l HU, reductlona b/
coabualloi vodlfIcatloa, aee tell. Note that NO, reduction liom theie «odlfIcetlona vlll
alao occur at reduced load conditions.
o
oo
-------
Studies Indicate that low NO^ burners (20 to 50 percent reduction) and ammonia
Injection (40 to 70 percent reduction) also offer NOx emission reductions.
Combinations of the above combustion modifications may also be employed to
reduce NO^ emissions further. In some boilers, for instance, NOx reductions
as high as 70 to 90 percent have been produced by employing several of these
techiques simultaneously. In general, however, because the net effect of any
of these combinations varies greatly, it is difficult to predict what the
reductions will be in individual applications.
Although not measured, all partlculate has been estimated to be less
than 1 micrometer in size. " Emission factors for natural gas combustion are
presented in Table 1.4-1, and factor ratings in Table 1.4-2.
TABLE 1.4-2. FACTOR RATINGS FOR NATURAL GAS COMBUSTION
Furnace
type
Utility
boiler
Industrial
boiler
Commercial
boiler
Residential
furnace
Particulate
B
B
B
B
Sulfur
oxides
A
A
A
A
Nitrogen
oxides
A
A
A
A
Carbon
monoxide
A
A .
A
A
Volatile organics
No nme thane
C
C
D
D
Methane
C
C
D
D
10/86
External Combustion Sources
1.4-3
-------
1J
u
0.5
(U
60
80
LOAD, percent
100
110
Figure 1.4-1. Load reduction coefficient as function of boiler load.
(Used to determine NOx reductions at reduced loads in large boilers.)
References for Section 1.4
1. D. M. Hugh, et al., Exhaust Gases from Combustion and Industrial Processes,
EPA Contract No. EHSD 71-36^ Engineering Science, Inc., Washington, DC,
October 2, 1971.
2. J. H. Perry (ed.), Chemical Engineer's Handbook, 4th Edition, McGraw-Hill,
New York, NY, 1963.
3. H. H. Hovey, et al., The Development of Air Contaminant Emission Tables
for Non-process Emissions, New York State Department of Health, Albany,
NY, 1965.
4. W. Bartok, et al., Systematic Field Study of NOy Emission Control Methods
for Utility Boilers, APTD-1163, U. S. Environmental Protection Agency,
Research Triangle Park, NC, December 1971.
1.4-4
EMISSION FACTORS
10/86
-------
5. F. A. Bagwell, et al . , "Oxides of Nitrogen Emission Reduction Program for
Oil and Gas Fired Utility Boilers", Proceedings of the American Power Con-
ference, j^:683-693, April 1970.
6. R. L. Chass and R. E. George, "Contaminant Emissions from the Combustion
of Fuels", Journal of the Air Pollution Control Association, 10:34-43,
February 1980.
7. H. E. Dietzmann, A Study of Power Plant Boiler Emissions, Final Report No.
AR-837, Southwest Research Institute, San Antonio, XX, August 1972.
8. R. E. Barrett, et al . , Field Investigation of Emissions from Combustion
Equipment for Space Heating, EPA-R2-7 3-084, U. S. Environmental Protection
Agency, Research Triangle Park, NC, June 1973.
9. Confidential Information, American Gas Association Laboratories, Cleveland,
OH, May 1970.
10. Unpublished data on domestic gas fired units, U. S. Environmental Pro-
tection Agency, Cincinnati, OH, 1970.
11. C. E. Blakeslee and H. E. Burbock, "Controlling NOjj Emissions from Steam
Generators", Journal of the Air Pollution Control Association, 23: 37-42,
January 1979.
12. L. K. Jain, et al . , "State of the Art" for Controlling NOy Emissions;
Part 1, Utility Boilers, EPA-Contract No. 68-02-0241, Catalytic, Inc.,
Charlotte, NC, September 1972.
13. J. W. Bradstreet and R. J. Fortman, "Status of Control Techniques for
Achieving Compliance with Air Pollution Regulations by the Electric
Utility Industry", Presented at the 3rd Annual Industrial Air Pollution
Control Conference, Knoxville, TN, March 1973.
14. Study of Emissions of NOg from Natural Gas Fired Steam Electric Power
Plants in Texas, Phase II, Volume II, Radian Corporation, Austin, TX,
May 8, 1972.
15. N. F. Suprenant, et al . , Emissions Assessment of Conventional Stationary
Combustion Systems, Volume I; Gas and Oil Fired Residential Heating
Sources, EPA-600/7-79-029b , U. S. Environmental Protection Agency,
Washington, DC, May 1979.
16. C. C. Shih, et al . , Emissions Assessment of Conventional Stationary Com-
bustion Systems, Volume III; External Combustion Sources for Electricity
Generation, EPA Contract No. 68-02-2197, TRW, Inc., Redondo Beach, CA,
November 1980.
17. N. F. Suprenant, et al . , Emissions Assessment of Conventional Stationary
Combustion Sources, Volume IV; Commercial Institutional Combustion
Sources , EPA Contract No. 68-02-2197, GCA Corporation, Bedford, MA,
October 1980.
10/86 External Combustion Sources 1.4-5
-------
18. N. F. Suprenant, et al., Emissions Assessment of Conventional Stationary
Combustion Systems, Volume V; Industrial Combustion Sources, EPA Contract
No. 68-02-2197, GCA Corporation, Bedford, MA, October 1980.
19. R. J. Mllligan, et al., Review of NO^. Emission Factors for Stationary
Fossil Fuel Combustion Sources, EPA-450/4-79-021, U. S. Environmental
Protection Agency, Research Triangle Park, NC, September 1979.
20. W. H. Thrasher and D. W. Dewerth, Evaluation of the Pollutant Emissions
from Gas Fired Water Heaters, Research Report No. 1507, American Gas
Association, Cleveland, OH, April 1977.
21. W. H. Thrasher and D. W. Dewerth, Evaluation of the Pollutant Emissions
from Gas Fired Forced Air Furnaces, Research Report No. 1503, American
Gas Association, Cleveland, OH, May 1975.
22. G. A. Cato, et al., Field Testing; Application of Combustion Modification
To Control Pollutant Emissions from Industrial Boilers, Phase I, EPA-650/
2-74-078a, U. S. Environmental Protection Agency, Washington, DC, October
1974.
23. G. A. Cato, et al., Field Testing; Application of Combustion Modification
To Control Pollutant~Emi33ions from Industrial Boilers, Phase II. EPA-600/
2-76-086a, U. S. Environmental Protection Agency, Washington, DC, April
1976.
24. W. A. Carter and H. J. Buening, Thirty-day Field Tests of Industrial
Boilers - Site 5, EPA Contract No. 68-02-2645, KVB Engineering, Inc.,
Irvine, CA, May 1981.
25. W. A. Carter and H. J. Buening, Thirty-day Field Tests of Industrial
Boilers - Site 6, EPA Contract No. 68-02-2645, KVB Engineering, Inc.,
Irvine, CA, May 1981.
26. K. J. Lira, et al., Technology Assessment Report for Industrial Boiler
Applications; NCy Combustion Modification, EPA Contract No. 68-02-3101,
Acurex Corporation, Mountain View, CA, December 1979.
27. H. J. Taback, et al., Fine Particle Emissions From Stationary and Miscel-
laneous Sources in the South Coast Air Basin, California Air Resources
Board Contract No. A6-191-30, KVB, Inc., Tustin, CA, February 1979.
1.4-6 EMISSION FACTORS 10/86
-------
1.6 WOOD WASTE COMBUSTION IN BOILERS
1.6.1 General1"3
The burning of wood waste in boilers is mostly confined to those industries
where it is available as a byproduct. It is burned both to obtain heat energy
and to alleviate possible solid waste disposal problems. Wood waste may include
large pieces like slabs, logs and bark strips, as well as cuttings, shavings,
pellets and sawdust, and heating values for this waste range from about 4,400
to 5,000 kilocalories per kilogram of fuel dry weight (7,940 to 9,131 Btu/lb).
However, because of typical moisture contents of 40 to 75 percent, the heating
values for many wood waste materials as actually fired are as low as 2,200 to
3,300 kilocalories per kilogram of fuel. Generally, bark is the major type of
waste burned in pulp mills, and either a varying mixture of wood and bark waste
or wood waste alone are most frequently burned in the lumber, furniture and
plywood industries.
1.6.2 Firing Practices1"3
Varied boiler firing configurations are used in burning wood waste. One
common type in smaller operations is the dutch oven, or extension type of
furnace with a flat grate. This unit is widely used because it can burn fuels
with very high moisture. Fuel is fed into the oven through apertures atop a
.firebox and is fired- in a cone shaped pile on a flat grate. The burning -is
done in two stages, drying and gasification, and combustion of gaseous products.
The first stage takes place in a cell separated from the boiler section by a
bridge wall. The combustion stage takes place in the main boiler section. The
dutch oven is not responsive to changes in steam load, and it provides poor
combustion control.
In another type, the fuel cell oven, fuel is dropped onto suspended fixed
grates and is fired in a pile. Unlike the dutch oven, the fuel cell also uses
combustion air preheating and repositioning of the secondary and tertiary air
injection ports to improve boiler efficiency.
In many large operations, more conventional boilers have been modified
to burn wood waste. These units may include spreader stokers with traveling
grates, vibrating grate stokers, etc., as well as tangentially fired or cyclone
fired boilers. The most widely used of these configurations is the spreader
stoker. Fuel is dropped in front of an air jet which casts the fuel out over
a moving grate, spreading it in an even thin blanket. The burning is done in
three stages in a single chamber, (1) drying, (2) distillation and burning of
volatile matter and (3) burning of carbon. This type of operation has a fast
response to load changes, has improved combustion control and can be operated
with multiple fuels. Natural gas or oil are often fired in spreader stoker .
boilers as auxiliary fuel. This is done to maintain constant steam when the
wood waste supply fluctuates and/or to. provide more steam than is possible
from the waste supply alone.
10/86 External Combustion Sources 1.6-1
-------
TABLE 1.6-1. EMISSION FACTORS FOR WOOD AND BARK COMBUSTION IN BOILERS
Pollutant/Fuel type
Particular*8
Bark°
Mulclclone, with flyash reinjectlonc
Multlclone, without flyash
relnj ectlonc
Uncontrolled
Wood /bark mixture*1
Multlclone, with flyash
relnj ecclonc»e
Multlclone, without flyash
relnj ectlonc>e
Uncontrolled'
WoodS
Uncontrolled
Sulfur dioxide"
Nitrogen oxides (as NO,)-)
50,000 - 400,000 Ib steam/hr
OO.OOO Ib steaa/hr
Carbon monoxide'0
VOC
Nonaethane21
Methane"
kg/Kg
7
4.5
24
3
2.7 .
3.6
4.4
0.075
(0.01 - 0.2)
1.4
0.34
2-24
0.7
0.15
Ib/ton
14
9
47
6
5.3
7.2
8.8
0.15
(0.02 - 0.4)
2.8
0.68
4-47
1.4
0.3
Emission Factor
Racing
8
B
B
C
C
C
C
B
3
B
C
D
£
References 2, 4, 9, 17-18, 20. With gas or oil as auxiliary fuel, all particulate assumed
to result from only wood waste fuel. May Include condenslble hydrocarbons of pitches and
tara, mostly from back half catch of EPA Method 5. Tests Indicate condenslble hydrocarbons
about 4! of total partlculate weight.
''Based on fuel moisture content about 50!.
References 4,7-8. After control equipment, assuming an average"collection efficiency of
80Z. Data indicate that 501 flyash relnjectlon Increases dust load at cyclone Inlet 1.2 to
1.5 times, and 100Z flyash relnjectlon Increases the load 1.5 to 2 times.
''Based on fuel-moisture content of 33Z.
eBased on large dutch ovens and spreader stokers (avg. 23,430 kg steam/hr) with steam
pressures 20 - 75 kp» (140 - 530 pst).
f Based on small dutch ovens and spreader stokers (usually £9075 kg steaa/hr), with steam
pressures 5-30 kpa (35 - 230 psi). Careful air adjustments and improved fuel separation and
firing soaecimes used, but effects can not be Isolated.
^References 12-13, 19, 27. Wood waste Includes cuttings, shavings, sawdust and chips, but
not bark. Moisture content ranges 3-50 weight Z. Baaed on small units (OOOO kg steaa/hr).
"Reference 23. Baaed on dry weight of fuel. Froa tests of fuel sulfur content and SOj
. emissions at 4 mills burning bark. Lower limit of range (in parentheses) should be used for
wood, and higher values for bark. Heating value of 5000 kcal/kg (9000 Btu/lb) is assumed.
•^References 7, 24-26. Several factors can Influence emission rates, including combustion
zone, temperature, excess air, boiler operating conditions, fuel moisture and fuel
nitrogen content.
^Reference 30.
""References 20, 30. Nonmethane VOC reportedly consists of compounds with high vapor
pressure, such as alpha plnene.
"Reference 30. Based on approximation of methane/nonmethane ratio, quite variable.
Methane, expressed as Z total VOC, varied 0-74 weight I.
1.6-2
EMISSION FACTORS
10/86
-------
Sander dust is often burned in various boiler types at plywood, particle
board and furniture plants. Sander dust contains fine wood particles with low
moisture content (less than 20 weight percent). It is fired in a flaming
horizontal torch, usually with natural gas as an ignition aid or supplementary
fuel.
1.6.3 Emissions And Controls4'28
The major emission of concern from wood boilers is particulate matter,
although other pollutants, particularly carbon monoxide, may be emitted in
significant amounts under poor operating conditions. These emissions depend
on a number of variables, including (1) the composition of the waste fuel
burned, (2) the degree of flyash reinjection employed and (3) furnace design
and operating conditions.
The composition of wood waste depends largely on the industry whence it
originates. Pulping operations, for example, produce great quantities of bark
that may contain more than 70 weight percent moisture and sand and other non-
combustibles. Because of this, bark boilers in pulp mills may emit considerable
amounts of particulate matter to the atmosphere unless they are well controlled.
On the other hand, some operations, such as furniture manufacturing, produce a
clean dry wood waste, 5 to 50 weight percent moisture, with relatively little
particulate emission when properly burned. Still other operations, such
as sawmills, burn a varying mixture of bark and wood waste that results in
particulate emissions somewhere between these two extremes.
Furnace design and operating conditions are particularly important when
firing wood waste. For example, because of the high moisture content that can
be present in this waste, a larger than usual area of refractory surface is
often necessary to dry the fuel before combustion. In addition, sufficient
secondary air must be supplied over the fuel bed to burn the volatiles that
account for most of the combustible material in the waste. When proper drying
conditions do not exist, or when secondary combustion is incomplete, the
combustion temperature is lowered, and increased particulate, carbon monoxide
and hydrocarbon emissions may result. Lowering of combustion temperature
generally means decreased nitrogen oxide emissions. Also, short term emissions
can fluctuate with significant variations in fuel moisture content.
Flyash reinj ec.cion, which is common to many larger boilers to improve
fuel efficiency, has a considerable effect on particulate emissions. Because
a fraction of the collected flyash is reinjected into the boiler, the dust
loading from the furnace, and consequently from the collection device, increases
significantly per unit of wood waste burned. It is reported that full reinjec-
tion can cause a tenfold increase in the dust loadings of some systems, although
increase of 1.2 to 2 times are more typical for boilers us"ing 50 to 100 percent
reinjection. A major factor affecting this dust loading increase is the extent
to which the sand and other noncombustibles can be separated from the flyash
before reinjection to the furnace.
Although reinjection increases boiler efficiency from 1 to 4 percent and
reduces emissions of uncombusted carbon, it increases boiler maintenance
requirements, decreases average flyash particle size and makes collection more
difficult. Properly designed reinjection systems should separate sand and char
10/86 External Combustion Sources 1.6-3
-------
TABLE 1.6-2. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR BARK FIRED BOILERS3
EMISSION FACTOR RATING: D
KactlcJe • txeb
(u->
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative •*•• Z £ atated *izt
Uncontrolled
42
35
28
21
15
13
9
100
Controlled
Multiple
cyclone6
90
79
64
40
26
21
15
100
Multiple
cyclone1*
40
36
30
19
14
11
8
100
Scrubber*
92
s;
78
56
29
23
14
100
Cumulative ealaaion factor
[kg/Mg (Ib/ton) bark. » fired)
Uncontrolled
10.1
CO. 2)
8.4
(16.8)
6.7
(13.4)
5.0
(10.0)
3.6
(7.2)
3.1
(6.2)
2.2
(4.4)
24
(48)
Controlled
Multiple
cyclonec
6.3
(12.6)
5.5
(11.0)
4.5
(9.0)
2.8
(5.6)
1.8
(3.6)
1.5
(3.0)
1.1
(2.2)
7
(14)
Multiple
cyclone"1
1.8
(3.6)
1.62
(3.24)
1.35
(2.7)
0.86
(1.72)
0.63
(1.26)
0.5
(1.0)
0.36
(0.72)
4.5
(9.0)
Scrubber*
1.32
' (2.64)
1.25
(2.50)
1.12
(2.24)
0.81
(1.62)
0.42
(0.84)
0.33
(0.66)
0.20
(0.40)
1.44
(2.88)
'Reference 31. All spreader etoker bollera.
bExpreaaed aa aerodynaatc equivalent dimeter.
cvith flya»h reinfection.
^Without flyaeh- reinfection. '
•Zatlaated control efficiency for scrubber, 94Z.
o
<• T>
w 4f
w
C —
O <*-
O> -O
^- C7I
*J Ot
C ^
o •*-»
25
20
15
10
Multiple cyclone
«ith flyash reinjection
Scrubber
Uncontrolled.
'
Multiple cyclone
without flyash -
reinjection
.61 2 4 6 10
Particle diameter (urn)
20
'
40 60 100
2.0
1.8
U
O
1.6 u
*J
1.4 §
irt
l/l
1'21
i.o "S
0.8 |
c
o
0.6 V
w
-------
from the exhaust gases, to reinject the larger carbon particles to the furnace
and to divert the fine sand particles to the ash disposal system.
Several factors can influence emissions, such as boiler size and type,
design features, age, load factors, wood species and operating procedures. In
addition, wood is often cofired with other fuels. The effect of these factors
on emissions is difficult to quantify. It is best to refer to the references
for further information.
The use of multitube cyclone mechanical' collectors provides particulate
control for many hogged boilers. Usually, two multicyclones are used in series,
allowing the first collector to remove the bulk of the dust and the second to
remove smaller particles. The efficiency of this arrangement is from 65 to 95
percent. Low pressure drop scrubbers and fabric filters have been used
extsnsively for many years, and pulse jets have been used in the western U. S.
' Emission factors and emission factor ratings for wood waste boilers are
presented in Table 1.6-1, except for cumulative size distribution data, size
specific emission factors for particulate, and emission factor ratings for the
cumulative particle size distribution, all presented in Tables 1.6-2 through
1.6-3. Uncontrolled and controlled size specific emission factors are in
Figures 1.6-1 and 1.6-2.
10/86 External Combustion Sources 1.6-5
-------
TABLE 1.6-3. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR WOOD/BARK FIRED BOILERS3
EMISSION FACTOR RATING: E (A for dry electrostatic granular filter (DEGFj)
Particle al«eb
(pa)
IS
10
6
2.5
1.25
1.00
0.625
TOTAL
. Cumulative mass t £ stated size
Uncontrolled'
94
90
86
76
69
67
-
100
Coiurol ltd
Multiple
cyclone''
96
91
80
54
30
24
16
100
Multiple
cyclone®
35
32
27
16
8
6
3
100
Scrubber'
9b
9H
98
98
96
95
-
100
DECF
77
74
69
65
61
58
SI
100
Cumulative emission factors (kg/Mg (Ib/ton) wood/bark, •• fired)'
Uncont rol 1 edc
3.38
(6.77)
3.24
(6.48)
3.10
(6.20)
2.74
(S.47)
2.48
(4.97)
2.41
(4.82)
-
3.6
(7.2)
Controlled
Multiple •
cyclone"
2.88
(5.76)
2.73
(5.46)
2.40
(4.80)
1.62
(1.24)
0.90
(1.80)
0.72
(I.U)
0.48
(0.96)
3.0
(6.0)
Multiple
cyclone6
0.95
(1.90)
0.66
(1.72)
0.73
(1.46)
0.43
(0.86)
0.22
(0.44)
0.16
(0.32)
0.081
(0.162)
2.7
(5.4)
Scrubber'
0.216
(0.431)
0.216
(0.432)
0.216
(0.432)
0.216
(0.432)
0.211
(0.422)
0.209
(0.418)
-
0.22
(0.44)
DECI*1
0.123
(0.246)
0.118
(0.236)
0.110
(0.220)
0.104
(0.208)
0.098
(0.196)
0.093
(0.186)
0.082
(0.164)
0.16
(0.32)
re
y.
C/5
H
O
•z
H
3
W
**Expressed aa aerodynamic equivalent dlaneter.
cFron data on underfeed stokers. May also be used uu alic
distribution for wood fired boilers.
''From data on spreader stokers. With fly auli rtl njecl I on.
eFrom data on spreader stokers. Without fly auh relnjectIon.
ffrom data on dutch ovens. Estimated control efficiency, 942.
03
ON
-------
o
00
PI
m
l-l
n
o
B
cr
cn
o
3
CO
o
i
o
re
ui
u 01
HJ (.
c
O i/i
••- > o>
u -*
u
"a.
.1 .2 .4 .6 1 2 46
Particle diameter
10 20
40 60 100
0.220
0.218
0.216
0.214
0.212
0.210
0.208
0.206
0.204
0.202
0.200
u
« *-*
>*- X)
it)
r— -Q
1— ^K
O T3
U O
^ i
8 en
41 Ok
jO vitf
3
U
I/)
0.2
o>
l_ "r W ^
* -r, "O
*J^ O
t/» _ O
°^ *
Figure 1.6-2. Cumulative size specific emission factors for wood/bark fired boilers.
cr
I
-------
References for Section 1.6
1. Steam, 38th Edition, Babcock and Wilcox, New York, NY, 1972.
2. Atomspheric Emissions from the Pulp and Paper Manufacturing Industry,
EPA-450/1-73-002, U. S. Environmental Protection Agency, Research Triangle
Park, NC, September 1973.
3. C-E Bark Burning Boilers, C-E Industrial Boiler Operations, Combustion
Engineering, Inc., Windsor, CT, 1973.
4. A. Barren, Jr., "Studies on the Collection of Bark Char throughout the
Industry", Journal of the Technical Association of the Pulp and Paper
Industry, 53(8):1441-1448, August 1970.
5. H. Kreisinger, "Combustion of Wood Waste Fuels", Mechanical Engineering,
6^:115-120, February 1939.
6. P. L. Magill (ed.), Air Pollution Handbook, McGraw-Hill Book Co., New
York, NY, 1956.
7. Air Pollutant Emission Factors, APTD-0923, U. S. Environmental Protection
Agency, Research Triangle Park, NC, April 1970.
8. J. F. Mullen, A Method for Determining Combustible Loss, Dust Emissions,
and Recirculated Refuse for a Solid Fuel Burning System, Combustion"
Engineering, Inc., Windsor, CT, 1966.
9. Source test data, Alan Lindsey, U. S. Environmental Protection Agency,
Atlanta, GA, May 1973.
10. H. K. Effenberger, et al., "Control of Hogged Fuel Boiler Emissions: A
Case History", Journal of the Technical Association of the Pulp and Paper
Industry, _56(2) : 111-115, February 1973.
11. Source test data, Oregon Department of Environmental Quality, Portland,
OR, May 19.73.
12. Source test data, Illinois Environmental Protection Agency, Springfield,
IL, June 1973.
13. J. A. Danielson (ed.), Air Pollution Engineering Manual, Second Edition,
AP-40, U. S. Environmental Protection Agency, Research Triangle Park, NC,
1973. Out of Print.
14. H. Droege and G. Lee, "The Use of Gas Sampling and Analysis for the
Evaluation of Teepee Burners", presented at the Seventh Conference on the
Methods in Air Pollution Studies, Los Angeles, CA, January 1967.
15. D. C. Junge and K. Kwan, "An Investigation of the Chemically Reactive
Constituents of Atmospheric Emissions from Hog-fuel Boilers in Oregon",
Northwest International Section of the Air Pollution Control Association,
November 1973.
1.6-8 EMISSION FACTORS 10/86
-------
16. S. F. Galeano and K. M. Leopold, "A Survey of Emissions of Nitrogen Oxides
in the Pulp Mill", Journal of the Technical Association of the Pulp and
Paper Industry, _56(3): 74-76, March 1973.
17. P. B. Bosseraan, "Wood Waste Boiler Emissions in Oregon State", presented
at the Annual Meeting of the Pacific Northwest International Section of
the Air Pollution Control Association, September 1976.
18. Source test data, Oregon Department of Environmental Quality, Portland,
OR, September 1975.
19. Source test data, New York State Department of Environmental Conservation,
Albany, NY, May 1974.
20. P. B. Bosserman, "Hydrocarbon Emissions from Wood Fired Boilers", pre-
sented at the Annual Meeting of the Pacific Northwest International
Section of the Air Pollution Control Association, November 1977.
21. Control of Particulate Emissions from Wood Fired Boilers, EPA-340/1-77-
026, U. S. Environmental Protection Agency, Research Triangle Park, NC,
1978.
22. Wood Residue Fired Steam Generator Particulate Matter Control Technology
Assessment, EPA-450/2-78-044, U. S. Environmental Protection Agency,
Research Triangle Park, NC, October 1978.
23. H. S. Oglesby and R. 0. Blosser, "Information on the Sulfur Content of
Bark and Its Contribution to S02 Emissions When Burned as a Fuel", Journal
of the Air Pollution Control Association, 30(7):769-772, July 1980.
24. A Study of Nitrogen Oxides Emissions from Wood Residue Boilers, Technical
Bulletin No. 102, National Council of the Paper Industry for Air and Steam
Improvement, New York, NY, November 1979.
25. R. A. Kester, Nitrogen Oxide Emissions from a Pilot Plant Spreader Stoker
Bark Fired Boiler, Department of Civil Engineering, University of
Washington, Seattle, WA, December 1979.
26. A. Nunn, NC^ Emission Factors for Wood Fired Boilers, EPA-600/7-79-219,
U. S. Environmental Protection Agency, September 1979.
27. C. R. Sanborn, Evaluation of Wood Fired Boilers and Wide Bodied Cyclones
in the State of Vermont, U. S. Environmental Protection Agency, Boston,
MA, March 1979.
28. Source test data, North Carolina Department of Natural Resources and
Community Development, Raleigh, NC, June 1981.
29. Nonfossil Fueled Boilers - Emission Test Report; Weyerhaeuser Company,
Longvlew, Washington, EPA-80-WFB-10, Office Of Air Quality Planning And
Standards, U. S. Environmental Protection Agency, Research Triangle Park,
NC, March 1981.
10/86 External Combustion Sources 1.6-9
-------
30. A Study of Wood Residue Fired Power Boiler Total Gaseous Nonmethane Organic
Emissions in the Pacific Northwest, Technical Bulletin No. 109, National
Council of the Paper Industry for Air and Steam Improvement, New York, NY,
September 1980.
31. Inhalable Particulate Source Category Report for External Combustion
Sources, EPA Contract No. 68-02-3156, Acurex Corporation, Mountain View,
CA, January 1985.
1-6-10 EMISSION FACTORS !0/86
-------
1.7 LIGNITE COMBUSTION
1.7.1 General1'4
Lignite Is a relatively young coal with properties intermediate to those
of bituminous coal and peat. It has a high moisture content (35 to 40 weight
percent) and a low wet basis heating value (1500 to 1900 kilocalories) and
generally is burned only near where it is mined, in some midwestern states and
Texas. Although a small amount is used in industrial and domestic situations,
lignite is used mainly for steam/ electric production in power plants. In the
past, lignite has been burned mainly in small stokers, but today the trend is
toward use in much larger pulverized coal fired or cyclone fired boilers.
The major advantages of firing lignite are that, in certain geographical
areas, it is plentiful, relatively low in cost and low in sulfur content (0.4
to 1 wet basis weight percent). Disadvantages are that more fuel and larger
facilities are necessary to generate a unit of power than is the case with
bituminous coal. . The several reasons for this are (1) the higher moisture
content means that more energy is lost in the gaseous products of combustion,
which reduces boiler efficiency; (2) more energy is required to grind lignite
'to combustion specified size, especially in pulverized coal fired units; (3)
greater tube spacing and additional soot blowing are required because of the
higher ash fouling tendencies; and (4) because of its lower heating value, more
fuel must be handled to produce a given amount of power, since lignite usually
is not cleaned or dried before combustion (except for some drying in the crusher
or pulverizer and during transfer to the burner). No major problems exist with
the handling or combustion of lignite when its unique characteristics are taken
into account.
1.7.2 Emissions And Controls2'11
The major pollutants from firing lignite, as with any coal, are particulate,
sulfur oxides, and nitrogen oxides. Volatile organic compounds (VOC) and carbon
monoxide emissions are quite low under normal operating conditions.
Particulate emission levels appear most dependent on the firing configu-
ration in the boiler. Pulverized coal fired units and spreader stokers, which
fire much or all of the lignite In suspension, emit the greatest quantity of
flyash per unit of fuel burned. Cyclone furnaces, which collect much of the
ash as molten slag in the furnace itself, and stokers (other than spreader),
which retain a large fraction of the ash In the fuel bed, both emit less par-
ticulate matter. In general, the relatively high sodium content of lignite
lowers particulate emissions by causing more of the resulting flyash to
deposit on the boiler tubes. This is especially so in pulverized coal fired
units wherein a high fraction of the ash is suspended in the combustion gases
and can readily come into contact with the boiler surfaces.
Nitrogen oxide emissions are mainly a function of the boiler firing
configuration and excess air. Stokers produce the lowest NOx levels, mainly
10/86 External Combustion Sources 1.7-1
-------
I
to
TABLE 1.7-1. EMISSION FACTORS FOR EXTERNAL COMBUSTION OF LIGNITE COAL3
Firing configuration
Pulverized coal fired
dry bottom
Cyclone furnace
Spreader stoker
Other stoker
Particulateb
kg/Mg
3.1A
3.3A
3.4A
1.5A
Ib/ton
6.3A
6.7A
6.8A
2.9A
Sulfur oxldesc
kg/Mg
I5S
I5S
I5S
I5S
Ib/ton
30S
30S
30S
30S
Nitrogen oxides^
kg/Mg
6e,f
8.5
3
3
Ib/ton
12e.f
17
6
6
Carbon
monoxide
g
&
&
g
Volatile organics
Nonmethane
g
g
g
g
Methane
g
g
g
g
m
M
CO
CO
1-1
o
25
H
§
CO
aFor lignite consumption as fired.
^References 5-6, 9, 12. A = wet basis % ash content of lignite.
References 2, 5-6, 10-11. S = wet basis weight % sulfur content of lignite. For high sodium/ash
lignite (Na20 >8Z), use 8.5S kg/Mg (17S Ib/ton); for low sodium/ash lignite (Na20 <22), use 17.5S
kg/Mg (35S Ib/ton). If unknown, use 15S kg/Mg (30S Ib/ton). The conversion of S02 is shown to be
a function of alkali ash constituents.
dReferences 2, 5, 7-8. Expressed as NO.,.
.eUse 7 kg/Mg (14 Ib/ton) for front wall fired and horizontally opposed wall fired units, and 4 kg/Mg (8 Ib/ton)
for tangentlally fired units.
'May be reduced 20 - 40% with low excess firing and/or staged combustion in front fired and opposed wall fired
units and cyclones.
HFactors in Table l.l-l may be used, based on combustion similarity of lignite and bituminous coal.
o
CD
-------
because most existing units are relatively small and have lower peak flame
temperatures. In most boilers, regardless of firing configuration, lower
excess combustion air means lower NO^ emissions.
Sulfur oxide emissions are a function of the alkali (especially sodium)
content of the lignite ash. Unlike most fossil fuel combustion, in which over
90 percent of the fuel sulfur is emitted as 862, a significant fraction of the
sulfur in lignite reacts with the ash components during combustion and is
retained In the boiler ash deposits and fly ash. Tests have shown that less
than 50 percent of the available sulfur may be emitted as S02 when a high
sodium lignite is burned, whereas more than 90 percent may be emitted from low
sodium lignite. As a rough average, about 75 percent of the fuel sulfur will
be emitted as S02» the remainder being converted to various sulfate salts.
Newer lignite fired utility boilers are equipped with large electrostatic
precipitators with as high as 99.5 percent particulate control. Older and
smaller electrostatic precipitators operate at about 95 percent efficiency.
Older industrial and commercial units use cyclone collectors that normally
achieve 60 to 80 percent collection efficiency on lignite flyash. Flue gas
desulfurization systems identical to those on bituminous coal fired boilers
are in current operation on several' lignite fired utility boilers. (See
Section 1.1).
Nitrogen oxide reductions of up to 40 percent can be achieved by changing
the burner geometry, controlling excess air and making other changes in operat-
ing procedures. The techniques for bituminous and lignite coal are identical.
TABLE 1.7-2. EMISSION FACTOR RATINGS FOR LIGNITE COMBUSTION
Firing configuration
Pulverized coal
fired dry bottom
Cyclone furnace
Spreader stoker
Other stokers
Particulate
A
C
B
B
Sulfur dioxide
A
A
B
C
Nitrogen oxides
A
A
C
D
10/86
External Combustion Sources
1.7-3
-------
TABLE 1.7-3. CUMULATIVE PARTICLE SIZE DISTRIBUTION AiND SIZE SPECIFIC
EMISSION FACTORS FOR BOILERS BURNING PULVERIZED LIGNITE COAL3
EMISSION FACTOR RATING: E
Particle slzeb
0|>)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass Z <_ stated size
Uncontrolled
51
35
26
10
7
6
3 -
100
Multiple cyclone
controlled
77
67
57
27
16
14
8
100
Cumulative emission factor0
Ikg/Mg (Ib/ton) coal, as fired)
Uncontrolled
1.58A (3.16A)
1.09A (2. ISA)
0.81A (1.62A)
0.31A (0.62A)
0.22A (0.44A)
0.19A (0.38A)
0.09A (0.18A)
3.1A (6.2A)
Multiple cyclone
controlled^
0.477A (0.954A)
0.415A (0.830A)
0.353A (0.706A)
0.167A (0.334A)
0.099A (0.198A)
0.087A (0.174A)
0.050A (0.100A)
0.62A (1.24A)
aReference 13.
''Expressed as aerodynamic equivalent diameter.
CA - coal ash weight ! content, as fired.
^Estimated control efficiency for multiple cyclone, 80Z.
3A
2.7A
2.4A -
2.1A
l.OA
l.SA
1.2A
0.9A
0.6A
0.3A
0
I
Multiple
cyclone
Uncontrolled
.4 .6 1 24 6 10
Particle dianeter (uin)
20
40 60 100
l.OA
0.9A
0.3A
0.7A
0.6A
0.5A
6.4A
0.3A
0.2A
0.1A
0.0
X
u
•I
1.7-4
Figure 1.7-1. Cumulative size specific emission factors
for boilers burning pulverized lignite coal
EMISSION FACTORS
10/86
-------
TABLE 1.7-4 CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR LIGNITE FUELED SPREADER STOKERS3
EMISSION FACTOR RATING: E
Particle size0
(*a)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative Baas I ± seated size
Uncontrolled
28
20
14
7
5
5
4
ioa
Multiple cyclone
controlled
55
41
31
26
23
22
e
100
Cuaulatlve •alsslon factor0
Ikg/Mg (Ib/ton) coal, aa fired]
Uncontrolled
0.95A (1.9A)
0.68A (1.36A)
0.48 A (0.96A)
0.24A (0.48A)
0.17A (0.34A)
0.17A (0.34A)
0.14A (0.28A)
3.4A (6.8A )
Multiple cyclone
controlled*1
0.374A (0.748A)
0.279A (0.558A)
0.211A (0.422A)
0.177A (0.354A)
0.156A (0.312A)
0.1 50A (0.30'OA)
e
0.68A (1.36A)
^Reference 13.
''Expressed as aerodynamic equivalent diameter.
cCo«l ash weight Z content, as fired.
^Estimated control efficiency for multiple cyclone, 80Z.
elnaufflclent data.
l.QA
0.9A -
Of
c
fs 0.8A
S-t^
«^2 0.7A
3-cC
-.2 ^ 0.6A
"Z •• <0
Sr .
•gl-3 0.5A
•T> 3
?2fO.U
— o --.
is
0.2A
0.1A
0
Uncontrolled
X_flu
H1ole cyclone
.4 .6 1 2 4 6 10
Particle diameter (y«)
20
40 60 100
10/86
Figure 1.7-2. Cumulative size specific emission factors
for lignite fueled spreader stokers.
External Combustion Sources
1.7-5
-------
Emission factors for particulate, sulfur dioxide and nitrogen oxides are
presented in Table 1.7-1, and emission factor ratings in Table 1.7-2. Specific
emission factors for particulate emissions, and emission factor ratings for the
cumulative particle size distributions, are given In Tables 1.7-3 and 11.7-4.
Uncontrolled and controlled size specific emission factors are presented in
Figures 1.7-1 and 1.7-2. Based on the similarity of lignite combustion and
bituminous coal combustion, emission factors for carbon monoxide and volatile
organic compounds (Table 1.1-1), and cumulative particle size distributions
for cyclone furnaces, uncontrolled spreader stokers and other stokers (Tables
1.1-5 through 1.1-8) may be used.
References for Section 1.7
1. Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Volume
12, John Wiley and Sons, New York, NY, 1967.
2. G. H. Gronhovd, et al., "Some Studies on Stack Emissions from Lignite
Fired Powerplants", Presented at the 1973 Lignite Symposium, Grand Forks,
NB, May 1973.
3. Standards Support and Environmental Impact Statement; Promulgated
Standards of Performance.for Lignite Fired Steam Generators: Volumes I
and II, EPA-450/2-76-030a and 030b, U. S. Environmental Protection Agency,
Research Triangle Park, NC, December 1976.
4. 1965 Keystone Coal Buyers Manual, McGraw-Hill, Inc., New York, NY, 1965.
5. Source test data on lignite fired power plants, North Dakota State Depart-
ment of Health, Bismarck, ND, December 1973.
6. G. H. Gronhovd, et al., "Comparison of Ash Fouling Tendencies of High and
Low Sodium Lignite from a North Dakota Mine", Proceedings of the American
Power Conference, Volume XXVIII, 1966.
7. A. R. Crawford, et al., Field Testing: Application of Combustion Modi-
fication To Control NCy Emissions from Utility Boilers, EPA-650/2-74-066,
U. S. Environmental Protection Agency, Washington, DC, June 1974.
8. "Nitrogen Oxides Emission Measurements for Lignite Fired Power Plant",
Source Test No. 75-LSG-33, Office Of Air Quality Planning And Standards,
U. S. Environmental Protection Agency, Research Triangle Park, NC, 1974.
9. Coal Fired Power Plant Trace Element Study, A Three Station Comparison,
U. S. Environmental Protection Agency, Denver, CO, September 1975.
10. C. Castaldini and M. Angwln, Boiler Design and Operating Variables
Affecting Uncontrolled Sulfur Emissions from Pulverized Coal Fired Steam
Generators, EPA-450/3-77-047, U. S. Environmental Protection Agency,
Research Triangle Park, NC, December 1977.
1.7-6 EMISSION FACTORS 10/86
-------
11. C. C. Shih, et al., Emissions Assessment of Conventional Stationary
Combustion Systems, Volume III; External Combustion Sources for
Electricity Generation, EPA Contract No. 68-02-2197, TRW Inc., Redondo
Beach, CA, November 1980.
12. Source test data on lignite fired cyclone boilers, North Dakota State
Department of Health, Bismarck, ND, March 1982.
13. Inhalable Partlculate Source Category Report for External Combustion
Sources, EPA Contract No. 68-02-3156, Acurex Corporation, Mountain View,
CA, January 1985.
10/86 External Combustion Sources 1.7-7
-------
3.0 Stationary Internal Combustion Sources
Internal combustion engines included in this source category generally are
used in applications similar to those associated with external combustion
sources. The major items within this category are gas turbines and large heavy
duty general utility reciprocating engines. Most stationary internal combustion
engines are used to generate electric power, to pump gas or other fluids, or to
compress air for pneumatic machinery.
9/85 Stationary Internal Combustion Sources 3.0-1
-------
3.1 Stationary Gas Turbines for Electric Utility Power Plants
3.1.1 General — Stationary gas turbines find application in electric power generators, in gas pipeline pump and
compressor drives, and in various process industries. The majority of these engines are used in electrical generation
for continuous, peaking, or standby power.1 The primary fuels used are natural gas and No. 2 (distillate) fuel oil.
although residual oil is used in a few applications.
3.1.2 Emissions — Data on gas turbines were gathered and summarized under an EPA contract.2 The contractor
found that several investigators had reported data on emissions from gas turbines used in electrical generation but
that little agreement existed among the investigators regarding the terms in which the emissions were expressed.
The efforts represented by this section include acquisition of the data and their conversion to uniform terms.
Because many sets of measurements reported by the contractor were not complete, this conversion often involved
assumptions on engine air flow or fuel flow rates (based on manufacturers* data). Another shortcoming of the
available information was that relatively, few data were obtained at loads below maximum rated (or base) load.
Available data on the population and usage of gas turbines in electric utility power plants are fairly extensive.
and information from the various sources appears to be in substantial agreement. The source providing the most
complete information is the Federal Power Commission, which requires major utilities (electric revenues of SI
million or more) to submit operating and financial data on an annual basis. Sawyer and Farmer-5 employed these
data to develop statistics on the use of gas turbines for electric generation in 1971. Although their report involved
only the major, publicly owned utilities (not the private or investor-owned companies), the statistics do appear to
include about 87 percent of the gas turbine power used for electric generation in 1971.
Of the 253 generating stations listed by Sawyer and Farmer, 137 have more than one turbine-generator unit.
From the available data, it is not possible to know how many hours each turbine was operated during 1971 for
these multiple-turbine plants. The remaining 116 (single-turbine) units, however, were operated an average of 1196
hours during 1971 (or 13.7 percent of the time), and their average load factor (percent of rated load) during
operation was 86.8 percent. This information alone is not adequate for determining a representative operating
pattern for electric utility turbines, but it should help prevent serious errors.
Using 1196 hours of operation per year and 250 starts per year as normal, the resulting average operating day is
about 4.8 hours long. One hour of no-load time per day would represent about 21 percent of operating time, which
is considered somewhat excessive. For economy considerations, turbines are not run at off-design conditions any
longer than necessary, so time spent at intermediate power points is probably minimal. The bulk of turbine
operation must be at base or peak load to achieve the high load factor already mentioned.
If it is assumed that time spent at off-design conditions includes 15 percent at zero load and 2 percent each at
25 percent, 50 percent, and 75 percent load, then the percentages of operating time at rated load (100 percent)
and peak load (assumed to be 125 percent of rated) can be calculated to produce an 86.8 percent load factor.
These percentages turn out to be 19 percent at peak load and 60 percent at rated load: the postulated cycle based
on this line of reasoning is summarized in Table 3.1-1.
12/77 Stationary Internal Combustion Sources 3.1-1
-------
Table 3.1-1. TYPICAL OPERATING CYCLE FOR ELECTRIC
UTILITY TURBINES
Condition.
% of rated
power
0
25
50
75
100 (base)
125 (peak)
Percent operating
time spent
at condition
15
2
2
2
60
19
Time at condition
based on 4.8-hr day
hours
0.72
0.10
0.10
0.10
2.88
0.91
4.81
minutes
43
6
6
6
173
55
289
Contribution to load
factor at condition
0.00x0.15 = 0.0
0.25 x 0.02 = 0.005
0.50 x 0.02 = 0.010
0.75x0.02 = 0.015
1.0 x 0.60 = 0.60
1.25x0.19 = 0.238
Load factor = 0.868
The operating cycle in Table 3.1-1 is used to compute emission factors, although it is only an estimate of actual
operating patterns.
Table 3.1-2. COMPOSITE EMISSION FACTORS FOR 1971
POPULATION OF ELECTRIC UTILITY TURBINES
EMISSION FACTOR RATING: B
Time basis
Entire population
Ib/hr rated load3
kg/hr rated load
Gas-fired only
Ib/hr rated load
kg/hr rated load
Oil-fired only
Ib/hr rated load
kg/hr rated load
Fuel basis
Gas-fired only
Ib/106ft3gas
kg/10* m3 gas
Oil-fired only
lb/103 gal oil
kg/103 liter oil
Nitrogen
oxides
8.84
4.01
7.81
3.54
9.60
4.35
413.
6615.
67.8
8.13
Hydro-
carbons
0.79
0.36
0.79
0.36
0.79
0.36
42.
673.
5.57
0.668
Carbon
Monoxide
2.18
0.99
2.18
0.99
_ *
2.18
0.99
115.
1842.
15.4
1.85
Partic-
ulate
0.52.
0.24
0.27
0.12
0.71
0.32
14.
224.
5.0
0.60
Sulfur
oxides
0.33
0.15
• 0.098
0.044
0.50
0.23
940S&
15.000S
140S
16.8S
Rated load expressed in megawatts.
S j* the percentage sulfur. Example: If the factor ii 9«0 and the sulfur content to 0.01 percent, the sulfur oxide* emitted would
be 94O time* 0.01. or 9.4 lb/106 ft3 ga*.
Table 3.1-2 is the resultant composite emission factors based on the operating cycle of Table 3.1-1 and the
1971 population of electric utility turbines.
3.1-2
EMISSION FACTORS
12/77
-------
Different values tor time at base and peak loads arc obtained by ijluinging the total time at lower loads (0
through 75 percent) or by changing ihc distribution ol' time spent at lower loads. The cycle given in Table 3.3-1
seems reasonable, however, considering the fixed load factor and the economies of lurbine operation. Note that the
cycle determines only the importance of each load condition in computing composite emission factors for each
type of turbine, inn overall operating hours.
The top portion of Table 3.1-2 gives separate factors for gas-tired and oil-tired units, and the bottom portion
gives fuel-based factors that can be used to estimate emission rates when overall fuel consumption data arc
available. Fuel-based emission factors on a mode basis would also he useful but present fuel consumption data are
not adequate for this purpose.
References for Section 3.1
I. O'Kecfe. W. and R. G. Schwieger. Prime Movers. Power. / IM I I): 522-53 I. November 1971.
2. Hare. C. T. and K. J. Springer. Kxhaust Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Final Report. Part 6: Gas Turbine Licet ric Utility Power Plants. Southwest
Research Institute. San Antonio. Tex. Prepared for Environmental Protection Agency. Research Triangle Park.
N.C.. under Contract No. EHS 70-108. February 1974.
3. Sawyer, V. W. and R. C. Fanner. Gas Turbines in U.S. Electric Utilities. Gas Turbine International. January -
April 1973.
12/77 Stationary Internal Combustion Sources 3.1-3
-------
3.2 Heavy Duty Natural Gas Fired Pipeline Compressor Engines
3.2.1 General1 - Engines in the natural gas industry are used primarily to power compressors used for pipeline
transportation, field gathering (collecting gas from wells), underground storage, and gas processing plant
applications. Pipeline engines are concentrated in the major gas producing states (such as those along the Gulf
Coast) and along the major gas pipelines. Both reciprocating engines and gas turbines are utilized, but the trend
has been toward use of large gas turbines. Gas turbines emit considerably fewer pollutants than do reciprocating
engines; however, reciprocating engines are generally more efficient in their use of fuel.
3.2.2 Emissions and Controls1'2 - The primary pollutant of concern is NOX, which readily forms in the high
temperature, pressure, and excess air environment found in natural gas fired compressor engines. Lesser amounts
of carbon monoxide and hydrocarbons are emitted, although for each unit of natural gas burned, compressor
engines (particularly reciprocating engines) emit significantly .more of these pollutants than do external
combustion boilers. Sulfur oxides emissions are proportional to the sulfur content of the fuel and will usually be
quite low because of the negligible sulfur content of most pipeline gas.
The major variables affecting NOX emissions from compressor engines include the air fuel ratio, engine load
(defined as the ratio of the operating horsepower divided by the rated horsepower), intake (manifold) air
temperature, and absolute humidity. In general, NOX emissions increase with increasing load and intake air
temperature and decrease with increasing absolute humidity and air fuel ratio. (The latter already being, in most
compressor engines, on the "lean" side of that air fuel ratio at which maximum NOX formation occurs.)
Quantitative estimates of the effects of these variables are presented in Reference 2.
Because NOX is the primary pollutant of significance emitted from pipeline compressor engines, control
measures to date have been directed mainly at limiting NOX emissions. For gas turbines, the most effective
method of controlling NOX emissions is the injection of water into the combustion chamber. Nitrogen oxides
reductions as high as 80 percent can be achieved by this method. Moreover, water injection results in only
nominal reductions in overall turbine efficiency. Steam injection can also be employed, but the resulting NOX
reductions may not be as great as with water injection, and it has the added disadvantage that a supply of steam
must be readily available. Exhaust gas recirculation, wherein a portion of the exhaust gases is recirculated back
into the intake manifold, may result in NOX reductions of up to 50 percent. This technique, however, may not be
practical in many cases because the recirculated gases must be cooled to prevent engine malfunction. Other
combustion modifications, designed to reduce the temperature and/or residence time of the combustion gases,
can also be effective in reducing NOX emissions by 10 to 40 percent in specific gas turbine units.
For reciprocating gas-fired engines, the most effective NOX control measures are those that change die air-fuel
ratio. Thus, changes in engine torque, speed, intake air temperature, etc., that in turn increase the air-fuel ratio,
may all result in lower NOX emissions. Exhaust gas recirculation may also be effective in lowering NOX emissions
although, as with turbines, there are practical limits because of the large quantities of exhaust gas that must be
cooled. Available data suggest that other NOX control measures, including water and steam injection, have only
limited application to reciprocating gas fired engines.
Emission factors for natural gas fired pipeline compressor engines are presented in Table 3.2-1.
4/76 Stationary Internal Combustion Sources 3.2-1
-------
Table 3.2-1. EMISSION FACTORS FOR HEAVY DUTY NATURAL
GAS FIRED PIPELINE COMPRESSOR ENGINES8
EMISSION FACTOR RATING: A
Reciprocating engines
lb/103 hp-hr
g/hp-hr
g/kW-hr
lb/106scff
kg/106Nm3f
Gas turbines
lb/103 hp-hr
g/hp-hr
g/kW-hr
lb/106 scf9
kg/106 Nnrfc
Nitrogen oxides
(as NO2)b
24
11
15
3.400
55,400
2.9
1.3
1.7
300
4,700
Carbon
monoxide
3.1
1.4
1.9
430
7,020
.1.1
0.5
0.7
120
1,940
Hydrocarbons
(as C)c
9.7
4.4
5.9
1,400
21,800
0.2
0.1
0.1
23
280
Sulfur
dioxide0*
0.004
0.002
0.003
0.6
9.2
0.004
0.002
0.003
0.6
9.2
Paniculate6
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
aAII factor* baled on References 2 and 3.
"These factors are for compressor engines operated at rated load. In general, NOX emissions will increase with increasing
load and intake (manifold) air temperature and decrease with increasing air-fuel ratios (excess air rates) and absolute
humidity; Quantitative estimates of the effects of these variables are presented in Reference 2.
cThe*e factors represent total hydrocarbons. Nonmethane hydrocarbons are estimated to make up to 5 to 10 percent of
these totals, on the average.
dBa*ed on an assumed sulfur content of pipeline gas of 2000 gr/10* scf (4600 g/Nm^). If pipeline quality natural gas is
not fired, a 'material balance should be performed to determine SOj emissions based on the actual sulfur content.
eNot available from existing data.
These factors are calculated from the above factors for reciprocating engines assuming a healing value of 1050 Btu/scf
(9350 kcal/Nm3) for natural gas and an average fuel consumption of 7500 Btu/hp-hr (2530 kcal/kW-hr).
9These factors are calculated from the above factors for gas turbines assuming a heating value of 1,050 Btu/scf 19.350 kcal/
Nm^l of natural gas and an average fuel consumption of 10,000 Btu/hp-hr (3.380 kcal/kW-hr).
References for Section 3.2
1. Standard Support Document and Environmental Impact Statement - Stationary Reciprocating Internal
Combustion Engines. Aerotherm/Acurex Corp., Mountain View, Calif. Prepared for Environmental Protection
Agency, Research Triangle Park, N.C. under Contract No. 68-02-1318, Task Order No. 7, November 1974.
2. Urban, CM. and KJ. Springer. Study of Exhaust Emissions from Natural Gas Pipeline Compressor Engines.
Southwest Research Institute, San Antonio, Texas. Prepared for American Gas Association, Arlington, Va.
February 1975.
3. Oietzmann, H.E. and K J. Springer. Exhaust Emissions from Piston and Gas Turbine Engines Used in Natural
Gas Transmission. Southwest Research Institute, San Antonio, Texas. Prepared for American Gas Association,
Arlington, Va. January 1974.
3.2-2
EMISSION FACTORS
4/76
-------
3.3 Gasoline and Diesel Industrial Engines
3.3.1 General - This engine category covers a wide variety of industrial applications of both gasoline and diesel
internal combustion power plants, such as fork lift trucks, mobile refrigeration units, generators, pumps, and
portable well-drilling equipment. The rated power of these engines covers a rather substantial range-from less than
15 kW to 186 kW (20 to 250 hp) for gasoline engines and from 34 kW to 447 kW (45 to 600 hp) for diesel engines.
Understandably, substantial differences in both annual usage (hours per year) and engine duty cycles also exist. It
was necessary, therefore, to make reasonable assumptions concerning usage in order to formulate emission
factors.1
3.3.2 Emissions - Once reasonable usage and duty cycles for this category were ascertained, emission values
from each of the test engines ' were aggregated (on the basis of nationwide engine population statistics) to arrive at
the factors presented in Table 3. 3-1. Because of their aggregate nature, data contained in this table must be
applied to a population of industrial engines rather than to an individual power plant.
The best method for calculating emissions is on the basis of "brake specific" emission factors (g/kWh or
Ib/hphr). Emissions are calculated by taking the product of the brake specific emission factor, the usage in hours
(that is, hours per year or hours per day), the power available (rated power), and the load factor (the power
actually used divided bythe power available).
fable 3.3-1. EMISSION FACTORS FOR GASOLINE
AND DIESEL POWERED INDUSTRIAL EQUIPMENT
EMISSION FACTOR RATING: C
Pollutant3
Carbon monoxide
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Exhaust hydrocarbons
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Evaporative hydrocarbons
g/hr
Ib/hr
Crankcase hydrocarbons
g/hr
Ib/hr
Engine category"
Gasoline
5700.
12.6
267.
199.
472.
3940,
191.
0.421
8.95
6.68
15.8
132.
62.0
0.137
38.3
0.084
Diesel
197. .
0.434
4.06
3.03
12.2
102.
72.8
0.160
1.50
1.12
4.49
37.5
-
• -
-
— '
1/75
Stationary Internal Combustion Sources
3.3-1
-------
Table 3.3-1 (continued). EMISSION FACTORS FOR GASOLINE
AND DIESEL POWERED INDUSTRIAL EQUIPMENT
EMISSION FACTOR RATING: C
Pollutant3
Nitrogen oxides
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Aldehydes
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Sulfur oxides
g/hr
Ib/hr
g/kWh
•g/hphr
kg/103 liter
lb/103 gal
Paniculate
g/hr
Ib/hr
g/kWh
g/hphr
kg/103 liter
lb/103 gal
Engine category"
Gasoline
148.
0.326
6.92
5.16
12.2
102.
6.33
0.014
0.30
0:22
0.522
4.36
7.67
0.017
0.359
0.268
0.636
5.31
9.33
0.021
0.439
0.327
0.775
6.47
Diesel
910.
2.01
18.8
14.0
56.2
469.
13.7
0.030
0.28
0.21
0.84
7.04
60.5
0.133
1.25
0.931
3.74
31.2
65.0
0.143
1.34
1.00
4.01
33.5
References 1 and 2. '
As discussed in the text, the engines used to determine the results in this
table cover a wide range of uses and power. The listed values do not,
however, necessarily apply to some very large stationary diesel engines.
References for Section 3.3
1. Hare, C. T. and K. J. Springer. Exhaust Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Final Report. Part 5: Heavy-Duty Farm, Construction, and Industrial Engines.
Southwest Research Institute. San Antonio, Texas. Prepared for Environmental Protection Agency. Research
Triangle Park, N.C., under Contract No. EHS 70-108. October 1973. 105 p.
2. Hare, C. T. Letter to C. C. Masser of the Environmental Protection Agency concerning Fuel-based emission
rates for farm, construction, and industrial engines. San Antonio, Tex. January 14, 1974.
3.3-2
EMISSION FACTORS
1/75
-------
3.4 STATIONARY LARGE BORE DIESEL AND DUAL FUEL ENGINES
3.4.1 General
The primary domestic use of large bore dlesel engines, I.e., chose
greater than 560 cubic inch displacement per cylinder (CID/CYL), is in oil
and gas exploration and production. These engines, in groups of three to
five, supply mechanical power to operate drilling (rotary table), mud pump-
ing and hoisting equipment, and may also operate pumps or auxiliary power
generators. Another frequent application of large bore diesels is elec-
tricity generation for both base and standby service. Smaller uses include
irrigation, hoisting and nuclear power plant emergency cooling water pump
operation.
Dual fuel engines were developed to obtain compression ignition
performance and the economy of natural gas, using a minimum of 5 to 6 percent
diesel fuel to ignite the natural gas. Dual fuel large bore engines (greater
than 560 CID/CYL) have been used almost exclusively for prime electric power
generation.
3.4.2 Emissions and Controls
The primary pollutant of concern from large bore diesel and dual fuel
engines is NOx, which readily forms in the high temperature, pressure and
excess air environment found in.these engines. Lesser amounts of carbon
monoxide and hydrocarbons are also emitted. Sulfur dioxide emissions will
usually be quite low because of the negligible sulfur content of diesel
fuels and natural gas. •
The major variables affecting NOX emissions from diesel engines are
injection timing, manifold air temperature, engine speed, engine load and
ambient humidity. In general, NOx emissions decrease with increasing
humidity.
Because NOx is the primary pollutant from diesel and dual fuel engines,
control measures to date have been directed mainly at limiting NOx emis-
sions. The most effective NOX control technique for diesel engines is fuel
injection retard, achieving reductions (at eight degrees of retard) of up to
40 percent. Additional NOx reductions are possible with combined retard and
air/fuel ratio change. Both retarded fuel injection (8°) and air/fuel ratio
change of five percent are also effective in reducing NOx emissions from
dual fuel engines, achieving nominal NOx reductions of about 40 percent and
maximum NOx reductions of up to 70 percent.
Other NOx control techniques exist but are not considered feasible
because of excessive fuel penalties, capital cost, or maintenance or opera-
tional problems. These techniques include exhaust gas recirculation (EGR),
combustion chamber modification, water injection and catalytic reduction.
8/82 Stationary Internal Combustion Sources 3.4-1
-------
TABLE 3.4-1. EMISSION FACTORS FOR STATIONARY LARGE BORE DIESEL
AND DUAL FUEL ENGINES3
EMISSION FACTOR RATING: C
Engine type
Diesel
lb/103 hph
g/hph
g/kWh
lb/103 gal£
8/1
Dual fuel
lb/10* hph
g/hph
g/kWh
Partlculate0
2.4
1.1
1.5
50
6
HA
HA
HA
Nitrogen
oxides0
24
11
15
500
60
13
a
11
Carbon
monoxide
6.4
2.9
3.9
130
16
5.9
2.7
3.6
VOC"
Methane
0.07
0.03
0.04
1
0.2
4.7
2.1
2.9
Nonmethane
0.63
0.29
0.4
13
1.6
1.5
0.7
0.9
Sulfur
dioxide*
2.8
1.3
1.7
60
7.2
0.70
0.32
0.43
"Representative uncontrolled levels for each fuel, determined by weighting data from
several manufacturers. Weighting baaed on I of total horsepower sold by each manu-
facturer during a five year period. HA - not available.
^Emission Factor Bating: E. Approximation based on test of a medium bore dlesel.
Emissions are minimum expected for engine operating at 50 - 100Z full rated load.
At OZ load, emissions would increase to 30 g/1. Reference 2.
cMeasured aa NOj- Factors are for engines operated at rated load and speed.
dNonmethaue VOC is 90Z of total VOC from dlesel engines but only 2SZ of total VOC
emissions from dual fuel engines. Individual chemical species within the non-
methane fraction are. not identified. Molecular weight of nonmethane gas stream is
assumed to be that of methane.
'Based on assumed sulfur content of 0.4 weight Z for dlesel fuel and 0.46 g/scm
(0.20 gr/scf) for pipeline quality natural gas. Dual fuel SO? emissions based on
5Z oil/9SZ gas mix. Emissions should be adjusted for other fuel ratios.
fThese factora calculated from the above factors, assuming heating values of 40
MJ/1 (145,000 Btu/gal) for oil and 41 MJ/scm (1100 Btu/scf) for natural gas, and
an average fuel consumption of 9.9 HJ/lcWh (7000 Btu/hph).
References .for Section 3.4
1. Standards Support And Environmental Impact Statement, Volume I;
Stationary Internal Combustion Engines, EPA-450/2-78-I25a, U. S.
Environmental Protection Agency, Research Triangle Park, NC, July 1979.
2. Telephone communication between William H. Lamason, Office Of Air
Quality Planning And Standards, U. S. Environmental Protection Agency,
Research Triangle Park, NC, and John H. Wasser, Office Of Research And
Development, U. S. Environmental Protection Agency, Research Triangle
Park, NC, July 15, 1983.
3.4-2
EMISSION FACTORS
8/84
-------
not more than 540°C (1000°F) to prevent warping of the drum. Emissions are
vented to an afterburner or secondary combustion chamber, where the g'ases are
raised to at least 760°C (1400°F) for a minimum of 0.5 seconds. The average
amount of material removed from each drum is 2 kilograms (4.4 pounds).
TABLE 4.8-2. EMISSION FACTORS FOR TANK TRUCK CLEANING3
EMISSION FACTOR RATING: D
Compound
Acetone
Perchloroethylene
Methyl methacrylate
Phenol
Propylene glycol
Chemical
Vapor
pressure
high
high
medium
low
low
class
Viscosity
low
low
medium
low
high
Total
emissions
g/ truck lb/ truck
311 0.686
215 0.474
32.4 0.071
5.5 .0.012
1.07 0.002
aReference 1. One hour test duration.
4.8.2 Emissions And Controls
4.8.2.1 Rail Tank Cars And Tank Trucks - Atmospheric emissions from tank car
and truck cleaning are predominantly volatile organic chemical vapors. 'To
achieve a practical but representative picture of these emissions, the organic
chemicals hauled by the carriers must be known by.classes of high, medium and
low viscosities and of high, medium and low vapor pressures. High viscosity
materials do not drain readily, affecting the quantity of material remaining
in the tank, and high vapor pressure materials volatilize more readily during
cleaning and tend to lead to greater emissions.
Practical and economically feasible controls of atmospheric emissions from
tank car and truck cleaning do not exist, except for containers transporting
commodities that produce combustible gases and water soluble vapors (such as
ammonia and chlorine). Gases displaced as tanks are filled are sent to a flare
and burned. Water soluble vapors are absorbed in water and are sent to the
wastewater system. Any other emissions are vented to the atmosphere.
Tables 4.8-1 and 4.8-2 give emission factors for representative organic
chemicals hauled by tank cars and trucks.
4.8.2.2 Drums - There is no control for emissions from steaming of drums.
Solution or caustic washing yields negligible air emissions, because the drum
is closed during the wash cycle. Atmospheric emissions from steaming or wash-
ing drums are predominantly organic chemical vapors.
Air emissions from drum burning furnaces are controlled by proper opera-
tion of the afterburner or secondary combustion chamber, where gases are
raised to at least 760°C (1400°F) for a minimum of 0.5 seconds. This normally
ensures complete combustion of organic materials and prevents the formation,
2/80 Evaporative Loss Sources 4.8-3
-------
and subsequent release, of large quantities of NO^, CO and particulate. In
open burning, however, there is no feasible way of controlling the release of
incomplete combustion products to the atmosphere. The conversion of open
cleaning operations to closed cycle cleaning and the elimination of open air
drum burning seem to be the only control alternatives immediately available.
Table 4.8-3 gives emission factors for representative criteria pollutants
emitted from drum burning and cleaning.
TABLE 4.8-3. EMISSION FACTORS FOR DRUM BURNING3
EMISSION FACTOR RATING: E
Pollutant
Particulate
NO*
voc
Total
Controlled
g/drum Ib/drum
12b
0.018
0.02646
0.00004
negligible
emissions .
Uncontrolled
g/drum Ib/drum
16
0.89
0.035
0.002
negligible
aReference 1. Factors are for weight of pollutant released/drum burned,
except for VOC, which are per drum washed.
^Reference 1, Table 17 and Appendix A.
Reference for Section 4.8
1. T. ?.. Blackwood, et al., Source Assessment: Rail Tank Car, Tank Truck,
and Drum Cleaning, State of the Art, EPA-600/2-78-004g, U. S. Environ-
mental Protection Agency, Cincinnati, OH, April 1978.
4.8-4
EMISSION FACTORS
2/80
-------
5.16 SODIUM CARBONATE
5.16.1 General1*2
Processes to produce sodium carbonate (Na2C03>, or soda ash, are classi-
fied as either natural or synthetic. Natural processes recover sodium carbon-
ate from natural deposits of trona ore (primarily sodium sesquicarbonate,
Na-CO,* NaHCO,* 2H-0), or from brine that contains sodium sesquicarbonate and
sodium carbonate. The synthetic (Solvay) process produces sodium carbonate by
reacting ammoniated sodium chloride with carbon dioxide. For about a century,
almost all sodium carbonate production was by the Solvay process. However,
since the mid-1960s, Solvay process production has declined substantially,
having been replaced by natural production. Only one plant in the U. S. now
uses the Solvay process. Available data on emissions from the Solvay process
are also presented, but because the natural processes are more prevalent in
this country, this Section addresses emissions from these processes.
Three different natural processes are currently in use, sesquicarbonate,
monohydrate, and direct carbonation. The sesquicarbonate process, the first
of the natural processes, is used at only one plant and is not expected to
be the process at future plants. Since data on uncontrolled emissions from
the sesquicarbonate process are not available, it is not discussed here.
Monohydrate and direct carbonation processes and emissions are described here.
These processes differ only in raw materials processing.
In the monohydrate process, sodium carbonate is produced from trona ore,
which consists of 86 to 95 percent sodium sesquicarbonate, 5 to 12 percent
gangues (clays and other insoluble impurities) and water. The mined trona ore
is crushed, screened and calcined to drive off carbon dioxide and water, form-
ing crude sodium carbonate. Most calciners are rotary gas fired, but the
newest plants use coal fired calciners. Future plants are also likely to have
coal fired calciners for economic reasons.
the crude sodium carbonate is dissolved and separated from the insoluble
impurities. Sodium carbonate monohydrate (Na2COo * ^0) is crystallized from
the purified liquid by means of multiple effect evaporators, then dried to
remove the free and bound water, producing the final product. Rotary steam
tube, fluid bed steam tube, and rotary gas fired dryers are used, with steam
tube dryers most likely in future plants.
In the direct carbonation process, sodium carbonate is produced from,
brine containing sodium sesquicarbonate, sodium carbonate, and other salts.
The brine is prepared by pumping a dilute aqueous liquor into salt deposits,
where the salts are dissolved in the liquor. The recovered brine is carbon-
ated by contact with carbon dioxide which converts all of the sodium carbonate
present into sodium bicarbonate. The sodium bicarbonate is then recovered
from the brine by crystallization in vacuum crystallizers. The crystal slurry
is filtered, and the crystals transferred to steam heated predryers to evapo-
rate some of the moisture. The partially dried sodium bicarbonate goes to a
steam heated calciner to drive off carbon dioxide and the remaining water,
forming impure sodium carbonate. The carbon dioxide is recycled to the brine
carbonators. The sodium carbonate is treated with sodium nitrate in a gas
10/86 . Chemical Process Industry 5.16-1
-------
fired rotary bleacher to remove discoloring impurities, then is dissolved and
recrystallized. The resulting crystals of sodium carbonate monohydrate are
dried as in the monohydrate process.
In the Solvay process, sodium chloride brine, ammonia, calcium carbonate
(limestone), and coke are the raw materials. The sodium chloride brine is
purified in a series of reactors and clarifiers by precipitating magnesium
and calcium ions with soda ash and sodium hydroxide. Sodium bicarbonate
(NaHC03) is formed by carbonating a solution of ammonia in the purified, satu-
rated brine.
Reaction:
NaCl + H20 + NH3 + C02 •• NaHC03 + NfyCL
brine sodium
bicarbonate
The sodium bicarbonate is virtually insoluble in the resulting solution, crys-
tallizes and is separated from the solution liquor by filtration. The crys-
tals are fed to either steam or gas heated rotary dryers where the bicarbonate
is converted (by calcining) to sodium carbonate.
5.16.2 Emissions and Controls
The principal emission points in the monohydrate and direct carbonation
processes are shown in.Figures 5.16-1 and 5.16-2. The major emission sources
in the monohydrate process are calciners and dryers, and the major sources in
the direct carbonation process are bleachers, dryers and predryers. Emission
factors for these sources are presented in Table 5.16-1, and emission factors
for the Solvay process are presented in Table 5.16-2.
In addition to the major emission points, emissions may also arise from
crushing and dissolving operations, elevators, conveyor transfer points, pro-
duct loading and storage piles. Emissions from these sources have not been
quantified.
Particulate matter is the only pollutant of concern from sodium carbonate
plants. Emissions of sulfur dioxide (SC^) arise from calciners fired with
coal, but reaction of the evolved S02 with the sodium carbonate in the calcin-
er keeps SC>2 emissions low. Small amounts of volatile organic compounds (VOC)
may also be emitted from calciners, possibly from oil shale associated with
the trona ore, but these emissions have not been quantified.
Particulate matter emission rates from calciners, dryers, predryers and
bleachers are affected by the gas velocity through the unit and by the par-
ticle size distribution of the feed material. The latter affects the emission
rate because small particles are more easily entrained in a moving stream of
gas than are large particles. Particle size distributions and emission factors
for predryers, calciners, bleachers, and dryers in natural process sodium
carbonate plants are presented in Table 5.16-3. Gas velocity through the
unit affects the degree of turbulence and agitation. As the gas velocity
increases, so does the rate of increase in total particulate matter emissions.
Thus, coal fired calciners may have higher particulate emission factors than
gas fired calciners because of higher gas flow rates. The additional parti-
culate from coal fly ash represents less than one percent of total particulate
5.16-2 EMISSION FACTORS 10/86
-------
o
03
TRONA
ORE
CONTRO1
DEVICE
f
CRUSHERS
AND
SCREENS
CONTROL
DEVICE
t
CALCINER
CONTROL
DEVICE
t
DISSOLVER
CRYSTALLIZER
CONTROL
DEVICE
I
DRYER -
DRY
. SODIUM
CARBONATE
n
y
8
M-
0
f»
Figure 5.16-1. Sodium carbonate production by monohydrate process.
o
o
n
en
to
c
(A
cor
DE
RECRYSTALLIZER
r
DRY
SODIUM
CARBONATE
Figure 5.16-2. Sodium carbonate production by direct carbonation process,
I
U)
-------
TABLE 5.16-1.
PARTICULATE EMISSION FACTORS FOR UNCONTROLLED NATURAL
PROCESS SODIUM CARBONATE PLANTS*
Emission Factor Rating: B
Source
Rotary steam heated predryer^
Gas fired calcinerc
Coal fired calciner0
Rotary gas fired bleacher^
Rotary steam tube dryer6
Fluid bed steam tube dryer6
Particulate
kg/Mg
1.55
184.0
195.0
155.0
33.0
73.0
Ib/ton
3.1
368.0
390.0
311.0
67.0
146.0
aReferences 3-5. Values are averages of 2 - 3 test runs.
bFactors are kg/Mg (Ib/ton) of dry NaHCO-j feed.
GFactors are kg/Mg (Ib/ton) of ore fed to calciner and includes particulate
emissions from coal fly ash « 1% of total). S02 from coal is roughly 0.007
kg/Mg (0.014 Ib/ton) of ore feed.
^Factors are kg/Mg (Ib/ton) of dry feed to bleacher.
eFactors are kg/Mg (Ib/.ton) of dry product from dryer.
TABLE 5.16-2.
EMISSION FACTORS FOR UNCONTROLLED SYNTHETIC SODA ASH
(SOLVAY) PLANT3
Emission Factor Rating: D
Pollutant
Ammonia losses'5
Particulate0
kg/Mg
2
25
Ib/ton
4
50
aReference 6. Factors are kg/Mg (Ib/ton) of product.
^Calculated by subtracting measured ammonia effluent discharged from ammonia
purchased.
cMaximum uncontrolled emissions, from New York State process certificates to
operate. Does not include emissions from fugitive or external combustion
sources.
5.16-4
EMISSION FACTORS
10/86
-------
emissions, and the emission factor for coal fired calciners is about 6 percent
higher than that for gas fired calciners. Fluid bed steam tube dryers have
higher gas flow rates and particulate emission factors than do rotary steam
tube dryers. No data are available on uncontrolled particulate emissions
from gas fired dryers, but these dryers also have higher gas flow rates than
do rotary steam tube dryers and would probably have higher particulate emis-
sions.
The particulate emission factors presented in Table 5.16-1 represent
emissions measured at the inlet to the control devices. Even in the absence
of air pollution regulations, these emissions usually are controlled to some
degree to prevent excessive loss of product. Particulate emissions from cal-
ciners and bleachers are most commonly controlled by cyclones in series with
electrostatic precipitaters (ESPs). Venturi scrubbers are also used, but
with less efficiency. Cyclone/ESP combinations have achieved removal effi-
ciencies from 99.5 to 99.96 percent for new coal fired calciners, and 99.99
percent for bleachers. Comparable efficiencies should be possible for new
gas fired calciners. Emissions from dryers and predryers are most commonly
controlled with venturi scrubbers because of the high moisture content of the
exit gas. Cyclones are used in series with the scrubbers for predryers and
fluid bed steam tube dryers. Removal efficiencies averaging 99.88 percent
have been achieved for venturi scrubbers on rotary steam tube dryers, at a
pressure drop of 6.2 kilopascals (kPa) (25 inches water). Acceptable collec-
tion efficiencies may be achieved with lower pressure drops. Efficiencies of
99.9 percent have been achieved for a cyclone/venturi scrubber on a fluid bed
steam tube dryer, at a pressure drop.of 9.5 kPa (38 inches water). Effici-
encies over 98 percent have been achieved for a cyclone/ venturi scrubber on
a predryer.
There are significant fugitive emissions from- limestone handling and
processing operations, product drying operations, and dry solids handling
(conveyance and bulk loading) in the manufacture of soda ash by the Solvay
process, but these fugitive, emissions have not been quantified. Ammonia
losses also occur because of leaks at pipe fittings and pump seals, dis-
charges of absorber exhaust, and exposed bicarbonate cake on filter wheels
and on feed floor prior to calcining.
10/86 Chemical Process Industry 5.16-5
-------
PARTICLE SIZE DISTRIBUTIONS AND SIZE SPECIFIC EMISSION FACTORS
FOR
NATURAL PROCESS SODIUM CARBONATE MANUFACTURING
UNGOlfTOUXD
— U*ighc p«rc«nc
- eal*»ioa factor
COVTICUD
1 > * ) • r • t I* im m *• » t* tt i
fardel* dlaa«c«r» via
Figure 5.16-3. Predryer.
I,
UHCOHTKHiED
• Cat••to* f«ccor
CONTVOUXD
- V«lfhc p«rc*BC
Particle dluecer. am
Figure 5.16-5. Bleacher.
J * ' • » \A
Particle dla
Figure 5.16-4.
ater, u«
Calciner.
Particle dlaaater. uai
Figure 5.16-6. Dryer.
5.16-6
EMISSION FACTORS .
10/86
-------
o
00
TABLE 5.16-3.
PARTICLE SIZE DISTRIBUTIONS AND EMISSION FACTORS FOR
NATURAL PROCESS SODIUM CARBONATE PLANTS3
n
n>
ft
n
to
n
o
n
n
M
w
a
a
u
rt
Particle elie
distribution11
Operation/partlcie slxea
Rotary predryer*
Uncontrolled
After cyclone/acrubber
Calclner!
Caa fired, uncontrolled
Caa fired, after cyclone/ESP
Caa fired, efter cyclone/acrubber
Coel fired, uncontrolled
Rotary gaa fired bleacher'
Uncontrolled
After cyclone/ESP
Product dryerS
Fluid bed ateaa tube, uncontrolled
Rotary itean tube, uncontrolled
2.5
2.8
46.0
2.6
64.5
60.0
2.0
0.6
8.0
6.5
20.0
6.0
4.2
51.0
5.2
79.0
69.5
6.5
1.5
22.0
12.5
20.5
10.0
5.2
52.5
6.7
86.0
71.0
9.5
2.5
35.0
13.0
21.0
Total
Size specific emission particulate
factora for correa ponding eolation
particle size ranges0"*' factor*''6
2.5 6.0
0.04 0.065
-
5.2 9.6
-
-
3.9 12.7
0.9 2.3
-
4.7 9.1
6.6 6.8
kg/Kg
10.0
0.08 1.55
-
12.3 184
-
_
18.5 195
3.9 155
- -
9.5 73
6.9 33
Rating of distri-
bution and alze
apeclflc ealaalon
factor data
C
D
C
E
E
8
C
0
B
E
•Particle alie la aerodynamic particle diameter In un.
bCuaulatlve weight X of particle* < atated particle alxe.
cSlia apeclflc emission factor - total particulate ealaelon factor x particle alze distribution, Z/IOO. .
''For predryera, calclnera, and bleachers, eat union factors are kg partlculate/Hg of feed to process unit,.
For product dryers, factora are kg partlculate/Hg of product. Daah equals no available data.
•Froa Table 5.16-1.
^Reference 5.
BReference 3-4.
-------
References for Section 5.16
1. Sodium Carbonate Industry - Background Information for Proposed Stand-
ards, EPA-450/3-80-029a, U. S. Environmental Protection Agency, Re-
search Triangle Park, NC, August 1980.
2. Air Pollutant Emission Factors, APTD-0923, Final Report, HEW Contract
Number CPA-22-69-119, Resources Research, Inc., Reston, VA, April 1970.
3. Sodium Carbonate Manufacturing Plant, EMB-79-SOD-1, U. S. Environmental
Protection Agency, Research Triangle Park, NC, August 1979.
4. Source Test Of A Sodium Carbonate Manufacturing Plant, EMB-79-SOD-2,
U. S. Environmental Protection Agency, Research Triangle Park, NC, March
1980.
5. Source Test Of Particulate Emissions From The Kerr-McGee Chemical Corpora-
tion Sodium Carbonate Plant, EMB-79-SOD-3, U. S. Environmental Protection
Agency, Research Triangle Park, NC, March 1980.
6. Written communication from W. S. Turetsky, Allied Chemical Company,
Morristown, NJ, to Frank M. Noonan, U. S. Environmental Protecton Agency,
Research Triangle Park, NC, June 1982.
5.16-8 EMISSION FACTORS 10/86
-------
7.1 PRIMARY ALUMINUM PRODUCTION
7.1.1 Process Descriptionl~2
The base ore for primary aluminum production Is bauxite, a hydrated oxide
of aluminum consisting of 30 to 70 percent alumina (AJ^C^) and lesser amounts
of iron, silicon and titanium. Bauxite ore is purified to alumina by the Bayer
process and then is reduced to elemental aluminum. The production of alumina
and the reduction of alumina to aluminum are seldom accomplished at the same
facility. A schematic diagram of the primary production of aluminum is shown
at Figure 7 .1-1.
In the Bayer process, the ore is dried, ground in ball mills and mixed
with a leaching solution of sodium hydroxide at an elevated temperature and
pressure, producing a sodium aluminate solution which is separated from the
bauxite impurities and cooled. As the solution cools, hydrated aluminum oxide
(Al20o * 31^0) precipitates. After separation and washing to remove sodium hy-
droxide and other impurities, the hydrated aluminum oxide is dried and is cal-
cined to produce a crystalline form of alumina, advantageous for electrolysis.
To produce aluminum metal, the crystalline A1203 is put through the Hall-
Heroult process, an electrolytic reduction of alumina dissolved in a molten salt
bath of cryolite (NajAlF^) and various salt additives:
2A1203 Electrolysis > 4A1 + 302
(Alumina) (Reduction) (Aluminum) (Oxygen)
The electrolytic reduction occurs in shallow rectangular cells, or "pots", which
which are steel shells lined with carbon. Carbon electrodes extending into the
pot serve as the anodes and the carbon lining the steel shell is the cathode.
Molten cryolite functions as both the electrolyte and the solvent for the
alumina. Electrical resistance to the current passing between the electrodes
generates heat that maintains cell operating temperatures between 950° and
1000°C (1730° and 1830°F). Aluminum is deposited at the cathode, where it
remains as molten metal below the surface of the cryolite bath. The carbon
anodes are continuously depleted by the reaction of oxygen (formed during the
reaction) and anode carbon, producing carbon monoxide and carbon dioxide.
Carbon consumption and other raw material and energy requirements for aluminum
production are summarized in Table 7.1-1. The aluminum product is periodically
tapped beneath the cryolite cover and fluxed to remove trace impurities.
Three types of aluminum reduction cells are now in use, distinguished by
anode type and pot configuration: prebaked (PB), horizontal stud Soderberg
(HSS), and vertical stud Soderberg (VSS) .
Most of the aluminum produced in the U. S. is processed in PB cells.
Anodes are produced as an ancillary operation at a reduction plant. In a paste
preparation plant, petroleum coke is mixed with a pitch binder to form a paste
which is used both for Soderberg cell anodes and for green anodes used in
10/86 Metallurgical Industry 7.1-1.
-------
SODIUM
HYDROXIDE
BAUXITE
DRYING
OVEN
TO CONTROL DEVICE
»•
SETTLING
CHAMBER
DILUTION
WATER
(RED MUD
(IMPURITIES)
DILUTE
SODIUM
HYDROXIDE
ALUMINUM
HYDROXIDE
TO CONTROL
DEVICE
CALC1NER
SPENT
ELECTRODES
ALUWNA
ANODE
PASTE
I
ELECTROLYTE
ANODE PASTE
CRYSTALLIZER
FILTER
AQUEOUS SODIUM
ALUKINATE
TO CONTROL DEVICE
BAKING
FURNACE
BAKED
ANODES
,. TO CONTROL DEVICE
I
PREBAKE
REDUCTION
CELL
1
TO CONTROL DEVICE
HORIZONTAL
OR VERTICAL
SOOERBERG
REDUCTION CELL
MOLTEN
ALUMINUM
Figure 7.1-1. Schematic diagram of aluminum production
process,
7.1-2
EMISSION FACTORS
-------
prebake ceils. Paste preparation includes crushing, grinding and screening of
coke and cleaned spent anodes (butts), and blending with a pitch binder in a
steam jacketed mixer. For Soderberg anodes, the thick paste mixture is trans-
ferred directly to the pot room and added to the anode casings. In prebake
anode preparation, the paste mixture is molded to form self supporting green
anode blocks. These blocks are baked in a direct fired ring furnace or an
indirect fired tunnel kiln. Baked anodes are then transferred to the rodding
room for attachment of electrical connections. Volatile organic vapors from
the pitch paste are emitted during anode baking, most of which are destroyed in
the baking furnace. The baked anodes, typically 14 to 24 per cell, are attached
to metal rods and are expended as they are used.
In the electrolytic reduction of alumina, the carbon anodes are lowered
into the cell and are consumed at a rate of about 2.5 centimeters (1 inch) per
day. PB cells are preferred over Soderberg cells for their lower power require-
ments, reduced generation of volatile pitch vapors from the carbon anodes, and
provision for better cell hooding to capture emissions.
The next most common reduction cell is the horizontal stud Soderberg.
This type of cell uses a "continuous" carbon anode. Green anode paste is
periodically added at the top of the anode casing of the pot and is baked by
the heat of the cell into a solid carbon mass, as the material moves down the
casing. The cell casing is of aluminum or steel sheeting, permanent steel skirt
and perforated steel channels, through which electrode connections (studs) are
inserted horizontally into the anode paste. During reduction, as the baking
anode is lowered, the lower row of studs and the bottom channel are removed, and
the flexible electrical connectors are moved to a higher row of studs.
TABLE 7.1-1.
RAW MATERIAL AND ENERGY REQUIREMENTS FOR
ALUMINUM PRODUCTION
Parameter
Typical value
Cell operating temperature
Current through pot line
Voltage drop per cell
Current efficiency
Energy required
Weight alumina consumed
Weight electrolyte
fluoride consumed
Weight carbon electrode
consumed
950°C (1740°F)
60,000 to 280,000 amperes
4.0 to 5.2
85 to 95 %
13.2 to 18.7 kwh/kg
(6.0 to 8.5 kwh/lb) aluminum
1.89 to 1.92 kg (Ib) A1203/
kg (Ib) aluminum
0.03 to 0.10 kg (Ib) fluoride/
0.45 to 0.55 kg (Ib) electrode/
kg (Ib) aluminum
10/86
Metallurgical Industry
7.1-3
-------
High molecular weight organ!cs from the anode paste are released, along with
other emissions. The heavy tars can cause plugging of exhaust ducts, fans and
emission control equipment.
The vertical stud Soderberg cell is similar to the HSS cell, except that
the studs are mounted vertically in the anode paste. Gases from the VSS cells
can be ducted to gas burners, and the tars and oils combusted. VSS cell con-
struction prevents the installation of an integral gas collection device, and
hooding is restricted to a canopy or skirt at the base of the cell where the
hot anode enters the cell bath.
Casting involves pouring molten aluminum into molds and cooling it with
water. At some plants before casting, the molten aluminum may be batch treated
in furnaces to remove oxide, gaseous impurities and active metals such as
sodium and magnesium. One process consists of adding a flux of chloride and
fluoride salts and then bubbling chlorine gas, usually mixed with an inert gas,
through the molten mixture. Chlorine reacts with the impurities to form HC1,
AJ-203 and metal chloride emissions. A dross forms to float on the molten
aluminum and is.removed before casting.12
7.1.2 Emissions And Controlsl-8»H
Controlled and uncontrolled emission factors for total particulate matter,
fluoride and sulfur oxides are in Table 7.1-2. Fugitive particulate and
fluoride emission factors for reduction cells are also presented in this Table.
Tables 7.1-3 through 7.1-5 and Figures 7.1-2 through 7.1-4 give size specific
particulate matter emissions for primary aluminum industry processes for which
this information is available.
Large amounts of particulate are generated during the calcining of hy-
drated aluminum oxide, but the economic value of this dust is such that exten-
sive controls are used to reduce emissions to relatively small quantities.
Small amounts of particuLace are emitted from the bauxite grinding and materials
handling processes.
Emissions from aluminum reduction processes are primarily gaseous hydrogen
fluoride and particulate fluorides, alumina, carbon monoxide, volatile organics,
and sulfur dioxide from the reduction cells; and fluorides, vaporized organics
and sulfur dioxide from the anode baking furnaces.
The source of fluoride emissions from reduction cells is the fluoride
electrolyte, which contains cryolite, aluminum fluoride (AlF^) and fluorspar
(CaF2). For normal operation, the weight, or "bath", ratio of sodium fluoride
(NaF) to A1F3 is kept between 1.36 and 1.43 by the addition of A1F3. This in-
creases the cell current efficiency and lowers the bath melting point permitting
lower operating temperatures in the cell. All fluoride emissions are also
decreased by lowering the operating temperature. The ratio of gaseous (mainly
hydrogen fluoride and silicon tetrafluoride) to particulate fluorides varies
from 1.2 to 1.7 with PB and HSS cells, but attains a value of approximately 3.0
with VSS cells.
Particulate emissions from reduction cells are alumina and carbon from
anode dusting, cryolite, aluminum fluoride, calcium fluoride, chiolite
7.1-4 EMISSION FACTORS 10/86
-------
TABLE 7.1-2. EMISSION FACTORS FOR PRIMARY ALUMINUM PRODUCTION PROCESSES3>b
EMISSION FACTOR RATING: A
Operation
Total
partlculataC
kg/Kg Ib/ton
Caseous
fluoride
kg/Mg Ib/ton
Psrtlculats
fluoride
kg/Mg Ib/coo
Reference
Bauxite grinding
Uncontrolled 3.0 6.0 Meg
Spray tower 0.9 1.8 Neg
Floating bed scrubber 0.8} 1.7 Meg
Quench tower and epray screen 0.5 1.0 Neg
Aluminum hydroxide calcining
Uncontrolled* 100.0 200.0 Neg
Spray tower 30.0 60.0 Neg
Floating bed scrubber 28.0 56.0 Neg
Quench tower 17.0 34. C Neg
ESP 2.0 4.0 Neg
Anode baking furnace
Uncontrolled 1.5 3.0 0.45 0.9
Fugitive NA NA NA NA
Spray tower 0.375 0.75 0.02 0.04
ESP 0.375 0.75 0.02 0.04
Dry alumina scrubber 0.03 0.06 0.0045 0.009
Prebake cell
Uncontrolled 47.0 94.0 12.0 24.0
Fugitive 2.5 5.0 0.6 1.2
Emissions to collector 44.5 89.0 11.4 22.8
Multiple cyclones 9.8 19.6 11.4 22.8
Dry alumina scrubber 0.9 1.8 O.I 0.2
Dry ESP plus spray tower 2.25 4.5 0.7 1.4
Spray tower 8.9 17.8 0.7 1.4
Floating bed scrubber 8.9 17.8 0.25 0.5
Coated bag filter dry scrubber 0.9 1.8 1.7 3.4
Crosa flow packed bed 13.15 26.3 3.25 6.7
Dry plus secondary scrubber 0.35 0.7 0.2 0.4
Vertical Soderberg stud cell
Uncontrolled 39.0 78.0 16.S 33.0
Fugitive 6.0 12.0 2.45 4.9
Emissions to collector . 33.0 66.0 14.05 28.1
Spray tower 8.25 16.5 0.15 0.3
Venturl scrubber 1.3 2.6 0.15 0.3
Multiple cyclones 16.5 33.0 14.05 28.1
Dry alualna scrubber 0.65 1.3 0.15 0.3
Scrubber plus ESP plus spray
screen and scrubber 3.85 7.7 0.75 1.5
NA
KA
NA
NA
NA
NA
NA
NA
NA
0.05 0.1
NA NA
0.015 0.03
0.015 0.03
0.001 0.002
10.0
0.5
9.5
2.1
0.2
1.7
1.9
1.9
0.2
2.8
0.15
5.5
0.85
4.65
1.15
0.2
2.35
0.1 .
0.65
20.0
1.0
19.0
4.2.
0.4
3.4
3.8
3.8
0.4
5.6
0.3
11.0
1.7
9.3
2.3
0.4
4.7
0.2
1.3
1.3
,3
.3
,3
.3
,3
,3
1,3
1.3
2,10-11
10
2
2,10
1-2.10-11
2.10
2
2
2,10
2,10
2
2
2
10
10
2.10
10
10
2
2
2
2
Horizontal Soderberg stud cell
Uncontrolled
Fugitive
Emission* to collector
Spray tower
Floating bed scrubber
Scrubber plus wet ESP
Wet ESP
Dry alumina scrubber
49.0
5.0
44:o
11.0
9.7
0.9
0.9
0.9
98.0
10.0
88.0
22.0
19.4
1.8
1.8
1.8
11.0
1.1
9.9
3.75
0.2
0.1
0.5
0.2
22.0
2.2
19.8
7.5
0.4
0.2
1.0
0.4
6.0
0.6
5.4
1.35
1.2
0.1
0.1
0.1
12.0
1.2
10.8
2.7
2.4
0.2
0.2
0.2
2.10
2,10
2.10
2,10
2
2,10
10
10
"For bauxite grinding, expressed aa kg/Mg (Ib/ton) of bauxite processed.For aluminum hydroxide calcining,
expressed aa kg/Mg (Ib/ton) of alumina produced. All other factors are/Mg (ton) of molten aluminum product.
ESP- electrostatic preclpltator. NA - not available. Neg - negligible.
DSulfur oxide* nay be estimated, with an Emission Factor Rating of C, by the following calculations.
Anode baking furnace, uncontrolled SOj aslsslone (excluding furnace fuel combustion missions):
20(C)(S)(1-0.01 K) kg/Mg (40(0(3X1-0.01 K) lb/ton|
Prebake (reduction) cell, uncontrolled SOj emissions:
0.2(C)(S)(K) kg/Mg (0.4(C)(S)(K) lb/too|
Where: C - Anode consumption* during electrolysis, Ib anode consumed/Ib Al produced
3-1 sulfur In snode before baking
K - I of total SOj cnltted by prebake (reduction) cell*.
•Anode consumption weight Is weight of anode paate (coke * pitch) before baking.
clnclude* pertlculate fluorides.
^After multlcyelone.
10/86
Metallurgical Industry
7.1-5
-------
TABLE 7.1-3. UNCONTROLLED EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION
FOR ROOF MONITOR FUGITIVE EMISSIONS FROM PREBAKE
ALUMINUM CELLS3
EMISSION FACTOR RATING: C
Particle
sizeb
(urn)
15
10
5
2.5
1.25
0.625
Cumulative
mass %
-------
TABLE 7.1-4.
UNCONTROLLED EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION
FOR ROOF MONITOR FUGITIVE EMISSIONS
FROM HSS ALUMINUM CELLS3
EMISSION FACTOR RATING: D
Particle
sizeb
(urn)
15
10
5
2.5
1.25
0.625
Total
Cumulative
mass Z
^stated
size
39
31
23
17
13
8
100
Cumulative emission factors
kg/Mg Al
1.95
1.55
1.15
0.85
0.65
0.40
5.0
Ib/ton Al.
3.9
3.1
2.3
1.7
1.3
0.8
10.0
aReference 4.
''Expressed as equivalent aerodynamic particle diameter.
2.0 -
«=c
c. 1.5
G71T3
s- o
O i-
4-> *->
u c
-------
TABLE 7.1-5. UNCONTROLLED EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION
FOR PRIMARY EMISSIONS FROM HSS REDUCTION CELLSa
EMISSION FACTOR RATING: D
Particle
sizeb
(um)
15
10
5
2.5
1.25
0.625
Total
Cumulative
mass Z
_< stated
size
63
58
50
40
32
26
100
Cumulative emission factors
kg/Mg Al
30.9
28.4
24.5
19.6
15.7
12.7
49.0
Ib/ton Al
61.7
56.8
49.0
39.2
31.4
25.5
98.0
aReference 4.
^Expressed as equivalent aerodynamic particle diameter.
01
s- O
O S-
—J *->
u c
^O O
**- <->
c 3
O
50
40
30
. 20
10
Figure 7.1-4.
0
0.625 1.25 2.50 6.0 10.0 15.0
Particle size (um)
Cumulative emission factors less than stated particle
size for primary emissions from HSS reduction cells.
7.1-8
EMISSION FACTORS
10/86
-------
and ferric oxide. Representative size distributions for fugitive
emissions from PB and HSS plants and for particulate emissions from HSS cells
are presented in Tables 7.1-3 through 7.1-5.
Emissions from reduction cells also include hydrocarbons or organics,
carbon monoxide and sulfur oxides. Small amounts of hydrocarbons are released
by PB pots, and larger amounts are emitted from HSS and VSS pots. In vertical
cells, these organics are incinerated in integral gas burners. Sulfur oxides
originate from sulfur in the anode coke and pitch, and concentrations of sulfur
oxides in VSS cell emissions range from 200 to 300 parts per million. Emissions
from PB plants usually have S02 concentrations ranging from 20 to 30 parts per
million.
Emissions from anode bake ovens include the products of fuel combustion;
high boiling organics from the cracking, distillation, and oxidation- of paste
binder pitch; sulfur dioxide from the sulfur in carbon paste, primarily from the
petroleum coke; fluorides from recycled anode butts; and other particulate mat-
ter. Concentrations of uncontrolled S02 emissions from anode baking furnaces
range from 5 to 47 parts per million (based on 3 percent sulfur in coke).9
A variety of control devices has been used to abate emissions from reduc-
tion cells and anode baking furnaces. To control gaseous and particulate
fluorides and particulate emissions, one or more types of wet scrubbers (spray
tower and chambers, quench towers, floating beds, packed beds, Venturis) have
been applied to all three types of reduction cells and to anode baking furnaces.
Also, particulate control methods such as wet and dry electrostatic precipi-
tators, multiple cyclones and dry alumina scrubbers (fluid bed, injected, and
coated filter types) are used with baking furnaces and on all three cell types.
Also, the alumina adsorption systems are being used on all three cell types to
• control both gaseous and particulate fluorides by passing the pot offgases
through the entering alumina feed, which adsorbs the" fluorides. This technique
has an overall control efficiency of 98 to 99 percent. Baghouses are then used
to collect residual fluorides- entrained in the alumina and recycle them to the
reduction cells. Wet ESPs approach adsorption in particulate removal efficien-
cy, but they must be coupled to a wet scrubber or coated baghouse to catch
hydrogen fluoride.
Scrubber systems also remove a portion of the SO? emissions. These
emissions could be reduced by wet scrubbing or by reducing the quantity of sulfur
in the anode coke and pitch, i. e., calcining the coke.
In hydrated aluminum oxide calcining, bauxite grinding, and materials
handling operations, various dry dust collection devices (centrifugal collec-
tors, multiple cyclones, or ESPs and/or wet scrubbers) have been used.
Potential sources of fugitive particulate emissions in the primary
aluminum industry are bauxite grinding, materials handling, anode baking, and
three types of reduction cells (see Table 7.1-2). These fugitives probably
have particulate size distributions similar to those presented in Table 7.1-3.
10/86 Metallurgical Industry 7.1-9
-------
References for Section 7.1
1. Engineering and Cost Effectiveness Study of Fluoride Emissions Control,
Volume I, APTD-0945, U. S. Environmental Protection Agency, Research
Triangle Park, NC, January 1972.
2. Air Pollution Control in the Primary Aluminum Industry, Volume I, EPA-450/
3-73-004a, U. S. Environmental Protection Agency, Research Triangle Park,
NC, July 1973.
3. Participate Pollutant System Study, Volume I, APTD-0743, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, May 1971.
4. Inhalable Particulate Source Category Report For The Nonferrous Industry,
Contract No. 6.8-02-3159, Acurex Corporation, Mountain View, CA, October 1985.
5. Emissions from Wet Scrubbing System, Y-7730-E, York Research Corporation,
Stamford, CT, May 1972.
6. Emissions From Primary Aluminum Smelting Plant, Y-7730-B, York Research
Corporation, Stamford, CT, June 1972.
7. Emissions from the Wet Scrubber System, Y-7730-F., York Research Corporation,
Stamford, CT, June 1972.
8. T. R. Hanna and M. J. Pilat, "Size Distribution of Particulates Emitted
from a Horizontal Spike Soderberg Aluminum Reduction Cell", Journal of the
Air Pollution Control Association, ^2_:533-536, July 1972.
9. Background Information for Standards .of Performance: Primary Aluminum
Industry: Volume I, Proposed^ Standards , EPA-450/2-74-020a, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, October 1974.
10. Primary Aluminum; Guidelines for Control of Fluoride Emissions from
Existing Primary Aluminum Plants, EPA-450/2-78-049b, U. S. Environmental
Protection Agency, Research Triangle Park, NC, December 1979.
11. Written communication from T. F. Albee, Reynolds Aluminum, Richmond, VA,
to A. A. McQueen, U. S. Environmental Protection Agency, Research Triangle
Park, NC, October 20, 1982.
12. Environmental Assessment; Primary Aluminum, Interim Report, U. S. Environ-
mental Protection Agency, Cincinnati, OH, October 1978.
7.1-10 EMISSION FACTORS 10/86
-------
7.2 COKE MANUFACTURING
7.2.1 Process Description
Metallurgical coke is manufactured by destructive distillation of coal in
a byproduct coke oven battery. The distillation, termed "coking", is accom-
plished in a series of ovens in the absence of oxygen. Volatile compounds are
driven from the coal, collected from each oven, and processed in an adjacent
plant for recovery of combustible gases and other coal byproducts. Virtually
all metallurgical coke is produced by this process, termed the "byproduct"
method. Metallurgical coke is used in blast furnaces for production of iron.
Coke is produced in narrow, slot type ovens constructed of silica brick.
A coke oven battery may have a series of 10 to 100 individual ovens, with a
heating flue between each oven pair. Ovens are charged with pulverized coal,
through ports in the oven top, by a larry car traveling on tracks along the top
of each battery. After charging, the ports are sealed, and the coking process
begins. Combustion of gases in burners in the flues between the ovens provides
heat for the process. Coke oven gas from the byproduct recovery plant is the
common fuel for underfiring the ovens at most plants, but blast furnace gas
and, infrequently, natural gas may also be used.
After a coking time typically between 12 and 20 hours, almost'all volatile
matter is driven from the coal mass, and the coke is formed. Maximum temper-
ature at the center of the coke mass is usually 1100 to 1150°C (2000 to 2100°F).
After coking, machinery located on tracks on each side of the battery
removes the vertical door on each end of an oven, and a long ram pushes the
coke from the oven into a rail quench car, whence it goes to a quench tower,
where several thousand gallons of water are sprayed onto the coke mass to cool
it. The car then discharges the coke onto a wharf along the battery for fur-
ther cooling and drainage of water. From here, coke is screened and sent to
the blast furnace or to storage in outdoor piles.
After -the coke is pushed from an oven, the doors are cleaned and reposi-
tioned, and the oven is then ready to receive another charge of coal. Figure
7.2-1 is a diagram of a typical byproduct coke process.
During the coking cycle, volatile matter driven from the coal mass is
collected by offtakes located at one or both ends of the oven. A common col-
lector main transports the gases from each oven to the byproduct recovery plant.
Here, coke oven gas is separated, cleaned and returned to heat the ovens. Only
40 percent of recovered coke oven gas is required for underfiring, and the
remainder is used throughout, the steel plant. Other coal byproducts also are
recovered in the byproduct plant for reuse, sale or disposal.
10/86 Metallurgical Industry 7.2-1
-------
Figure 7.2-1.
The major steps in the carbonization of coal
with the byproduct process.
7.2-2
EMISSION FACTORS
10/86
-------
7.2.2 Emissions And Controls
Particulate, volatile organic compounds, carbon monoxide and other
emissions originate from several byproduct coking operations: (1) coal pre-
paration, (2) coal preheating (if used), (3) charging coal into ovens incan-
descent with heat, (4) oven leakage during the coking period, (5) pushing the
coke out of the ovens, (6) quenching the hot coke and (7) underfire combustion
stacks. Gaseous emissions collected from the ovens during the coking process
in the byproduct plant are subjected to various operations for separating
ammonia, coke oven gas, tar, phenol, light oil (benzene, toluene, xylene) and
pyridine. These unit operations are potential sources of volatile organic
compound emissions.
Coal preparation consists of pulverizing, screening, blending of several
coal types, and adding oil or water for bulk density control. Particulate
emissions are sometimes controlled by evacuated or unevacuated enclosures.
A few domestic plants heat coal to about 260°C (500°F) before charging, using.a
flash drying column heated by combustion of coke oven or natural gas. The air
steam that conveys the coal through the drying column usually is passed through
conventional wet scrubbers for particulate removal before discharge to the
atmosphere.
Oven charging can produce emissions of particulate matter and volatile
organic compounds from coal decomposition. The stage, or sequential, charging
techniques used on virtually all batteries draw most charging emissions into
the battery collector main and on to the byproduct plant. During the coking
cycle, volatile organic emissions from the thermal distillation process occa-
sionally leak to the atmosphere through poorly sealed doors, charge lids'and
offtake caps, and through cracks which may develop.in oven brickwork, the
offtakes and collector mains. Door leaks are controlled by diligent door
cleaning and maintenance, rebuilding of doors, and in some plants, by manual
application of lute (seal) material. Charge lid and offtake leaks are con-
trolled by an effective patching and luting program.
Pushing coke into the quench car is another major source of particulate
emissions, and if the coke mass is not fully coked, also of volatile organic
compounds and combustion products. Most batteries use pushing emission con-
trols such as hooded, mobile scrubber cars; shed enclosures evacuated to a gas
cleaning device; or traveling hoods with a fixed duct leading to a stationary
gas cleaner. The quench tower activity emits particulate from the coke mass,
and dissolved solids from the quench water may become entrained in the steam
plume rising from the tower. Trace organic compounds also may be present.
The gas combustion in the battery flues produces emissions through the
underfire or combustion stack. If coke oven gas is not desulfurized, sulfur
oxide emissions accompany the particulate and combustion emissions. If oven
wall brickwork is damaged, coal fines and coking decomposition products from a
recently charged oven may leak into the waste combustion gases. Figure 7.2-2
portrays major air pollution sources from a typical coke oven battery.
10/86 Metallurgical Industry 7.2-3
-------
to
I
P)
2
W
M
o .
z
Quenching
Emissions,
Charge Lid Door
Emissions Emissions
Combustion (Underfire)
Stock
Coke Guide
o
^.
co
Figure 7.2-2. Byproduct coke oven battery, with major emission points shown.
-------
Associated with the byproduct coke production are open source fugitive dust
operations from material handling. These operations consist of unloading, stor-
ing grinding and sizing of coal; and screening, crushing, storing and loading of
coke. Fugitive emissions may also result from vehicles traveling on paved and
unpaved surfaces. The emission factors available for coking operations for
total particulate, sulfur dioxide, carbon monoxide, volatile organic compounds,
nitrogen oxides and ammonia are given in Table 7.2-1. Table 7.2-2 gives avail-
able size specific emission factors. Figures 7.2-3 through 7.2-13 present
emission factor data by particle size. Extensive information on the data used
to develop the particulate emission factors can be found in Reference 1.
TYPES OF AIR POLLUTION EMISSIONS
FROM COKE OVEN BATTERIES
(T) Pushing emissions
(2) Charging emissions
(5) Door emissions
(5) Topside emissions
(§) Battery underfire emissions
Pennsylvania Air Pollution
Control Aiioci«nonl
10/86
Metallurgical Industry
7.2-5
-------
K)
1
Cf-
U
UJLt /..
i-l. LMJbblUN rAUlUKS fUK CURE, MANUr AL, IUK 1 NO
*-*
EMISSION FACTOK RATING: D (except Participate)
Partlculate
p)
in
M
O
z
Tl
H
0
8
Type of
operation
Coal crushing
with cyclone
Coal preheating
Uncontrolled6
With scrubber
With wet ESP
Wet coal charging^
Larry car
Uncontrolled
With sequential
charging
With scrubber
Door 1'eak
Uncontrolled
Coke pushing
Uncontrolled
With ESP£
With venturl
scrubber*1
With baghouse*1
With mobile
scrubber carJ
Emission
Factor
Ratingb
D
C
C
C
E
E
E
D
B
C
D
D
C
Sulfur Carbon Volatile
Paniculate') dioxide0 monoxide0 organlcsc>('
kg/Mg
0.055
1.75
0.125
0.006
0.24
0.008
0.007
0.27
0.58
0.225
0.09
0.045
0.036
Ib/ton kg/Mg Ib/ton kg/Mg Ib/ton kg/Mg Ib/ton
O.ll - -
3.50 - - - - -
0.25 - - - -
0.012 - - - -
•
0.48 0.01 0.02 0.3 0.6 1.25 2.5
0.016 - - - - -
0.014 - - - -
0.54 - - . 0.3 0.6 0.75 1.5
1.15 - - 0.035 0.07 0.1 0.2
0.45 - -
0.18 . - - - - -
0.0'J - - -
0.072 - - - - -
Nitrogen
oxides0 Ammonia0
kg/Mg Ib/ton kg/Mg Ib/ton
•
- - — —
_ _
_ _ _
- -
0.015 0.03 0.01 0.02
- _
_ _
0.005 0.01 0.03 0.06
0.05 0.1
- _
- - - -
_ _
_ _ —
00
a*
-------
o
00
TABLE 7.2-1 (cont.). EMISSION FACTORS FOR COKE MANUFACTURING3
n
r»
W
o
to
a
c
(0
Particular
Type of Emission
operation Factor
Ratlngb
Quenching
Uncontrolled
Dirty water'1
Clean water"
With baffles
Dirty water*1
Clean water11
Coabustlon stack
Uncontrolled (COG)
Uncontrolled (BFG)
With ESP (COG)
With baghouae (COG)
Coke handling
With cycloneP
Conblned operational
D
D
B
B
A
A
D
D
D
D
i Sulfur Carbon Volatile
Partlculateb dloxldec monoxide0 organlcsc»^
kg/Mg
2.62
0.57
0.65
0.27
0.234
0.085
0.046
0.055
0.003
-
Ib/ton kg/Kg Ib/ton kg/Mg Ib/ton kg/Mg Ib/ton
5.24 - - - - - -
1.13 - - - -
1.30 -
0.54 - - ' -
0.47 2.0" 4.0" -
0.17 - - - - -
0.091 - - - -
O.ll - _ -
0.006 - - -
_ ' _
Nitrogen
oxldesc Aaaonlac
kg/Mg Ib/ton kg/Mg Ib/ton
•
- - -
_ _
- - -
- — - —
_ _
_ _
_ _
- - -
— - — —
- -
--J
aExpressed as units/unit of coal charged. Dash » no data. ESP » electrostatic preclpltator. COG - coke oven gas.
BFG - blast furnace gas. i
^Reference 1.
cReferencea 2-3.
''Expressed as methane.
eExhaust gas discharged from series of primary and secondary cyclones used to separate flash dried coal from hot gas.
fCharged coal has not been dried.
^Emissions captured by coke side uhcd.
"Emissions captured by traveling hood.
-(Emissions captured by quench car enclosure.
kDlrty water >5000 mg/1 total dissolved solids.
""Clean water O500 mg/1 total dissolved solids.
"Reference 4. Factor for SOo Is based on these representative conditions: (1) sulfur content of coal charged to oven
Is 0.8 weight Z; (2) about 33 weight Z of total sulfur In coal charged to oven Is transferred to coke oven gas;
(3) about 40Z of coke oven gas la burned during underflrlng operation, and about 60Z is used In other operations where
the rest of the S02 13 kg/Mg (6 Ib/ton) of coal charged) Is discharged; (4) gas used in underflrlng has not been
desulfurlzed.
PDeflned as crushing and screening.
^References 19-20. Uncontrolled lead einlaulona are 0.00018 kg/Mg (0.00035 Ib/ton).
-------
TABLE 7.2-2. SIZE SPECIFIC EMISSION FACTORS FOR COKE MANUFACTURING
Particulate
emission
factor
Process rating
Coal preheating D
Uncontrolled
Controlled D
with venturl
scrubber
Coal charging E
Sequential
or stage
Coke pushing D
Uncontrolled
Controlled D
with Venturl
scrubber
Cumulative
Particle mass %
size <_ stated
(urn) size
0.5
1.0
2.0
2.5
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
0.5
• i.o
2.0
2.5
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
44
48.5
55
59.5
79.5
97.5
99.9
100
78
80
83
84
88
94
96.5
100
13.. 5
25.2
33.6
39.1
45.8
48.9
49.0
100
3.1
7.7
14.8
- • 16.7
26.6
43.3
50.0
100
24
47
66.5
73.5
75
87
92
100
Cumulative
! mass emission
factors
kg/Mg
0.8
0.8
1.0
1.0
1.4
1.7
1.7
1.7
0.10
0.10
0.10
0.11
0.11
0.12
0.12
0.12
0.001
0.002
0.003
0.003
0.004
0.004
0.004
0.008
0.02
0.04
0.09
0.10
0.15
0.25
0.29
0.58
0.02
0.04
0.06
0.07
0.07
0.08
0.08
0.09
Ib/ton
1.5
1.7
1.9
2.1
2.8
3.4
3.5
3.5
0.20
0.20
0.21
0.21
0.22
0.24
0.24
0.25
0.002
0.004
0.005
0.006
0.007
0.008
0.008
0.016
0.04
0.09
0.17
0.19
0.30
0.50
0.58
1.15
0.04
0.08
0.12
0.13
0.13
0.16
0.17
0.18
Reference
source
number
6
6
7
8-13
8,10
7.2-8
(continued)
EMISSION FACTORS
10/86
-------
TABLE 7.2-2 (continued)
Partlculate
emission
factor
Process rating
Mobile D
scrubber car
Quenching D
Uncontrolled
(dirty water)
Uncontrolled B
(clean water)
With baffles D
(dirty water)
With baffles D
(clean water)
Combustion stack D
Uncontrolled
Particle
size
(urn)
1.0
2.0
2.5
5.0
10.0
15.0
1.0
2.5
5.0
10.0
15.0
1.0
. 2.5
5.0
10.0
15.0
1.0
2.5
5.0
10.0
15.0
1.0
2.5
5.0
10.0
15.0
1.0
2.0
2.5
5.0
10.0
15.0
Cumulative
mass X
< stated
size
28. ff
29.5
30.0
30.0
32.0
35.0
100
13.8
19.3
21.4
22.8
26.4
100
4.0
11.1
19.1
30.1
37.4
100
8.5
20.4
24.8
32.3
49.8
100
1.2
6.0
7.0
9.8
15.1
100
77.4
85.7
93.5
95.8
95.9
96
100
Cumulative
> mass emission
factors
kg/Mg
0.010
0.011
0.011
0.011
0.012
0.013
0.036
0.36
0.51
0.56
0.60
0.69
2.62
0.02
0.06
0.11
0.17
0.21
0.57
0.06
0.13
0.16
0.21
0.32
0.65
0.003
0.02
0.02
0.03
0.04
0.27
0.18
0.20
0.22
0.22
0.22
0.22
0.23
Ib/ton
0.020
0.021
0.022
0.022
0.024
0.023
0.072
0.72
1.01
1.12
1.19
1.38
5.24
0.05
0.13
0.22
0.34
0.42
1.13
0.11
0.27
0.32
0.42
0.65
1.30
0.006
0.03
0.04
0.05
0.08
0.54
0.36
0.40
0.44
0.45
0.45
0.45
0.47
Reference
source
number
14
15
15
15
• 15
16-18
-
10/86
Metallurgical Industry
7.2-9
-------
TOTAL PARTICIPATE _
EMISSION RATE "
lb« PARTICIPATE
ton COAL CHARGED
99.99V
99.950
99.90
99.60
99.50
99
98
95
UJ
s *>
O
UJ 80
<
»- 70
in
v 60
Z 50
8 40
ui 30
o.
uj 20
P
< 10
D
2 5
o
2
\
0.5
0.2
0.15
O.I
0.0
M
* /
/
^ ^
/ ""
••
/
y
y
>/
^ ^~^^^
vi
^
~
-
T
-
-
-
-
-
3.5O
3.43 uj
N
3.32 w
a
UJ
3.15 K
>-
2.80 y
2.45 {f
2.10 J
1.75 if
1.40 «
a
•i
UJ
P
<
3
2
o
a
UJ
o
-------
99.930
99.90
99.80
99.50
99
98
95
UJ
£ 9°
ju eo
* 70
c/)
v 60
2 50
3 40
a 30
uj 20
< 10
2 5
o
0.5
0.2
0.15
O.I
n n
EMISSION RATE ' ton COAL CHARGED
X «
•
. • . •
-
-
-
-
-
-
-
iii iiiiiil i i iiiiiil i i 11111
UJ
N
0.24 "
a
0.23 H
H-
co
0.20 v
0.18 {H
-t
3
U
i
a.
.a
UJ
<
2
. o
CHARGED
_J
O
U
c
o
I0-l .10° I01 I02
PARTICLE DIAMETER, micrometers
Note: Extrapolated to the 15 urn size, using engineering estimates.
Figure 7.2-4. Coal preheating (controlled with scrubber).
10/86
Metallurgical Industry
7.2-11
-------
TOTAL PARTICIPATE -
Ibs PARTICULATE
EMISSION RATE ton COAL CHARGED
99.930
99.90
99.80
99.50
99
98
95
UJ
M
Q
UJ 80
H 70
CO
v 60
£ 50
g 40
UJ 30
0.
uj 20
p
< 10
2 5
<->
<
1
0.5
0.2
0.15
O.I
n n
' /^ ~ "
S'
4
*~ • ' mt
-
^
••
-
- •
-
-
Ill Illllll 1 1 Illllll 1 1 Illlll
UJ
M
V)
Q
UJ
K
CO
V
UJ
1-
_J
^5
aooebf
0.006 «
0.005 °-
V)
UJ
0.002 >
<
. .- 2
o
a
UJ
0
Q£
<
x
o
' _1
<
o
o
c
o
10
IOU 10'
PARTICLE DIAMETER, micrometers
10'
Note: Extrapolated to the 15 urn size, using engineering estimates,
Figure 7:2-5. Coal charging (sequential) average of 2 tests.
7.2-12
EMISSION FACTORS
10/86
-------
TOTAL PARTICIPATE _, .«
EMISSION RATE " '
Ibs PARTICULATE
ton COAL CHARGED
Ul
V
99.950
99.90
99.80
99.50
99
98
95
90
j
| 80
f
70
1
60
; so
i 40
i 30
j 20
>
5 10
D
E 5
D
J
<
0.5
0.2
0.15
O.I
0.0
1C
'
" A
Jf'
S*
/^
Jr
»^
//
9m
^
-
-
-
-
Ill Illllll 1 1 Illllll 1 1 Illll
Ul
N
v>
o
Ul
K-
co
V
Ul
^f
J
•3
0.58 2
0.46
0.06 5
0.02 i
o
a
Ul
0
-------
EMISSION RATE ' ton COAL CHARGED
99.950
99. 9O
99.8O
99.50
99
98
95
Ul
N
V)
Q
w 80
£ 70
v 60
£ 50
% 40
£ 30
a.
ui 20
P
< 10
D
2 5
o
2
1
0.5
0.2
0.15
O.I
^\ f
9
/•' -
y»
^/
•^"^
9r^
/
S
i- /
/
/
—
-
-
^
-
-
-
-
, , i i i i i . J i i . i 1 1 1 il i i i ... i ,,
0.17
0.16
0.14
0.13
0.11
0.09
0.07
0.05
0.04
"lO'1 10° 10 ' I02
Ul
N
CO
Q
Ul
>-
V)
V
UJ
^f
_l
«D
o
-------
Ibs PARTICULATE
99.990 r
99.9SO •
99.90
99.80 •
99.50
99
98
95
Ul
3 9°
Q
£ 80
£ 70
w
v 60
Z 50
S 40
£ 30
ui 20
< 10
D
2 5
o
2
0.5
0.2
0.15
0.
n n
EMISSION RATE ton COAL CHARGED
»
•»
—
:
-
: * 0 0^- ^
rr^^~ — O Q^~^jQ •*
^
-
-
-
Ill Illllll 1 I Illllll 1 1 Illlll
Ul
N
v>
0
Ul
K-
V
Ul
t-
o
0.029 oc
0.022 ^
0.014 £
0.007 >
h-
• o.ooi i
.0.001°
IARGED
i
o
o
o
c
o
I0-l 10° .O1
PARTICLE DIAMETER, micrometers
10'
Figure 7.2-8. Mobile scrubber cars.
10/86
Metallurgical Industry
7.2-15
-------
TOTAL PARTICULATE
EMISSION RATE
5.24
Ibs PARTICULATE
ton COAL CHARGED
99.950
99. 9O
99.80
99.50
99
98
95
80
»
; 70
i
60
: 50
) 40
j 30
m
J 2O
>
t 10
D
S5
v
J
j
2
1
0.5
0.2
0.15
O.I
n n
•
••
^ *^*
^ ,
^
••
•
-
-
-
iii i i i 1 1 1 1 i i i i 1 1 1 1 1 i i i i i 1 1 1
UJ
N
to
a
UJ
>-
>-
CO
V
UJ
^_
<
_1
3
o
a:
1.57 a-
1.05 |
Ul
0.52 >
P
<
_i
3
2
D
O
a
Ul
5,000 mg/L IDS.
7.2-16
EMISSION FACTORS
10/86
-------
Ibs PARTICIPATE
99.990
99.950
99.90
99.80
99.50
99
98
95
UJ
3 90
Q
W 80
Z 70
en
v 60
£ 50
S 40
£ 30
0.
U 20
P
< 10
_i
2 5
D
<->
4
1
0.5
0.2
0.15
O.I
n n
EMISSION RATE ' ton COAL CHARGED
'
/S
.S
s^
s^ ™ •
jr
*s
«
^
-
-
-
-
Ill Illllll 1 1 Illllli 1 1 Illll
UJ
N
tn
a
UJ
h-
H
(/>
V
UJ
_l
o
0.45
0.06 ^
_
2
0.02 3
u
Q
UJ
0
o:
z
a
^
o
o
c
o
10'' 10° 10 ' I0-
PARTICLE DIAMETER, micrometers
Figure 7.2-10. Quenching (uncontrolled) clean water <1,500 mg/L IDS.
10/86
Metallurgical Industry
7.2-17
-------
Ibs PARTICIPATE
99.950
99.90
99.80
99.50
99
98
95
Ul
M
co
I 80
1- 70
CO
v 60
£ 50
8 40
a:
ui 30
a.
u. 20
< (0
2 5
2
0.5
0.2
0.15
O.I
n n
EMISSION RATE ton COAL CHARGED
•»
' ^^ '-
S^*^
*s ^
.
_
-
-
-
-
iiiiiiiiil i i iiiiiil i i 11111
Ul
M
W
a
Ul
K
i—
§
ICULATE
0.07 <
2
o
CHARGED
O
0
c
o
10° 10' IOJ
PARTICLE DIAMETER, micrometers
Figure 7.2-11. Quenching (controlled with baffles) dirty water >5,000 mg/L IDS.
7.2-18
EMISSION FACTORS
10/86
-------
TOTAL PARTICULATE _
lbs PARTICIPATE
EMISSION RATE ' ton COAL CHARGED
99.950
99.90
99.80
99.50
99
98
95
UJ
M rt
tO
a
w 80
£ 70
CO
v 60
Z 50
S 40
£ 30
w 20
p
< 10
2 5
0
<
l
0.5
0.2
0.15
O.I
n n
-
-
-
- " .
^x*
^^^
/^^
/
/ m
S
-
-
-
-
'
iii iiiiiil i i iiiiiil i i iiiii
UJ
N
V)
a
UJ
h-
t-
(0
V
UJ
_J
3
0
0.027 ^
3
2
0.011 3
0
a
Ul
o
-------
TOTAL PARTICIPATE =Q 4? Ibs PARTICIPATE
EMISSION RATE ' ton COAL CHARGED
UJ
N
CO
Q
UJ
£
99.930
99.90
99.80
99.50
99
98
95
90
I SO
70
60
: 50
\ 40
J 30
j 20
>
I 10
D
5 5
3
J
2
l
0.5
0.2
0.15
O.I
n r»
— m
_ m -•
^-^"^ ^ ^^^ ^^
^r
/
/ 0
/
.
••
-
-
_
-
^
-
-
'
-
ill iiiiiil 1 1 Illlill 1 l liiiii
0.46 UJ
N
0.45 OT
a
Ul
0.42 H
^t
CO
0.38 v
0.33 £
<
j
3
O
P
a
Ul
>
\-
<
•3
o
c
Ul
0
-------
References for Section 7.2
1. John Fitzgerald, et al., Inhalable Partlculate Source Category Report For
The Metallurgical Coke Industry, TR-83-97-G, Contract No. 68-02-3157, GCA
Corporation, Bedford, MA, July 1986.
2. Air Pollution By Coking Plants, United Nations Report: Economic Commis-
sion for Europe, ST/ECE/Coal/26, 1968.
3. R. W. Fullerton, "Impingement Baffles To Reduce Emissions from Coke
Quenching", Journal of the Air Pollution Control Association, 17:807-809,
December 1967.
4. J. Varga and H. W. Lownie, Jr., Final Technological Report On A Systems
Analysis Study Of The Integrated Iron And Steel Industry, Contract No.
PH-22-68-65, U. S. Environmental Protection Agency, Research Triangle
Park, NC, May 1969.
5. Particulate Emissions Factors Applicable To The Iron And Steel Industry,
EPA-450/4-79-028, U. S. Environmental Protection Agency, Research Triangle
Park, NC, September 1979.
6. Stack Test Report for J & L, Steel, Aliquippa Works, Betz Environmental
Engineers, Plymouth Meeting, PA, April 1977.
7. R. W. Bee, et al., Coke Oven Charging Emission Control Test Program,
Volume I, EPA-650/2-74-062-1, U. S. Environmental Protection Agency,
Washington, DC, July 1974. . .
8. Emission Testing And Evaluation Of Ford/Koppers Coke Pushing Control
System, EPA-600/2-77-187b, U. S. Environmental Protection Agency,
Washington, DC, September 1977.
9. Stack Test Report, Bethlehem Steel, Burns Harbor, IN, Bethlehem Steel,
Bethlehem, PA, September 1974.
10. Stack Test Report for Inland Steel Corporation, East Chicago, IN Works,
Betz Environmental Engineers, Pittsburgh, PA, June 1976.
11. Stack Test Report for Great Lakes Carbon Corporation, St. Louis, MO,
Clayton Environmental Services, Southfield, MO, April 1975.
12. Source Testing Of A Stationary Coke Side Enclosure, Bethlehem Steel,
Burns Harbor Plant, EPA-340/1-76-012, U. S. Environmental Protection
Agency, Washington, DC, May 1977.
13. Stack Test Report for Allied Chemical Corporation, Ashland, KY, York
Research Corporation, Stamford, CT, April 1979.
14. Stack Test Report, Republic Steel Company, Cleveland, OH, Republic Steel,
Cleveland, OH, November 1979.
10/86 Metallurgical Industry . .7.2-21
-------
15. J. Jeffrey, Wet Coke Quench Tower Emission Factor Development, Dofasco,
Ltd., EPA-600/X-85-34CI, U. S. Environmental Protection Agency, Research
Triangle Park, NC, August 1982.
16. Stack Test Report for Shenango Steel, Inc., Neville Island, PA, Betz
Environmental Engineers, Plymouth Meeting, PA, July 1976.
17. Stack Test Report for J & L Steel Corporation, Pittsburgh, PA, Mostardi-
Platt Associates, Bensenville, IL, June 1980.
18. Stack Test Report for J & L Steel Corporation, Pittsburgh, PA, Wheelabrator
Frye, Inc., Pittsburgh, PA, April 1980.
19. R. B. Jacko, et al., By-product Coke Oven Pushing Operation; Total And
Trace Metal Particulate Emissions, Purdue University, West Lafayette, IN,
June 27, 1976.
20. Control Techniques For Lead Air Emissions, EPA-450/2-77-012, U. S. Envi-
ronmental protection Agency, Research Triangle Park, NC, December 1977.
7.2-22 EMISSION FACTORS 10/86
-------
7.3 PRIMARY COPPER SMELTING
7.3.1 Process Description^'^
In Che United States, copper is produced from sulfide ore concentrates,
principally by pyrometallurgical smelting methods. Because the ores usually
contain less than 1 percent copper, they must be concentrated before transport
to smelters. Concentrations of 15 to 35 percent copper are accomplished at the
mine site by crushing, grinding and flotation. Sulfur content of the concen-
trate ranges from 25 to 35, percent and most of the remainder is iron (25
percent) and water (10 percent-). Some concentrates also contain significant
quantities of arsenic, cadmium, lead, antimony, and other heavy metals.
A conventional pyrometallurgical copper smelting process is illustrated
in Figure 7.3-1. The process includes roasting of ore concentrates to produce
calcine, smelting of roasted (calcine feed) or unroasted (green feed) ore
concentrates to produce matte, and converting of the matte to yield blister
copper product (about 99 percent pure). Typically, the blister copper is fire
refined in an anode furnace, cast into "anodes" and sent to an electrolytic
refinery for further impurity elimination.
In roasting, charge material of copper concentrate mixed with, a siliceous .
flux (often a low grade ore) is heated in air to-about 650°C (1200°F), eliminat-
ing 20 to 50 percent of the sulfur as sulfur dioxide (S02). Portions of such
impurities as antimony, arsenic and lead are driven off, and some iron is con-
verted to oxide. The roasted product, calcine, serves as a dried and heated
charge for the smelting furnace. Either multiple hearth or fluidized bed roast-
ers are used for roasting copper concentrate. Multiple hearth roasters accept
moist concentrate, whereas fluid bed roasters are fed finely ground material
(60 percent minus 200 mesh). With both of these types, the roasting is autog-
enous. Because there is less air dilution, higher S02 concentrations are
present in fluidized bed roaster gases than in multiple hearth roaster gases.
In the smelting process, either hot calcines from the roaster or raw
unroasted concentrate is melted with siliceous flux in a smelting furnace to
produce copper matte, a molten mixture of cuprous sulfide (Cu2S), ferrous
sulfide (FeS) and some heavy metals. The required heat comes from partial
oxidation of the sulfide charge and from burning external fuel. Most of the
iron and some of the impurities in the charge oxidize with the fluxes to form
atop the molten bath a slag, which is periodically removed and discarded.
Copper matte remains in the furnace until tapped. Mattes produced by the
domestic industry range from 35 to 65 percent copper, with 45 percent the most
common. The copper content percentage is referred to as the matte grade.
Currently, five smelting furnace technologies are used in the U. S., reverber-
atory, electric, Noranda, Outokumpu (flash), and Inco (flash).
Reverberatory furnace operation is a continuous process, with frequent
charging of input materials and periodic tapping of matte and skimming of slag.
10/86 Metallurgical Industry . 7.3-1
-------
ORE CONCENTRATES WITH SILICA FLUXES
FUEL.
AIR.
ROASTING
CONVERTER SLAG (2% Cu)
FUEL-
AIR.
-*-OFFGAS
CALCINE
SMELTING
SLAG TO DUMP
(0.5S Cu)
AIR-
•OFFGAS
MATTE (-40% Cu)
CONVERTING
GREEN POLES OR GAS-
FUEL"
AIR-
BLISTER COPPER
(98.S*% Cu)
FIRE REFINING
-»»OFFGAS
SLAG TO CONVERTER
ANODE COPPER (99.5% Cu)
TO ELECTROLYTIC REFINERY
Figure 7.3-1. Typical primary copper smelter process,
7.3-2
EMISSION FACTORS
10/86
-------
1300 tons) of charge per day. Heat is supplied by combustion of oil, gas or
pulverized coal, and furnace temperature may exceed 1500°C (2730°F).
For smelting in electric arc furnaces, heat is generated by the flow of an
electric current in carbon electrodes lowered through the furnace roof and
submerged in the slag layer of the molten bath. The feed generally consists of
dried concentrates or calcines, and charging wet concentrates is avoided. The
chemical and physical changes occurring in the molten bath are similar to those
occurring in the molten bath of a reverberatory furnace. Also, the matte and
slag tapping practices are similar at both furnaces. Electric furnaces do not
produce fuel combustion gases, so flow rates are lower and S02 concentrations
higher in the effluent gas than in that of reverberatory furnaces.
Flash furnace smelting combines the operations of roasting and smelting to
produce a high grade copper matte from concentrates and flux. In flash smelt-
ing, dried ore concentrates and finely ground fluxes are injected, together with
oxygen, preheated air, or a mixture of both, into a furnace of special design,
where temperature is maintained at approximately 1000°C (1830°F). Flash fur-
naces, in contrast to reverberatory and electric furnaces, use the heat gener-
ated from partial oxidation of their sulfide charge to provide much or all of
the energy (heat) required for smelting. They also produce offgas streams
containing high concentrations of S02-
Slag produced by flash furnace operations contains significantly higher
amounts of copper than does that from reverberatory or electric furnace opera-
tions. As a result, the flash furnace and converter slags are treated in a
slag cleaning furnace to recover the copper. Slag cleaning furnaces usually
are small electric furnaces. The flash furnace and converter slags are charged
to a slag cleaning furnace and are allowed to settle under reducing conditions,
with the addition of coke or iron sulfide. The copper, which is in oxide form
in the slag, is converted to copper sulfide, is subsequently removed from the
furnace and is charged to a converter with regular matte. If the slag's copper
content is low, the slag is discarded.
The Noranda process, as originally designed, allowed the continuous produc-
tion of blister copper in a single vessel by effectively combining roasting,
smelting and converting into one operation. Metallurgical problems, however,
led to the operation of these reactors for the production of copper matte. As
in flash smelting, the Noranda process takes advantage of the heat energy
available from the copper ore. The remaining thermal energy required is sup-
plied by oil burners, or by coal mixed with the -ore concentrates.
The final step in the production of blister copper is converting, with the
purposes of eliminating the remaining iron and sulfur present in the matte and
leaving molten "blister" copper. All but one U. S. smelter uses Fierce-Smith
converters, which are refractory lined cylindrical steel shells mounted on
trunnions at either end, and rotated about the major axis for charging and
pouring. An opening in the center of the converter functions as a mouth through
which molten matte, siliceous flux, and scrap copper are charged and gaseous
products are vented. Air or oxygen rich air is blown through the molten matte.
Iron sulfide (FeS) is oxidized to iron oxide (FeO) and SO-), and the FeO blowing
and slag skimming are repeated until an adequate amount of relatively pure CuoS,
called "white metal", accumulates in the bottom of the converter. A renewed air
blast oxidizes the copper sulfide sulfur to S02» leaving blister copper in the
10/86 Metallurgical Industry 7.3-3
-------
converter. The blister copper is subsequently removed and transferred to
refining facilities. This segment of converter operation is termed the finish
blow. The S02 produced throughout the operation is vented to pollution control
devices.
One domestic smelter uses Hoboken converters, the primary advantage of
which lies in emission control. The Hoboken converter is essentially like a
conventional Fierce-Smith converter, except that this vessel is fitted with a
side flue at one end shaped as an inverted U. This flue arrangement permits
siphoning of gases from the interior of the converter directly to the offgas
collection system, leaving the converter mouth under a slight vacuum.
Blister v. r usually contains from 98.5 to 99.5 percent pure copper.
Impurities may include gold, silver, antimony, arsenic, bismuth, iron, lead,
nickel, selenium, sulfur, tellurium, and zinc. To purify blister copper further,
fire refining and electrolytic refining are used. In fire refining, blister
copper is placed in a fire refining furnace, a flux is usually added, and air
is blown through the molten mixture to oxidize remaining impurities, which are
removed as a slag. The remaining metal bath is subjected to a reducing atmos-
phere to reconvert cuprous oxide to copper. Temperature in the furnace is
around 1100°C (2010°F). The fire refined copper is cast into anodes, after
which, further electrolytic refining separates copper from impurities by elec-
trolysis in a solution containing copper sulfate and sulfuric acid. Metallic
impurities precipitate from the solution and form a sludge that is removed and
treated to recover precious metals. Copper is dissolved from the anode and
deposited at the cathode. Cathode copper is remel ted and made into bars, .
ingots, or slabs for marketing purpose. The copper produced is 99.95 to 99.97
percent pure.
7.3.2 Emissions And Controls
particulate matter and sulfur dioxide are the principal air contaminants
emitted by primary copper smelters. These emissions are generated directly
from the processes involved, as in the liberation of SC>2 from copper concentrate
during roasting, or in the volatilization of trace elements as oxide fumes.
Fugitive emissions are generated by leaks from major equipment during material
handling operations.
Roasters, smelting furnaces and converters are sources of both particulate
matter and sulfur oxides. Copper and iron oxides are the primary constituents
of the particulate matter, but other ox-ides, such as arsenic, antimony, cadmium,
lead, mercury and zinc, may also be present, with metallic sulfates and sulfuric
acid mist. Fuel combustion products also contribute to the particulate emis-
sions from multiple hearth roasters and reverberatory furnaces.
Single stage electrostatic precipitators (ESP) are widely used in the
primary copper industry to control particulate emissions from roasters, smelting
furnaces and converters. Many of the existing ESPs are operated at elevated
temperatures, usually from 200° to 340°C (400° to 650°F) and are termed "hot
ESPs". If properly designed and operated, these ESPs remove 99 percent or more
of the condensed particulate matter present in gaseous effluents. However, at
these elevated temperatures, a significant amount of volatile emissions such as
arsenic trioxide (As2C>3) and sulfuric acid mist is present as vapor in the
gaseous effluent and thus can not be collected by the particulate control
7.3-4 EMISSION FACTORS 10/86
-------
device at elevated temperatures. At these temperatures, the arsenic trioxide
in the vapor state will pass through an ESP. Therefore, the gas stream to be
treated must be cooled sufficiently to assure that most of the arsenic present
is condensed before entering the control device for collection. At some smelt-
ers, the gas effluents are cooled to about 120°C (250°F) temperature before
entering a particulate control system, usually an ordinary ("cold") ESP. Spray
chambers or air infiltration are used for gas cooling. Fabric filters can also
be used for particulate matter collection.
Gas effluents from roasters usually are sent to an ESP or spray chamber/ESP
system or are combined with smelter furnace gas effluents before particulate
collection. Overall, the hot ESPs remove only 20 to 80 percent of the total
particulate (condensed and vapor) present in the gas. Cold ESPs may remove
more than 95 percent of the total particulate present in the gas. Particulate
collection systems for smelting furnaces are similar to those for roasters.
Reverberatory furnace offgases are usually routed through waste heat boilers
and low velocity balloon flues to recover large particles and heat, then are
routed through an ESP or spray chamber/ESP system.
In the standard Pierce-Smith converter, flue gases are captured during the
blowing phase by the primary hood over the converter mouth. To prevent the
hood's binding to the converter with splashing molten metal, there is a gap
between the hood and the vessel. During charging and pouring operations,
significant fugitives may be emitted when the hood is removed to allow crane
access. Converter offgases are treated in ESPs to remove particulate matter
and in sulfuric acid plants to remove S02-
Remaining smelter processes handle material that contains very little
sulfur, hence S02 emissions from these processes are relatively insignificant.
Farticulate emissions from fire refining operations, however, may be of concern.
Electrolytic refining does not produce emissions unless the associated sulfuric
acid tanks are open to the atmosphere. Crushing and grinding systems used in
ore, flux and slag processing also contribute to fugitive dust problems.
Control of S02 emissions from smelter sources is most commonly performed
in a single or double contact sulfuric acid plant. Use of a sulfuric acid
plant to treat copper smelter effluent gas streams requires that gas be free
from particulate matter and that a certain minimum SC>2 concentration be main-
tained. Practical limitations have usually restricted sulfuric acid plant
application to gas streams that contain at least 3 percent S02« Table 7.3-1
shows typical average SO? concentrations for the various smelter unit offgases.
Currently, converter gas effluents at most smelters are treated for S02 control
in sulfuric acid plants. Gas effluents of some multiple hearth roaster opera-
tions and of all fluid bed roaster operations also are treated in sulfuric acid
plants. The weak. S02 content gas effluents from reverberatory furnace opera-
tions are usually released to the atmosphere with no reduction of S02« The gas
effluents from the other types of smelter furnaces, because of their higher
contents of S02, are treated in sulfuric acid plants before being vented.
Typically, single contact acid plants achieve 92.5 to 98 percent conversion of
S02 to acid, with approximately 2000 parts per million S02 remaining in the acid
plant effluent gas. Double contact acid plants collect from 98 to more than 99
percent of the S02 and emit about 500 parts per million S02» Absorption of the
S02 in dimethylaniline (DMA) solution has also been used in U. S. smelters to
produce liquid SO?.
10/86 Metallurgical Industry 7.3-5
-------
TABLE 7.3-1. TYPICAL SULFUR DIOXIDE CONCENTRATIONS
IN OFFGASES FROM PRIMARY COPPER
SMELTING SOURCES
Unit
S02 concentration
(volume %)
Multiple hearth roaster
Fluidized bed roaster
Reverberatory furnace
Electric arc furnace
Flash smelting furnace
Continuous smelting furnace
Pierce-Sraith converter
Hoboken converter
Single contact ^204 plant
Double contact ^SO^ plant
1.5 to 3
10 to 12
0.5 to 1.5
4 to 8
10 to 70
5 to 15
4 to 7
8
0.2 to 0.26
0.05
Emissions from hydroraetallurgical smelting plants generally are small in
quantity and are easily controlled. In the Arbiter process, ammonia gas escapes
from the leach reactors, mixer/settlers, thickeners and tanks. For control,
all of these units are covered and are vented to a packed tower scrubber co
recover and recycle the ammonia.
Actual emissions from a particular smelter unit depend upon the configura-
tion of equipment in that smelting plant and its operating parameters. Table
7.3-2 gives the emission factors for various smelter configurations, and.Tables
7.3-3 through 7.3-5 and Figures 7.3-2 through 7.3-4 give size specific emission
factors for those copper production processes, where information is available.
7.3.3 Fugitive Emissions
The process sources of particulate matter and S02 emission are also the
potential fugitive sources of these emissions: roasting, smelting, converting,
fire refining and slag cleaning. Table 7.3-6 presents the potential fugitive
emission factors for these sources, while Tables 7.3-7 through 7.3-9 and Figures
7.3-5 through 7.3-7 present cumulative size specific particulate emission
factors for fugitive emissions from reverberatory furnace matte, slag tapping,
converter slag, and copper blow operations. The actual quantities of emissions
from these sources depend on the type and condition of the equipment and on the
smelter operating techniques. Although emissions from many of these sources are
released inside a building, ultimately they are discharged to the atmosphere.
7.3-6
EMISSION FACTORS
10/86
-------
TABLE 7.3-2. EMISSION FACTORS FOR PRIMARY COPPER SMELTERSa»b
EMISSION FACTOR RATING: B
Particulace
Sulfur dioxided
Configuration0
References
Reverberatory furnace (RP)
followed by converters (C)
Multiple hearth roaster (MHR)
followed by reverberatory
furnace (RF) and converters (C)
Fluid bed roaster (FBR) followed
by reverberatory furnace (RF)
and converters (C)
Concentrate dryer (CD) followed
by electric furnace (EF) and
converters (C)
Fluid bed roaster (FBR) followed
by electric furnace (EF) and
converters (C)
Concentrate dryer (DC) followed
by flash furnace (FF),
cleaning furnace (S3) and
converters (C)
Concentrate dryer (CD) followed
by Noranda reactors (NR) and
converters (C)
By
unit
RF
C
MHR
RF
C
FBR
RF
C •
CD
EF
C
FBR
EF
C
CD
FF
ssf
C«
CD
NR
C
**
25
18
22
25
18
NA
25
18
5
50
18
NA
50
18
5.
70
5
NA8 .
5.
NA
NA
Ib/ton
50
36
45
50
36
NA
50
36
10
100
36
NA
100
36
10
140
10
HAS
10
NA
NA
k«/Mg
160
370
140
90
300
180
90
270
0.5
120
410
180 •
45
300
0.5
410
0.5
120
0.5
NA
NA
Ib/ton
320
740
280
180
600
360
160
540
1
240
820
360
90
600
I
820
1
240
1
NA
NA
.4-10,
9,11-15
4-5,16-17
4-9,18-19
8,11-13
20
e
e
21-22
15
8,11-13,15
20
15,23
e
21-22
24
22
22.
21-22
aExpressed as units/unit weight of concentrated ore processed by the saelter. Approximately 4
unit weights of concentrate are required to produce 1-unit weight of blister copper. NA - aot
available.
^For particulate matter removal, gaseous effluents from roasters, smelting furnaces and
converters usually are treated in hot ESPs at 200 to 340*C (400 to 650°F) or in cold ESPs with
gases cooled to about 120°C (250°F) before ESP. Particulate emissions from copper smelters
contain volatile metallic oxides which remain in vapor form at higher temperatures (120*C or
250'F). Therefore, overall partlculate removal in hot ESPs may range 20 to 80Z and in cold ESPs
may be 99Z. Converter gas effluents and, ac some smelters, roaster gas effluents are treated in
single contact acid plants (SCAP) or double contact acid plants (DCAP) for SOj removal. Typical
SCAPs are about 96Z efficient, and DCAPs are up to 99.8Z efficient in S02 removal. They also
remove over 99Z of participate matter. Noranda and flash furnace offgases are also processed
through acid plants and are subject to the same collection efficiencies aa cited for
converters and some roasters.
cln addition to sources indicated, each saelter configuration contains fire refining anode
furnaces after the converters. Anode furnaces emit negligible 302- No particulate emission
data are available for anode' furnaces.
dFactors for all configurations except reverberatory furnace followed by converters have been
developed by normalizing tesc data for several smelters to represent 30Z sulfur content in
concentrated ore.
eBased on the test data for the configuration multiple hearth roaster followed by reverberatory
furnace and converters.
^Used to recover copper from furnace slag and converter slag.
SSince converters at flash furnace and Noranda furnace smelters treat high copper content matte,
converter particulate emissions from flash furnace smelters are expected -to be lower
than those from conventional smelter* with multiple hearth roasters, reverberatory furnace and
converters.
10/86
Metallurgical Industry
7.3-7
-------
TABLE 7.3-3. PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION FACTORS
FOR MULTIPLE HEARTH ROASTER AND REVERBERATORY SMELTER OPERATIONS3
EMISSION FACTOR RATING: D
Cumulative mass Z
< stated size
Cumulative emission factors
Particle
size"
(urn)
Uncontrolled
ESP
controlled
Uncontrolled
Kg/Mg
Ib/ton
ESP controlled0
Kg/Mg
Ib/ton
15
10
5
2.5
1.25
0.625
100
100
100
97
66
25
100
99
98
84
76
62
47
47
47
46
31
12
95
94
93
80
72
59
0.47
0.47
0.46
0.40
0.36
0.29
0.95
0.94
0.93
0.80
0.72
0.59
Total
100
100
47
95
0.47 0.95
aReference 25. Expressed as units/unit weight of concentrated ore processed
by the smelter.
^Expressed as aerodynamic equivalent diameter.
cNominal particulate removal efficiency is 99%.
50
•o
-------
TABLE 7.3-4.
PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION FACTORS
FOR REVERBERATORY SMELTER OPERATIONSA
EMISSION FACTOR RATING: E
Cumulative mass %
< stated size
Cumulative emission factors
Particle Uncontrolled ESP
size*5 (um) controlled
15
10
5
2,5
1.25
0.625
Total
NR
27
23
21
16
9
100
83
78
69
56
40
32
100
Uncontrolled
Kg/Mg
NR
6.8
5.8
5.3
4.0
2.3
25
Ib/ton
NR
13.6
11.6
10.6
8.0
4.6
50
ESP controlled0
Kg/Mg
0.21
0.20
0.18
0.14
0.10
0.08
0.25
Ib/ton
0.42
0.40
0.36
0.28
0.20
0.16
0.50
aReference 25. Expressed as units/unit weight of concentrated ore processed
by the smelter. NR = not reported because of excessive extrapolation.
^Expressed as aerodynamic equivalent diameter.
cNominal particulate removal efficiency is 99%.
0.24
0.20
0.16
0.12
0.08
0.04
0.625
1.25
10
15
2.5 5
Particle Size (um)
Figure 7.3-3. Size specific emission factors for
reverberatory smelting.
10/86
Metallurgical Industry
7.3-9
-------
TABLE 7.3-5.
PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION FACTORS
FOR COPPER CONVERTER OPERATIONS3
EMISSION FACTOR RATING: E
Cumulative mass %
< stated size
Cumulative emission factors
Particle Uncontrolled ESP
size^ (urn) controlled
15
10
5
2.5
1.25
0.625
Total
NR
59
32
12
3
1
100
100
99
72
56
42
30
100
Uncontrolled
Kg/Mg
NR
10.6
5.8
2.2
0.5
0.2
18
Ib/ton
NR
21.2
11.5
4.3
1.1
0.4
36
ESP controlled0
Kg/Mg
.0.18
0.17
0.13
0.10
0.08
0.05
0.18
Ib/ton
0.36
0.36
0.26
0.20
0.15
0.11
0.36
aReference 25. Expressed as units/unit weight of concentrated ore processed
by the smelter. NR = not reported because of excessive extrapolation.
^Expressed as aerodynamic equivalent diameter.
cNominal particulate removal efficiency is 99 %.
12.0 _
9.0
^ 6.0
o i —
*J O
U 1-
o
c u
3.0
0.0
I
0.20
-3 O
3
O
O -n
0-15 |£
o o
0.10 £,
0.05
0.625 1.25 2.50 6.0 10.0 15.0
Particle Size (urn)
Figure 7.3-4. Size specific emission factors for copper converting,
7.3-10
EMISSION FACTORS
10/86
-------
Fugitive emissions are generated during the discharge and transfer of
hot calcine from multiple hearth roasters, with negligible amounts possible
from the charging of these roasters. Fluid bed roasting, a closed loop opera-
tion, has negligible fugitive emissions.
Matte tapping and slag skimming operations are sources of fugitive
emissions from smelting furnaces. Fugitive emissions can also result from
charging of a smelting furnace or from leaks, depending upon the furnace type
and condition. A typical single matte tapping operation lasts from 5 to 10
minutes and a single slag skimming operation lasts from 10 to 20 minutes.
Tapping frequencies vary with furnace capacity and type. In an 8 hour shift,
matte is tapped 5 to 20 times, and slag is skimmed 10 to 25 times.
Each of the various stages of converter operation - the charging, blow-
ing, slag skimming, blister pouring, and holding - is a potential source of
fugitive emissions. During blowing, the converter mouth is in stack (i. e., a
close fitting primary hood is over the mouth to capture offgases). Fugitive
emissions escape from the hoods. During charging, skimming and pouring opera-
tions, the converter mouth is out of stack (i. e., the converter mouth is
rolled out of its vertical position, and the primary hood is isolated).
Fugitive emissions are discharged during rollout.
TABLE 7.3-6. FUGITIVE EMISSION FACTORS FOR PRIMARY COPPER SMELTERS3
EMISSION FACTOR RATING: B .
Source of emission
Roaster calcine discharge
Smelting furnace^3
Converter
Converter slag return
Anode furnace
Slag cleaning furnace0
Particulate
kg/Mg
1.3
0.2
2.2
NA
0.25
4
Ib/ton
2.6
0.4
4.4
• NA
0.5
8
S02
kg/Mg
0.5
2
65
0.05
0.05
3
Ib/ton
1
4
130
0.1
0.1
6
References 16,22,25-32. Expressed as mass units/unit weight of
concentrated ore processed by the smelter. Approximately 4 unit weights of
concentrate are required to produce 1 unit weight of copper metal. Factors
for flash furnace smelters and Noranda furnace smelters may be lower than
reported values. NA =* not available.
"Includes fugitive emissions from matte tapping and slag skimming operations,
About 50% of fugitive particulate emissions and about 90% of total S02 emis-
sions are from matte tapping operations, with remainder from slag skimming.
GUsed to treat slags from smelting furnaces and converters at the flash
furnace smelter.
10/86 Metallurgical Industry 7.3-11
-------
TABLE 7.3-7. UNCONTROLLED PARTICLE SIZE AND SIZE SPECIFIC EMISSION FACTORS
FOR FUGITIVE EMISSIONS FROM REVERBERATORY FURNACE MATTE TAPPING OPERATIONS3
EMISSION FACTOR RATING: D
Particle sizeb
Cumulative mass %
Cumulative emission factors
vum;
15
10
5
2.5
1.25
0.625
Total
\ s>LaLt:u »j.ie
76
74
72
69
67
65
100
kg/Mg
0.076
0.074
0.072
0.069
0.067
0.065
0.100
Ib/ton
0.152
0.148
0.144
0.138
0.134
0.130
0.200
aReference 25. Expressed as units/unit weight of concentrated ore
processed by the smelter.
^Expressed as aerodynamic equivalent diameter.
O)
•i o.oso
_ 0.075
01
£ 0.070
o
° 0.065
I
I
I
I
I
0.625 1.25 2.50 6.0 10.0 15.0
Particle size
Figure 7.3-5. Size specific fugitive emission factors for
reverberatory furnace matte tapping operations.
7.3-12
EMISSION FACTORS
10/86
-------
TABLE 7.3-8. PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION FACTORS
FOR FUGITIVE EMISSIONS FROM REVERBERATORY FURNACE SLAG TAPPING OPERATIONS3
EMISSION FACTOR RATING: D
Particle size*5
Cumulative mass
Cumulative emission factors
\, urn ) x a L. a i cu » A f. e
15 33
10 28
5 25
2.5 22
1.25 20
0.625 17
Total 100
kg/Mg
0.033
0.028
0.025
0.022
0.020
0.017
0.100
Ib/ton
0.066
0.056
0.050
0.044
0.040
0.034
0.200
aReference 25. Expressed as units/unit weight of concentrated ore
processed by the smelter.
"Expressed as aerodynamic equivalent diameter.
01 •
o
+J
o
Z!
en
3C
O
.w
-------
TABLE 7.3-9. PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION FACTORS
FOR FUGITIVE EMISSIONS FROM CONVERTER SLAG AND COPPER BLOW OPERATIONS3
EMISSION FACTOR RATING: D
Particle size*5
Cumulative mass %
Cumulative emission factors
\.umj
15
10
5
2.5
1.25
0.625
Total
S sLaueu sx^e
98
96
87
60
47
38
100
kg/Mg
2.2
2.1
1.9
1.3
1.0
0.8
2.2
Ib/ton
4.3
4.2
3.8
2.6
2.1
1.7
4.4
aReference 25. Expressed as units/unit weight of concentrated ore
processed by the smelter.
^Expressed as aerodynamic equivalent diameter.
2.5
2.0
-o
— !U
0 "~ I 5
<4-J f * - ^
u c
ra s-
1 Q
1 . U
0.5
I
I
I
I
I
0.625 1.25 2.50 6.0 10.0 15.0
Particle size (/jm)
Figure 7.3-7. Size specific fugitive-emission factors for
converter slag and copper blow operations.
7.3-14
EMISSION FACTORS
10/86
-------
At times during normal smelting operations, slag or blister copper can not
be transferred immediately from or to the converters. This condition, holding
stage, may occur for several reasons, including insufficient matte in the
smelting furnace, the unavailability of a crane, and others. Under these
conditions, the converter is rolled out of its vertical position and remains in
a holding position and fugitive emissions may result.
7.3.4 Lead Emissions
At primary copper smelters, both process emissions and fugitive particulate
from various pieces of equipment contain oxides of many inorganic elements,
including lead. The lead content of particulate emissions depends upon both
the lead content of the smelter feed and the process offgas temperature. Lead
emissions are effectively removed in particulate control systems operating at
low temperatures, about 120°C (250°F).
Table 7.3-10 presents process and fugitive lead emission factors for
various operations of primary copper smelters.
TABLE 7.3-10. LEAD EMISSION FACTORS FOR PRIMARY COPPER SMELTERSa
EMISSION FACTOR RATING: C
Operation
Roasting
Smelting
Converting
Refining
* • - • •
Emission
kg/Mg
0.075
0.036
0.13
NA
factor'3
Ib/ton
0.15
0'.072
0.27
NA
aReference 33. Expressed as units/unit weight of concentrated ore
processed by smelter. Approximately four unit weights of concentrate
are required to produce one unit weight of copper metal. Based on
test data for several smelters with 0.1 to 0.4 % lead in feed
throughput. NA = not available.
kpor process and fugitive emissions totals.
cBased on test data on multihearth roasters. Includes total of
process emissions and calcine transfer fugutive emissions. The
latter are about 10% of total process and fugitive emissions.
CBased on test data on reverberatory furnaces. Includes total
process emissions and fugitive emissions from matte tapping and
slag skimming operations. Fugitive emissions from matte tapping
and slag skimming operations amount to about 35% and 2%, respectively.
elncludes total of process and fugitive emissions. Fugitives
constitute about 50% of total.
10/86 Metallurgical Industry 7.3-15
-------
Fugitive emissions from primary copper smelters are captured by applying
either local ventilation or general ventilation techniques. Once captured,
emissions may be vented directly to a collection device or be combined with
process offgases before collection. Close fitting exhaust hood capture systems
are used for multiple hearth roasters and hood ventilation, systems for smelt
matte tapping and slag skimming operations. For converters, secondary hood
systems or building evacuation systems are used.
References for Section 7.3
1. Background Information for New Source Performance Standards: Primary
Copper, Zinc and Lead Smelters, Volume I, Proposed Standards, EPA-450/2-
74-002a, U. S. Environmental Protection Agency, Research Triangle Park,
NC, October 1974.
2. Arsenic Emissions from Primary Copper Smelters - Background Information
for Proposed Standards, Preliminary Draft, EPA Contract No. 68-02-3060,
Pacific Environmental Services, Durham, NC, February 1981.
3. Background Information Document for Revision of New Source Performance
Standards for Primary Copper Smelters, EPA Contract No. 68-02-3056,
Research Triangle Institute, Research Triangle Park, NC, March 31, 1982.
4. Air Pollution Emission Test: Asarco Copper Smelter, El Paso, TX,
EMB-77-CUS-6, Office Of Air Quality Planning And Standards, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1977.
5. Written communications from W. F. Cummins, Inci, El Paso, TX, to A. E.
Vervaert, U. S. Environmental Protection Agency, Research Triangle Park,
NC, June 1977.
6. AP-42 Background Files, Office Of Air Quality Planning And Standards,
LI. S. Environmental Protection Agency, Research Triangle Park, NC, March
1978.
7. Source Emissions Survey of Kennecott Copper Corporation, Copper Smelter
Converter Stack Inlet'and Outlet and Reverberatory Electrostatic Precipi-
tator Inlet and Outlet, Hurley, NM, EA-735-09, Ecology Audits, Inc.,
Dallas, TX, April 1973.
8. Trace Element Study at a Primary Copper Smelter, EPA-600/2-78-065a and
065b, U. S. Environmental Protection Agency, Research Triangle Park, NC,
March 1978.
9. Systems Study for Control of Emissions, Primary Nonferrous Smelting
Industry, Volume II; Appendices A and B, PB 184885, National Technical
Information Service, Springfield, VA, June 1969.
10. Design and Operating Parameters for Emission Control Studies; White Pine
Copper Smelter, EPA-600/2-76-036a, U. S. Environmental Protection Agency,
Washington, DC, February 1976.
7.3-16 EMISSION FACTORS 10/86
-------
11. R. M. Statnick, Measurements of Sulfur Dioxide, Particulate and Trace
Elements in Copper Smelter Converter and Roaster/Reverberatory Gas Streams,
PB 238095, National Technical Information Service, Springfield,VA, October
1974.
12. AP-42 Background Files, Office Of Air Quality Planning And Standards, U. S.
Environmental Protection Agency, Research Triangle Park, NC.
13. Design and Operating Parameters for Emission Control Studies, Kennecott-
McGill Copper Smelter, EPA-600/2-76-036c, U. S. Environmental Protection
Agency, Washington, DC, February 1976.
14. Emission Test Report (Acid Plant) of Phelps Dodge Copper Smelter, Ajo, AZ,
EMB-78-CUS-11, Office Of Air Quality Planning And Standards, Research
Triangle Park, NC, March 1979.
15. S. Dayton, "Inspiration's Design for Clean Air", Engineering and Mining
Journal, 175:6, June 1974.
16. Emission Testing of Asarco Copper Smelter, Tacoma, WA, EMB-78-CUS-12,
Office Of Air Quality Planning And Standards, U. S. Environmental Protec-
tion Agency, Research Triangle Park, NC, April 1979.
17. Written communication from A. L. Labbe, Asarco,. Inc., Tacoma, WA, to S. T.
Cuffe, U. S. Environmental Protection Agency, Research Triangle Park, NC,
November 20, 1978.
18. Design and Operating Parameters for Emission Control Studies; Asarco-'Hayden
.Copper Smelter, EPA-600/2-76-036J, U. S. Environmental Protection Agency,
Washington, DC, February 1976.
19. Design and Operating Parameters for Emission Control Studies: Kennecott,
Hayden Copper Smelter, EPA-600/2-76-036b, U. S. Environmental Protection
Agency, Washington, DC, February 1976.
20. R. Larkin, Arsenic Emissions at Kennecott Copper Corporation, Hayden, AZ,
EPA-76-NFS-1, U. S. Environmental Protection Agency, Research Triangle
Park, NC, May 1977.
21. Emission Compliance Status, Inspiration Consolidated Copper Company,
Inspiration, AZ, U. S. Environmental Protection Agency, San Francisco, CA,
1980.
22. Written communication from M. P. Scanlon, Phelps Dodge Corporation,
Hidalgo, AZ, to D. R. Goodwin, U. S. Environraenal Protection Agency,
Research Triangle Park, NC, October 18, 1978.
23. Written communication from G. M. McArthur, The Anaconda Company, to D. R.
Goodwin, U. S. Environmental Protection Agency, Research Triangle Park,
NC, June 2, 1977.
24.. Telephone communication from V. Katari, Pacific Environmental Services,
Durham, NC, to R. Winslow, Hidalgo Smelter, Phelps Dodge Corporation,
Hidalgo, AZ, April 1, 1982.
LO/86 Metallurgical Industry 7.3-17
-------
25. Inhalable Partlculate Source Category Report for the Nonferrous Industry,
Contract 68-02-3159, Acurex Corp., Mountain View, CA, August 1986.
26. Emission Test Report, Phelps Dodge Copper Smelter, Douglas, AZ, EMB-78-
CUS-8, Office Of Air Quality Planning And Standards, U. S. Environmental
Protection Agency, Research Triangle Park, NC, February 1979.
27. Emission Testing of Kennecott Copper Smelter, Magna, UT, EMB-78-CUS-13,
Office Of Air Quality Planning And Standards, U. S. Environmental Protec-
tion Agency, Research Triangle Park, NC, April 1979.
28. Emission Test Report, Phelps Dodge Copper Smelter, Ajo, AZ, EMB-78-CUS-9,
Office Of Air Quality Planning And Standards, U. S. Environmental Protec-
tion Agency, Research Triangle Park, NC, February 1979.
29. Written communication from R. D. Putnam, Asarco, Inc., co M. 0. Varner,
Asarco, Inc., Salt Lake City, UT, May 12, 1980.
30. Emission Test Report, Phelps Dodge Copper Smelter, Playas, NM, EMB-78-
CUS-10, Office Of Air Quality Planning And Standards, U. S. Environmental
Protection Agency, Research Triangle Park, NC, March 1979.
31. Asarco Copper Smelter, El Paso, TX. EMB-78-CUS-7, Office Of Air Quality
Planning And Standards, U. S. Environmental Protection Agency, Research
Triangle Park, NC, April 25, 1978.
32. A. D. Church, et al., "Measurement of Fugitive Particulate and Sulfur
Dioxide Emissions at Inco's Copper Cliff Smelter", Paper A-79-51, The
Metallurgical Society, American Institute of Mining, Metallurgical and
Petroleum Engineers (AIME), New York, NY.
33. Copper Smelters, Emission Test Report - Lead Emissions, EMB-79-CUS-14,
Office Of Air Quality Planning And Standards, Q. S. Environmental Protec-
tion Agency, Research Triangle Park, NC, September 1979.
7.3-18 EMISSION FACTORS 10/86
-------
7.4 FERROALLY PRODUCTION
7.4.1 General
A ferroalloy is an alloy of iron and one or more other elements, such as
silicon, manganese or chromium. Ferroalloys are used as additives to impart
unique properties to steel and cast iron. The iron and steel industry consumes
approximately 95 percent of the ferroalloy produced in the United States. The
remaining 5 percent is used in the production of nonferrous alloys, including
cast aluminum, nickel/cobalt base alloys, titanium-alloys, and in making other
ferroalloys.
Three major groups, ferrosilicon, ferroraanganese, and ferrochrorae, con-
stitute approximately 85 percent of domestic production. Subgroups of these
alloys Include siliconmanganese, sil'iqon metal and ferrochroraium. The variety
of grades manufactured is distinguished primarily by carbon, silicon or aluminum
content. The remaining 15 percent of ferroalloy production is specialty alloys,
typically produced in small amounts and containing elements such as vanadium,
columbium, molybdenum, nickel, boron, aluminum and tungsten.
Ferroalloy facilities in the United States vary greatly in size. Many
facilities have only one furnace and require less than 25 megawatts. Othjers
consist of 16 furnaces, produce six different types of ferroalloys, and require
over 75 megawatts of electricity.'
A typical ferroalloy plant is illustrated in Figure 7.4-1. A variety of
furnace types produces ferroalloys, including submerged electric arc furnaces,
induction furnaces, vacuum furnaces, exothermic reaction furnaces and elec-
trolytic cells. Furnace descriptions and their ferroalloy products are given
in Table 7.4-1. Ninety-five percent of all ferroalloys, including all bulk
ferroalloys, are produced in submerged electric arc furnaces, and it is the
furnace type principally discussed here.
The basic design of submerged electric arc furnaces is generally the same
throughout the ferroalloy industry in the United States. The submerged elec-
tric arc furnace comprises a cylindrical steel shell with a flat bottom or
hearth. The interior of the shell is lined with two or more layers of carbon
blocks. Raw materials are charged through feed chutes from above the furnace.
The molten metal and slag are removed through one or more tapholes extending
through the furnace shell at the hearth level. Three carbon electrodes,
arranged in a delta formation, extend downward through the charge material to
a depth of 3 to 5 feet to melt the charge.
Submerged electric arc furnaces are of two basic types, open and covered.
About 80 percent of submerged electric arc furnaces in the United States are of
the open type. Open furnaces have a fume collection hood at least one meter
above the top of the furnace. Moveable panels or screens sometimes are used to
reduce the open area between the furnace and hood to improve emissions capture
10/86 Metallurgical Industry 7.4-1
-------
I
N)
OUST
OUST OUST
en
CO
o
z
i.
OUST
OUST
.3L ifc ,!_.-
UNLOADING STORAGE
CRUSHING WEIGH-FEEDING
SMELTING TAPPING CASTING
OUST
CRUSHING STORAGE
SCREENING
SHIPMENT
Figure 7.A-1. Typical ferroalloy production process, showing emission points.
O
CO
-------
TABLE 7.4-1. FERROALLOY PROCESSES AND RESPECTIVE PRODUCT GROUPS
Process
Product
Submerged arc furnace3
Exothermic13
Silicon reduction
Aluminum reduction
Mixed aluminothermal/
silicothermal
Electrolytic0
Vacuum furnace**
Induction furnace6
Silvery iron (15 - 22% Si)
Ferrosilicon (507. Si)
Ferrosilicon (65 - 75% Si)
Silicon metal
Silicon/manganese/zirconium (SMZ)
High carbon (HC) ferroraanganese
Siliconmanganese
HC ferrochrorae
Ferrochrome/silicon
FeSi (90% Si)
Low carbon (LC) ferrochrorae, LC
ferroraanganese, Medium carbon (MC)
ferroraanganese
Chromium metal, FerrotItanium,
Ferrocolumbium, Ferrovanadium
Ferroraolybdenum, Ferrotungsten
Chromium metal, Manganese metal
LC ferrochrorae
Ferrotitanium
aProcess by which metal Is smelted in a refractory lined cup shaped steel
shell by three submerged graphite electrodes.
^Process by which molten charge material is reduced, in exthertnic reaction,
by addition of silicon, aluminum or combination of the two.
cProcess by which simple ions of a metal, usually chromium or manganese
in an electrolyte, are plated on cathodes by direct low voltage current.
dProcess by which carbon is removed from solid state high carbon
ferrochrorae within vacuum furnaces maintained at temperature near melting
point of alloy.
eProcess which converts electrical energy without electrodes into heat,
without electrodes, to melt metal charge in a cup or drum shaped vessel.
10/86
Metallurgical Industry
7.4-3
-------
efficiency. Covered furnaces have a water cooled steel cover to seal the top,
with holes through it for the electrodes. The degree of emission containment
provided by the covers is quite variable. Air infiltration sometimes is reduced
by placing charge material around the electrode holes. This type is called a
mix seal or semienclosed furnace. Another type is a sealed or totally closed
furnace having mechanical seals around the electrodes and a sealing compound
packed around the cover edges.
The submerged arc process is a reduction smelting operation. The reactants
consist of metallic ores and quartz (ferrous oxides, silicon oxides, manganese
oxides, chrome oxides, etc.). Carbon, usually as coke, low volatility coal or
wood chips, is charged to the furnace as a reducing agent. Limestone also may
be added as a flux material. After crushing, sizing, and in some cases, dry-
ing, the raw materials are conveyed to a mix house for weighing and blending,
thence by conveyors, buckets, skip hoists, or cars to hoppers above the furnace.
The mix is then fed by gravity through a feed chute either continuously or
intermittently, as needed. At high temperatures in the reaction zone the car-
bon sources react chemically with oxygen in the metal oxides to form carbon mon-
oxide and to reduce the ores to base metal. A typical reaction, illustrating 50
percent ferrosilicon production, is:
Fe203 + 2 Si02 + 7C -»• 2 FeSi + 7CO.
Smelting in an electric arc furnace is accomplished by conversion of
electrical energy to heat. An alternating current applied to the electrodes
causes a current flow through the charge between the electrode tips. This
provides a reaction zone of temperatures up to 2000°C (3632°F). The tip of
each electrode changes polarity continuously as the alternating current flows
between the tips. To maintain a uniform electric .load, electrode depth is con-
tinuously varied automatically by mechanical or hydraulic means, as required.
Furnace power requirements vary from 7 megawatts to over 50 megawatts, depending
upon the furnace size and the product being made. The average is 17.2 mega-
watts^. Electrical requirements for the most common ferroalloys are given in
Table 7.4-2.
TABLE 7.4-2. FURNACE POWER REQUIREMENTS FOR DIFFERENT FERROALLOYS
Product
50% FeSl
Silicon metal
High carbon FeMn
High carbon FeCr
SiMn
Furnace load
(kw-hr/lb alloy produced)
Range
2.4 - 2.5
6.0 - 8.0
1.0 - 1.2
2.0 - 2.2
2.0 - 2.3
Approximate
average
2.5
7.0
1.2
2.1
2.2
7.4-4
EMISSION FACTORS
10/86
-------
The molten alloy and slag that accumulate on the furnce hearth are removed
at 1 to 5 hour Intervals through the taphole. Tapping typically lasts 10 to 15
minutes. Tapholes are opened with a pellet shot from a gun, by drilling or by
oxygen lancing. The molten metal and slag flow from the taphole into a carbon
lined trough, then into a carbon lined runner which directs the metal and slag
into a reaction ladle, ingot molds, or chills. Chills are low flat Iron or
steel pans that provide rapid cooling of the molten metal. Tapping is termin-
ated and the furnace resealed by inserting a carbon paste plug Into the taphole.
When chemistry adjustments after furnace smelting are necessary to produce
a specified product, a reaction ladle is used. Ladle treatment reactions are
batch processes and may include chlorination, oxidation, gas mixing, and slag-
metal reactions.
During tapping, and/or in the reaction ladle, slag is skimmed from the
surface of the molten metal. It can be disposed of in landfills, sold as road
ballast, or used as a raw material in a furnace or reaction ladle to produce a
chemically related ferroalloy product.
After cooling and solidifying, the large ferroalloy castings are broken
with drop weights or hammers. The broken ferroalloy pieces are then crushed,
screened (sized) and stored in bins until shipment.
7.4.2 Emissions And Controls
Particulate is generated from several activities, at a ferroalloy facility,
including raw material handling, smelting and product handling. The furnaces
are the largest potential sources of particulate emissions.• The emission fac-
tors in Tables 7.4-3 and 7.4-4 and the particle size information in Figures
7.4-2 through 7.4-11 reflect controlled and uncontrolled emissions from ferro-
alloy smelting furnaces. Emission factors for sulfur dioxide, carbon monoxide
and organic emissions are presented in Table 7.4-5.
Electric arc furnaces emit particulate in the form of fume, accounting for
an estimated 94 percent of the particulate emissions in the ferroalloy industry.
Large amounts of carbon monoxide and organic materials also are emitted by sub-
merged electric arc furnaces. Carbon monoxide is formed as a byproduct of the
chemical reaction between oxygen in the metal oxides of the. charge and carbon
contained in the reducing agent (coke, coal, etc.). Reduction gases containing
organic compounds and carbon monoxide continuously rise from the high temper-
ature reaction zone, entraining fine particles and fume precursors. The mass
weight of carbon monoxide produced sometimes exceeds that of the metallic
product (see Table 7.4-5). The chemical constituents of the heat induced fume
consist of oxides of the products being produced, carbon from the reducing
agent, and enrichment by SK^, CaO and MgO, if present in the charged*
In an open electric arc furnace, all carbon monoxide burns with induced
air at the furnace top. The remaining fume, captured by hooding about 1 meter
above the furnace, is directed to a gas cleaning device. Baghouses are used to
control emissions from 85 percent of the open furnaces in the United States.
10/86 Metallurgical Industry 7.4-5
-------
TABLE 7.A-3. EMISSION FACTORS FOR PARTICIPATE FROM SUBMERGED ARC FERROALLOY FURNACES3
m
3;
w
CO
h- 4
O
•z
^
H
O
CO
Product1*
PeSI (501)
PtSI (75Z)
PeSI (901)
SI BCtal (981)
PeMn (801)
PeHn (II SI)
PeCr (high
carbon)
Slhn
Furnace
type
Open
Covered
Open
Covered
Open
Open
Open
Covered
Sealed
Open
Open
Sealed
Paniculate ealialon factort
Uncontrolled'
kg/Mg (Ib/lon)
alloy
15 (70)
46 (92)
158 (116)
10) (206)
202 (564)
4)6 (872)
14. (28)
6 (12)
17 (74)
78 (157)
96 (192)
(-)
kg (lb)/M*-hr
7.4 (16.1)
9.1 (20.5)
16 (15)
11 (29)
24 (51)
11 (71)
4.8 (II)
: 2.4 (5.1)
'17 (17)
15 (11)
2n (44)
(-)
SUe
data
tea
Yea
ten
Yea
Yes
Yea
Not en
e.f.g
h
k
h.J
.
n.P
q.r
h.t
u.v
«.y
i.aa
bleelon
factor
la ting
B
E
I
e
e
• B
B
e
. c
c
c
Control device^
Baghouee
Scrubber
High energy
Low energy
Scrubber
Low energy
Baghouae
Baghouae
Scrubber
High energy
High energy
ESP
Scrubber
Scrubber
High energy
Paniculate ralttlcn (actora
Controlled'
kg/Hg (Ih/lon)
alloy
0.9 (1.8)
0.24 (0.48)
4.5 (9.0)
4.0 (8.0)
16 (12)
0.24 (0.48)
0.8 (1.6)
0.25 (0.5)
1.2 (2.1)
2.1 (4.2)
0.15 (0.10)
kg (Ib)/Mw~hr
0.2 (0.4)
0.05 (O.I)
0.77 (1.7)
0.5 (I.I)
1.2 (2.6)
0.078 (0.2)
0.14 (0.7)
0.10 (0.2)
0.2) (0.})
0.44 (1.0)
0.016 (0.04)
SUe
data
Yet
Tet
Tea
Tet
Tet
Motet
• .<
h.J
h.J
h.J
n.P
-------
^j TABLE 7.4-3 (Cont.). NOTES
aFactors are for main furnace dust collection system before and after control device. Where other emissions,
such as leaks or tapping, are Included or quantified separately, such is noted. Participate sources not
Included: raw material handling, storage, preparation; and product crushing, screening, handling, packaging.
^Percentages are of the main alloying element In product.
cln most source testing, fugitive emissions not measured or collected. Where tapping emissions are
controlled by primary system, their contribution to total emissions could not be determined. Fugitive
emissions may vary greatly among sources, with furnace and collection system design and operating practices.
dLow energy scrubbers are those with A P <20 in. H20; high energy, with A P >20 In. H20.
elncludes fumes captured by tapping hood (efficiency estimated near 100Z).
fReferences 4, 10, 21.
^Factor is average of 3 sources, fugitive emissions not Included. Fugitive emissions at one source
measured an additional 10.5 kg/Mg alloy, or 2.7 kg/Mw hr.
n? "References 4, 10.
£ Jooes not Include emissions from tapping or mix seal-leaks.
£ ^References 25-26.
c ""Reference 23.
Included In factor).
£L PReferences 10, 13.
,_, ^Estimated 50Z of tapping emissions captured by control system (escaped fugitive emissions not
g_ Included in factor).
c ""References 4, 10, 12.
n 8Includes fume only from primary control system.
3 Includes tapping fumes and mix seal leak fugitive emissions. Fugitive emissions measured at 33Z of total
uncontrolled emissions.
"Assumes tapping fumes not Included In emission factor.
"Reference 14. Dash • No data.
"Does not Include tapping or fugitive emissions.
xTapping emissions included. Factor developed from two test series performed on the same furnace 7
years apart. Measured emissions In latter test were 36Z less than In former.
/References 2, 15-17.
'Factor is average of two test series. Tests at one source Included fugitive emissions (3.4Z of total
uncontrolled emissions). Second test Insufficient to determine if fugitive emissions were included
in total.
"References 2, 18-19.
Factors developed from two scrubber controlled sources, one operated at A P - 47-57" H20, the other at
unspecified A P. Uncontrolled tapping operations emissions are 2.1 kg/Mg alloy.
T
-------
TABLE 7.4-4. SIZE SPECIFIC MISSION FACTORS FOR SUBMEKfiEl) ARC FERROALLOY FURNACES
•o
00
rn
O
z
O
H
O
O
>^
CO
Product
50% FeSl
Open furnace
1
80% FeMn
Open furnace
Cont rol
device
None^ »c
Baghuuse
Nonee»*
Particle size3
(urn)
0.63
\ 1.00
1.25
2.50
6.00
10.00
15.00
20.00
d
0.63
1.00
1.25
2.50
6.00
10.00
15.00
20.00
0.63
1.00
1.25
2.50
6.00
10.00
15.00
20.00
d
Cumulative mass 7,
< stated size
45
50
53
57
61
63
66
69
100
31
39
44
54
63
72
80
85
100
30
46
52
62
72
86
96
97
100
Cumulative mass
emission factor
kg/Mg (Ib/ton)
alloy
16 (32)
18 (35)
19 (37)
20 (40)
21 (43)
22 (44)
23 (46)
24 (48)
35 (70)
0.28 (0.56)
0.35 (0.70)
0.40 (0.80)
0.49 (1.0)
0.57 (1.1)
0.65 (1.3)
0.72 (1.4)
0.77 (1.5)
0.90 (1.8)
4 (8)
7 (13)
8 (15)
9 (17)
10 (20)
12 (24)
13 (26)
14 (27)
14 (28)
Emission Factor
Rating
B
B
B
(cont1nued)
-------
TABLE 7.4-4 (cont.)
00
o\
SC
n
n
ft)
C
i-l
00
H-
n
ft)
Q-
c
CA
Product
80% FeMn
Open furnace
Si Metalh
Open furnace
Control
device
Baghouse6
NoneS
Baghouse
Particle size8
(pm)
0.63
1.00
1.25
2.50
6.00
10.00
15.00
20.00
d
0.63
1.00
1.25
2.50
6.00
10.00
15.00
20.00
d
1.00
. 1.25
2.50
6.00
10.00
15.00
20.00
Cumulative mass%
< stated size
20
30
35
49
67
83
92
97
100
57
67
70
.75
80
86
91
95
100
49
53
64
76
87
96
99
100
Cumulative mass
emission factor
kg/Mg (Ib/ton)
alloy
0.048 (0.10)
0.070 (0.14)
0.085 (0.17)
0.120 (0.24)
0.160 (0.32)
. 0.200 (0.40)
0.220 (0.44)
0.235 (0.47)
0.240 (0.48
249 (497)
292 (584)
305 (610)
327 (654)
349 (698)
375 (750)
397 (794)
414 (828)
436 (872)
7.8 (15.7)
8.5 (17.0)
10.2 (20.5)
12.2 (24.3)
13.9 (28.0)
15.4 (31.0)
15.8 (31.7)
16.0 (32.0)
Emission Factor
Rating
B
B
B
(continued)
-------
TABLE 7.4-4 (cont.)
I
o
c/i
o
z
n
H
o
5»
to
Product
FeCr (HC)
Open furnace
SiMn
Open furnace
Control
device
Noneh » J
ESP
Noneb»m
Particle size3
(urn)
0.5
1.0
2.0
2.5
4.0
6.0
10.0
d
0.5
1.0
2.5
5.0
6.0
10.0
d
0.5
- 1.0
2.0
2.5
4.0
6.0
10.0
. d
Cumulative mass%
< stated size
19
36
60
63k
76
88k
91
100
33
47
67
80
86
90
100
28
44
60
65
76
85
96k
100
Cumulative mass
emission factor
kg/Mg (Ib/ton)
alloy
15 (30)
28 (57)
47 (94)
49 (99)
59 (119)
67 (138)
71 (143)
78 (157)
0.40 (0.76)
0.56 (1.08)
0.80 (1.54)
0.96 (1.84)
1.03 (1.98)
1.08 (2.07)
1.2 (2.3)
27 (54)
42 (84)
58 (115)
62 (125)
73 (146)
82 (163)
92k (177)k
96 (192)
Emission Factor
Rating
C
C
C
(contlnued)
co
ON
-------
TABLE 7.4-4 (cont.)
00
o>
n>
n
B>
o
P
a
c
Product
SiMn
Open furnace
(cont.)
Control
d ev 1 c e
Sc rub-
ber" »n
Particle size3
(Aim)
0.5
1.0
2.5
5.0
6.0
10.0
Cumulative mass%
< stated size
56
80
96
99
99.5
99. 9k .
100
Cumulative mass
emission factor
kg/Mg (Ib/ton)
alloy
1.18 (2.36)
1.68 (3.44)
2.02 (4.13)
2.08 (4.26)
2.09 (4.28)
2.10k (4.30)k
2.1 (4.3)
Emission Factor
Rating
C
aAerodynamic diameter, based on Task Group On Lung Dynamics definition.
Particle density = 1 g/cm^.
bIncludes tapping emissions.
References 4, 10, 21.
^Total particulate, based on Method 5 total catch (see Table 7.4-3).
elncludes tapping fume (capture efficiency 50%).
^References 4, 10, 12.
^Includes tapping fume (estimated capture efficiency 60%).
^References 10, 13.
jReferences 1, 15-17.
^Interpolated data.
"References 2, 18-19.
"Primary emission control system only, without tapping emissions.
-------
^^
99.950
99.90
99.60
99.50
99
98
95
UJ
M
en ^
0
UJ SO
£ 70
CO
v 60
z 50
^
o 40
-------
yy.aaup
99.950
99.90
99.80 •
TOTAL PARTICULATE Kg PARTICULATE
- EMISSION RATE Mg ALLQY
99.50-
99h
98-
95
UJ
M
» 90
o
£ 80
»- 70
en
v 60
£ 50
o 40
§ 30
UJ 20
;
- ./ '--
i- ^^"^ -
\
< toL-
5 5
u
2
1
0.5
0.2
0.15
O.I
0.0
l(
-
-
-
-
:
iii iiiiiii i i iiiiiii i i iiiiii
UJ
M
O
1-
0.77 W
O.72 V
0.65 UJ
0.57 5
0.49 _1
0.40 g
0.35 ^
0.28 o:
<
a.
. o»
j«
UJ
>
H
5
=
O
O
_)
_l
<
5
}"' 10° 10 ' I02
PARTICLE DIAMETER, micrometers
Figure 7.4-3 Controlled (baghouse), 50% FeSi, open furnace particle
size distribution
10/86
Metallurgical Industry
7.4-13
-------
99.990
99.950
99.90
99.80
99.50
99
98
M
in
o
u
t/5
z
UJ
u
a:
UJ
a,
UJ
TOTAL PARTICIPATE kg PARTlCULATE
- EMISSION RATE
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
O.I
0.0
10
Mg ALLOY
I I I I I 11
.0° , .o1
PARTICLE DIAMETER, micrometers
14
3
12
O
9
8
7
UJ
M
(fl
O
UJ
co
V
UJ
o»
UJ
>
13
O
Figure 7.4-4,
Uncontrolled, 80% FeMn producing, open furnace particle
size distribution
7.4-14
EMISSION FACTORS'
10/86
-------
99.990
99.950
99.90
99.80
99.50
99
98-
UJ
V)
0
UJ
UJ
o
IT
UJ
a.
UJ
TOTAL PARTICIPATE _- ~Ankg PARTICIPATE
EMISSION RATE '° ^ Mg ALLOY
95
90
2
I
0.5
0.2
0.15
O.I
0.0
10
...I
0.235
0.220
.
O.2OO
0.160
0.120
0.085
O.07O
UJ
M
a
u
V
UJ
i-
<
_i
z>
o
O.O48 "o.
>
o
o>
I I I I I I
o»
UJ
O
10° 10 ' IOJ
PARTICLE DIAMETER, micrometers
Figure 7.4-5. Controlled (baghouse), 80% FeMn producing, open furnace
size distribution
10/86
Metallurgical Industry
7.4-15
-------
UJ
99.9901—
99.9501-
99.90
99.80
99.50
99
98-
95
9O
TOTAL PARTICULATE
EMISSION RATE
a
UJ
\-
Crt
v
»-
z
£'
0.
kg PARTICULATE
Mg ALLOY
80
70
60
50
30
2O
10
:
2
I
0.5
0.2
0.15
O.I
i iiiiiil i i iiii ill
414
397
375
349
327
3O5
292
249
UJ
N
I-
<
V
UJ
K
<
_l
Z)
O
)-
cc
<
UJ
•O'1 .0° ,0' ,0J
PARTICLE DIAMETER, micrometers
Figure 7.4-6. Uncontrolled, Si metal producing, open furnace
particle size distribution
7.4-16
EMISSION FACTORS
10/86
-------
99.990
99.930
99.90
99.80
99.50
99
98
Id
10
a
UJ
C/l
V
H
Z
UJ
o
P
13
U
TOTAL PARTICULATE
- EMISSION RATE
" lb'U
kg PARTICULATE
MgALLOY
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
O.I
0.0
5.8
5.4
3.9
2.2
0.2
8.5
7. 8
UJ
M
en
a
UJ
V
UJ
i-
<
_i
=>
o
<
Q.
UJ
10
10 10 IO
PARTICLE DIAMETER, micrometers
Figure 7.4-7. Controlled (baghouse), Si metal producing, open
furnace particle size distribution
10/86
Metallurgical Industry
7.4-17
-------
99.990
99.950
99.90
99.80
99.50
99
98
UJ
M
cn
o
UJ
z
UJ
o
a:
UJ
a.
UJ
13
5
TOTAL PARTICIPATE .70 kg PARTICIPATE
r EMISSION RATE
Mg ALLOY
95
90
80
70
60
50
40
30
20
10
5
0.5
0.2
0.15
O.I
0.0
10
71
59
47
28
15
.0° 10'
PARTICLE DIAMETER, micrometers
ui
M
CO
a
UJ
co
V
UJ
>
o
o»
o»
UJ
>
Z)
o
Figure 7.4-8. Uncontrolled, FeCr producing, open furnace particle
size distribution
7.4-18
EMISSION FACTORS
10/86
-------
99.950
99.90
99.80
99.50
99
98
uj
N
UJ
O
UJ
a.
UJ
<
_i
2
o
TOTAL PARTICULATE
EMISSION RATE
= 1
Kg PARTICULATE
MgALLOY
95
80
70
60
50
40
30
10
5
2
I
0.5
0.2
0.15
O.I
0.0
10
•' .0° .o1
PARTICLE DIAMETER, micrometers
-
1-08
0.96
0-80
0-56
0.40
10'
ui
M
O
UI
cr
<
0»
UI
o»
o
Figure 7.4-9. Controlled (ESP), FeCr (HC) producing, open furnace
particle size distribution
10/86
Metallurgical Industry
7.4-19
-------
99.99O
99.950
99.90
99.80
99.50
99
98
95
UJ
£ 9°
o
* 80
>- 70
CO
v 60
z SO
UJ
o 40
£ 30
u 20
>
^_
< 10
2 5
o
2
I
0.5
0.2
0. 4
.15
O.I
On
TOTAL PARTICULATE _QR kg PARTICULATE
EMISSION RATE Mg ALLQY
/-
-
_
_
-
v
—
-
-
-
_
*
-
iii i i i i i i i i i i i i i i 1 1 i i i i t i 1 1
UJ
M
in
Q
UJ
92 5
tn
73 \/
58 W
»-
<
42 ^
O
27 £
<
Q.
o>
JC
UJ
>
jl
5
2
^
0
>
O
_J
_l
<
5
10"' 10° 10 ' io2
PARTICLE DIAMETER, micrometers
Figure 7.4-10. Uncontrolled, SiMn producing, open furnace
particle size distribution
7.4-20 •
EMISSION FACTORS
10/86
-------
99.990 r
99.9SO
99.90
99.80
99.5o[-
99 h
98
95
90
80
70
60
50
40
30
20
10
LU
O
UJ
<
CO
V
H
Z
UJ
u
Figure 7.4-11. Controlled (scrubber) , SiMn producing, open furnace
particle size distribution
10/86
Metallurgical Industry
7.4-21
-------
NJ
N)
TABLE 7.4-5. EMISSION FACTORS FOR SULFUR DIOXIDE, CARBON MONOXIDE, LEAD
AND VOLATILE ORGANICS FROM SUBMERGED ARC FERROALLOY FURNACES3
CO
M
o
as
H
I
EMISSION FACTOR RATING: D
LEAD: C
Product
FeSl - 50Z
PeSl - 75Z
SI Metal - 98Z
FeMn - 80Z
PeCr (HC)
PeCr-Sl
SIMn
Furnace
type
Open
Covered
Open
Covered
Open
Open
Covered
Sealed
Open
Open
Open
Sealed
so2b
(Ib/ton)
-
-
-
0.010"
5.4h«J
0.070e>k
0.021e»k
coc,d,e
(Ib/ton)
2180
3230
-
1690
Lead*
kg/Mg (Ib/ton)
0.15 (0.29)
0.001S (0.0031)
0.0015 (0.0031)
0.06 (0.11)
0.17 (0.34)
0.04 (0.08)
0.0029 (0.0057)
Volatile Organic Compounds
Uncont rol led**'6
kg/Mg (Ib/ton)
2.25 (4.5)
6.35 (12.7)
10.25 (20.5)
35.90 (71.8)
3.05 (6.1)
0.70 (1.4)
-
Controlled^
kg/Mg (Ib/ton)
2.2 (4.4)
0.28 (0.56)
0.75 (1.5)
2.4 (4.8)
25.9 (51.6)
1.85 (3.7)
0.70 (1.4)
0.40 (0.8)
0.05 (0.10)
Control
device
Baghouse
Scrubber
High energy
Low energy
Scrubber
Baghouse
Baghouse
High energy scrubber
Scrubber
High energy scrubber
o
CJ
•Expressed as weight/unit weight of specified product (alloy). Dash - No data.
^References 14-15, 17, 19, 30. Emissions depend on amount .of sulfur In feed material.
cReferences 4, 14. Measured before control by flare. CO cmlsslonB from open furnaces are low. Quantity
froa covered furnaces will vary with volume of air drawn Into cover. Increased air will reduce CO emissions.
^References 4, 10, 12-15, 17, 19, 21. May Increase If furnace feed Is dirty scrap Iron or Hleel.
eDoes not Include seal leqks or tapping emissions. Open furnace hoods may capture some tapping emissions.
References 2, 20, 27-29.
(^Measured before any flare In the control system.
"Uncontrolled.
J Includes tapping emissions.
''Scrubber outlet.
-------
Scrubbers are used on 13 percent of the furnaces, and electrostatic precipita-
tors on 2 percent. Control efficiences for well designed and operated control
systems [i. e., baghouses with air to cloth ratios of 1:1 to 2:1 ft^/ft^, and
and scrubbers with a pressure drop from 14 to 24 kilopascals (kPa) (55 to 96
inches H20)], have been reported to be in excess of 99 percent. Air to cloth
ratio is the ratio of the volumetric air flow through the filter media to the
media area.
Two emission capture systems, not usually connected to the same gas clean-
ing device, are necessary for covered furnaces. A primary capture system with-
draws gases from beneath the furnace cover. A secondary system captures fume
released around the electrode seals and during tapping. Scrubbers are used
almost exclusively to control exhaust gases from sealed furnaces. The gas from
sealed and mix sealed furnaces is usually flared at the exhaust of the scrub-
ber. The carbon monoxide rich gas has an estimated heating value of 300 Btu
per cubic foot and is sometimes used as a fuel in kilns and sintering machines.
.The efficiency of flares for the control of carbon monoxide and the reduction
of organic emission has been estimated to be greater than 98 percent for steam
assisted flares with a velocity of less than 60 feet per second and a gas heat-
ing value of 300 Btu per standard cubic foot^^. For unassisted flares, the
reduction of organic and carbon monoxide emissions is 98 percent efficient with
a velocity of less than 60 feet per second and a gas heating value greater than
200 Btu per standard cubic foot..24
Tapping operations also generate fumes. Tapping is intermittent and is
usually conducted during 10 to 20 percent of the furnace operating time. Some
fumes originate from the carbon lip liner, but most are a result of induced
heat transfer from the molten metal or slag as it contacts the runners, ladles,
casting beds and ambient air. Some plants capture these emissions to varying
degrees with a main canopy hood. Other plants employ separate tapping hoods
ducted to either the furnace emission control device or a separate control
device. Emission factors for tapping emissions are unavailable because of a
lack of data.
A reaction ladle may be involved to adjust the metallurgy after furance
tapping by chlorination, oxidation, gas mixing and slag metal reactions. Ladle
reactions are an intermittent process, and emissions have not been quantified.
Reaction ladle emissions often are captured by the tapping emissions control
system.
Available data are insufficient to provide emission factors for raw
material handling, pretreatment and product handling. Dust particulate is
emitted from raw material handling, storage and preparation activities (see
Figure 7.4-1), from such specific activities as unloading of raw materials from
.delivery vehicles (ship, railcar or truck), storage of raw materials in piles,
loading of raw materials from storage piles into trucks or gondola cars and
crushing and screening of raw materials. Raw materials may be dried before
charging in rotary or other type dryers, and these dryers can generate signif-
icant particulate emissions. Dust may also be generated by heavy vehicles used
for loading, unloading and transferring material. Crushing, screening and
storage of the ferroalloy product emit particulate in the form of dust. The
10/86 Metallurgical Industry - 7.4-23
-------
properties of particulate emitted as dust are similar to the natural properties
of the ores or alloys from which they originated, ranging in size from 3 to 100
micrometers.
Approximately half of ferroalloy facilities have some type of control for
dust emissions. Dust generated from raw material storage may be controlled
in several ways, including sheltering storage piles from the wind with block
walls, snow fences or plastic covers. Occasionally, piles are sprayed with
water to prevent airborne dust. Emissions generated by heavy vehicle traffic
may be reduced by using a wetting agent or paving the plant yard.3 Moisture
In the raw materials, which may be as high as 20 percent, helps to limit dust
emissions from raw material unloading and loading. Dust generated by crushing,
sizing, drying or other pretreatment activities is sometimes controlled by dust
collection equipment such as scrubbers, cyclones or baghouses. Ferroalloy pro-
duct crushing and sizing usually require a baghouse. The raw material emission
collection equipment may be connected to the furnace emission control system.
For fugitive emissions from open sources, see Section 11.2 of this document.
References for Section 7.4
1. F. J. Schottman, "Ferroalloys", 1980 Mineral Facts and Problems, Bureau Of
Mines, U. S. Department Of The Interior, Washington, DC, 1980.
2. J. 0. Dealy, and A. M. Killin, Engineering and Cost Study of the Ferroalloy
Industry, EPA-450/2-74-008, U. S. Environmental Protection Agency, Research
Triangle Park, NC, May 1974.
3. -Backgound Information on Standards of Performance; Electric Submerged Arc
Furnaces for Production of Ferroalloys, Volume I; Proposed Standards,
EPA-450/2-74-018a, U. S. Environmental Protection Agency, Research Triangle
Park, NC, October 1974.
4. C. W. Westbrook, and D. P. Dougherty, Level I Environmental Assessment of
Electric Submerged Arc Furnaces Producing Ferroalloys, EPA-600/2-81-038,
U. S. Environmental Protection Agency, Washington, DC, March 1981.
5. F. J. Schottman, "Ferroalloys", Minerals Yearbook, Volume I; Metals and
Minerals, Bureau Of Mines, Department Of The Interior, Washington, DC,
1980.
6. S. Beaton and H. Klemm, Inhalable Particulate Field Sampling Program for
the Ferroalloy Industry, TR-80-115-G, GCA Corporation, Bedford, MA,
November 1980.
7. G. W. Westbrook and D. P. Dougherty, Environmentall Impact of Ferroalloy
Production Interim Report: Assessment of Current Data, Research Triangle
Institute, Research Triangle Park, NC, November 1978.
8. K. Wark and C. F. Warner, Air Pollution; Its Origin and Control, Harper
and Row Publisher, New York, 1981.
7.4-24 EMISSION FACTORS 10/86
-------
9. M. Szabo and R. Gerstle, Operations anJ rialntenanee of Particulate Control
Devices on Selected Steel and Ferroalloy Processes, EPA-600/2-78-037, U. S.
Environmental Protection Agency, Washington, DC, March 1978.
10. C. W. Westbrook, Multimedia Environmental Assessment of Electric Submerged
Arc Furnaces Producing Ferroalloys, EPA-600/2-83-092, U. S. Environmental
Protection Agency, Washington, DC, September 1983.
11. S. Gronberg, et al., Ferroalloy Industry Particulate Emissions; Source
Category Report, EPA-600/7-86-039, U. S. Environmental Protection Agency,
Cincinnati, OH, November 1986.
12. T. Epstein, et al., Ferroalloy Furnace Emission Factor Development, Roane
Limited. Rockwood, Tennessee, EPA-600/X-85-325, U. S. Environmental Pro-
tection Agency, Washington, DC, June 1981.
13. S. Beaton, et al., Ferroalloy Furnace Emission Factor Development, Inter-
lake Inc., Alabama Metallurgical Corp., Selma, Alabama, EPA-600/X-85-324,
U. S. Environmental Protection Agency, Washington, DC, May 1981.
14. J. L. Rudolph, et al., Ferroalloy Process Emissions Measurement, EPA-600/
2-79-045, U. S. Environmental Protection Agency, Washington, DC, February
1979.
15. Written communication from Joseph F. Eyrich, Macalloy Corporation, Charles-
ton, SC to GCA Corporation, Bedford, MA, February 10, 1982, citing Airco
Alloys and Carbide test-R-07-7774-000-1, Gilbert Commonwealth, Reading,
PA, 1978.
16. Source test, Airco Alloys and Carbide, Charleston, SC, EMB-71-PC-16(FEA),
U. S. Environmental Protection Agency, Research Triangle Park, NC,- 1971.
17. Telephone communication between Joseph F. Eyrich, Macalloy Corporation,
Charleston, SC and Evelyn J. Limberakis, GCA Corporation, Bedford, MA,
February 23, 1982.
18. Source test, Chromium Mining and Smelting Corporation, Memphis, TN, EMB-
72-PC-05 (FEA), U. S. Environmental Protection Agency, Research Triangle
Park, NC, June 1972.
19. Source test, Union Carbide Corporation, Ferroalloys Division, Marietta,
Ohio, EMB-71-PC-12(FEA), U. S. Environmental Protection Agency, Research
Triangle Park, NC, 1971.
20. R. A. Person, "Control of Emissions from Ferroalloy Furnace Processing",
Journal Of Metals, 2.3(4): 17-29, April 1971.
21. S. Gronberg, Ferroalloy Furnace Emission Factor Development Foote Minerals,
Graham, W. Virginia, EPA-600/X-85-327, U. S. Environmental Protection
Agency, Washington, DC, July 1981.
22. R. W. Gerstle, et al., Review of Standards of Performance for New Station-
ary Air Sources - Ferroalloy Production Facility, EPA-450/3-80-041, U. S.
Environmental Protection Agency, Research Triangle Park, NC, December 1980.
10/86 Metallurgical Industry 7.4-25
-------
23. Air Pollutant Emission Factors, Final Report, APTD-0923, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, April 1970.
24. Telephone communication between Leslie B. Evans, Office Of Air Quality
Planning And Standards, U. S. Environmental Protection Agency, Research
Triangle Park, NC, and Richard Vacherot, GCA Corporation, Bedford, MA,
October 18, 1984.
25. R. Ferrari, Experiences in Developing an Effective Pollution Control
System for a Submerged Arc Ferroalloy Furnace Operation, J. Metals,
p. 95-104, April 1968.
26. Fredriksen and Nestaas, Pollution Problems by Electric Furnace Ferroalloy
Production, United Nations Economic Commission for Europe, September 1968.
27. A. E. Vandergrift, et al., farticulate Pollutant System Study - Mass Emis-
sions, PB-203-128, PB-203-522 and P-203-521, National Technical Information
Service, Springfield, VA, May 1971.
28. Control Techniques for Lead Air Emissions, EPA-450/2-77-012, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, December 1977.
29. W. E. Davis, Emissions Study of Industrial Sources of Lead Air Pollutants,.
1970, EPA-APTD-1543, W. E. Davis and Associates, Leawood, KS, April 1973.
30. Source test, Foote Mineral Company, Vancoram Operations, Steubenville, OH,
EMB-71-PC-08(FEA), U. S. Environmental Protection Agency, Research Triangle
Park, NC, August 1971.
7.4-26 EMISSION FACTORS 10/86
-------
7.5 IRON AND STEEL PRODUCTION
7.5.1 Process Descriptionl-3
The production of steel at an integrated iron and steel plant is
accomplished using several interrelated processes. The major operations are:
(1) coke production, (2) sinter production, (3) iron production, (4) iron
preparation, (5) steel production, (6) semifinished product preparation, (7)
finished product preparation, (8) heat and electricity supply, and (9) handling
and transport of raw, intermediate and waste materials. The interrelation of
these operations is depicted in a general flow diagram of the iron and steel
industry in Figure 7.5-1. Coke production is discussed in detail in Section
7.2 of this publication, and more information on the handling and transport of
materials is found in Chapter 11.
7.5.1.1 Sinter Production - The sintering process converts fine sized raw
materials, including iron ore, coke breeze, limestone, mill scale, and flue
dust, into an agglomerated product, sinter, of suitable size for charging into
the blast furnace. The raw materials are sometimes mixed with water to provide
a cohesive matrix, and then placed on a continuous, travelling grate called the
sinter strand. A burner hood, at the beginning of the sinter strand ignites
the coke in the mixture, after which the combustion is self supporting and it
provides sufficient heat, 1300 to 1480°C (2400 to 2700°F), to cause surface
melting and agglomeration of the mix. On the underside of the sinter strand
is a series of windboxes that draw combusted air down through the material
bed into a common duct leading to a gas cleaning device. The fused sinter is
discharged at the end of the sinter strand, where it is crushed and screened.
Undersize sinter is recycled to the mixing mill and back to the strand. . The
remaining sinter product is cooled in open air or in a circular cooler with
water sprays, or mechanical fans. The cooled sinter is crushed and screened for
a final time, then the fines are recycled, and the product is sent to be charged
to the blast furnaces. Generally, 2.5 tons of raw materials, including water
and fuel, are required to produce one ton of product sinter.
7.5.1.2 Iron Production - Iron is produced in blast funaces by the reduction
of iron bearing materials with a hot gas. The large, refractory lined furnace
is charged through its top with iron as ore, pellets, and/or sinter; flux as
limestone, dolomite and sinter; and coke for fuel. Iron oxides, coke and fluxes
react with the blast air to form molten reduced iron, carbon monoxide and slag.
The molten iron and slag collect in the hearth at the base of the furnace. The
byproduct gas is collected through offtakes located at the top of the furnace
and is recovered for use as fuel.
The production of one ton of iron requires 1.4 tons of ore or other iron
bearing material; 0.5 to 0.65 tons of coke; 0.25 tons of limestone or dolomite;
and 1.8 to 2 tons of air. Byproducts consist of 0.2 to 0.4 tons of slag, and
2.5 to 3.5 tons of blast furnace gas containing up to 100 Ibs of dust.
The molten iron and slag are removed, or cast, from the furnace perio-
dically. The casting process begins with drilling a hole, called the taphole,
into the clay filled iron notch at the base of the hearth. During casting,
molten iron flows into runners that lead to transport ladles. Slag also flows
10/86 Metallurgical Industry 7.5-1
-------
Ln
M
B
co
O
55
I
Jmlnui«"|
IU I l*MI
(If 141*11 t-« — —. MUIMMUMIM
IHUMI «MI
UltMl
ItMIUMMI
•HIICIIIIH
I«HI
Figure 7.5-1. General flow diagram for the iron and steel industry.
o
oo
-------
into the clay filled iron notch at the base of the hearth. During casting,
molten iron flows Into runners that lead to transport ladles. Slag also flows
from the furnace, and is directed through separate runners to a slag pit
adjacent to the cast house, or into slag pots for transport to a remote slag
pit. At the conclusion of the cast, the taphole is replugged with clay. The
area around the base of the furnace, Including all iron and slag runners, is
enclosed by a casthouse. The blast furnace byproduct gas, which is collected
from the furnace top, contains carbon monoxide and particulate. Because of
its high carbon monoxide content, this blast furnace gas has a low heating
value, about 2790 to 3350 joules per liter (75 to 90 BTU/ft3) and is used as a
fuel within the steel plant. Before it can be efficiently oxidized, however,
the gas must be cleaned of particulate. Initially, the gases pass through a
settling chamber or dry cyclone to remove about 60 percent of the particulate.
Next, the gases undergo a one or two stage cleaning operation. The primary
cleaner is normally a wet scrubber, which removes about 90 percent of the
remaining particulate. The secondary cleaner is a high energy wet scrubber
(usually a venturi) or an electrostatic precipitator, either of which can
remove up to 90 percent of the particulate that eludes the primary cleaner.
Together these control devices provide a clean fuel of less than 0.05 grams
per cubic meter (0.02 gr/ft3). A portion of this gas is fired in the blast
furnace stoves to preheat the blast air, and the rest is used in other plant
operations.
7.5.1.3 Iron Preparation Hot Metal Desulfurization - Sulfur in the molten
iron is sometimes reduced before charging into the steelmaking furnace by
adding reagents. The reaction forms a floating slag which can be skimmed off.
Desulfurization may be performed in the hot metal transfer (torpedo) car at a
location between the blast furnace and basic oxygen furnace (BOF), or it may
be done in the hot metal transfer (torpedo) ladle at a station inside the.BOF
shop.
The most common reagents are powdered calcium carbide (CaC2) and calcium
carbonate (CaC03) or salt coated magnesium granules. Powdered reagents are
injected into the metal through a lance with high pressure nitrogen. The pro-
cess duration varies with the injection rate, hot metal chemistry, and desired
.final sulfur content, and is in the range of 5 to 30 minutes.
7.5.1.4 Steelmaking Process - Basic Oxygen Furnaces - In the basic oxygen
process (BOP), molten iron from a blast furance and iron scrap are refined in
a furnace by lancing (or injecting) high purity oxygen. The input material is
typically 70 percent molten metal and 30 percent scrap metal. The oxygen reacts
with carbon and other impurities to remove them from the metal. The reactions
are exothermic, i. e., no external heat source is necessary to melt the scrap
and to raise the temperature of the metal to the desired range for tapping.
The large quantities of carbon monoxide (CO) produced by the reactions in the
BOF can be controlled by combustion at the mouth of the furnace and then vented
to gas cleaning devices, as with open hoods, or combustion can be suppressed at
the furnace mouth, as with closed hoods. BOP Steelmaking is conducted in large
(up to 400 ton capacity) refractory lined pear shaped furnaces. There are two
major variations of the process. Conventional BOFs have oxygen blown into the
top of the furnace through a water cooled lance. In the newer, Quelle Basic
Oxygen process (Q-BOP), oxygen is injected through tuyeres located in the bot-
tom of the furnace. A typical BOF cycle consists of the scrap charge, hot
metal charge, oxygen blow (refining) period, testing for temperature and
10/86 Metallurgical Industry
7.5-3
-------
chemical composition of the steel, alloy additions and reblows (if necessary),
tapping, and slagging. The full furnace cycle typically ranges from 25 to 45
minutes.
7.5.1.5 Steel malting Process - Electric Arc Furnace - Electric arc furnaces
(EAF) are used to produce carbon and alloy steels. The input material to an
EAF is typically 100 percent scrap. Cylindrical, refractory lined EAFs are
equipped with carbon electrodes to be raised or lowered through the furnace
roof. With electrodes retracted, the furnace roof can be rotated aside to
permit the charge of scrap steel by overhead crane. Alloying agents and flux-
ing materials usually are added through the doors on the side of the furnace.
Electric current of the opposite polarity electrodes generates heat between the
electrodes and through the scrap. After melting and refining periods, che slag
and steel are poured from the furnace by tilting.
The production of steel in an EAF is a batch process. Cycles, or "heats",
range from about 1 1/2 to 5 hours to produce carbon steel and from 5 to 10
hours or more to produce alloy steel. Scrap steel is charged to begin a cycle,
and alloying agents and slag materials are added for refining. Stages of each
cycle normally are charging and melting operations, refining (which usually
includes oxygen blowing), and tapping.
7.5.1.6 Steelmaklng Process-Open Hearth Furnaces - The open hearth furnace
(OHF) is a shallow, refractory-lined basin in which scrap and molten iron are
melted and refined into steel. Scrap is charged to the furnace through doors
in the furnace front. Hot metal from the blast furnace is added by pouring
from a ladle through a trough positioned in the door. The mixture of scrap
and hot metal can vary from all scrap to. all hot metal, but a half and half
mixture is most common. Melting heat is provided by gas burners above and at
the side of the furnace. Refining is accomplished by the oxidation of carbon
in the metal and the formation of a limestone slag to remove impurities. Most
furnaces are equipped with oxygen lances to speed up melting and refining.
The steel product is tapped by opening a hole in the base of the furnace with
an explosive charge. The open hearth steelmaking process with oxygen lancing
normally requires from 4 to 10 hours for each heat.
7.5.1.7 Semifinished Product Preparation - After the steel has been tapped,
the molten metal is teemed (poured) into ingots which are later heated and
formed into other shapes, such as blooms, billets, or slabs. The molten steel
may bypass this entire process and go directly to a continuous casting opera-
tion. Whatever the production technique, the blooms, billets, or slabs undergo
a surface preparation step, scarfing, which removes surface defects before
shaping or rolling. Scarfing can be performed by a machine applying jets of
oxygen to the surface of hot semifinished steel, or by hand (with torches) on
cold or slightly heated semifinished steel.
7.5.2 Emissions And Controls
7.5.2.1 Sinter - Emissions from sinter plants are generated from raw material
handling, windbox exhaust, discharge end (associated sinter crushers and hot
screens), cooler and cold screen. The windbox exhaust is the primary source
of particulate emissions, mainly iron oxides, sulfur oxides, carbonaceous cora-
7.5-4 . EMISSION FACTORS . 10/86
-------
pounds, aliphatic hydrocarbons', and chlorides. At the discharge end, emissions
are mainly iron and calcium oxides. Sinter strand wlndbox emissions commonly
are controlled by cyclone cleaners followed by a dry or wet ESP, high pressure
drop wet scrubber, or baghouse. Crusher and hot screen emissions, usually con-
trolled by hooding and a baghouse or scrubber, are the next largest emissions
source. Emissions are also generated from other material handling operations.
At some sinter plants, these emissions are captured and vented to a baghouse.
7.5.2.2 Blast Furnace - The primary source of blast furnace emissions is the
casting operation. Particulate emissions are generated when the molten iron
and slag contact air above their surface. Casting emissions also are generated
by drilling and plugging the taphole. The occasional use of an oxygen lance
to open a clogged taphole can cause heavy emissions. During the casting opera-
tion, iron oxides, magnesium oxide and carbonaceous compounds are generated as
particulate. Casting emissions at existing blast furnaces are controlled by
evacuation through retrofitted capture hoods to a gas cleaner, or by suppres-
sion techniques. Emissions controlled by hoods and an evacuation system are
usually vented to a baghouse. The basic concept of suppression techniques is
to prevent the formation of pollutants by excluding ambient air contact with
the molten surfaces. New furnaces have been constructed with evacuated runner
cover systems and local hooding ducted to a baghouse.
Another potential source of emissions is the blast furnace top. Minor
emissions may occur during charging from imperfect bell seals in the double
bell system. Occasionally, a cavity may form in the blast fuernace charge,
causing a collapse of part of the burden (charge) above it. The resulting
pressure surge in the furnace opens a relief valve to the atmosphere to pre-
vent damage to the furnace by the high pressure created and is referred to as
a "slip".
7.5.2.3 Hot Metal Desulfurization - Emissions during the hot metal desulfur-
ization process are created by both the reaction of the reagents injected Into
the metal and the turbulence during injection. The pollutants emitted are
mostly iron oxides, calcium oxides and oxides of the compound injected. The
sulfur reacts with the reagents and is skimmed off as slag. The emissions
generated from desulfurization may be collected by a hood positioned over the
ladle and vented to a baghouse.
7.5.2.4 Steelmaking - The most significant emissions from the BOF process
occur during the oxygen blow period. The predominant compounds emitted are
iron oxides, although heavy metals and fluorides are usually present. Charging
emissions will vary with the quality and quantity of scrap metal charged to the
furnace and with the pour rate. Tapping emissions include iron oxides, sulfur
oxides, and other metallic oxides, depending on the grade of scrap used. Hot
metal transfer emissions are mostly iron oxides.
BOFs are equipped with a primary hood capture system located directly
over the open mouth of the furnaces to control emissions during oxygen blow
periods. Two types of capture systems are used to collect exhaust gas as it
leaves the furnace mouth: closed hood (also known as an off gas, or 0. G. ,
system) or open, combustion type hood. A closed hood fits snugly against the
furnace mouth, ducting all particulate and carbon monoxide to a wet scrubber
10/86 Metallurgical Industry 7.5-5
-------
gas cleaner. Carbon monoxide is flared at Che scrubber outlet stack. The open
hood design allows dilution air to be drawn into the hood, thus combusting the
carbon monoxide in the hood system. Charging and tapping emissions are con-
trolled by a variety of evacuation systems and operating practices. Charging
hoods, tapside enclosures, and full furnace enclosures are used in the industry
to capture these emissions and send them to either the primary hood gas cleaner
or a second gas cleaner.
7.5.2.5 Steelmaking - Electric Arc Furnace - The operations which generate
emissions during the electric arc furnace Steelmaking process are melting and
refining, charging scrap, tapping steel, and dumping slag. Iron oxide is the
predominant constituent of the particulate emitted during melting. During
refining, the primary particulate compound emitted is calcium oxide from the
slag. Emissions from charging scrap are difficult to quantify, because they
depend on the grade of scrap utilized. Scrap emissions usually contain iron
and other metallic oxides from alloys in the scrap metal. Iron oxides and
oxides from the fluxes are the primary constituents of the slag emissions.
During tapping, iron oxide is the major particulate compound emitted.
Emission control techniques Involve an emission capture system and a gas
cleaning system. Five emission capture systems used in the industry are
fourth hold (direct shell) evacuation, side draft hood, combination hood, can-
opy hood, and furnace enclosures. Direct shell evacuation consists of ductwork
attached to a separate or fourth hole in the furnace roof which draws emissions
to a gas cleaner. The fourth hole system works only when the furnace is up-
right with the roof in place. Side draft hoods collect furnace off gases from
around the electrode holes and the work doors after the gases leave the furnace.
The combination hood incorporates elements from the side draft and fourth hole
ventilation systems. Emissions are collected both from'the fourth hole and
around the electrodes. An air gap in the ducting introduces secondary air for
combustion of CO in the exhaust gas. The combination hood requires careful
regulation of furnace interval pressure. The canopy hood is the least effi-
cient of the four ventilation systems, but it does capture emissions during
charging and tapping. Many new electric arc furnaces incorporate the canopy
hood with one of the other three systems. The full furnace enclosure com-
pletely surrounds the furnace and evacuates furnace emissions through hooding
in the top of the enclosure.
7.5.2.6 Steelmaking - Open Hearth Furnace - Particulate emissions from an open
hearth furnace vary considerably during the process. The use of oxygen lancing
increases emissions of dust and fume. During the melting and refining cycle,
exhaust gas drawn from the furnace passes through a slag pocket and a regener-
ative checker chamber, where some of the particulate settles out. The emissions,
mostly iron oxides, are then ducted to either an ESP or a wet scrubber. Other
furnace related process operations which produce fugitive emissions Inside the
shop include transfer and charging of hot metal, charging of scrap, tapping
steel and slag dumping. These emissions are usually uncontrolled.
7.5.2.7 Semifinished Product Preparation - During this activity, emissions are
produced when molten steel is poured (teemed) into ingot molds, and when semi-
finished steel is machine or manually scarfed to remove surface defects.
Pollutants emitted are iron and other oxides (FeO, Fe203, S102, CaO, MgO).
7.5-6 EMISSION FACTORS 10/86
-------
TABLE 7.5-1 (cont.). PARTICULATE EMISSION FACTORS FOR IRON AND STEEL MILLS3
Source
BOF Charging
At source
At building monitor
Controlled by baghouee
BOF Tapping
At source
At building nranltor
Controlled by beghouee
Hot netel transfer
At source
At building monitor
BOF aonltor (ell sources)
Q-BOP aeltlng end refining
Controlled by scrubber
Electric ere furnace
Melting end refining
Uncontrolled carbon
steel
Charging, capping and
slagging
Uncontrolled emission*
•scaping aonltor
Melting, refining.
charging, tapping
and slagging
Uncontrolled
Alloy steel
Carbon steel
Controlled by:*
Building evacuation
co baghouae for
alloy eteel
Direct shell
evecuatlon (plue
charging hood)
vented to coaaon
baghouee for
carbon steel
Units
kg/Mf (Ib/ton) hot metal
kg/Kg (Ib/ton) steel
kg/Mg (Ib/toa) hot aetal
kg/Mg (Ib/toa) steel
kg/Mg (Ib/ton) steel
kg/tig < Ib/ton) steel
kg/Mg (Ib/ton) etcel
kg/Mg (Ib/toa). steel
Mission Factor
0.3 (0.6)
0.071 (0.142)
0.0003 (0.0006)
0.46 (0.92)
0.145 (0.29)
0.0013 (0.0026)
0.093 (0.19)
0.028 (0.056)
0.23 (0.3)
0.028 (0.036)
19.0 (38.0)
0.7 (1.4)
3.63 (11.3)
23.0 (30.0)
0.13 (0.3)
0.0213 (0.043)
Ealsslon
Factor
Rating
D
3
3
D
3
B
A
B
B
3
C
C
A
C
A
e
Particle
Size
Data
Yes
Yes
Yes
Yes
Yes
"
Yes
Yes
10/86
Metallurgical Industry
7.5-9
-------
TABLE 7.5-1 (Cone.)- PARTICULATE EMISSION FACTORS FOR IRON AND STEEL MILLS
Source
Open hearth furnace
Melting and refining
Uncontrolled
Controlled by ESP
Roof monitor
Teeming
Leaded steel
| Uncontrolled (measured
•c source)
Controlled by side draft hood
vented to baghouse
Unleaded sceel
i Uncontrolled (measured
! at source)
Controlled by side draft hood
vented to baghouse
1 Machine scarfing
Uncontrolled
-
Controlled by ESP
Miscellaneous combustion sources-
Units
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
.
kg/Mg (Ib/ton) metal
through scarfer
Boiler, soaking pit and slab
i reheat kg/109 J (lb/106 Btu)
Ealssion Factor
10.55 (21.1)
0.14 (0.28)
0.084 (0.168)
0.405 (0.81)
0.0019 (0.0038)
0.035 (0.07)
0.0008 (0.0016)
0.05 (0.1)
0.0115 (0.023)
f f
Emission
Factor
Racing
D
Particle
Size
Data
Yes
D Yes '
C
|
A
1
A '
i
A i
A
i
B
1 :
A
i
' i
i ' •
31ast furnace gas* 0.015 (0.035) j D •
.!oke oven gas« i 0.0052 (0.012) ', 3
'Reference 3, except as noted.
'Typical of older furnaces with no controls, or for canopy hoods or total casthouse evacuation.
cTypical of large, new furnaces with local hoods and covered evaucated runners. Emissions are
higher than without capture systems because they are not diluted by outside environment.
^Emission factor of 0.55 kg/Mg (1.09 Ib/ton) represents oae torpedo car; 1.26 kg/Mg (2.53 Ib/ton) for
two torpedo cars, and 1.37 kg/Mg (2.74 Ib/ton) for three torpedo cars.
"Building evacuation collects all process emissions, and direct shell evacuation collects only
Mlcing and refining emissions.
'For various fuels, use the emission factors la Chapter 1 of this document. The emission factor
racing, for these fuels in boilers Is A, and in soaking pits and slab reheat furnaces Is D.
2B*sed on methane content and cleaned partlculate loading.
7.5-10
EMISSION FACTORS
10/86
-------
Teeming emissions are rarely controlled. Machine scarfing operations generally
use as ESP or water spray chamber for control. Most hand scarfing operations
are uncontrolled.
7.5.2.8 Miscellaneous Combustion - Every iron and steel plant operation
requires energy in the form of heat or electricity. Combustion sources that
produce emissions on plant property are blast furnace stoves, boilers, soaking
pits, and reheat furnaces. These facilities burn combinations of coal, No. 2
fuel oil, natural gas, coke oven gas, and blast furnace gas. In blast furnace
stoves, clean gas from the blast furnace is burned to heat the refractory
checker work, and in turn, to heat the blast air. In soaking pits, ingots are
heated until the temperature distribution over the cross section of the ingots
is acceptable and the surface temperature is uniform for further rolling into
semifinished products (blooms, billets and slabs). In slab furnaces, a slab is
heated before being rolled into finished products (plates, sheets or strips).
Emissions from the combustion of natural gas, fuel oil or coal in the soaking
pits or slab furnaces are estimated to be the same as those for boilers. (See
Chapter 1 of this document.) Emission factor data for blast furnace gas and
coke oven gas are not available and must be estimatexW There are three facts
available for making the estimation. First, the gas exiting the blast furnace
passes through primary and secondary cleaners and can be cleaned to less than
0.05 grams per cubic meter (0.02 gr/ft3). Second, nearly one third of the
coke oven gas is methane. Third, there are no blast furnace gas constituents
that generate particulate when burned. The combustible constituent of blast
furnace gas is CO, which burns clean. Based on facts one and three, the emis-
sion factor for combustion of blast furnace gas is equal to the particulate
loading of that fuel, 0.05 grams per cubic meter (2.9 lb/106 ft3) having, an
average heat value of 83 BTU/ft3. .
Emissions for combustion of coke oven gas can be estimated in the sane
fashion. Assume that cleaned coke oven gas has as much particulate as cleaned
blast furnace gas. Since one third of the coke oven gas is methane, the main.
component of natural gas, it is assumed that the combustion of this methane in
coke oven gas generates 0.06 grams per cubic meter (3.3 lb/10^ ft3) of partic-
ulate. Thus, the emission factor for the combustion of coke oven gas is the
sum of the particulate loading and that generated by the methane combustion, or
0.1 grams per cubic meter (6.2 lb/10^ ft3) having an average heat value of 516
BTU/ft3. ' '
The particulate* emission Victor? for ococes-jes In Table 7.5-1 are the
result of an extensive investigation by EPA and the American Iron and Steel
Institute.3 Particle size distributions for controlled and uncontrolled emis-
sions from specific iron and steel industry processes have been calculated and
summarized from the best available data.l Size distributions have been used
with particulate emission factors to calculate size specific factors for the
sources listed in Table 7.5-1 for which data are available. Table 7.5-2
presents these size specific particulate emission factors. Particle size dis-
tributions are presented in Figures 7.5-2 to 7.5-4. Carbon monoxide emission
factors are in Table 7.5-3.6
10/86 Metallurgical Industry 7.5-7
-------
TABLE 7.5-1. PARTICULATE EMISSION FACTORS FOR IRON AND STEEL MILLS3
Sou re*
Sintering
Wlndbox
Uncontrolled
Leaving grace
After coarse parti c-
ulace removal
Controlled by dry ESP
Controlled by vet ESP
Controlled by venturl
•crubber
Controlled by cyclone
Sinter discharge (breaker
and hot screens)
Uncontrolled
Controlled by baghouse
Controlled by veaturl
scrubber
Wlndbox and discharge
Controlled by baghousa
Blase furnace
Slip
Uncontrolled caschouse
Roof Monitor^
Furnace with local
evacuaclonC
Taphole and trough only
(not runners)
Hot accal deeulfurlzaclon
Uncontrolled^
Controlled by baghouse
Basic oxygen furnace (BOD
Top blown furnace melting
and refining
Uncontrolled
Controlled by open hood
vented Co:
ESP
Scrubber
Controlled by closed hood
vented to:
Scrubber
Units
kg/Hg (Ib/ton) finished
sinter
kg/Hg (Ib/ton) finished
sinter
kg/Hg (Ib/ton) finished
sinter
kg/Hg (Ib/ton) slip
kg/Hg (Ib/ton) hot aetal
kg/Hg (Ib/ton) hot aetal
kg/Hg (Ib/ton) steal
Caleslon Factor
5.36 (11.1)
4.33 (8.7)
0.8 (1.6)
0.083 (0.17)
0.233 (0.47)
0.3 (1.0)
3.* (6.8)
0.03 (0.1)
0.293 (0.39)
0.13 (0.3)
39.3 (87.0)
0.3 (0.6)
0.65 (1.3)
0.13 (0.3)
0.33 (1.09)
0.0043 (0.009)
14.23 (28.3)
0.065 (0.13)
0.043 (0.09)
0.0034 (0.0068)
Ealssl on
factor
Rating
B
A
a
3
a
a
a
a
A
A
D
3
3
3
3
0
f
a
A
B
A
Particle
Size
Data
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
7.5-8
EMISSION FACTORS
10/86
-------
TABLE 7.5-2. SIZE SPECIFIC EMISSION FACTORS
Source
Sintering
Windbox
UnconC rolled
Leaving grate
Controlled by wet
ESP
Controlled by
venturl scrubber
Controlled by
cyclone6
Controlled by
baghouse
Emission
Factor
Rating
D
C
C
C
C
Particle
Size yraa
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5'
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10.0
15.0
d
Cumulative
Mass % <
Stated size
4b
4
5
9
15
20C
100
18b
25
33
48
59b
69
100
55
75
89
93
96
98
100
•" 25C
37b
52
64
74
80
100
3.0 •
9.0
27.0
47.0
69.0
79.0
100.0
Cumulative mass
emission factor
kg/Mg (Ib/ton)
0.22 (0.44)
0.22 (0.44)
0.28 (0.56)
0.50 (1.00)
0.83 (1.67)
1.11 (2.22)
5.56 (11.1)
0.015 (0.03)
0.021 (0.04)
0.028 (0.06)
0.041 (0.08)
0.050 (0.10)
0.059 (0.12)
0.085 (0.17)
' -
0.129 . (0.26)
• 0.176 (0.35)
0.209 (0.42)
0.219 (0.44)
0.226 (0.'45)
0.230 (0.46)
0.235 (0.47)
0.13 (0.25)
0.19 (0.37)
0.26 (0.52)
0.32 (0.64)
0.37 (0.74)
0.40 (0.80)
0.5 (1.0)
0.005 (0.009)
0.014 (0.027)
0.041 (0.081)
0.071 (0.141)
0.104 (0.207)
0.119 (0.237)
0.15 (0.3)
10/86
Metallurgical Industry
7.5-11
-------
TABLE 7.5.2 (cone.) SIZE SPECIFIC EMISSION FACTORS
Source
Sinter discharge
(breaker and hot
screens) controlled
by baghouse
Blast furnace
Uncontrolled cast-
house emissions
Roof monitor^
Furnace with local
evacuations
Hot netal
desulfurization'^
Uncontrolled
Hot metal
desulfurization*1
Controlled baghouse
Emission
Factor
Rating
C
C
C
E
D
Particle
Size uma
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
- 5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
Cumulative
Mass % <
Stated size
2b
4
11
20
32b
42b
100
4
15
23
35
51
61
100
. ?c
9
15
20
24
26
100
j
2C
11
19
19
21
100
8
18
42
62
74
78
100
Cumulative mass
emission factor
kg/Mg (Ib/ton)
0..001 (0.002)
0.002 (0.004)
0.006 (0.011)
0.010 (0.020)
0.016 (0.032)
0.021 (0.042)
0.05 (0.1)
0.01 (0.02)
0.05 (0.09)
0.07 (0.14)
0.11 (0.21)
0.15 (0.31)
0.18 (0.37)
0.3 (0.6)
0.04 (0.09)
0.06 (0.12)
0.10 (0.20)
0.13 (0.26)
•0.16 (0.31)
0.17 (0.34)
0.65 (1.3)
•
0.01 (0.02)
0.06 (0.12)
0.10 (0.22)
0.10 (0.22)
0.12 (0.23)
0.55 (1.09)
0.0004 (0.0007)
0.0009 (0.0016)
0.0019 (0.0038)
0.0028 (0.0056)
0.0033 (0.0067)
0.0035 (0.0070)
0.0045 (0.009)
7.5-12
EMISSION FACTORS
10/86
-------
TABLE 7.5-2 (cont.) SIZE SPECIFIC EMISSION FACTORS
Source
Basic oxygen furnace
Top blown furnace
melting and refining
controlled by closed
hood and vented to
scrubber
BOF Charging
At source^
Controlled by
baghouse
i
• • ; •
-
BOF Tapping
At source^
Emission
Factor
Rating
C
E
D
E
Particle
Size uma
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
. d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
Cumulative
Mass % <
Stated size
34"
55
65
66
67
72c
100
8C
12
22
35
46
56
100
3
10
22
31
45
60
100
j
11
37
43
45
50
100
Cumulative mass
emission factor
kg/Mg (Ib/ton)
0.0012 (0.0023)
0.0019 (0.0037)
0.0022 (0.0044)
0.0022 (0.0045)
0.0023 (0.0046)
0.0024 (0.0049)
0.0034 (0.0068)
0.02 (0.05)
0.04 (0.07)
0.07 (0.13)
0.10 (0.21)
0.14 (0.28)
0.17 (0.34)
0.3 (0.6)
9.0xlO-6 1.8x10-5
3.0xlO-5 6.0x10-5
6.6x10-5 (0.0001)
9.3x10-5 (0.0002)
0.0001 (0.0003)
0.0002 (0.0004)
0.0003 (0.0006)
j j
0.05 (0.10)
0.17 (0.34)
0.20 (0.40)
0.21 (0.41)
0.23 (0.46)
0.46 (0.92)
10/86
Metallurgical Industry
7.5-13
-------
TABLE 7.5-2 (cont.) SIZE SPECIFIC EMISSION FACTORS
Source
BOF Tapping
Controlled by
baghouse
Q-BOP melting and
refining controlled
by scrubber
Electric arc furnace
melting and refin-
ing carbon steel
uncontrolled"1
Electric. arc furnace
j Melting, refining,
charging, tapping,
slagging
Controlled by
direct shell
evacuation (plus
charging hood)
vented to common
baghouse for
carbon steel n
Emiss ion
Factor
Rating
D
D
D
E
Particle
S i ze ma
0.5
1.0
2.5
5.0-
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
Cumulative
Mass % <
Stated size
4
7
16
22
30
40
100
45
52
56
58
68
85C
. 100
8
23
43
53
58
61
100
74b
74
74
74
76
80
100
" *
Cumulative mass A
emission factor 1
kg/Mg (Ib/ton) f
1
5.2x10-5 (0.0001)
0.0001 (0.0002)
0.0002 (0.0004)
0.0003 (0.0006)
0.0004 (0.0008)
0.0005 (0.0010)
0.0013 (0.0026)
0.013 (0.025)
0.015 (0.029)
0.016 (0.031)
0.016 (0.032)
0.019 (0.038)
0.024 (0.048)
0.028 (0.056) !
1.52 (3.04)
4.37 (8.74)
8.17 (16.34)
10.07 (20.14)
1-1.02 (22.04)
11.59 (23.18)
19.0 (38.0)
0.0159 (0.0318)
0.0159 (0.0318)
0.0159 (0.0313)
0.0159 (0.0318)
0.0163 (0.0327)
0.0172 (0.0344)
0.0215 (0.043)
7.5-14
EMISSION FACTORS
10/86
-------
TABLE 7.5-2 (cone.) SIZE SPECIFIC EMISSION FACTORS
Source
Open hearth furnace
Melting and refining
Uncontrolled
Open Hearth Furnaces
Controlled by
ESPP
Emission
Factor
Rating
E
E
Particle
Size pma
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
Cumulative
Mass, % <
Stated size
lb
21
60
79
83
85C
100
10°
21
39
47
53b
56b
100
Cumulative mass
emission factor
kg/Mg (Ib/ton)
0.11 (0.21)
2.22 (4.43)
6.33 (12.66)
8.33 (16.67)
8.76 (17.51)
8.97 (17.94)
10.55 (21.1)
0.01 (0.02)
0.03 (0.06)
0.05 (0.10)
0.07 (0.13)
0.07 (0.15)
0.08 (0.16)
0.14 (0.28)
aParticle aerodynamic diameter micrometers (urn) as defined by Task Group on Lung
Dynamics. (Particle density =1 gr/cm^).
^Interpolated data used to develop size distribution.
GExtrapolated, using engineering estimates.
dTotal particulate based on Method 5 total catch. See Table 7.5-1.
eAverage of various cyclone efficiencies.
DTotal casthouse evacuation control system.
SEvacuation runner covers and local hood over taphole, typical of new state of
the art blast furnace technology.
^Torpedo ladle desulfurization with CaC2 and CaCO-j.
JUnable to extrapolate because of insufficient data and/or curve exceeding limits
^Doghouse type furnace enclosure using front and back sliding doors, totally
enclosing the furnace, with emissions vented to hoods.
mFull cycle emissions captured by canopy and side draft hoods.
"Information on control system not available.
PMay not be representative. Test outlet size distribution was larger than inlet
and may indicate reentrainment problem.
10/86
Metallurgical Industry
7.5-15
-------
Ul
I
m
•2.
M
in
in
c-i
O
O
H
O
73
in
SOURCE CATEGORY/CONTROLS
SINren PLANT wiNoeox/UNCONTROLLED
SINTER PLANT WINOBOK/CYCLONES — — •
SINUR PLANT WINOBOM/SCRUBBCR — • —
SINTER PLANT WINDBOI/ESP
SINTER PLANT wiNoaoi/BAGHOusE •-
SINTER BREAKER/BAGHOUSE •
EXTRAPOLATED BY EXTENDING
THE CURVES ON THE GRAPH
IO 19
PARTICLE AERODYNAMIC DIAMETER
(micrometers)
(Calculated according to the Task Group Lung
Dynamics definition of Aerodynamic Diameter)
100
80
60
tu
N
to
tn
z
<
X
40 '
in
20
ui
2-
D
U
o
CO
Figure 7.5-2. ('article size distribution of sinter plant emissions.
-------
o
oo
fD
rt
6)
C
n
OT
a.
c
01
SOURCE CATEGORY/CONTROLS
BO?-CHARGE/UNCONTROLLED
BOF - CHARGE / BAGMOUSE
BOF-TAP/UNCONTROLLED
BOF-TAP/BAOHOUSE
BOF-REFINING/SCRUBBER
QBOP-REFINING / SCRUBBER '
EXTRAPOLATED BY EXTENDING
'THE CURVES ON THE GRAPH
I I
0.5
1.0
2.3
3.0
10 15
PARTICLE AERODYNAMIC DIAMETER
(micrometers)
(Calculated according to the Tosk Group Lung
Dynamics definition of Aerodynamic Diameter)
IOO
N
8O *"
in
z
60 5
V)
VI
IU
J*
V)
ui
20
U
I
--I
Figure 7.5-3. Particle size distribution of -basic oxygen furnace emissions,
-------
01
I
oo
en
GO
V.
l-l
o
z
5?
n
H
o
73
SOURCE CATP60RY/CONTROLS
BLAST FURNACE CASTMOUSE/UNCONIHOLLEO.
10IAL BUILDING (VACUA1ION
BLAST FURNACE CASTMOUSE /UNCONTROLLED.
LOCAL HOOD • RUNNER EVACUATION StSTEM
OPEN HEARTH/UNCONTROLLED
OPEN HEARTH /ESP
ELECTRIC AftC FURNACE /UNCONTROLLED
ELECTRIC ARC FURNACE/BAOHOUSE
HOT METAL OESULfuRlZATION/UNCONTROLLED
HOT METAL OESULFURIZATION/IAGHOUSC
EXTRAPOLATED BY EXTENDING
THE CURVES ON THE GRAPH
IOO
8O
6O
(A
O
LU
<
v\
z
x
40 *
3
2
D
u
0.5
1.0
2.3
5.0
IO 15
PARTICLE AERODYNAMIC DIAMETER
(micromtters)
(Colculoled according lo Iht Tosh Group Lung
Dynamics definition of Aerodynamic Diameter)
O
03
Figure 7.5-4.
Panicle size distribution of blast furnace, open hearth,
electric arc furnace and hot metal desuifurization emissions,
-------
TABLE 7.5-3. UNCONTROLLED CARBON MONOXIDE EMISSION FACTORS
FOR IRON AND STEEL MILLS3
EMISSION FACTOR RATING:
Source
Sintering windbox"
Basic oxygen furnace0
Electric arc furnace0
kg/Mg
22
69
9
Ib/ton
44
138
18
aReference 6.
bkg/Mg (Ib/ton) of finished sinter.
Ckg/Mg (Ib/ton) of finished steel.
7.5.2.9 Open Dust Sources - Like process emission sources, open dust sources
contribute to the atmospheric particulate burden. Open dust sources include
vehicle traffic on paved and unpaved roads, raw material handling outside of
buildings and wind erosion from storage piles and exposed terrain. Vehicle
traffic consists of plant personnel and visitor vehicles, plant service
vehicles, and trucks handling raw materials, plant deliverables, steel pro-
ducts and waste materials. Raw materials are handled by clamshell buckets,
bucket/ladder conveyors, rotary railroad dumps, bottom railroad dumps, front
end loaders, truck dumps, and conveyor transfer stations, all of which disturb
the raw material and expose fines to the wind. Even fine materials resting on
flat areas or in storage piles are exposed and are subject to wind erosion. It
is not unusual to have several million tons of raw materials stored at a plant
and to have in the range of 10 to 100 acres of exposed area there.
Open dust source emission factors for iran and steel production are
presented in Table 7.5-4. These factors were determined through source testing
at various integrated iron and steel plants.
As an alternative to the single valued open dust emission factors
given in Table 7.5-4, empirically derived emission factor equations are pre-
sented in Section 11.2 of this document. Each equation was developed for a
source operation defined on the basis of a single dust generating mechanism
which crosses industry lines, such as vehicle traffic on unpaved roads. The
predictive equation explains much of the observed variance in measured emission
factors by relating emissions to parameters which characterize source conditions.
These parameters may be grouped into three categories: (1) measures of source
activity or energy expended (e. g., the speed and weight of a vehicle traveling
on an unpaved road), (2) properties of the material being disturbed (e. g. , the
content of suspendible fines in the surface material on an unpaved road) and
(3) climatic parameters (e. g., number of precipitation free days per year, when
emissions tend to a maximum).
7.5-19
Metallurgical Industry
10/86
-------
TABLE 7.5-4. UNCONTROLLED PARTICULATE EMISSION FACTORS FOR
OPEN DUST SOURCES AT IRON AND STEEL MILLS3
Operation
Continuous drop
Conveyor transfer station
sincere
Pile formation stacker pellet orec
Luap orec
Coal*
Batch drop
Prone end loader/truck'
High silt slag
Low silc slag
7ehlcla travel on unpaved roads
Light duty vehicle4
Medlua duty vehicle1*
Seavv duty vehicle"1
i
Vehicle travel on paved roads
Light/heavy vehicle miff
Ealsslons by particle size range
(serodynaaic disaster)
£ 30 ua
13
0.026
1.2
0.0024
0.15
0.00030
0.055
0.00011
13
0.026
4.4
0.0088
0.51
1.3
Z.I
7.3
3.9
14
0.22
0.78
< 15 ua
9.0
0.018
0.75
0.0015
0.095
0.00019
0.034
0.000068
8.5
0.017
2.9
0.0058
0.37
1.3
1.5
5.2
2.7
9.7
0.16
0.58
£ 10 u»
6.5
0.013
0.55
0.0011
0.075
0.00015
0.026
0.000052
6.5
0.013
2.2
0.0043
0.28
1.0
1.2
4.1
2.1
7.6
0.12
0.44
£ 5 UB
4.2
0.0084
0.32
0.00064
0.040
0.000081
0.014
0.000028
4.0
0.0080
1.4
0.0028
0.13
0.64
0.70
2.5
1.4
4.3
0.079
,0.28
£ 2.5 .«
2.3
0.0046
0.17
0.00034
0.022
0.000043
0.0075
0.000015
2.3
0.0046
0.80
0.0016
0.10
0.36
0.42
1.5
0.76
2.7
Units'"
g/M«
Ib/ton
g/Mg
Ib/ton
g/«g
Ib/con
g/Mg
Ib/ton
g/Mg
Ib/ton
g/Hg
Ib/ton
SCg/VKT
Ib/VMT
Kg/VKT
Ib/VMT
Kg/VKT
Ib/VMT
Emission
Fsctor
Rating
D
D
a
3
c
c
?
=
1
c
c
c
c
c
c
G.
C
a
3
i
0..042 Kg/VKT
0.15
Ib/VHT
C
C
^Predictive eaisslon (actor equations »re generally preferred over these single values eaisslon factors.
Predictive mission (actors estlaatss are presented In Chapter 11, Section 11.2. VKT.- Vehicle kilometer
traveled. VMT • Vehicle alls traveled.
^Units/unit ot oaterlal transferred or units/unit of distance traveled.
'Reference 4. Interpolation to other particle sizes will be spproxinate.
dfteference 5. Interpolation to other particle sizes will be approxlaace.
7.5-20
EMISSION FACTORS
10/86
-------
Because the predictive equations allow for emission factor adjustment to
specific source conditions, the equations should be used in place of the fac-
tors in Table 7.5-4, if emission estimates for sources in a specific iron and
steel facility are needed. However, the generally higher quality ratings
assigned to the equations are applicable only if (1) reliable values of correc-
tion parameters have been determined for the specific sources of interest and
(2) the correction parameter values lie within the ranges tested in developing
the equations. Section 11.2 lists measured properties of aggregate process
materials and road surface materials in the iron and steel industry, which can
be used to estimate correction parameter values for the predictive emission
factor equations, in the event that site specific values are not available.
Use of mean correction parameter values from Section 11.2 reduces the
quality ratings of the emission factor equation by one level.
References for Section 7.5
1. J. Jeffery and J. Vay, Source Category Report for the Iron and Steel
Industry, EPA-600/7-86-036, U.S. Environmental Protection Agency,
Research Triangle Park, NC, October 1986.
2. H. E. McGannon, ed. , The Making, and Shaping and Treating of Steel, U. S.
Steel Corporation, Pittsburgh, PA, 1971.
3. T. A. Cuscino, Jr. , Particulate Emission Factors Applicable to the Iron and
Steel Industry, EPA-450/4-79-028, U. S. Environmental Protection Agency,
Research Triangle Park, NC, September 1979.
4. R. Bohn,. et al., Fugitive Emissions from Integrated Iron.and Steel Plants,
EPA-600/2-78-050, U. S. Environmental Protection Agency, Research Triangle
Park., NC, March 1978.
5. C. Cowherd,. Jr. , et al. , Iron and Steel Plant Open Source Fugitive Emis-
sion Evaluation, EPA-600/2-79-103, U. S. Environmental Protection Agency,
Research Triangle Park, NC, May 1979.
6. Control Techniques for Carbon Monoxide Emissions from Stationary Sources,
AP-65, U. S. Department of Health, Education and Welfare, Washington, DC,
March 1970.
10/86 Metallurgical Industry 7.5-21
-------
7.6 PRIMARY LEAD SMELTING
7.6.1 Process Description
Lead is usually found naturally as a sulfide ore containing small amounts
of copper, iron, zinc and other trace elements. It is usually concentrated at
the mine from an ore of 3 to 8 percent lead to a .concentrate of 55 to 70 percent
lead, containing from 13 to 19 weight percent free and uncombined sulfur.
Processing involves three major steps, sintering, reduction and refining.
A typical diagram of the production of lead metal from ore concentrate,
with particle and gaseous emission sources indicated, is shown in Figure 7.6-1.
Sintering - Sinter is produced by a sinter machine, a continuous steel
pallet conveyor belt moved by gears and sprockets. Each pallet consists of
perforated or slotted grates, beneath which are wind boxes connected to fans to
provide a draft, either up or down, through the moving sinter charge. Except
for draft direction, all machines are similar in design, construction and
operation.
The primary reactions occurring during the sintering process
are autogenous, occurring at approximately 1000°C (1800°F):
2PbS + 302 > 2PbO + 2S02 ' (1)
PbS + 202 > PbS04 (2)
Operating experience has shown that system operation and product quality
are optimum when the- sulfur content of. the sinter charge is from 5 to 7 weight
percent. To maintain this desired sulfur content, sulfide free fluxes such as
silica and limestone, plus large amounts of recycled sinter.and smelter resi-
dues, are added to the mix. The quality of the product sinter is usually
determined by its Ritter Index hardness, which is inversely proportional to the
sulfur content. Hard quality sinter (low sulfur content) is preferred, because
it resists crushing during discharge from the sinter machine. Undersize sinter,
usually from" insufficient desulfurization, is recycled for further processing.'
Of the two kinds of sintering machines, the updraft design is superior for
many reasons. First, the sinter bed is more permeable (and hence can be larg-
er), thereby permitting a higher production rate than with a downdraft machine
of similar dimensions. Secondly, the small amounts of elemental lead that form
during sintering will solidify at their point of formation in updraft machines,
but, in downdraft operation, the metal flows down and collects on the grates or
at the bottom of the sinter charge, thus causing increased pressure drop and
attendant reduced blower capacity. The updraft system also can produce sinter
10/86 Metallurgical Industry 7.6-1
-------
NJ
s
M
to
Cft
o
z
H
§
Liwslone
Silica
. Sinter recycle
.Flue dust
.Coke
Coke
Soda ash
Sulfur
Due dust
Coke
I
Dross
revttrberalory
furnace
I Milestone
-Silica
— Soda aih
-Sulfur
— Pig iron
—I'hO
O
"^
00
Figure l.b-l. Typical primary lead processing scheme.
-------
of higher lead content, and it requires less maintenance than the downdraft
machine. Finally, and most important from an air pollution control standpoint,
updraft sintering can produce a single strong sulfur dioxide (S02) effluent
stream from the operation, by the use of weak gas recirculation. This permits
more efficient and economical use of control methods such as sulfuric acid
recovery devices.
Reduction - Lead reduction is carried out in a blast furnace, which basic-
ally is a water jacketed shaft furnace supported by a refractory base. Tuyeres,
through which combustion air is admitted under pressure, are located near Che
bottom and are evenly spaced on either side of the furnace.
The furnace is charged with a mixture of sinter (80 to 90 percent of
charge), metallurgical coke (8 to 14 percent of charge), and other materials
such as limestone, silica, litharge, slag forming constituents, and various
recycled and cleanup materials. In the furnace, the sinter is reduced to lead
bullion by Reactions 3 through 7.
C + 02—» C02 (3)
C + C02 —» 2CO (4)
PbO + CO—» Pb + C02 (5)
2PbO -i- PbS—> 3Pb + S02 (6)
PbS04 + EbS-» 2Pb + 2S02 (7)
Carbon monoxide and heat required for reduction are supplied by the
combustion of coke. Most of the impurities are eliminated in the slag. Solid
products from the blast furnace generally separate into four layers, speiss
(the lightest material, basically arsenic and antimony), matte (copper sulfide
and other metal sulfides), slag (primarily silicates), and lead bullion. The
first three layers are called slag, which is continually collected from the
furnace and is either processed at the smelter for its metal content or shipped
to treatment facilities.
Sulfur oxides are also generated in blast furnaces from small quantities
of residual lead sulfide and lead'sulfates in the sinter feed. The quantity of
these emissions is a function not only of the sinter's residual sulfur content,
but also of the sulfur captured by copper and other impurities in the slag.
Rough lead bullion from the blast furnace usually requires preliminary
treatment (dressing) in kettles before undergoing refining operations. First,
the bullion is cooled to 370° to 430°C (700 to 800°F). Copper and small amounts
of sulfur, arsenic, antimony and nickel collect on the surface as a dross and
are removed from the solution. This dross, in turn, is treated in a reverber-
atory furnace to concentrate the copper and other metal impurities before being
routed to copper smelters for their eventual recovery. To enhance copper re-
moval, drossed lead bullion is treated by adding sulfur bearing material, zinc,
and/or aluminum, lowering the copper content to approximately 0.01 percent.
10/86 Metallurgical Industry 7.6-3
-------
Refining - The third and final phase in smelting, the refining of the
bullion in cast iron kettles, occurs in five steps:
- Removal of antimony, tin and arsenic
- Removal of precious metals by Parke's Process, in which zinc combines
with gold and silver to form an insoluble intermetallic at operating
temperatures
.-. Vacuum removal of zinc
- Removal of bismuth by the Betterson Process, which is the addition of
calcium and magnesium to form an Insoluble compound with the bismuth
that is skimmed from the kettle
- Removal of remaining traces of metal impurities by addition of NaOH and
NaN03
The final refined lead, commonly from 99.990 to 99.999 percent pure, is
then cast into 45 kilogram (100 pound) pigs for shipment.
7.6.2 Emissions And Controlsl-2
Each of the three major lead smelting process steps generates substantial
quantities of SC>2 and/or particulate.
Nearly 85 percent of the sulfur present in the lead ore concentrate.is
eliminated in the sintering operation. In handling process offgases, either a
single weak stream is taken from the machine hood at less than 2 percent SOo,
or two streams are taken, a strong stream (5 to 7 percent SC^) from the feed end
of the machine and a weak stream (less than 0.5 percent 802) from the discharge
end. Single stream operation has been used if there is little or no market for
recovered sulfur, so that the uncontrolled, weak S02 stream is emitted to the
atmosphere. When sulfur removal is required, however, dual stream operation is
preferred. The strong stream is sent to a sulfuric acid plant, and the weak
stream is vented to the atmosphere after removal of particulate.
When dual gas stream operation is used with updraft sinter machines, the
weak gas stream can be recirculated through the bed to mix with the strong gas
stream, resulting in a single stream with an S02 concentration of about 6
percent. This technique decreases machine production capacity, but it does
permit a more convenient and economical recovery of the S02 by sulfuric acid
plants and other control methods.
Without weak gas recirculation, the end portion of the sinter machine
acts as a cooling zone for the sinter and, consequently, assists in the reduc-
tion of dust formation during product discharge and screening. However, when
recirculation is used, sinter is usually discharged at 400° to 500°C (745° to
950°F), with an attendant increase in particulate. Methods to reduce these
dust quantities include recirculatng offgases through the sinter bed (to use
the bed as a filter) or ducting gases from the sinter machine discharge through
a particulate collection device and then to the atmosphere. Because reaction
activity has ceased in the discharge area, these gases contain little S02«
7.6-4 EMISSION FACTORS 10/86
-------
Particulate emissions from sinter machines range from 5 to 20 percent of
the concentrated ore feed. In terms of product weight, a typical emission is
estimated to be 106.5 kilograms per megagram (213 pounds per ton) of lead
produced. This value, and other particulate and S02 factors, appears in Table
7.6-1.
Typical material balances from domestic lead smelters indicate that about
15 percent of the sulfur in the ore concentrate fed to the sinter machine is
eliminated in the blast furnace. However, only half of this amount, about 7
percent of the total sulfur in the ore, is emitted as SC>2.
The remainder is captured by the slag. The concentration of this S02
stream can vary from 1.4 to 7.2 grams per cubic meter (500 to 2500 parts per
million) by volume , depending on the amount of dilution air injected to oxidize
the carbon monoxide and to cool the stream before baghouse particulate removal.
Particulate emissions from blast furnaces contain many different kinds of
material, including a range of lead oxides, quartz, limestone, iron pyrites,
iron-lime-silicate slag, arsenic, and other metallic compounds associated with
lead ores. These particles readily agglomerate and are primarily submicron in
size, difficult to wet, and cohesive. They will bridge and arch in hoppers.
On average, this dust loading is quite substantial, as is shown in Table 7.6-1.
Minor quantities of particulates are generated by ore crushing and mater-
ials handling operations, and these emission factors are also presented in
Table 7.6-1.
TABLE 7.6-1. UNCONTROLLED EMISSION FACTORS FOR PRIMARY LEAD SMELTING3
EMISSION FACTOR RATING: B
Particulate
Process
kg/Mg
Ib/ton
Sulfur dioxide
kg/Mg Ib/ton
Ore crushing^
Sintering (updraft)c
Blast furnaced
Dross reverberatory furnace6
Materials handling*
1.0
106.5
180.5
10. 0
2.5
2.0
213.0
361.0
20.0
5.0
_,
275.0
22.5
Neg
™ •
_
550.0
45.0
Neg
""
aBased on quantity of lead produced. Dash = no data. Neg = negligible.
bReference 2. Based on quantity of ore crushed. Estimated from similar
nonferrous metals processing.
cReferences 1, 5-7.
References 1-2, 8.
eReference 2.
fReference 2. Based on quantity of materials handled.
10/86
Metallurgical Industry
7.6-5
-------
Table 7.6-2 and Figure 7.6-2 present size specific emission factors for
the controlled emissions from a primary lead blast furnace. No other size
distribution data can be located for point sources within a primary lead pro-
cessing plant. Lacking definitive data, size distributions for uncontrolled
assuming that the uncontrolled size distributions for the sinter machine and
blast furnace are the same as for fugitive emissions from these sources.
Tables 7.6-3 through 7.6-7 and Figures 7.6-3 through 7.6-7 present size
specific emission factors for the fugitive emissions generated at a primary lead
processing plant. The size distribution of fugitive emissions at a primary lead
processing plant is fairly uniform, with approximately 79 percent of these
emissions at less than 2.5 micrometers. Fugitive emissions less than 0.625
micrometers in size make up approximately half of all fugitive emissions, except
from the sinter machine, where they constitute about 73 percent.
Emission factors for total fugitive particulate from primary lead smelting
processes are presented in Table 7.6-8. The factors are based on a combination
of engineering estimates, test data from plants currently operating, and test
data from plants no longer operating. The values should be used with caution,
because of the reported difficulty in accurately measuring the source emission
rates.
Emission controls on lead smelter operations are for particulate and
sulfur dioxide. The most commonly employed high efficiency particulate control
devices are fabric filters and electrostatic precipitators (ESP), which often
follow centrifugal collectors and tubular coolers (pseudogravity collectors).
Three of the six lead.smelters presently operating in the United States use
single absorption sulfuric acid plants to control SC>2 emissions from sinter
machines and, occasionally, from blast furnaces. Single stage plants can
attain sulfur oxide levels of 5.7 grams per cubic meter (2000 parts per mill-
ion) , and dual stage plants can attain levels of 1.6 grams per cubic meter (550
parts per million). Typical efficiencies of dual stage sulfuric acid plants in
removing sulfur oxides can exceed 99 percent. Other technically feasible S02
control methods are elemental Sulfur recovery plants and dimethylaniline (DMA)
and ammonia absorption processes. These methods and their representative
control efficiencies are given in Table 7.6-9.
7.6-6 EMISSION FACTORS 10/86
-------
TABLE 7.6-2. LEAD EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION FOR.
BAGHOUSE CONTROLLED BLAST FURNACE FLUE GASES3
EMISSION FACTOR RATING: C
Particle
size"
(um)
15
10
6
2.5
1.25
1.00
0.625
Total
_ . , Of
Lumuxacive mass /<•
< stated size
98
86.3
71.8
56.7
54.1
53.6
52.9
100.0
Cumulative em
kg/Mg
1.17
1.03
0.86
0.68
0.65
0.64
0.63
1.20
ission factors
Ib/ton
2.34
2.06
1.72
1.36
1.29
1.28
1.27
2.39
aReference 9.
^Expressed as aerodynamic equivalent diameter.
I I
1.20
1.00
0.80 -_
o
0.60 .2
0.625 1.0 1.25 2.5 6.0 10.0 15.0
Particle size (pm)
Figure 7.6-2. • Size specific emission factors for baghouse
controlled blast furnace.
10/86
Metallurgical Industry
7.6-7
-------
TABLE 7.6-3 UNCONTROLLED FUGITIVE EMISSION FACTORS AND PARTICLE
SIZE DISTRIBUTION FOR LEAD ORE STORAGE3
EMISSION FACTOR RATING: D
Particle
a-4 — oO
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
< stated size
91
86
80.5
69.0
61.0
59.0
54.5
100.0
Cumulative
kg/Mg
0.011
0.010
0.010
0.009
0.008
0.007
0.007
0.012
emission factors
Ib/ton
0.023
0.021
0.020
0.017
0.015
0.015
0.013
0.025
aReference 10.
^Expressed as aerodynamic equivalent diameter.
0.011 -
T3
Ol
o 0.010
u
0.009
u
T:
c
o
l/l
I/I
0.008
,5 0.007
I
0.625 1.0 1.25 2.5 6.0 10.0 15.0
Particle size (pm)
Figure 7.6-3. Size specific uncontrolled fugitive emission factors
for lead ore storage.
7.6-8
EMISSION FACTORS
10/86
-------
TABLE 7.6-4. UNCONTROLLED LEAD FUGITIVE EMISSION FACTORS AND
PARTICLE SIZE DISTRIBUTION FOR SINTER MACHINE3
EMISSION FACTOR RATING: D
Particle
SI Z C
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
< stated size
99
98
94.1
87.3
81.1
78.4
73.2
100.0
Cumulative em
kg/Mg
0.10
0.10
0.09
0.08
0.07
0.07
0.07
0.10
ission factors
Ib/ton
0.19
0.19
0.17
0.16
0.15
0.15
0.14
0.19
aReference 10.
^Expressed as aerodynamic equivalent diameter.
•o
cu
8 °-10
c
S> 0.09
c
o
0.08
0.07
_L
J L
0.625 1.0 1.25 2.5 6.0 10.0 15.0
Particle size (vim)
Figure 7.6-4. Size specific fugitive emission factors for
uncontrolled sinter machine.
10/86
Metallurgical Industry
7.6-9
-------
TABLE 7.6-5. UNCONTROLLED LEAD FUGITIVE EMISSION FACTORS AND PARTICLE
SIZE DISTRIBUTION FOR BLAST FURNACE3
EMISSION FACTOR RATING: D
Particle
size
(um)
15
10
6
2.5
1.25
1.00
0.625
Total
< stated size
94
89
83.5
73.8
65.0
61.8
54.4
100.0
Cumulative
kg/Mg
0.11
0.11
0.10
0.09
0.08
0.07
0.06
0.12
emission factors
Ib/ton
0.23
0.21
0.20
0.17
0.15
0.15
0.13
0.24
aReference 10.
^Expressed as aerodynamic equivalent diameter.
-o
Ol
s_
4->
O
.0.11
0.09
0.08
0.07
0.06
0.05
I I
0.625 1.0 1.5 2.5 6.0 10.0 15.0
Particle size (pm) .
Figure 7.6-5. Size specific lead fugitive emission factors
for uncontrolled blast furnace.
7.6-10
EMISSION FACTORS
10/86
-------
TABLE 7.6-6.
UNCONTROLLED LEAD FUGITIVE EMISSION FACTORS AND PARTICLE
SIZE DISTRIBUTION FOR DROSS KETTLE3
EMISSION FACTOR RATING: D
Particle
size"
(urn)
15
10
6
2.5
1.25
1.00
0.625.
Total
Cumulative mass %
< stated size
99
98
92.5
83.3
71.3
66.0
51.0
100.0
Cumulative
kg/Mg
0.18
0.18
0.17
0.15
0.13
0.12
0.09
0.18
emission factors
Ib/ton
0.36
0.35
0.33
0.30
0.26
0.24
0.18
0.36
aReference 10.
^Expressed as aerodynamic equivalent diameter.
•o
CD
c
o
u
c
3
l/l
i/l
0.18
0.15
0.12
0.09
0.06
j I
10/86
0.625 1.0 1.25 2.5 6.0 .10.0 15.0
Particle size (ym)
Figure 7.6-6. Size specific lead fugitive emission factors for
uncontrolled dross kettle.
Metallurgical Industry
7.6-11
-------
TABLE 7.6-7. UNCONTROLLED LEAD FUGITIVE EMISSION FACTORS AND PARTICLE
SIZE DISTRIBUTION FOR REVERBERATING FURNACE3
EMISSION FACTOR RATING: D
Particle
sizeb
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
Cumulative mass %
< stated size
99
98
92.3
80.8
67.5
61.8
49.3
100.0
Cumulative
kg/Mg
0.24
0.24
0.22
0.20
0.16
0.15
0.12
0.24
emission factors
Ib/ton
0.49
0.48
0.45
0.39
0.33
0.30
0.24
0.49
aReference 10.
^Expressed as aerodynamic equivalent diameter.
-0.25
-------
TABLE 7.6-8. UNCONTROLLED FUGITIVE EMISSION FACTORS FOR
PRIMARY LEAD SMELTING PROCESSESSa.b
Emission
points
Ore storage*3
Ore mixing and
pelletizing (crushing)
Car charging (conveyor loading,
transfer) of sinter
Sinter machine
Machine leakage0
Sinter return handling
Machine discharge,
sinter crushing, screening0
Sinter transfer to dump area
Sinter product dump area
Total building13 .
Blast furnace
Lead pouring to ladle, transferring
slag pouring0
Slag coolingd
Zinc fuming furnace vents
Dross kettleb
Reverberatory furnace leakage*3
Silver retort building
Lead casting
Parti
kg/Mg
0.012
1.13
0.25
0.34
4.50
0.75
0.10
0.005
0.10
0.47
0.24
2.30
0.24
1.50
0.90
0.44 .
zulate
Ib/ton
0.025
2.26
0.50
0.68
9.00
1.50
0.20
0.01
0.19
0.93
0.47
4.60
0.48
3.00
1.80
0.87
Emission
V o /* ^ rt f
r act o L
Rating
D
E
E
E
E
E
E
E
D '
D
E
E
D
D
E
E
a£xpressed in units/end product lead produced, except sinter operations,
which are units/sinter handled, transferred, charged.
^Reference 10.
°References 12-13. Engineering judgment, using steel sinter machine
leakage emission factor.
^Reference 2. Engineering judgment, estimated to be half the magnitude
of lead pouring and ladling operations.
10/86
Metallurgical Industry
7.6-13
-------
TABLE 7.6-9. TYPICAL CONTROL DEVICE EFFICIENCIES IN
PRIMARY LEAD SMELTING OPERATIONS
Control
method P
Centrifugal collector3
Electrostatic precipitator3
Fabric filter3
Tubular cooler (associated with waste
' heat boiler) a
Sulfuric acid plant (single contact)***0
Sulfuric acid plant (dual contact)b»d
Elemental sulfur recovery plant13*6
Dimethylaniline (DMA) absorption process*3*
Ammonia absorption process^>^
El
artici
80
95
95
70
99.5
99.5
c
rficiency i
jlate J
- 90
- 99
- 99
- 80
- 99.9
- 99.9
NA
NA
NA
range (%)
5ulfur dioxide
NA
NA
NA
NA
96 - 97
96 - 99.9
90
95 - 99
92 - 95
aReference 2. NA = not available.
^Reference 1.
cHigh particulate control efficiency from action of acid plant
gas cleaning systems. With S02 inlet concentrations 5-72, typical
outlet emission levels are 5.7 g/m3 (2000 ppm) for single contact,
1.4 g/m3 (500 ppm) for dual contact.
^Collection efficiency for a two stage uncontrolled Claus type plant.
See Section 5.18, Sulfur Recovery.
S02 inlet concentrations 4-6 %, typical outlet emission levels
are from 1.4-8.6 g/m3 (500-3000 ppm).
S02 inlet concentrations of 1.5-2.5 %, typical outlet emission
level is 3.4 g/m3 (1200 ppm).
References for Section 7.6
1. C. Darvin and F. Porter, Background Information for New Source Performance
Standards; Primary Copper, Zinc and Lead Smelters, Volume I, EPA-450/2-
74-002a, U. S. Environmental Protection Agency, Research Triangle Park.,
NC, October 1974.
2. A. E. Vandergrift, et al., Particulate Pollutant System Study, Volume I;
Mass Emissions, APTD-0743, U. S. Environmental Protection Agency, Research
Triangle Park, NC, May 1971.
3. A. Worcester'and D. H. Beilstein, "The State of the Art: Lead Recovery",
presented at the 10th Annual Meeting of the Metallurgical Society, AIME,
New York, NY, March 1971.
7-6-14 EMISSION FACTORS 10/86
-------
A. Environmental Assessment of the Domestic Primary Copper, Lead and Zinc
Industries (Prepublicatlon), EPA Contract No. 68-03-2537, Pedco Environ-
mental, Cincinnati, OH, October 1978.
5. T. J. Jacobs, Visit to St. Joe Minerals Corporation Lead Smelter,
Herculaneum, MO, Office Of Air Quality Planning And Standards, U. S.
Environmental Protection Agency, Research Triangle Park, NC, October 21,
1971.
6. T. J. Jacobs, Visit to Amax Lead Company, Boss, MO, Office Of Air Quality
Planning And Standards, U. S. Environmental Protection Agency, Research
Triangle Park, NC, October 28, 1971.
7. Written communication from R. B. Paul, American Smelting and Refining Co.,
Glover, MO, to Regional Administrator, U. S. Environmental Protection
Agency, Kansas City, MO, April 3, 1973.
8. Emission Test No. 72-MM-14, Office Of Air Quality Planning And Standards,
U. S. Environmental Protection Agency, Research Triangle Park, NC, May
1972.
9. Source Sampling Report: Emissions from Lead Smelter at American Smelting
and Refining Company, Glover, MO, July 1973 to July 23. 1973, EMB-73-
PLD-1, Office Of Air Quality Planning And Standards, U. S. Environmental
Protection Agency, Research Triangle .Park, NC, August 1974.
10. Sample Fugitive Lead Emissions From Two Primary Lead Smelters, EPA-450/3-
77-031, U. S. Environmental Protection Agency, Research Triangle Park, NC,
October 1977.
11. Silver Valley/Bunker Hill Smelter Environmental Investigation (Interim
Report), Contract No. 68-02-1343, Pedco Environmental, Durham, NC,
February 1975.
12. R. E. Iversen, Meeting with U. S. Environmental Protection Agency and A1SI
on Steel Facility Emission Factors, Office Of Air Quality Planning And
Standards, U. S. Environmental Protection Agency, Research Triangle Park,
NC, June 1976.
13. G. E. Spreight, "Best Practicable Means in the Iron and Steel Industry",
The Chemical Engineer, London, England, 271:132-139, March 1973.
14. Control Techniques for Lead Air Emissions, EPA-450/2-77-012, U. S. Envi-
ronmental Protection Agency, Research Triangle Park, NC, January 1978.
10/86 Metallurgical Industry 7.6-15
-------
7.7 PRIMARY ZINC SMELTING
7.7.1 Process Descriptionl-2
Zinc is found primarily as the sulfide ore sphalerite (ZnS). Its common
coproduct ores are lead and copper. Metal impurities commonly associated with
ZnS are cadmium (up to 2 percent) and minor quantities of germanium, gallium,
indium and thalium. Zinc ores typically contain from 3 to 11 percent zinc.
Some ores containing as little as 2 percent are recovered. Concentration at
the mine brings this to 49 to 54 percent zinc, with approximately 31 percent.
free and uncombined sulfur.
Zinc ores are processed into metallic slab zinc by two basic, processes.
Four of the five domestic U. S. zinc smelting facilities use the electrolytic
process, and one plant uses a pyrometallurgical smelting process typical of the
primary nonferrous smelting industry. A general diagram of the industry is
presented in Figure 7.7-1.
Electrolytic processing involves four major steps, roasting, leaching,
purification and electrolysis, details of which follow.
Pyrometallurigical processing involves three major steps, roasting (as
above), sintering and retorting.
Roasting is a process common to both electrolytic .and pyrometallurgical
processing. Calcine is produced by the roasting reactions in any one of three
different types of roasters, multiple hearth, suspension, or fluidized bed.
Multiple hearth roasters are the oldest type used in the United States, while
fluidized bed roasters are the most modern. The primary zinc roasting reaction
occurs between 640° and 1000°C (1300° and 1800°F), depending on the type of
roaster used, and is as follows:
2ZnS + 302 > 2ZnO + 2S02 (1)
In a multiple hearth roaster, the concentrate is blown through a series of
nine or more hearths stacked inside a brick lined cylindrical column. As the
feed concentrate drops through the furnace, it is first dried by the hot gases
passing through the hearths and then oxidized to produce calcine. The reactions
are slow and can only be sustained by the addition of fuel.
In a suspension roaster, the feed is blown into a -combustion chamber very
similar to that of a pulverized coal furnace. Additional grinding, beyond that
required for a multiple hearth furnace, is normally required to assure that
heat transfer to the material is sufficiently rapid for the desulfurization and
oxidation reactions to occur in the furnace chamber. Hearths at the bottom of
the roaster capture the larger particles, which require additional time within
the furnace to complete the desulfurization reaction.
10/86 Metallurgical Industry 7.7-1
-------
^J
•
I
C/J
M
O
Z
Tl
H
O
iun hydroxide
or sodium carbonate
O
-»v
00
Figure 7.7-1. Typical primary zinc smelting process.
-------
In a fluid!zed bed roaster, finely ground sulfide concentrates are suspend-
ed and oxidized within a pneumatically supported feedstock bed. This achieves
the lowest sulfur content calcine of the three roaster designs.
Suspension and fluidized bed roasters are superior to the multiple hearth
for several reasons. Although they emit more uncontrolled particulate, their
reaction rates are much faster, allowing greater process rates. Also, the
sulfur dioxide (862) content of the effluent streams of these two types of
roasters is significantly higher, thus permitting more efficient and economical
use of acid plants to control S02 emissions.
Leaching is the first step of electrolytic reduction, in which the zinc
oxide reacts to form aqueous zinc sulfate in an electrolyte solution containing
sulfuric acid.
ZnO + 80 -» Zn+2(aq) + S0~2(aq) + tO (2)
Single and double leach methods can be used, although the former exhibits
excessive sulfuric acid losses and poor zinc recovery. In double leaching, the
calcine is first leached in a neutral or slightly alkaline solution. The
readily soluble sulfates from the calcine dissolve, but only a portion of the
zinc oxide enters the solution. The calcine is then leached in the acidic
electrolysis recycle electrolyte. The zinc oxide is dissolved through Reaction
2, as are many of the impurities, especially iron. The electrolyte is neutral-
ized by this process, and it serves as the leach solution for.the first stage
of the calcine leaching. This recycling also serves as the first stage of
refining, since much of the dissolved iron precipitates out of the solution.
Variations on this basic procedure include the use of progressively stronger
and.hotter acid baths to bring as much of the zinc as possible into solution.
Purification is a process in which a variety of reagents are added to the
zinc laden electrolyte to force impurities to precipitate. The solid precipi-
tates are separated from the solution by filtration. The techniques used are
among the most advanced industrial applications of inorganic solution chemistry.
Processes vary from smelter to smelter, and the details are proprietary and
often patented. Metallic impurities, such as arsenic, antimony, cobalt, german-
ium, nickel and thallium, interfere severely with the electrolyte deposition of
zinc, and their final concentrations are limited to less than 0.05 milligrams
per liter (4 x 10~? pounds per gallon).
Electrolysis takes place in tanks, or cells, containing a number of closely
spaced rectangular metal plates acting as anodes (made of lead with 0.75 to 1.0
percent silver) and as cathodes (made of aluminum). A series of three major
reactions occurs within the electrolysis cells:
10/86 Metallurgical Industry 7.7-3
-------
H2S04
> . 4H+(aq) + 4e~ + 0 (3)
anode
cathode
2Zn+2 + 4e~ » 2Zn (4)
4H+(aq) + 2SO ~2(aq) » 2H,SO, (5)
Oxygen gas is released at the anode, metallic zinc is deposited at the
cathode, and sulfuric acid is regenerated within the electrolyte.
Electrolytic zinc smelters contain a large number of cells, often several
hundred. A portion of the electrical energy released in these cells dissipates
as heat. The electrolyte is continuously circulated through cooling towers,
both to lower its temperature and to concentrate the electrolyte through the
evaporation of water. Periodically, each cell is shut down and the zinc is
removed from the plates.
The final stage of electrolytic zinc smelting is the melting and casting
of the cathode zinc into small slabs, 27 kilograms (60 pounds), or large slabs,
640 to 1100 kilograms (1400 to 2400 pounds).
Sintering is the first stage of the pyrometallurgical reduction of zinc
oxide to slab zinc. Sintering removes lead and cadmium impurities by volatil-
ization and produces an agglomerated permeable mass suitable for feed to re-
torting furnaces. Downdraft sintering machines of the Dwight-Lloyd type are
used in the industry. Grate pallets are joined to form a continuous conveyor
system. Combustion air is drawn down through the grate pallets and is exhausted
to a particulate control system. The feed is a mixture of calcine, recycled
sinter and coke or coal fuel. The low boiling point oxides of lead and cadmium
are volatilized from the sinter bed and are recovered in the particulate control
system.
In retorting, because of the low boiling point of metallic zinc, 906°C
(1663°F), reduction and purification of zinc bearing minerals can be accom-
plished to a greater extent than with most minerals. The sintered zinc oxide
feed is brought into high temperature reducing atmosphere of 900° to 1499°C
(1650° to 2600°F). Under these conditions, the zinc oxide is simultaneously
reduced and volatilized to gaseous zinc:
ZnO + CO-* Zn(vapor) -I- C02 (6)
Carbon monoxide regeneration also occurs:
C02 + C-» 2CO (7)
7.7-4 EMISSION FACTORS - 10/86
-------
The zinc vapor and carbon monoxide produced pass from the main furnace to a
condenser, for zinc recovery by bubbling through a molten zinc bath.
Retorting furnaces can be heated either externally by combustion flames or
internally by electric resistance heating. The latter approach, electrothermic
reduction, is the only method currently practiced in the United States, and it
has greater thermal efficiency than do external heating methods. In a retort
furnace, preheated coke and sinter, silica and miscellaneous zinc bearing
materials are fed continuously into the top of the furnace. Feed coke serves
as the principle electrical conductor, producing heat, and it also provides the
carbon monoxide required for zinc oxide reduction. Further purification steps
can be performed on the molten metal collected in the condenser. The molten
zinc finally is cast into small slabs 27 kilograms (60 pounds), or the large
.slabs, 640 to 1000 kilograms (1400 to 2400 pounds).
Each of the two zinc smelting processes generates emissions along the
various process steps. Although the electrolytic reduction process emits less
particulate than does pyrometallurgical reduction, significant quantities of
acid mists are generated by electrolytic production steps. No data are current-
ly available to quantify the significance of these emissions.
Nearly 90 percent of the potential S02 emissions from zinc ores is released
in roasters. Concentrations of SC>2 in the exhaust gases vary with the roaster
type, but they are sufficiently high to allow recovery in an acid plant.
Typical S02 concentrations for multiple hearth, suspension, and fluidized bed
roasters are 4.5 to 6.5 percent, 10 to 13 percent, and 7 to 12 percent, respe-
ctively. Additional S02 is emitted from the sinter plant, the quantity depend-
ing on the sulfur content of the calcine feedstock. The S02 concentration of
sinter plant exhaust gases ranges from 0.1 to 2.4 percent. No sulfur controls
are used on this exhaust stream. Extensive desulfurization before electro-
thermic retorting results in practically no S02 emissions from these devices.
The majority of particulate emissions in the primary zinc smelting industry
is generated in the ore concentrate roasters. Depending on the type of roaster
used, emissions range from 3.6. to 70 percent of the concentrate feed. When
expressed in terms of zinc production, emissions are estimated to be 133 kilo-
grams per megagram (266 pounds per ton) for a multiple hearth roaster, 1000
kilograms per megagram (2000 pounds per ton) for a fluidized bed roaster,
expressed in terms of zinc production. Particulate emission controls are
generally required for the economical operation of a roaster, with cyclones and
electrostatic precipitators (ESP) the- primary methods used. No data are avail-
able for controlled particulate emissions from a roasting plant.
Controlled and uncontrolled emission factors for point sources within a
zinc smelting plant appear in Table 7.7-1. Sinter plant emission factors
should be applied carefully, because the data source is different from the only
plant currently in operation in the United States, although the technology is
identical. Additional data have been obtained for a vertical retort, although
no examples of this type of plant are operating in the United States. Particu-
late factors also have been developed for uncontrolled emissions from an elec-
tric retort and the electrolytic process.
10/86 Metallurgical Industry 7.7-5
-------
Fugitive emission factors, have been estimated for the zinc Smelting indus-
try and are presented in Table 7.7-2. These emission factors are based on
similar operations in the steel, lead and copper industries.
TABLE 7.7-1. PARTICIPATE EMISSION FACTORS FOR
PRIMARY SLAB ZINC PROCESSING3
Process
Roasting
Multiple hearthb
Suspension0
Fluidized bedd
Sinter plant
Uncontrolled6
With cyclone^
With cyclone
and ESPf
Vertical retortS
Electric retortn
Emission
Uncontrolled Factor
kg/Mg
113
1000
1083
62.5
' NA
NA
7.15
10.0
Ib/ton
227 E
2000 E
2167 E
125 E
NA
NA
14.3 . D
20.0 E
Emission
Controlled Factor
____.-____ .__„_.. J££ J- ^ Qg
kg/Mg Ib/ton
4 8 E
24.1 48.2 D
8.25 16.5 . D
—
_ _
lectrolytic
processJ
3.3
6.6
aBased on quantity of slab zinc produced. NA = not applicable. Dash = no
data.
^•References 3-5. Averaged from an estimated 10% of feed released as
particulate emissions, zinc production rate at 60% of roaster feed rate,
and other estimates.
cReferences 3-5. Based on an average 60% of feed released as particulate
emission and a zinc production rate at 60% of roaster feed rate. Controlled
emissions based on 20% drop out in waste heat boiler and 99.5% drop out in
cyclone and ESP.
^References 3,6. Based on an average 65% of feed released as particulate
emissions and a zinc production rate of 60% of roaster feed rate.
eReference 3. Based on unspecified industrial source data.
fReference 7. Data not necessarily compatible with uncontrolled emissions.
^Reference 7.
^Reference 2. Based on unspecified industrial source data.
JReference 13.
7.7-6
EMISSION FACTORS
10/86
-------
TABLE 7.7-2. UNCONTROLLED FUGITIVE PARTICULATE EMISSION FACTORS FOR
PRIMARY SLAB ZINC PROCESSING3
EMISSION FACTOR RATING: E
Emission factor0
Process
(kg/Mg) (Ib/con)
Roasting Negligible Negligible
Sinter plantc
Wind box. 0.12 - 0.55 0.24 - 1.10
Discharge and screens 0.28-1.22 0.56-2.44
Retort building4 1.0 - 2.0 2.0 - 4.0
Casting6 1.26 2.52
aBased on quantity of slab zinc produced, except as noted.
^Reference 8.
GFrom steel industry operations for which there are emission
factors. Based on quantity of sinter produced.
^From lead industry operations.
eFrom copper industry operations.
References for Section 7.7
1. V. Anthony Cammerota, Jr., "Mineral Facts and Problems: 1980", Zinc,
Bureau Of Mines, U. S. Department Of Interior, Washington, DC, 1980.
2. Environmental Assessment of the Domestic Primary Copper, Lead and Zinc
Industries, EPA-600/2-82-066, U. S. Environmental Protection Agency,
Cincinnati, OH, October 1978.
3.. Particulate Pollutant System Study, Volume I; Mass Emissions, APTD-0743,
U. S. Environmental Protection Agency, Research Triangle Park, NC, May
1971.
4. G. Sallee, personal communication anent Reference 3, Midwest Research
Institute, Kansas City, MO, June 1970.
5. Systems Study for Control of Emissions in the Primary Nonferrous Smelting
Industry, Volume I, APTD-1280, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1969.
6. Encyclopedia of Chemical Technology, John Wiley and Sons, Inc., New York,
NY, 1967.
10/86 Metallurgical Industry 7.7-7
-------
7. Robert B. Jacko and David W. Nevendorf, "Trace Metal Emission Test Results
from a Number of Industrial and Municipal Point Sources", Journal of the
Air Pollution Control Association, 27Jt 10):989-994, October 1977.
8. Technical Guidance for Control of Industrial Process Fugitive Particulate
Emissions, EPA-450/3-77-010, U. S. Environmental Protection Agency,
Research Triangle Park, NC, March 1977.
9. Linda J. Duncan and Edwin L. Keitz, "Hazardous Particulate Pollution from
Typical Operations in the Primary Non-ferrous Smelting Industry", presented
at the 67th Annual Meeting of the Air Pollution Control Association,
Denver, CO, June 9-13, 1974.
10. Environmental Assessment Data Systems, FPEIS Test Series No. 3, U. S.
Environmental Protection Agency, Research Triangle Park, NC. •
11. Environmental Assessment Data Systems, FPEIS Test Series No. 44, U. S.
Environmental Protection Agency, Research Triangle Park, NC.
12. R. E. Lund, et al., "Josephtown Electrothermic Zinc Smelter of St. Joe
Minerals Corporation", AIME Symposium on Lead and Zinc, Volume II, 1970.
13. Background Information For New Source Performance Standards: Primary
Copper, Lead and Zinc Smelters, EPA-450/2-74-002a, U. S. Environmental
Protection Agency, Research Triangle Park, NC October 1974.
7-7-8 EMISSION FACTORS 10/86
-------
7.8 SECONDARY ALUMINUM OPERATIONS
7.8.1 General
Secondary aluminum operations involve the cleaning, melting, refining,
alloying and pouring of aluminum recovered from scrap, foundry returns and
dross. The processes used to convert scrap aluminum to secondary aluminum
products such as lightweight metal alloys for industrial castings and ingots
are presented in Figure 7.8-1. Production involves two general classes of
operations, scrap treatment and smelting/refining.
Scrap treatment involves receiving, sorting and processing scrap to
remove contaminants and to prepare the material for smelting. Processes
based on mechanical, pyrometallurgical and hydrometallurgical techniques are
used, and those employed are selected to suit the type of scrap processed.
The smelting/refining operation generally involves the following steps:
o charging o mixing
o melting o demagging
o fluxing o degassing
o alloying o skimming
o pouring
All of these steps may be involved at each facility, with process distinctions
being in the furnace type used and in emission characteristics. However, as
with scrap treatment, not all of these steps are necessarily incorporated
into the operations at a particular plant. Some steps may be combined or
reordered, depending on furnace design, scrap quality, process inputs and
product specifications.
Scrap treatment - Purchased aluminum scrap undergoes inspection upon delivery.
Clean scrap requiring no treatment is transported to storage or is charged
directly into the smelting furnace. The bulk of the scrap, however, must be
manually sorted as it passes along a steel belt conveyor... Free iron, stainless
steel, zinc, brass and oversized materials are removed. The sorted scrap
then goes to appropriate scrap treating processes or is charged directly to
the smelting furnace.
Sorted scrap is conveyed to a ring crusher or hammer mill, where the
material is shredded and crushed, with the iron torn away from the aluminum.
The crushed material is passed over vibrating screens to remove dirt and
fines, and tramp iron is removed by magnetic drums and/or belt separators.
Baling equipment compacts bulky aluminum scrap into 1x2 meter (3x6 foot)
bales.
Pure aluminum cable with steel reinforcement or insulation is cut by
alligator type shears and granulated or further reduced in hammer mills, to
separate the iron core, and the plastic coating from the aluminum. Magnetic
processing accomplishes iron remo- •'., and air classification separates the
insulation.
10/86 Metallurgical Industry 7.8-1
-------
oo
I
to
PRETHEATMENT
SMELTING/REFINING
A
PI
O
z
fc
-CHLORINE
-FLUX
-FUEL
REVERBERATORV
(CHLORINE)
SMELTING/REFINING
— FLUORINE
— FLUX
FUEL
r
REVERBERATORY
(FLUORINE)
SMELTING/REFINING
FLUX
FUEL
CRUCIBLE
SMELTING/REFINING
FLUX
ELECTRICITY
INDUCTION
SMELTING/REFINING
PRODUCT
A
H HARDENERS
O
00
Figure 7.8-1 Typical process diagram for secondary aluminum processing industry.
-------
Borings and turnings, in most cases, are treated to remove cutting oils,
greases, moisture and free iron. The processing steps involved are (a)
crushing in hammer mills or ring crushers, (b) volatilizing the moisture and
organics in a gas or oil fired rotary dryer, (c) screening the dried chips to
remove aluminum fines, (d) removing iron magnetically and (e) storing the
clean dried borings in tote boxes.
Aluminum can be recovered from the hot dross discharged from a refining
furnace by batch fluxing with a salt/cryolite mixture in a mechanically ro-
tated, refractory lined barrel furnace. The metal is tapped periodically
through a hole in its base. Secondary aluminum recovery from cold dross and
other residues from primary aluminum plants is carried out by means of this
batch fluxing in a rotary furnace. In the dry milling process, cold aluminum
laden dross and other residues are processed by milling, screening and con-
centrating to obtain a product containing at least 60-70 percent aluminum.
Ball, rod or hammer mills can be used to reduce oxides and nonmetallics to
fine powders. Separation of dirt and other unrecoverables from the metal is
achieved by screening, air classification and/or magnetic separation.
Leaching involves (a) wet milling, (b) screening, (c) drying and (d)
magnetic separation to remove fluxing salts and other non-recoverables from
drosses, skimmings and slags. First, the raw material is fed into a long
rotating drum or an attrition or ball mill where soluble contaminants are
leached. The washed material is then screened to remove fines and dissolved
salts and is dried and passed through a magnetic separator to remove ferrous
materials. The nonmagnetics then are stored or charged directly to the
smelting furnace.
In the roasting process, carbonaceous materials associated with aluminum
foil are charred and then separated from the metal product.
Sweating is a pyrometallurgical process used to recover aluminum from
high iron content scrap. Open flame reverberatory furnaces may be used.
Separation is accomplished as aluminum and other low melting constituents
melt and trickle down the hearth, through a grate and into air cooled molds
or collecting pots.. This product is termed "sweated pig". The higher melting
materials, including iron, brass and oxidation products formed during the
sweating process, are periodically removed from the furnace.
Smelting/refining - In reverberatory (chlorine) operations, reverberatory
furnaces are commonly used to convert clean sorted scrap, sweated pigs or
some untreated scrap to specification ingots, shot or hot metal. The scrap
is first charged to the furnace by some mechancial means, often through
charging wells designed to permit introduction of chips and light scrap below
the surface of a previously melted charge ("heel"). Batch processing is
generally practiced for alloy ingot production, and continuous feeding and
pouring are generally used for products having less strict specifications.
Cover fluxes are used to prevent air contact with and consequent oxidation
of the melt. Solvent fluxes react with nonmetallics such as burned coating
residues and dirt to form insolubles which float to the surface as part of
the slag.
10/86 Metallurgical Industry 7.8-3
-------
Alloying agents are charged through the forewell in amounts determined
by product specifications. Injection of nitrogen or other inert gases into
the molten metal can be used to aid in raising dissolved gases (typically
hydrogen) and intermixed solids to the surface.
Demagging reduces the magnesium content of the molten charge from
approximately 0.3 to 0.5 percent (typical scrap value) to about 0.1 percent
(typical product line alloy specification). When demagging with chlorine
gas, chlorine is injected under pressure through carbon lances to react with
magnesium and aluminum as it bubbles to the surface. Other chlorinating
agents, or fluxes, are sometimes used such as anhydrous aluminum chloride or
chlorinated organics.
In the skimming step, contaminated semisolid fluxes (dross, slag or
skimmings) are ladled from the surface of the melt and removed through the
forewell. The melt is then cooled before pouring.
The reverberatory (fluorine) process is similar to the reverberatory
(chlorine) smelting/refining, process, except that aluminum fluoride (Al?3)
is employed in the demagging step instead of chlorine. The Al?3 reacts with
magnesium to produce molten metallic aluminum and solid magnesium fluoride
salt which floats to the surface of the molten aluminum and is skimmed off.
The crucible smelting/refining process is used to melt small batches of
aluminum scrap, generally limited to 500 kg (1000 Ib) or less. The metal
treating process steps are essentially the same as those of reverberatory
furnaces.
The induction smelting/refining process is designed to produce hardeners
by blending pure aluminum and hardening agents in an electric induction
furnace. The process steps include charging scrap to the furnace, melting,
adding and blending the hardening agent, skimming, pouring and casting into
notched bars.
7.8.2 Emissions and Controls^
Table 7.8-1 presents emission factors for the 'principal emission sources
in secondary aluminum operations. Although each step in scrap treatment and
smelting/refining'is a potential source of emissions, emissions from most of
the scrap treatment operations are either not characterized here or represent
small amounts of pollutants. Table 7.8-2 presents particle size distributions
and corresponding emission factors for uncontrolled chlorine demagging and
metal refining in secondary aluminum reverberatory furnaces.
Crushing/screening and shredding/classifying produce small amounts of
metallic and nonmetallic particulate. Baling operations produce particulate
emissions, primarily dirt and alumina dust resulting from aluminum oxidation.
These processing steps are normally uncontrolled.
Burning/drying operations emit a wide range of pollutants, particulate
matter as well as VOCs. Afterburners are used generally to convert unburned
VOCs to C02 and 1^0. Other gases potentially present, depending on the compo-
sition of the organic contaminants, include chlorides, fluorides and sulfur
oxides. Oxidized aluminum fines blown out of the dryer by the combustion
7.8-4 EMISSION FACTORS 10/86
-------
TABLE 7.8-1. PARTICULATE EMISSION FACTORS FOR SECONDARY
ALUMTN'JM OPERATIONS3
Operation
Sweating furnace''
Smelting
Crucible furnace'1
Reverberatory furnace0
Chlorine demagglng
Uncontrolled
kg/Mg Ib/ton
7.25 14.5
0.95 1.9
2.15 4.3
500 1000
Electrostatic
Baghouse preclpltator
kg/Mg Ib/ton kg/Mg Ib/ton
1.65 3.3
_
0.65e 1.3e 0.65 1.3
25 50 -
Emission
factor
rating
C
C
B
a
aReference 2. Emission factors for sweating and smelting furnaces expressed as units per unit
weight of metal processed. For chlorine demagglng, emission factor Is kg/Mg (Ib/ton) of
chlorine used.
''Based on averages of two source tests.
cllncontrolled, based on averages of ten source tests. Standard deviation of uncontrolled
emission factor is 1.75 kg/Mg (3.5 Ib/ton), that of controlled factor is 0.15 kg/Ms (0.3 Ib/ton).
^Based on average of ten source tests. Standard deviation of uncontrolled emission factor is
215 kg/Mg (430 Ib/ton); of controlled factor, 18 kg/Mg (36 Ib/ton).
eThls factor may be lower If a coated baghouse Is used.
gases comprise particulate emissions. Wet scrubbers are sometimes used in
place of afterburners.
Mechanically generated dust from the rotating barrel dross furnace
constitutes the main air emission of hot dross processing. Some fumes"are
produced from the fluxing reactions. Fugitive emissions are controlled by
enclosing the barrel in a hood system and by ducting the stream to a bag-
house. Furnace offgas emissions, mainly fluxing salt fume, are controlled
by a venturi scrubber.
In dry milling, large amounts of dust are generated from the crushing,
milling, screening, air classification and materials transfer, s.teps. Leach-
ing operations may produce particulate emissions during drying. Emissions
from roasting are particulates from the charring of carbonaceous materials.
Emissions from sweating furnaces vary with the feed scrap composition.
Smoke may result from incomplete combustion of organic contaminants (e.g.,
rubber, oil and grease, plastics, paint, cardboard, paper) which may be
present. Fumes can result from oxidation of magnesium and zinc contaminants
and from fluxes in recovered drosses and skims.
Atmospheric emissions from reverberatory (chlorine) smelting/refining
represent a significant fraction of the total particulate and gaseous eff-
luents generated in the secondary aluminum industry. Typical furnace eff-
luent gases contain combustion products, chlorine, hydrogen chloride and
metal chlorides of zinc, magnesium and aluminum, aluminum oxide and various
metals and metal compounds, depending on the quality of scrap charged.
Emissions from reverberatory (fluorine) smelting/refining are similar
to those from reverberatory (chlorine) smelting/refining. The use of A1F3
10/86 Metallurgical Industry 7.8-5
-------
Particle Size Distributions and Size Specific Emission
Factors for Uncontrolled Reverberatory Furnaces
•JHCONTHOLLCD
*ci(ht 3«rctnt
iaistion factor
rticIt dl«ovctr. ua
v?«coyr ROLLED
| -•- W«ltht a«rc*n:
l Saisslon f*ctcr
PareicI* ;:i**:«r.
Figure 7.8-2. Chlorine demagging.
Figure 7.8-3. Refining.
TABLE 7.8-2.
PARTICLE SIZE DISTRIBUTIONS AND SIZE SPECIFIC EMISSION FACTORS
FOR UNCONTROLLED REVERBERATORY FURNACES IN SECONDARY ALUMINUM
OPERATIONS3
SIZE-SPECIFIC EMISSION FACTOR RATING: D
Particle size distribution"
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Chlorine
demagging
19.8
36.9
53.2
Refining
50.0
53.4
60.0
Size specific emission
factor0,
Chlorine
demagging
99.5
184.5
266.0
kg/Mg
Refining
1.08
1.15
1.30
References 4-5.
^Cumulative weight % < aerodynamic particle diameter, um.
cSize specific emission factor = total particulate emission factor x
particle size distribution, %/100. From Table 7.8-1, total particulate
emission factor for chlorine demagging is 500 kg/Mg chlorine used, and
for refining, 2.15 kg/Mg aluminum processed.
7.8-6
EMISSION FACTORS
-10/86
-------
rather than chlorine in the demagging step reduces demagging emissions.
Fluorides are emitted as gaseous fluorides (hydrogen fluoride, aluminum and
magnesium fluoride vapors, and silicon tetrafluoride) or as dusts. Venturi
scrubbers are usually used for fluoride emission control.
References for Section 7.8
1. W. M. Coltharp, et al., Multimedia Environmental Assessment of the
Secondary Nonferrous Metal Industry, Draft Final Report, 2 vols.,
EPA Contract No. 68-02-1319, Radian Corporation, Austin, XX, June 1976.
2. W. F. Hammond and S. M. Weiss, Unpublished report on air contaminant
emissions from metallurgical operations in Los Angeles County, Los
Angeles County Air Pollution Control District, July 1964.
3. R. A. Baker, et al., Evaluation of a Coated Baghouse at a Secondary
Aluminum Smelter, EPA Contract No. 68-02-1402, Environmental Science
and Engineering, Inc., Gainesville, FL, October 1976.
4. Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System (FPEIS), Series Report No. 231, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1983.
5. Environmental Assessment Data Systems, op. cit., Series Report No. 331.
6. J. A. Danielson, (ed.), Air Pollution Engineering Manual, 2nd Ed., AP-40,
U. S. Environmental Protection Agency, Research Triangle Park, NC,-May
1973. Out of Print.
7. E. J. Petkus, Precoated Baghouse Control for Secondary Aluminum Smelting,
presented at the 71st Annual Meeting of the Air Pollution Control Associ-
ation, Houston, TX, June 1978.
10/86 Metallurgical Industry 7.8-7
-------
7.10 GRAY IRON FOUNDRIES
7.10.1 General 1-5
Gray iron foundries produce gray iron castings from scrap iron, pig iron
and foundry returns by melting, alloying and molding. The production of gray
iron castings involves a number of integrated steps, which are outlined in
Figures 7.10-1 and 7.10-2. The four major production steps are raw materials
handling and preparation, metal melting, mold and core production, and casting
and finishing.
Raw Materials Handling And Preparation - Handling operations include re-
ceiving, unloading, storing and conveying of all raw materials for both furnace
charging and mold and core preparation. The major groups of raw materials re-
quired for furnace charging are metallics, fluxes and fuels. Metallic raw
materials include pig iron, iron and steel scrap, foundry returns and metal
turnings. Fluxes include carbonates (limestone, dolomite), fluoride (fluor-
spar), and carbide compounds (calcium carbide).^* Fuels include coal, oil,
natural gas and coke. Coal, oil and natural gas are used to fire reverberatory
furnaces. Coke, a derivative of coal, is used as a fuel in cupola furnaces.
Carbon electrodes are required for electric arc furnaces.
As shown in Figures 7.10-1 and 7.10-2, the raw materials, metallics and
fluxes are added to the melting furnaces directly. For electric induction
furnaces, however, the scrap metal added to the furnace charge must first be
pretreated to remove any-grease and/.or oil, which can cause'explosions. Scrap
metals may- be degreased with solvents, by centrifugation, or by preheating to
combust the organics.
In addition to the raw materials used to produce the molten raetal, a
.variety of materials is needed to prepare the sand cores and molds that form
the iron castings. Virgin sand, recycled sand and chemical additives are
combined in a sand handling system typically comprising receiving areas, con-
veyors, storage silos and bins, mixers (sand mullers), core and mold making
machines, shakeout grates, sand cleaners, and sand screening.
Raw materials are received in ships, railroad cars, trucks and containers,
then transferred by truck, loaders and conveyors to both open piles and enclosed
storage areas. When needed, the raw materials are transferred from storage to
process areas by similar means.
Metal Melting - The furnace charge includes metallics, fluxes and fuels.
The composition of the charge depends upon the specific metal characteristics
required. Table 7.10-1 lists the different chemical compositions of typical
irons produced. The three most common furnaces used in the gray iron foundry
industry are cupolas, electric arc, and electric induction furnaces.
The cupola, which is the major type of furnace used in industry today, is
typically a vertical cylindrical steel shell with either a refractory lined or
water cooled inner wall. Refractory linings usually consist of silica brick,
or dolomite or magnesium brick. Water cooled linings, which involve circulating
10/86 Metallurgical Industry 7.10-1
-------
o
N)
m
M
CO
co
M
o
z
•n
>
o
H
O
s*»
CO
PtMchoted
Strop
f~
— *J Melalllci I 1—I Pirlxulcr I
Coke
Scieeniny
Melting Unit
Cupola
EAF
Induction
Furnace Charge Preparation
Slag
Ductile
lion
Inoculation
OlKci
Melting und Catling
Waile Sand
1
1
. . L Aerulion/ I I
Screening [*-[ Coo,.||fl ^*-[
Magnetic
Separaloi
Uxiip
Knockout
>
Return
Sand
Suiid llundllng Sullen)
(0
T3
IHH
.4 I
I etndcit I i*-
Mi.ei o,
Mulle,
Coie und
for motion
I— Pulleim
Good
Scrap
Metal
Cleaning and Finitlting
A>ian«j|/ ol
Coiei and
Moldt
Core and
Mold fiepurulion
O
oo
Figure 7.10-1. Typical iron foundry diagram.
-------
o
03
e.
>-•
c
o
w
a
c
at
FINISHING
COOLING AND
CLEANING
SAND
PREPARATION
Figure 7.10-2. Emission points in .a typical iron foundry.
2-3
o
I
CO
-------
TABLE 7.10-1.
CHEMICAL COMPOSITION OF FERROUS CASTINGS
BY PERCENTAGE
Element
Gray iron
Malleable iron
(as white iron)
Ductile iron3
Steel
Carbon
Silicon
Manganese
Sulfur
Phosphorus
2.5 -
1.0 -
0.40 -
0.05 -
0.05 -
4.0
3.0
1.0
0.25
1.0
1.8
0.5
0.25
0.06-
0.06
- 3.6
- 1.9
- 0.80
- 0.20
- 0.18
3.0 - 4.0
1.4 - 2.0
0.5 - 0.8
<0.12
<0.15
<2.0b
0.2 - 0.8
0.5 - 1.0
<0.06
<0.05
aNecessary chemistry also includes 0.01 - 1.0% Mg.
^Steels are further classified by carbon content: low carbon, <0.20%;
medium carbon, 0.20 - 0.50%; high carbon, >0.50%.
water around the outer steel shell, are used to protect the furnace wall from
interior temperatures. The cupola is charged at the top with alternate layers
of coke, metallics and fluxes.2 The cupola is the only furnace type to use
coke as a fuel; combustion air used to burn the coke is introduced through
tuyeres located at the base of the cupola.2 Cupolas use either cold blast air,
air introduced at ambient temperature, or hot blast air with a regenerative
system which utilizes heat from the cupola exhaust gases to preheat the com-
bustion air.2 Iron is melted by the burning coke and flows down the cupola.
As the melt proceeds, new charges are added at the top. The flux removes non-
metallic impurities in the iron to form slag. Both the molten iron and the slag
are removed through tap holes at the bottom of the cupola. Periodically, the
heat period is completed, and the bottom of the cupola is opened to remove the
remaining unburned material. Cupola capacities range from 1.0 to 27 megagrams
per hour (1 to 30 tons per hour), with a few larger units approaching 90 mega-
grams per hour (100 tons per hour). Larger furnaces operate continuously and
are inspected and cleaned at the end of each week or melting cycle.
Electric arc furnaces (EAF) are large, welded steel cylindrical vessels
equipped with a removable roof through which three retractable carbon electrodes
are inserted. The electrodes are lowered through the roof of the furnace and
are energized by three phase alternating current, creating arcs that melt the
metallic charge with their heat. Additional heat is produced by the resistance
of the metal between the arc paths. The most common method of charging an
electric arc furnace is by removing the roof and introducing the raw materials
directly. Alternative methods include introducing the charge through a chute
cut in the roof or through a side charging door in the furnace shell . Once
the melting cycle is complete, the carbon electrodes are raised, and the roof
is removed. The vessel is tilted, and the molten iron is poured into a ladle.
Electric arc furnace capacities range from 0.23 to 59 megagrams (0.25 to 65
tons). Nine to 11 pounds of electrode are consumed per ton of metal melted.
7.10-4
EMISSION FACTORS
10/86
-------
Electric induction furnaces are either cylindrical or cup shaped refractory
lined vessels that are surrounded by electrical coils which, when energized with
high frequency alternating current, produce a fluctuating electromagnetic field
to heat the metal charge. For safety reasons, the scrap metal added to the
furnace charge is cleaned and heated before being introduced into the furnace.
Any oil or moisture on the scrap could cause an explosion in the furnace.
Induction furnaces are kept closed except when charging, skimming and tapping.
The molten metal is tapped by tilting and pouring through a hole in the side of
the vessel. Induction furnaces also may be used for metal refining in conjunc-
tion with melting in other furnaces and for holding and superheating the molten
metal before pouring (casting).
The basic melting process operations are 1) furnace charging, in which
metal, scrap, alloys, carbon, and flux are added to the furnace; 2) melting,
during which the furnace remains closed; 3) backcharging, which involves the
addition of more metal and alloys, as needed; 4) refining and treating, during
which the chemical composition is adjusted to meet product specifications; 5)
slag removing; and 6) tapping molten metal into a ladle or directly into molds.
Mold And Core Production - Molds are forms used to shape the exterior of
castings. Cores are molded sand shapes used to make the internal voids in cast-
ings. Cores are made by mixing sand with organic binders, molding the sand into
a core, and baking the core in an oven. Molds are prepared of a mixture of wet
sand, clay and organic additives to make the mold shapes, which are usually
dried with hot air. Cold setting binders are being used more frequently in both
core and mold production. The green sand mold, the most common type, uses
moist sand mixed with 4 to 6 percent clay (bentonlte) for bonding. The mixture
is 4 to 5 percent water content. Added to the mixture, to prevent casting
defects from sand expansion when the hot metal is poured, is about 5 percent
organic material, such as sea coal (a pulverized high volatility bituminous
coal), wood flour, oat hulls, pitch or similar organic matter.
Common types of gray iron cores are:
- Oil core, with typical sand binder percents of 1.0 core oil, 1.0 cereal,
and 0 to 1 pitch or resin. Cured by oven baking at 205 to 315°C (400 to
600°F), for 1 to 2 hours.
- Shell core, with sand binder typically 3 to 5 percent phenolic and/or
urea formaldehyde, with hexamine activator. Cured as a thin layer on a
heated metal pattern at 205 to 315"C (400 to 600°F), for 1 to 3 minutes.
- Hot box core, with sand binder typically 3 to 5 percent furan resin, with
phosphoric acid activator. Cured as a solid core in a heated metal pat-
tern at 205 to 315°C (400 to 600°F), for 0.5 to 1.5 minutes.
- Cold set core, with typical sand binder percents of 3 to 5 furan resin,
with phosphoric acid activator; or 1 to 2 core oil, with phosphoric acid
activator. Hardens in the core box. Cured for 0.5 to 3 hours.
- Cold box core, with sand binder typically 1 to 3 percent of each of two
resins, activated by a nitrogen diluted gas. Hardens when the green core
is gassed in the box with polyisocyanate in air. Cured for 10 to 30
seconds.
10/86 Metallurgical Industry ' 7.10-5
-------
Used sand from castings shakeout is recycled to the sand preparation area
and cleaned to remove any clay or carbonaceous buildup. The sand is then
screened and reused to make new molds. Because of process losses and discard
of a certain amount of sand because of contain!nation, makeup sand is added.
Casting And Finishing - After the melting process, molten metal is tapped
from the furnace. Molten iron produced in cupolas is tapped from the bottom of
the furnace into a trough, thence into a ladle. Iron produced in electric arc
and induction furnaces is poured directly into a ladle by tilting the furnace.
At this point, the molten iron may be treated with magnesium to produce ductile
iron. The magnesium reacts with the molten iron to nodularize the carbon in
the molten metal, giving the iron less brittl *ss. At times, the molten metal
may be inoculated with graphite to adjust ca content. The treated molten
iron is then ladled into molds and transported co a cooling area, where it
solidifies in the mold and is allowed to cool further before separation (shake-
out) from the mold and core sand. In larger, more mechanized foundries, the
molds are conveyed automatically through a cooling tunnel. In simpler found-
ries, molds are placed on an open floor space, and the molten iron is poured
into the molds and allowed to cool partially. Then the molds are placed on a
vibrating g 10 shake the mold and core sand loose from the casting. In the
simpler foun^. . >, molds, core sand and castings are separated manually, and
the sand from tne mold and core is then returned to the sand handling area.
When castings have cooled, any unwanted appendages, such as spurs, gates,
and risers, are removed. These appendages are removed with oxygen torch,
abrasive band saw, or friction cutting tools. Hand hammers may be used, in
less mechanized foundries, to knock the appendages off. After this, the cast-
ings are subjected to abrasive blast cleaning and/or tumbling to remove any
remaining mold sand or scale.
Another step in the metal melting process involves removing the slag in the
furnace through a tapping hole or door. Since the slag is lighter than molten
iron, it remains atop the molten iron and can be raked or poured out of cupola
furnaces thro, :he slag hole located above the level of the molten iron.
Electric arc auu induction furnaces are tilted backwards, and their slag is
removed through a slag door.
7.10.2 Emissions And Controls
Emissions from the raw materials handling operations are fugitive particu-
late generated from the receiving, unloading, storage and conveying of raw mate-
rials. These emissions are controlled by enclosing the major emission points
(e. g., conveyor belt transfer points) and routing air from the enclosures
through fabric filters or wet collectors. Figure 7.10-2 shows emission points
and types of emissions from a typical foundry.
Scrap preparation with heat will emit smoke, organic compounds and carbon
monoxide, and scrap preparation with solvent degreasers will emit organics.
Catalytic incinerators and afterburners can control about 95 percent of organic
and carbon monoxide emissions. (See Section 4.6, Solvent Degreasing.)
Emissions released from the melting furnaces include particulate matter,
carbon monoxide, organic compounds, sulfur dioxide, nitrogen oxides and small
quantities of chloride and fluoride compounds. The particulates, chlorides and
7.10-6 EMISSION FACTORS . 10/86
-------
fluorides are generated from incomplete combustion of coke, carbon additives,
flux additions, and dirt and scale on the scrap charge. Organic material on
the scrap, the consumption of coke in the furnace, and the furnace temperature
all affect the amount of carbon monoxide generated. Sulfur dioxide emissions,
characteristic of cupola furnaces, are attributable to sulfur in the coke.
Fine particulate fumes emitted from the melting furnaces come from the
condensation of volatilized metal and metal oxides.
During melting in an electric arc furnace, particulate emissions are gen-
erated by the vaporization of iron and the transformation of mineral additives.
These emissions occur as metallic and mineral oxides. Carbon monoxide emissions
come from the combustion of the graphite lost from the electrodes and the carbon
added to the charge.. Hydrocarbons may come from vaporization and partial
combustion of any oil remaining on the scrap iron added to the furnace charge.
The highest concentrations of furnace emissions occur during charging,
backcharging, alloying, slag removal, and tapping operations, because furnace
lids and doors are opened. Generally, these emissions escape into the furnace
building or are collected and vented through roof openings. Emission controls
for melting and refining operations usually involve venting the furnace gases
and fumes directly to a control device.. Controls for fugitive furnace
emissions include canopy hoods or special hoods near the furnace doors and
tapping hoods to capture emissions and route them to emission control systems.
High energy scrubbers and baghouses (fabric filters) are used to control
particulate emissions from cupolas and electric arc furnaces in this country. .
When properly designed and maintained, these control devices can achieve" respec-
tive efficiencies of 95 and 98 percent. A cupola with- such controls typically
has an afterburner with up to 95 percent efficiency, located in the furnace
stack, to oxidize carbon monoxide and to burn organic fumes, tars and oils.
Reducing these contaminants protects the particulate control device from poss-
ible plugging and explosion. Because induction furnaces emit negligible amounts
of hydrocarbon and carbon monoxide emissions, and relatively little particulate,
they are usually uncontrolled.-
The major pollutant emitted in mold and core production operations is par-
ticulate from sand reclaiming, sand preparation, sand mixing with binders and
additives, and mold and core forming. Organics, carbon monoxide and particulate
are emitted from core baking, and organic emissions from mold drying. Baghouses
and high energy scrubbers generally are used to control particulate from mold
and core production. Afterburners and catalytic incinerators can be used to
control organics and carbon monoxide emissions.
Particulate emissions are generated during the treatment and inoculation
of molten iron before pouring. For example, during the addition of magnesium
to molten metal to produce ductile iron, the reaction between the magnesium and
molten iron is very violent, accompanied by emissions of magnesium oxides and
metallic fumes. Emissions from pouring consist of hot metal fumes, and carbon
monoxide, organic compounds and particulate evolved from the mold and core
materials contacting the molten iron. Emissions from pouring normally are
captured by a collection system and vented, either controlled or uncontrolled,
to the atmosphere. Emissions continue as the molds cool. A significant quan-
tity of particulate is also generated during the casting shakeout operation.
These fugitive emissions must be captured, and they usually are controlled by
10/86 Metallurgical Industry 7.10-7
-------
either high energy scrubbers or bag filters.
Finishing operations emit large, coarse particles during the removal of
burrs, risers and gates, and during shot blast cleaning. These emissions are
easily controlled by cyclones and baghouses.
Emission factors for total particulate from gray iron furnaces are pre-
sented in Table 7.10-2, and emission factors for gaseous and lead pollutants
are given in Table 7.10-3. Tables 7.10-4 and 7.10-5, respectively, give factors
for ancillary process operations and fugitive sources and for specific particle
sizes. Particle size factors and distributions are presented also in Figures
7.10-3 through 7.10-8.
TABLE 7.10-2. EMISSION FACTORS FOR GRAY IRON FURNACES3
Process Control
device
Cupola Uncontrolled*5
Scrubber0
Venturi scrubber'*
Electrostatic
precipitatore
Baghouse^
Single wet capg
Impingement scrubber^
High energy scrubberS
Electric arc furnace Uncontrolled"
BaghouseJ
Electric induction
furnace Uncontrolled*
Bag house™
Reverberatory Uncontrolled11
Baghouse"1
Total Emission
particulate Factor
Rating
kg/Mg Ib/ton
6.9
1.6
1.5
0.7
0.3
4.0
2.5
0.4
6.3
0.2
0.5
0.1
1.1
0.1
13.8
3.1
3.0
1.4
0.7
8.0
5.0
0.8
12.7
0.4
0.9
0.2
2.1
0.2
C
C
C
E
C
' B
B.
B
C
C
D
E
D
E
aExpressed as weight of pollutant/weight of gray iron produced.
References 1,7,9-10.
cReferences 12,15. Includes averages for wet-cap and other scrubber types not
already listed.
References 12,17,19.
References 8,11.
^References 12-14.
gReferences 8,11,29-30.
References 1,6,23.
JReferences 6,23-24.
References 1,12. For metal melting only.
""Reference 4.
nReference 1.
7.10-8
EMISSION FACTORS
10/86
-------
o
I
VO
TABLE 7.10-3. GASEOUS AND LEAD EMISSION FACTORS FOR GRAY IRON FOUNDRIES
EMISSION FACTOR RATING: B
Furnace
type
Cupola
Uncontrolled
High energy
scrubber
Electric arce
Electric
Induction*
Reverberatory
Carbon monoxide Sulfur
kg/Mg Ib/ton kg/Mg
73C 145C 0.6Sd
- . 0.3Sd
0.5-19 1-37 Neg
Neg Neg Neg
_
Volatile organic
dioxide Nitrogen oxides compounds Lead"
Ib/ton kg/Mg Ib/ton kg/Mg Ib/ton kg/Mg Ib/ton
1.2Sd - 0.05-0.6 0.1-1.1
0.6Sd ' T-
Neg 0.02-0.3 0.04-0.6 0.03-0.15 0.06-0.3
Neg - - 0.005-0.05 0.009-0.1
- 0.006-0.07 0.012-0.14
en
CO
M
i
n
H
o
TO
co
"Expressed aa weight of pollutant/weight of gray iron produced. Dash - no data. Neg ° negligible.
bReference8 11,31,34.
cReference 2.
Reference 4. S • Z sulfur In the coke. Ausumes 30% of sulfur is converted to SU?.
eReference 4,6.
fReferences 8,11,29-30.
CO
cr
-------
o
I
TABLE 7.10-4. PARTICIPATE EMISSION FACTORS FOR ANCILLARY PROCESS OPERATIONS
AND FUGITIVE SOURCES AT CRAY IRON FOUNDRIES
Total Emitted to
Process
Scrap and charge'
handling, heating'3
Magnesium treatment0
Inoculation"
Pouring, cooling6
Shakeoutf
Cleaning, finishing1*
Sand handlings
Core making, baking'1
Cont rol
device
Uncont rol 1 ed
UncqnC rol led
Uncont roll ed
Uncont rol led
Uncont rol ledc
Uncont rol 1 ed
Uncont rol 1 edc
Scrubber'1
BaghouseJ
Uncont rol 1 ed
emission
kg/Mg
metal
0.3
0.9
1.5 - 2.5
2.1
1.6
8.5
1.8
0.023
0.10 '
0.6
factor work environment
Ib/ton kg/Mg Ib/ton
metal metal metal
0.6 0.25 0.5
1.8 0.9 1.8
3-5
4.2
3.2
17 0.15 0.3
3.6
0.046
0.20
1.1 0.6 1.1
Emitted to
atmosphere Emission
Factor
kg/Mg Ib/ton Rating
metal metal
0.1 0.2 D
0.2 0.4 E
- - D
D
D
0.05 O.I D
- - E
D
D
0.6 1.1 D
in
en
CH
O
z
o
H
O
73
C/3
o
-~-
00
bJVplCBDCU OO WCAglll. UL pUJtULa
^Reference 4.
cReferences 1,4.
Reference 35.
eRe£erences 1,3,25.
^Reference I.
8Kg of sand/Mg of sand handled.
"References 12,27.
jReference 12.
-------
o
00
TABLE 7.1U-5.
PARTICLE SIZE DISTRIBUTION DATA AND EMISSION FACTORS
FOR GRAY IRON FOUNDRIES3
Emission Particle
Source Factor size
Rating (urn)
Cupola Furnace*5
Uncontrolled C 0.5
1.0
2.0
2.5
5.0
10". 0
15.0
Controlled by baghouse E 0.5
1.0
2.0
2.5 .
5.0
10.0
15.0
Controlled by venturi
scrubber0 C 0.5
1.0
2.0
2.5
5.0
10.0
15.0
Cumulative mass %
< stated size*5
44.3
69.1
79.6
84.0
90.1
90.1
90.6
100.0
83.4
91.5
94.2
94.9
94.9
94.9
95.0
100.0
56.0
70.2
77.4
77.7
77.7
77.7
77.7
100.0
Cumulative mass
kg/Mg metal
3.1
4.8
5.5
5.8
6.2
6.2
6.3
6.9
0.33
0.37
0.38
0.38
0.38
0.38
0.38
0.4
0.84
1.05
1.16
1.17
1.17
1.17
1.17
1.5
emission factor
Ib/ton metal
6.1
9.5
11.0
11.6
12.4
12.4
12.5
13.8
0.58
0.64
0.66
0.66
0.66
0.66
0.67
0.7
1.7
2.1
2.3
2.3
2.3
2.3
2.3
3.0
K
ft
ft)
t-<
h-
C
a
c
(A
O
I
-------
TABLE 7.10-5 (cont.).
Process
Electric arc furnace''
Uncontrolled
Pouring, cooling^
Uncontrolled
Shakeoutb
Uncontrolled
Particle
size
(um)
1.0
2.0
5.0
10.0
15.0
0.5
i.o
2.0
2.5
5.0
10.0
15.0
0.5
1.0
2.0
2.5
5.0
10.0
15.0
Cumulative mass %
< stated size"
13.0
57.5
82.0
90.0
93.5
100.0
d
19.0
20.0
24.0
34.0
49.0
72.0
100.0
23.0
37.0
41.0
42.0
44.0
70.0
99.9
100.0
Cumulative mass
kg/Mg metal
0.8
3.7
5.2
5.8
6.0
6.4
-
0.40
0.42
0.50
0.71
1.03
1.51
2.1
0.37
0.59
0.66
0.67
0.70
1.12
1.60
1.60
emission factor
Ib/ton metal
1.6
7.3
10.4
11.4
11.9
12.7
-
0.80
0.84
1.00
1.43
2.06
3.02
4.2
0.74
1.18
1.31
1.34
1.41
2.24
3.20
3.20
Emission
Factor
Rating
E
D
E
o
h—
NJ
PJ
X
c/J
M
O
z
H
O
00
o,
aExpressed as weight of pollutant/weight of metal melted (produced). Dash = no data. Mass emission
rate data available in Tables 7.10-2 and 7.10-4 to calculate size specific emission factors.
References 13,21-22,25-26. See Figures 7.10-3 through 7.10-8.
cPressure drop across venturi: approx. 102 inches of water.
^Reference 3, Exhibit VI-15. Averaged from data on two foundries. Because original test data could
not be obtained, Emission Factor Rating is E.
-------
z
UJ
o
o
99.990
99.950
99.90
99.80
99.50
99.
98.
95.
90.
80.
70.
60.
50.
40.
30.
20.
10.
5.
2.
I.
0.5
0.2
0.15
O.I
0.0
TOTAL PARTICIPATE
EMISSION RATE
_ 6.9 Kg PARTICIPATE
Mg METAL
MELTED (PRODUCED)
i i i i 111
I i i i i I
6.2
5.9
5.5
4.8
3.1
UJ
CO
Q
UJ
V
UJ
or
a.
o»
UJ
>
<
t-
UJ
I0
PARTICLE DIAMETER, micrometers
Figure 7.10-3. Particle size distribution for uncontrolled cupola.21-22
10/86
Metallurgical.Industry
7.10-13
-------
3».a^u
99.950
99.90
99.80
99.50
99.
98.
95
90.
^_
5 80.
a
£ 70.
°- 60.
ui 50,
P 40-
< 30.
| 20.
o
0 10.
5.
2.
1.
0.5
0.2
0.15
O.I
o.o
TOTAL PARTICULATE ^ * kg PARTICULATE
EMISSION RATE '"•* Mq METAL
MELTED (PRODUCED)
-
-
-
<*^- ^ — 0-0
/^
-
'-
_
- • • .
f
I
-
\ 1 Illlllll 1 Illlllll 1 Illlll
UI
|S|
(A
0.38 o
Iti
vu
0.36 ^
K
tf)
0.32 V
UI
H
<
_J
3
O
H
e
<
a.
o
UI
>
H
<
-1
3
2
0
1 METAL
2
10'
PARTICLE DIAMETER, micrometers
Figure 7.10-4.
Particle size distribution for
baghouse controlled cupola.13
7.10-14
EMISSION FACTORS
10/86
-------
UJ
o
ac
UJ
a.
o
2
o
u
yy.yyu
99.950
99.90
99.80
99.50
99.
98.
95.
90.
80.
70.
60.
j 50.
: 40.
i 30.
| 20.
«
3 10.
5.
2.
.
0.5
0.2
0:15
O.I
r»n
TOTAL PARTICIPATE , „. kg PARTICIPATE
EMISSION RATE ' LO Mg META,_
MELTED (PRODUCED)
^0— -0 0-TD
2^^
o//X^
-
-
-
-
-
-
-
-.
-
-
• i i 1 1 1 1 1 1 i i i i 1 1 1 1 1 i i i * 1 1 1
1.2
I.I
0.9
0.8
Ul
IS
35
o
lu
<
_l
3
U
H
oe
<
a.
UJ
2
3
u
Ul
2
0>
2
IOW I01
PARTICLE DIAMETER, micrometers
Figure 7.10-5. Particle size distribution for venturi scrubber
controlled cupola.21-22
10/86
Metallurgical Industry
7.10-15
-------
99.990
99.93O
99.9O
99.80H
99.30
99
98
93
90
80
70
60
50
4O
30
20
u
cr
ui
2
'3
U
10
5
2
I
0.5
0.2
O.J5
O.I
TOTAL PARTICULATE= 6.4
. EMISSION RATE
0.0
10
kg PARTICIPATE
Mq METAL
MELTED (PRODUCED)
10° ,0'
PARTICLE DIAMETER, micrometers
5.9
5.7
5.2
M
V)
a
UJ
I-
<
V)
V
UJ
3.6 £
P
2
ui
Figure 7.10-6.
Particle size distribution for uncontrolled
electric arc furnace.3
7.10-16
EMISSION FACTORS
10/86
-------
** *• rf * v
99.950
99.90
99.80
99.50
99
98
95
90
j 80
j
J 70
»
J 60
L
50
> 40
»
j 30
a 20
E
3
-> JO
5
l
0.5
0.2
0.15
O.I
0.0
1C
TOTAL PARTICULATE = 2.1 Kg PARTICULATE
_ EMISSION RATE Mq METAL
MELTED (PRODUCED)
M
!•
^^ —
/
/
/
£L
J*
s^
t*—^ '.
"
-
^
~
-
-
- , •
-
Ill Illllll t 1 Illllll 1 1 Illlll
UJ
M
-------
15. Stack Test Report, DunLirk Radiator Corporation Cupola Scrubber, State
Department Of Environmental Conservation, Region IX, Albany, NY, November
1975.
16. Particulate Emission Test Report For A Scrubber Stack For A Gray Iron
Cupola At Dewey Brothers, Goldsboro, NC, Department Of Natural Resources,
Raleigh, NC, April 7, 1978.
17. Stack Test Report, Worthington Corp. Cupola, State Department Of Environ-
mental Conservation, Region IX, Albany, NY, November 4-5, 1976.
18. Stack Test Report, Dresser Clark Cupola Wet Scrubber, Orlean, NY, State
Department Of Environmental Conservation, Albany, NY, July 14 & 18, 1977.
19. Stack Test Report, Chevrolet Tonawanda Metal Casting, Plant Cupola //3 And
Cupola #4, Tonawanda, NY, State Department Of Environmental Conservation,
Albany, NY, August 1977.
20. Stack. Analysis For Particulate Emission, Atlantic States Cast Iron Foun-
dry/Scrubber, State Department Of Environmental Protection, Trenton, NJ,
September 1980.
21. S. Calvert, et al., Fine Particle Scrubber Performance, EPA-650/2-74-093,
U. S. Environmental Protection Agency, Cincinnati, OH, October 1974.
22. S. Calvert, et al., National Dust Collector Model 850 Variable Rod Module
Venturi Scrubber Evaluation, EPA-600/2-76-282, U. S. Environmental Protec-
tion Agency, Cincinnati, OH, December 1976.
23. Source Test, Electric Arc Furnace At Paxtoh-Mitchell Foundry, Omaha, NB,
Midwest Research Institute, Kansas City, MO, October 1974.
24. Source Test, John Deere Tractor Works, East Moline, IL, Gray Iron Electric
Arc Furnace, Walden Research, Wilmington, MA, July 1974
25. S. Gronberg, Characterization Of Inhalable Particulate Matter Emissions
From An Iron Foundry, Lynchburg Foundry, Archer Creek Plant, EPA-600/X-
85-328, U. S. Environmental Protection Agency, Cincinnati, OH, August 1984.
26. Particulate Emissions Measurements From The Rotoclone And General Casting
Shakeout Operations Of United States Pipe & Foundry, Inc, Anniston, AL,
State Air Pollution Control Commission, Montgomery, AL. Further informa-
tion unavailable.
27. Report Of Source Emissions Testing At Newbury Manufacturing, Tail adega, AL,
State Air Pollution Control Commission, Montgomery, AL, May 15-16, 1979,
28. Particulate Emission Test Report For A Gray Iron Cupola At Hardy And New-
son, La Grange, NC, State Department Of Natural Resources And Community
Development, Raleigh, NC, August 2-3, 1977.
29. H. R. Crabaugh, et al., "Dust And Fumes From Gray Iron Cupolas: How Are
They Controlled In Los Angeles County", Air Repair, 4^(3): 125-130, November
1954.
7.10-20 EMISSION FACTORS 10/86
-------
30. J. M. Kane, "Equipment For Cupola Control", American Foundryman's Society
Transactions, 6^:525-531, 1956.
31. Control Techniques For Lead Air Emissions, 2 Volumes, EPA-450/2-77-012, U.
S. Environmental Protection Agency, Research Triangle Park, NC, December
1977.
32. W. E. Davis, Emissions Study Of Industrial Sources Of Lead Air Pollutants,
1970, APTD-1543, U. S. Environmental Protection Agency, Research Triangle
"Park", NC, April 1973.
33. Emission Test No. EMB-71-CI-27, Office Of Air Quality Planning and Stan-
dards, U. S. Environmental Protection Agency, Research Triangle Park, NC,
February 1972.
34. Emission Test No. EMB-71-CI-30, Office Of Air Quality Planning And Stan-
dards, U. S. Environmental Protection Agency, Research Triangle Park, NC,
March 1972.
35. John Zoller, et al., Assessment Of Fugitive Particulate Emission Factors
For Industrial Processes, EPA-450/3-78-107, U. S. Environmental Protection
Agency, Research Triangle Park, NC, September 1978.
36. J. Jeffery, et al., Inhalable Particulate Source Category Report For The
Gray Iron Foundry Industry, TR-83-15-G, EPA Contract No. 68-02-3157, GCA
Corporation, Bedford, MA, July 1986.
10/86 Metallurgical Industry 7.10-21
-------
7.11 SECONDARY LEAD PROCESSING
7.11.1 Process Descriptionl-7
The secondary lead industry processes a variety of lead bearing scrap and
residue to produce lead and lead alloy ingots, battery lead oxide, and lead
pigments (Pb30^ and PbO). Processing may involve scrap pretreatment, smelting,
and refining/casting. Processes typically used in each operation are shown in
Figure 7.11-1.
Scrap pretreatment is the partial removal of metal and norjnetal contamin-
ants from leadbearing scrap and residue. Processes used for scrap pretreatment
include battery breaking, crushing and sweating. Battery breaking is the
draining and crushing of batteries, followed by manual separation of the lead
from nonmetallic materials. Oversize pieces of scrap and residues are usually
put through jaw crushers. This separated lead scrap is then mixed with other
scraps and is smelted in reverberatory or blast furnaces to separate lead from
metals with higher melting points. Rotary gas or oil furnaces usually are used
to process low lead content scrap and residue, while reverberatory furnaces are
used to process high lead content scrap. The partially purified lead is peri-
odically tapped from these furnaces for further processing in smelting furnaces
or pot furnaces.
Smelting is the production of purified lead by melting and separating lead
from metal and nonmetallic contaminants and by reducing oxides to elemental
lead. Reverberatory smelting furnaces are used to produce a semisoft lead
product that contains typically 3 to 4 percent antimony. Blast furnaces produce
hard or antimonial lead containing about 10 percent antimony.
A reverberatory furnace,to produce semisoft lead, is charged with lead
scrap, metallic battery parts, oxides, drosses, and other residues. The rever-
beratory furnace is a rectangular shell lined with refractory brick, and it is
fired directly with oil or. gas to a temperature of 1260°C (2300°F). The mater-
ial to be melted is heated by direct contact with combustion gases. The average
furnace can process about 45 megagratas per day (50 tons per day). About 47
percent of the charge is recovered as lead product and is periodically tapped
into molds or holding pots. Forty-six percent of the charge is removed as slag
and later processed in blast furnaces. The remaining 7 percent of the furnace
charge escapes as dust or fume.
Blast furnaces produce hard lead from charges containing siliceous slag
from previous runs (about 4.5 percent of the charge), scrap iron (about 4.5
percent), limestone (about 3 percent), and coke (about 5.5 percent). The re-
qaining 82.5 percent of the charge is comprised of oxides, pot furnace refining
drosses, and reverberatory slag. The proportions of rerun slags, limestone,
and coke, respectively vary to as high as 8 percent, 10 percent, and 8 percent
of the charge. Processing capacity of the blast furnace ranges from 18 to 73
megagrams per day (20 to 80 tons per day). Similar to iron cupolas, the blast
furnace is a vertical steel cylinder lined with refractory brick. Combustion
10/86 Metallurgical Industry 7.11-1
-------
5
M
CO
in
M
C
Z
"I
H
o
p=
co
Onides, flue
dust, slied
scrip
B.ilteries
Cure scrip
Drosses.
residues.
overs lie
scrap
Residues.
die scrap.
lead sheathed
cable and
• ire
Nigh lead
content
scrap
Fuel
• I lues tone
• Recycled dust
• Coke
. Slag residue
.lead ocldes
• Scrap Iron
> Rerun slag
o
00
Figure 7.11-1. Typical secondary lead smelting and refining scheme.
-------
air at 3.4 to 5.2 kilopascals (0.5 to 0.75 pounds per square inch) is introduced
through tuyeres at the bottom of the furnace. Some of the coke combusts to melt
the charge, while the remainder reduces lead oxides to elemental lead. The
furnace exhaust is from 650° to 730°C (1200° to 1350°F).
As the lead charge melts, limestone and iron float to the top of the mol-
te molten bath and form a flux that retards oxidation of the product lead. The
molten lead flows from the furnace into a holding pot at a nearly continuous
rate. The product lead constitutes roughly 70 percent of the charge. From the
holding pot, the lead is usually cast into large ingots, called pigs, or sows.
About 18 percent of the charge is recovered as slag, with about 60 percent
of this being a. sulfurous slag called matte. Roughly 5 percent of the charge
is retained for reuse, and the remaining 7 percent of the charge escapes as
dust or fume.
Refining/casting is the use of kettle type furnaces for remelting, alloy-
ing, refining, and oxidizing processes. Materials charged for remelting are
usually lead alloy ingots that require no further processing before casting.
The furnaces used for alloying, refining and oxidizing are usually gas fired,
and operating temperatures range from 370° to 480°C (700° to 900°F). Alloying
furnaces simply melt and mix ingots of lead and alloy materials. Antimony,
tin, arsenic, copper, and nickel are the most common alloying materials.
Refining furnaces are used either to remove copper and antimony for soft
lead production, or to remove arsenic, copper and nickel for hard lead
production. Sulfur may be added to the molten lead bath to remove copper.
Copper sulfide skimmed off as dross may subsequently be processed in a blast
furnace to recover residual lead..Aluminum chloride flux may be used to*
remove copper, antimony and nickel. The antimony content can be reduced to
about 0.02 percent by bubbling air through the molten lead. Residual
antimony can be removed by. adding sodium nitrate and sodium hydroxide to the
bath and skimming off the resulting dross. Dry dressing consists of adding
sawdust to the agitated mass of molten metal. The sawdust supplies carbon to
help separate globules of lead suspended in the dross and to reduce some of
the lead oxide to elemental lead.
Oxidizing furnaces, either kettle or reverberatory units, are used to
oxidize lead and to entrain the product lead oxides in the combustion air
stream, with subsequent recovery in high efficiency baghouses.
7.11.2 Emissions And Controlsl»4-5
Emission factors for controlled and uncontrolled processes and fugitive
particulate are given in Tables 7.11-1 and 7.11-2. Particulate emissions from
most processes are based on accumulated test data, whereas fugitive particulate
emission factors are based on the assumption that 5 percent of uncontrolled
stack emissions is released as fugitive emissions.
Reverberatory and blast furnaces account for the vast majority of the
total lead emissions from the secondary lead industry. The relative quantities
emitted from these two smelting processes can not be specified, because of a
lack of complete information. Most of the remaining processes are small emis-
sion sources with undefined emission characteristics.
10/86 Metallurgical Industry 7.11-3
-------
TABLE 7.11-1. EMISSION FACTORS FOR SECONDARY LEAD PROCESSING3
Pollutant
Sweating19 Leachingc
Smelting
Reverberatory
Blast (cupol«)d
Kettle Kettle Cacti
refining oxidation
Partlculate*
Uncontrolled (kg/Mg)
{lb/ton)
Controlled (kg/Mg)
(lb/ton)
Lead6
Uncontrolled (kg/Kg)
(lb/ton)
Controlled (kg/Mg)
(lb/ton)
Sulfur dioxides
Uncontrolled (kg/Mg)
(lb/ton)
Emission Factor Rating
16-35
32-70
4-8P
7-16P
Neg*
Neg
Neg
Neg
Neg
Neg
Neg
162 (87-242)8
323 (173-483)«»8
0.50 (0.26-0.77)"
1.01 (0.53-1.55)"
32 (17-48)1
65 (35-97)99I.
SReferences 8-11.
hReferences 8,11-12.
jReference 13. Lead content of kettle refining emissions Is 40Z
and of casting emissions is 36Z.
^References 1-2. Essentially all product lead oxide Is entrained in an air streaa and subsequently
recovered by baghouse with average collection efficiency >99Z. Factor represents emissions of
lead oxide chat escape a baghouse used to collect the lead oxide product. Baaed on the amount of lead
produced and represents approximate upper Unit for missions.
"References 6,8-11.
"Inferences 6,3,11-12,14-15.
PVaterences 3,5. Based on assumption that uncontrolled reverberatory furnace flu* emissions are 231 lead.
"^Reference 13. Uncontrolled reverberatory furnace Hue emissions assumed to be 23Z lead. 3lasc furnace
emissions have lead content of 34Z, based on single uncontrolled plant test.
rReference 13. Blast furnace emissions have lead content of 26Z. baaed on single controlled plant teat.
'Based on quantity of oaterlal charged to furnaces.
-7.11-4
EMISSION FACTORS
10/86
-------
TABLE 7.11-2. FUGITIVE EMISSION FACTORS FOR SECONDARY LEAD PROCESSING3
EMISSION FACTOR RATING: E
Sweating
Smelting
Kettle refining
Casting
Parti
kg/Mg
0.8 - 1.8
4.3 - 12.1
0.001
0.001
culate
Ib/ton
1.6 - 3.5b
8.7 - 24.2
0.002
0.002
Le
kg/Mg
0.2 - 0.9
0.88 - 3.5d
0.0003d
0.0004d
.ad
Ib/ton
0.4 - 1.8C
1.75 - 7.0d
0.0006d
0.0007d
aReference 16. Based on amount of lead product, except for sweating, which
is based on quantity of material charged to furnace. Fugitive emissions
estimated to be 5% of uncontrolled stack emissions.
^Reference 1. Sweating furnace emissions estimated from nonlead secondary
nonferrous processing industries.
GReferences 3,5. Assumes 23% lead content of uncontrolled blast furnace
flue emissions.
^Reference 13.
Emissions from battery breaking are mainly of sulfuric acid mist and dusts
containing dirt, battery case material and lead compounds. Emissions from
crushing are also mainly dusts.
Emissions from sweating operations are fume, dust, soot particles and
combustion products, including sulfur dioxide (S02)« The S02 emissions come
from combustion of sulfur compounds in the scrap and fuel. Dusts range in
particle size from 5 to 20 micrometers, and unagglomerated lead fumes range
from 0.07 to 0.4 micrometers, with an average diameter of 0.3. Particulate
loadings in the stack gas from reverberatory sweating range from 3.2 to 10.3
grams per cubic meter (1.4 to 4.5 grains per cubic foot). Baghouses are usually
used to control sweating emissions, with removal efficiencies exceeding 99
percent. The emission factors for lead sweating in Table 7.11-1 are based on
measurements at similar sweating furnaces in other secondary metal processing
industries, not on measurements at lead sweating furnaces.
Reverberatory smelting furnaces emit particulate and oxides of sulfur and
nitrog-en. Particulate consists of oxides, sulfides and sulfates of lead, anti-
mony, arsenic, copper and tin, as well as unagglomerated lead fume. Particulate
loadings range from to 16 to 50 grams per cubic meter (7 to 22 grains per cubic
foot. Emissions are generally controlled with settling and cooling chambers,
followed by a baghouse. Control efficiencies generally exceed 99 percent. Wet
scrubbers are sometimes used to reduce S02 emissions. However, because of the
small particles emitted from reverberatory furnaces, baghouses are more often
used than scrubbers for particulate control.
Two chemical analyses by electron spectroscopy have shown the particulate
to consist of 38 to 42 percent lead, 20 to 30 percent tin, and about 1 percent
zinc.I' particulate emissions from reverberatory smelting furnaces are esti-
mated to contain 20 percent lead.
10/86 Metallurgical Industry 7.11-5
-------
TABLE 7.11-3. EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION FOR
BAGHOUSE CONTROLLED BLAST FURNACE FLUE GASES3
EMISSION FACTOR RATING: D
Particle
sizeb
(urn)
15 .
10
6
2.5
1.25
1.00
0.625
Total
Cumulative
mass %
-------
TABLE 7.11-4.
EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION FOR UNCONTROLLED
AND BAGHOUSE CONTROLLED BLAST FURNACE VENTILATION3
EMISSION FACTOR RATING: D
Particle
size15
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
Cumulative
< stated
mass %
size
Uncontrolled Controlled
40.5
39.5
39.0
35.0
23.5
16.5
4.5
100.0
88.5
83.5
78.0
65.0
43.5
32.5
13.0
100.0
Cumulative emission factors
Uncontrolled
kg/Mg
25.7
25.1
24.8
22.2
14.9
10.5
2.9
63.5
Ib/ton
51.4
50.2
49.5
44.5
29.8
21.0
5.7
127.0
Controlled
kg/Mg
0.41
0.39
0.36
0.30
0.20
0.15
0.06
0.47
Ib/ton
0.83
0.78
0.73
0-61
0.41
0.30
0.12
0.94
aBased on lead, as produced. Includes emissions from charging,
metal and slag tapping.
cExpressed as equivalent aerodynamic particle diameter.
' 25 -
T3
01
5 20
10
C
o
l/l
in
J I
0.5
n .1 "O
U . t QJ
O
0 ->
o.i •;
Figure 7.11-3.
10/86
0.625 1.0 1.25 2.5 6.0 10.0 15.0
Particle size (pm)
Emission factors less than stated particle size for uncontrolled
and baghouse controlled blast furnace ventilation.
Metallurgical Industry
7.11-7
-------
TABLE 7.11-5. EFFICIENCIES OF PARTICULATE CONTROL EQUIPMENT
ASSOCIATED WITH SECONDARY LEAD SMELTING FURNACES
Control Furnace Control efficiency
equipment type (%)
Fabric filter3 Blast 98.4
Reverberatory 99.2
Dry cyclone plus fabric filter3 Blast 99.0
Wet cyclone plus fabric filterb Reverberatory 99.7
Settling chamber plus dry
cyclone plus fabric filter0 Reverberatory 99.8
Venturi scrubber plus demister^ Blast 99.3
3Reference 8.
^Reference 9.
^Reference 10.
dReference 14.
Particle size distributions and size specific emission factors for blast
furnace flue gases and for charging and tapping operations, respectively, 'are
presented in Tables 7.11-3 and 7.11-4, and Figures 7.11-2 and 7.11-3.
Emissions from blast furnaces occur at charging doors, the slag tap, the
lead well, and the furnace stack.. The emissions are combustion gases (including
carbon monoxide, hydrocarbons, and oxides of sulfur and nitrogen) and partic—
ulate. Emissions from the charging doors and the slag tap are hooded and rout-
ed to the devices treating the furnace stack emissions. Blast furnace partic-
ulate is smaller than that emitted from reverberatory furnaces and is suitable
for control by scrubbers or fabric filters downstream of coolers. Efficiencies
for various control devices are shown,in Table 7.11-5. In one application,
fabric filters alone captured over 99 percent of the blast furnace particulate
emissions.
Particulate recovered from the uncontrolled flue emissions at six blast
furnaces had an average lead content of 23 percent.3.5 particulate recovered
from the uncontrolled charging and tapping hoods at one blast furnace had an
average lead content of 61 percent.13 Based on- relative emission rates, lead
is 34 percent of uncontrolled blast furnace emissions. Controlled emissions
from the same blast furnace had lead content of 26 percent, with 33 percent
from flues, and 22 percent from charging and tapping operations.13 particulate
recovered from another blast furnace contained 80 to 85 percent lead sulfate and
lead chloride, 4 percent tin, 1 percent cadmium, 1 percent zinc, 0.5 percent
antimony, 0.5 percent arsenic, and less than 1 percent organic matter.18
Kettle furnaces for melting, refining and alloying are relatively minor
emission sources. The kettles are hooded, with fumes and dusts typically
7.11-8 EMISSION FACTORS 10/86
-------
vented to baghouses and recovered at efficiencies exceeding 99 percent. Twenty
measurements of the uncontrolled particulates from kettle furnaces showed a
mass median aerodynamic particle diameter of 18.9 micrometers, with particle
size ranging from 0.05 to 150 micrometers. Three chemical analyses by electron
spectroscopy showed the composition of particulate to vary from 12 to 17 percent
lead, 5 to 17 percent tin, and 0.9 to 5.7 percent zinc.^
Emissions from oxidizing furnaces are economically recovered with bag-
houses. The particulates are mostly lead oxide, but they also contain amounts
of lead and other metals. The oxides range in size from 0.2 to 0.5 micrometers.
Controlled emissions have been estimated to be 0.1 kilograms per megagram (0.2
pounds per ton) of lead product, based on a 99 percent efficient baghouse.
References for Section 7.11
1. William M. Coltharp, et al., Multimedia Environmental Assessment of the
Secondary Nonferrous Metal Industry (Draft). Contract No. 68-02-1319,
Radian Corporation, Austin, TX, June 1976.
2. H. Nack, et al., Development of an Approach to Identification of Emerging
Technology and Demonstration Opportunities, EPA-650/2-74-048, U. S. Envi-
ronmental Protection Agency, Cincinnati, OH, May 1974.
3. J. M. Zoller, et al., A Method of Characterization and Quantification of
Fugitive Lead Emissions from Secondary Lead Smelters, Ferroalloy Plants
and Gray Iron Foundries (Revised), EPA-450/3-78-003 (Revised), U. S. Envi-
ronmental Protection Agency, Research Triangle Park, NC, August 1978.
4.. Air Pollution Engineering Manual, Second Edition, AP-40, U. S. Environr-
mental Protection Agency, Research Triangle Park, NC, May 1973. Out of
Print.
5. Control Techniques for Lead Air Emissions, EPA-450/2-77-012, U. S. Envi-
ronmental Protection Agency, Research Triangle Park, NC, January 1978.
6. Background Information for Proposed New Source Performance Standards, Vol-
umes I and II: Secondary Lead Smelters and Refineries, APTD-1352a and b,
U. S. Environmental Protection Agency, Research Triangle Park, NC, June
1973.
7. J. W. Watson and K. J. Brooks, A Review of Standards of Performance for New
Stationary Sources - Secondary Lead Smelters, Contract No. 68-02-2526,
Mitre Corporation, McLean, VA, January 1979.
8. John E. Williamson, et al. , A Study of Five Source Tests on Emissions from
Secondary Lead Smelters, County of Los Angeles Air Pollution Control
District, Los Angeles, CA, February 1972.
9. Emission Test No. 72-CI-8, Office Of Air Quality Planning And Standards,
U. S. Environmental Protection Agency, Research Triangle Park, NC, July
1972.
10/86 Metallurgical Industry 7.11-9
-------
10. Emission Test No. 72-CI-7, Office Of Air Quality Planning And Standards,
U. S. Environmental Protection Agency, Research Triangle Park, NC, August
1972.
11. A. E. Vandergrift, et al., Particulate Pollutant Systems Study, Volume I:
Mass Emissions, APTD-0743, U. S. Environmental Protection Agency, Research
Triangle Park, NC, May 1971.
12. Emission Test No. 71-CI-34, Office Of Air Quality Planning And Standards,
U. S. Environmental Protection Agency, Research Triangle Park, NC, July
1972.
13. Emissions and Emission Controls at a Secondary Lead Smelter (Draft),
Contract No. 68-03-2807, Radian Corporation, Durham, NC, January 1981.
14. Emission Test No. 71-CI-33, Office Of Air Quality Planning And Standards,
U. S. Environmental Protection Agency, Research Triangle Park, NC, August
1972.
15. Secondary Lead Plant Stack Emission Sampling At General Battery Corpora-
tion, Reading, Pennsylvania, Contract No. 68-02-0230, Battelle Institute,
Columbus, OH, July 1972.
16. Technical Guidance for Control of Industrial Process Fugitive Particulate
Emissions, EPA-450/3-77-010, U. S. Environmental Protection Agency,
Research Triangle Park, NC, March 1977.
17. E. I. Hartt, An Evaluation of Continuous Particulate Monitors at A Secon-
dary Lead Smelter, M. S. Report No. 0. R.r-16, Environment Canada, Ottawa,
Canada. Date unknown.
18. J. E. Howes, et al., Evaluation of Stationary Source Particulate Measure-
ment Methods, Volume V: Secondary Lead Smelters, Contract No. 68-02-0609,
Battelle Laboratories, Columbus, OH, January 1979.
19. Silver Valley/Bunker Hill Smelter Environmental Investigation (Interim
Report), Contract No. 68-02-1343, Pedco, Inc., Cincinnati, OH, February
1975.
7-11-10 EMISSION FACTORS . 10/86
-------
8.1 ASPHALTIC CONCRETE PLANTS
8.1.1 General 1-2
Asphaltic concrete paving is a mixture of well graded, high quality ag-
gregate and liquid asphaltic cement which is heated and mixed in measured quan-
tities to produce bituminous pavement material. Aggregate constitutes over
92 weight percent of the total mixture. Aside from the amount and grade
of asphalt used, mix characteristics are determined by the relative amounts
and types of aggregate used. A certain percentage of fine aggregate (7, less
than 74 micrometers in physical diameter) is required for the production of
good quality asphaltic concrete.
Hot mix asphalt paving can be manufactured by batch mix, continuous mix
or drum mix process. Of these various processes, batch mix plants are cur-
rently predominant. However, most new installations or replacements to ex-
isting equipment are of the drum mix type. In 1980, 78 percent of the total
plants were of the conventional batch type, with 7 percent being continuous
mix facilities and 15 percent drum mix plants. Any of these plants can be
either permanent installations or portable.
Conventional Plants - Conventional plants produce finished asphaltic
concrete through either batch (Figure 8.1-1) or continuous- (Figure 8.1-2)
mixing operations. Raw aggregate normally is stockpiled near the plant at a
location where the bulk moisture content will stabilize to between 3 and
5 weight percent. .
As processing for either type of operation begins, the aggregate is
hauled from the storage piles and is placed in the appropriate hoppers of the
cold feed unit. The material is metered from the hoppers onto a conveyor belt
and is transported into a gas or oil fired rotary dryer. Because a substantial
portion of the heat is transferred by radi.ation, dryers are equipped with
flights designed to tumble the aggregate to promote drying.
As it leaves the dryer, the hot material drops into a bucket elevator
and is transferred to a set of vibrating screens and classified into as many
as four different grades (sizes). The classified material then enters the
mixing operation.
In a batch plant, the classified aggregate drops into four large bins
according to size. The operator controls the aggregate size distribution by
opening various bins over a weigh hopper until the desired mix and weight are
obtained. This material is dropped into a pug mill (mixer) and is mixed dry
for about 15 seconds. The asphalt, a solid at ambient temperature, is pumped
from a heated storage tank, weighed and injected into the mixer. Then the
hot mix is dropped into a truck and is hauled to the job site.
In a continuous plant, the dried and classified aggregate drops into a
set of small bins which collects the aggregate and meters it through a set of
feeder conveyors to another bucket elevator and into the mixer. Asphalt
is metered through the inlet end of the mixer, and retention time is
10/86 Mineral Products Industry 8.1-1
-------
g
w
CO
H
O
H
O
f.o>.M lugM,
.X FJim Ayyieyule
~Pile
Coarse Aggregate
Storage Pile
Cold
Clillvuyul
Figure 8.1-1. General process flow diagram for batch mix
asphalt paving plants.
O
00
-------
o
oo
P
n
n
r»
w
P
a
UGIMO
Exhaust to
Almospliere
Draft Fan ( Location
Dependent Upon
Type ol Secondary)
„_. Prlmary Dull
IL 'Collecl01
Fine Agyregu
Storage Pile
Couisu Aggregate
Storage Pile
Storage
Figure 8.1-2. General process flow diagram for continuous mix
asphalt paying plants.
00
-------
controlled by an adjustable dam at the opposite end. The hot mix flows out
of the mixer into a surge hopper, from which trucks are loaded.
Drum Mix Plants - The drum mix process simplifies the conventional pro-
cess by using proportioning feed controls in place of hot aggregate storage
bins, vibrating screens and the mixer. Aggregate is introduced near the
burner end of the revolving drum mixer, and the asphalt is injected midway
along the drum. A variable flow asphalt pump is linked electronically to the
aggregate belt scales to control mix specifications. The hot mix is dis-
charged from the revolving drum mixer into surge bins or storage silos. Fig-
ure 8.1-3 is a diagram of the drum mix process.
Drum mix plants generally use parallel flow design for hot burner gases
and aggregate flow. Parallel flow has the advantage of giving the mixture a
longer time to coat and to collect dust in the mix, thereby reducing partic-
ulate emissions. The amount of particulate generated within the dryer in
this process is usually lower than that generated within conventional dryers,
but because asphalt is heated to high temperatures for a long period of time,
organic emissions (gaseous and liquid aerosol) are greater than in conven-
tional plants.
Recycle Processes - In recent years, recycling of old asphalt paving has
been initiated in the asphaltic concrete industry. Recycling significantly
reduces the amount of new (virgin) rock and asphaltic cement needed to repave
an existing road. The various recycling techniques include both cold and hot
methods, with the hot processing conducted at a central plant.
In recycling, old asphalt pavement is broken.up at- a job site and is re-
moved from the road base. This material is then transported to the plant,
crushed and screened to the appropriate size for further processing. The
paving material is then heated and mixed with new aggregate (if applicable),
to which the proper amount of new asphaltic cement is added to produce a
grade of hot asphalt paving suitable for laying.
There are three methods which can be used to heat recycled asphalt pav-
ing before the addition of the asphaltic cement: direct flame heating, in-
direct flame heating, and superheated aggregate.
Direct flame heating is typically performed with a drum'mixer, wherein
all materials are simultaneously mixed in the revolving drum. The first ex-
perimental attempts at recycling used a standard drum mix plant and introduced
the recycled paving and virgin aggregate concurrently at the burner end of
the drum. Continuing problems with excessive blue smoke emissions led to
several process modifications, such as the addition of heat shields and the
use of split feeds.
One method of recycling involves a drum mixer with a heat dispersion
shield. The heat shield is installed around the burner, and additional cool-
ing air is provided to reduce the hot gases to a temperature below 430 to
650°C (800 to 1200°F), thus decreasing the amount of blue smoke. Although
now considered obsolete, a drum within a drum design has also been successfully
8.1-4 EMISSION FACTORS 10/86
-------
o
oo
w
o
a.
c
n
it
w
a.
e
CO
rt
f ina Aggregate
Storage Pile
Coarie Aggregate
Storage Pile
Aggregate Feed Bint
Exhautt
Slack
Heated Aiphall Storage Tank
Truck UK d-out
CO
Figure 8.1-3. Conural process flow diagram for drum mix asphalt
paving plants.
-------
used for recycling. Reclaimed material is introduced into the outer drum
through a separate charging chute while virgin material is introduced into
the inner drum.
Split feed drum mixers were first used for recycling in 1976 and are now
the most popular design. At about the midpoint of the drum, the recycled
bituminous material is introduced by a split feed arrangement and is heated
by both the hot gases and heat transfer from the superheated virgin aggregate.
Another type of direct flame method involves the use of a slinger conveyor to
throw recycled material into the center of the drum mixer from the discharge
end. In this process, the recycled material enters the drum along an arc,
landing approximately at the asphalt injection point.
Indirect flame heating has been performed with special drum mixers
equipped with heat exchanger tubes. These tubes prevent the mixture of
virgin aggregate and recycled paving from coming into direct contact with the
flame and the associated high temperatures. Superheated aggregate can also
be used to heat recycled bituminous material.
In conventional plants, recycled paving can be introduced either into
the pug mill or at the discharge end of the dryer, after which the tempera-
ture of the material is raised by heat from the virgin aggregate. The proper
amount of new asphaltic cement is then added to the virgin aggregate/recycle
paving mixture to produce high grade asphaltic concrete.
Tandem drum mixers can also be used to heat the recycle material. The
first drum or aggregate dryer is used to superheat the virgin aggregate, and
a second drum or dryer either heats recycled paving only or mixes and heats a-
combination of virgin and recycled material. Sufficient heat remains in the
exhaust gas from the first dryer to heat the second unit also.
3.1.2 Emissions and Controls
Emission points at batch, continuous and drum mix asphalt plants dis-
cussed below refer to Figures 8.1-1, 8.1-2 and 8.1-3, respectively.
Conventional Plants - As with most facilities in the mineral products
industry, conventional asphaltic concrete plants have two major categories of
emissions, those which are vented to the atmosphere through some type of
stack, vent or pipe (ducted sources), and those which are not confined to
ducts and vents but are emitted directly from the source to the ambient air
(fugitive sources). Ducted emissions are usually collected and transported
by an industrial ventilation system with one or more fans or air movers,
eventually to be emitted to the atmosphere through some type of stack.
Fugitive emissions result from process sources, which consist of a combina-
tion of gaseous pollutants and particulate matter, or open dust sources.
The most significant source of ducted emissions from conventional as-
phaltic concrete plants is the rotary dryer. The amount if aggregate dust
carried out of the dryer by the moving gas stream depends upon a number of
factors, including the gas velocity in the drum, the particle size distribution
8.1-6 EMISSION FACTORS I0/86
-------
of the aggregate, and the specific gravity and aerodynamic characteristics of
the particles. Dryer emissions also contain the fuel combustion products of
the burner.
There may also be some ducted emissions from the heated asphalt storage
tanks. These may consist of combustion products from the tank heater.
The major source of process fugitives in asphalt plants is enclosures
over the hot side conveying, classifying and mixing equipment which are
vented into the primary dust collector along with the dryer gas. These vents
and enclosures are commonly called a "fugitive air" or "scavenger" system.
The scavenger system may or may not have its own separate air mover device,
depending on the particular facility. The emissions captured and transported
by the scavenger system are mostly aggregate dust, but they may also contain
gaseous volatile organic compounds (VOC) and a fine aerosol of condensed
liquid particles. This liquid aerosol is created by the condensation of gas
into particles during cooling of organic vapors volatilized from the asphal-
tic cement in the pug mill. The amount of .liquid aerosol produced depends to
a large extent on the temperature of the asphaltic cement and aggregate
entering the pug mill. Organic vapor and its associated aerosol are also
emitted directly to the atmosphere as process fugitives during truck loadout,
from the bed of the truck itself during transport to the job site, and from
the asphalt storage tank, which also may contain small amounts of polycyclic
compounds.
The choice of applicable control equipment for the drier exhaust and
vent line ranges from dry mechanical collectors to scrubbers and fabric col-
lectors. Attempts to apply electrostatic precipitators have met with -little
success. Practically all plants use primary dust collection equipment like
large diameter cyclones, skimmers or settling chambers. These chambers are
often used as classifiers to return collected material to the hot elevator
and to combine it with the drier aggregate. Because of high pollutant levels,
the primary collector effluent is ducted to a secondary collection device.
Table 3.1-1 presents total particulate emission factors for conventional
asphaltic concrete plants, with the factors based on the type of control
technology employed. Size specific emission factors for conventional asphalt
plants, also based on the control of technology used, are shown in Table 3.1-2
and Figure 8.1-4. Interpolations of size data other than those shown in Fig-
ure 8.1-4 can be made from the curves provided.
There are also a number of open dust sources associated with conven-
tional asphalt plants. These include vehicle traffic generating fugitive
dust on paved and unpaved roads, handling aggregate material, and similar
operations. The number and type of fugitive emission sources associated with
a particular plant depend on whether the equipment is portable or stationary
and whether it is located adjacent to a gravel pit or quarry. Fugitive dust
may range from 0.1 micrometers to more than 300 micrometers in diameter. On
the average, 5 percent of cold aggregate feed is less than 74 micrometers
(minus 200 mesh). Dust that may escape collection before primary control
generally consists of particulate having 50 to 70 percent of the total mass
being less than 74 micrometers. Uncontrolled particulate emission factors
for various types of fugitive sources in conventional asphaltic concrete
plants can be found in Section 11.2.3 of this document.
10/86 Mineral Products Industry 8.1-7
-------
TABLE 8.1-1. EMISSION FACTORS FOR TOTAL PARTICULATE
FROM CONVENTIONAL ASPHALTIC CONCRETE PLANTS3
Type of control Emission factor
kg/Mg Ib/ton
Uncontrolled '
Precleaner
High efficiency cyclone
Spray tower
Baffle spray tower
Multiple centrifugal scrubber
Orifice scrubber
Venturi scrubber
Baghouse
22.5
7
0
0
0
0
0
0
0
.5
.85
.20
.15
.035
.02
.02
.01
45.0
15.0
1.7
0.4
0.3
0.07
0.04
0.04
0.02
References 1-2, 5-10, 14-16. Expressed in terms of
emissions per unit weight of asphaltic concrete pro-
duced. Includes both batch mix and continuous mix
.processes.
Almost all plants have at least a precleaner follow-
ing the rotary drier.
Keference 16. These factors differ from those given
in Table 8.1-6 because they are for uncontrolled
.emissions and are from an earlier survey.
Keference 15. Range of values = 0.004 - 0.0690 kg/Mg.
Average from a properly designed, installed, operated
and maintained scrubber, based on a study to develop
New Source Performance Standards.
References 14-15. Range of values = 0.013 - 0.0690
fkg/Mg.
References 14-15. Emissions from a properly de-
signed, installed, operated and maintained bag-
house, based on a study to develop New Source Per-
formance Standards. Range of values = 0.008 - 0.018
kg/Mg.
8.1-8 EMISSION FACTORS 10/86
-------
o
~~,
00
TABLE 8.1-2. SUMMARY OF SIZE SPECIFIC EMISSION FACTORS FOR CONVENTIONAL ASPHALT PLANTS3
EMISSION FACTOR RATING: D
p
n
n
o
a
£
n
r»
w
0
a
w
Cuaulative oj
Particle
8'"b
2.5 |iA
10.0 |niA
15.0 |«mA
20.0 |inA
Total laass
Uncontrolled
0.83
3.5
14
23
30
eailailon (actor
Cyclone
collector*
i.O
11
21
29
36
as i slated size (JJ
Multiple Gravity
centrifugal spruy Bagliouse
scrubbers lowers collector
67 21 33
74 27 36
80 37 40
83 39 47
84 41 54
Ci
.initiative particulale emission (actor S itated alze
Multiple
Cyclone
Uncontrolled
kg/Mg
0.19
0.78
3.1
5.3
6.8
23
Ib/ton
0.37
1.6
6.1
II
14
45
collectors
kg/Hg
0.0id
0.13
0.18
0.25
0.30
0.85
Ib/ton
O.IOd
0.26
0.36
0.50
0.60
1.7
centrifugal
acrul
kg/Hg
0.023
0.026
0.028
0.029
0.030
0.035
libers
Ib/ton
0.046
0.052
0.056
0.058
0.060
0.070
Gravity
*j>ray_
kg/Mg
0.041
0.053
0.073
0.078
0.081
0.20
toueri
Ib/ton
0.082
0.11
0.15
0.16
0.16
0.40
Baghous e .
collector
kg/Mg
0.003
0.004
0.004
0.005
0.005
0.01
Ib/Un
0.006
0.008
0.008
0.010
0.010
0.02
^Reference 23, Table 3-36. Rounded to two •ignlflcanl flgurea.
Aerodynamic dianeter.
Baaed on eaiiailon (actora (or total parllculale iliowu In Table 8.1-1. Expressed In terms of emisilona per u«ll weight of anplialtlc concrete produced.
dMg = 10* g; ton = 2,000 Ib.
Hounded to one algnldcant (igure.
00
t—•
I
-------
10.0
•o
u
VI
3
u
0.1
0.01
0.001
0.1
1. Doghouses
2. Centrifugal Scrubbers
3. Spray Towers
•1. Cyclones
5. Uncont roiled
1.0 10.0
Aerodynamic Particle Oiamerer (fj.mA)
10.0
1.0
0.1
0.01
0.001
iOO.O
Figure 8.1-4. Size specific emission factors for conventional
asphalt plants.
8.1-10
EMISSION FACTORS
10/86
-------
Drum Mix Plants - As with the other two asphaltic concrete production
processes, the most significant ducted source of particulate emissions is the
drum mixer itself. Emissions from the drum mixer consist of a gas stream with
a substantial amount of particulate matter and lesser amounts of gaseous VOC
of various species. The solid particulate generally consists of fine aggre-
gate particles entrained in the flowing gas stream during the drying process.
The organic compounds, on the other hand, result from heating and mixing of
asphalt cement inside the drum, which volatilizes certain components of the
asphalt. Once the VOC have sufficiently cooled, some condense to form the
fine liquid aerosol (particulate) or "blue smoke" plume typical of drum mix
asphalt plants.
A number of process modifications have been introduced in the newer plants
to reduce or eliminate the blue smoke problem, including installation of flame
shields, rearrangement of the flights inside the drum, adjustments, in the
asphalt injection point, and other design changes. Such modifications result
in significant improvements in the elimination of blue smoke.
Emissions from the drum mix recycle process are similar to emissions from
regular drum mix plants, except that there are more volatile crganics because
of the direct flame volatilization of petroleum derivatives contained in the
old asphalt paving. Control of liquid organic emissions in the drum mix re-
cycle process is through some type of process modification, as described above.
Table 8.1-3 provides total particulate emission factors for ducted emis-
sions in drum mix asphaltic concrete plants, with available size specific emis-
sion factors shown in Table 8.1-4 and Figure 8.1-5.
TABLE 8.1-3. TOTAL PARTICULATE EMISSION FACTORS FOR
DRUM MIX ASPHALTIC CONCRETE PLANTS3
EMISSION FACTOR RATING: B
Type of control Emission factor
kg/Mg Ib/ton
Uncontrolled
Cyclone or multiclone ,
Low energy wet scrubber
Venturi scrubber
2.45
0.34
0.04
0.02
4.9
0.67
0.07
0.04
Reference 11. Expressed in terms of emissions per
unit weight of asphaltic concrete produced. These
factors differ from those for conventional asphaltic
concrete plants because the aggregate contacts .and
is coated with asphalt early in the drum mix pro-
fess.
Either stack sprays, with water droplets injected
into the exit stack, or a dynamic scrubber with a
wet fan.
10/86 Mineral Products Industry 8.1-11
-------
TABLE 8.1-4. PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION FACTORS FOR
DRUM MIX ASPHALT PLANTS CONTROLLED BY A BAGHOUSE COLLECTOR3
EMISSION FACTOR RATING: D
Cumulative particulate emission factors
Cumulative mass $ stated £ stated size
(jjmA) Uncontrolled Controlled kg/Mg Ib/ton 10"3 kg/Mg
2.5 5.5 11 0.14 0.27 0.53
10.0 23 32 0.57 1.1 1.6
15.0 27 35 0.65 1.3 1.7
Total mass
emission •
factor 2.5 4.9 4.9
Condensable
organics8 3.9
llede
10~3 Ib/ton
1. 1
3.2
3.5
. 9.8
7.7
*
„ _._ . __ _ _ __„ __D
Expressed in terms of emissions per unit weight of asphaltic concrete produced. Mot
.generally applicable to recycle processes.
^Based on an uncontrolled emission factor of 2.45 kg/Mg (see Table 8.1-3).
Reference 23. Calculated using an overall collection efficiency of 99.3% for a
-baghouse applied to an uncontrolled emission factor of 2.45 kg/Mg.
"Includes data from two out of eight tests where ~ 30% recycled asphalt paving was
processed using a split feed process.
°Determined at outlet of a baghouse collector while plant was operating- with - 30%
recycled asphalt paving. Factors are applicable only to a direct flame heating
process with a split feed.
8.1-12
EMISSION FACTORS
10/86
-------
100.0
VI
- 10.0
I
0.1
0
U = Uncontrolled
C = 3aghaus*
u /
I
I ' 1 ! t t f 1
1.0 10.0
Aerodynamic Particle Diameter
VI
v»
0.01 I
u
3
0.001
4
J
t
~i
0.
100.0
Figure 8.1-5. Particle size distribution and size
specific emission factors for drum mix
asphaltic concrete plants.
10/86
Mineral Products Industry
8.1-13
-------
Interpolations of the data shown in Figure 8.1-5 to particle sizes other than
those indicated can be made from the curves provided.
Process fugitive emissions normally associated with batch and continuous
plants from the hot side screens, bins, elevators and pug mill have been
eliminated in the drum mix process. There may be, however, a certain amount
of fugitive VOC and liquid aerosol produced from transport and handling of
hot mix from the drum mixer to the storage silo, if an open conveyor is used,
and also from the beds of trucks. The open dust sources associated with drum
mix plants are similar to those of batch or continuous plants, with regard to
truck traffic and aggregate handling operations.
8.1.3 Representative Facility
Factors for various materials emitted from the stack of a typical
asphaltic concrete plant are given in Table 8.1-5, and the characteristics of
such a plant are shown in Table 8.1-6. With the exception of aldehydes, the
materials listed in Table 8.1-6 are also emitted from the mixer, but in con-
centrations 5 to 100 fold smaller than stack gas concentrations, and they
last only during the discharge of the mixer.
Reference 16 reports mixer emissions of SO , NO , and VOC as "less than"
values, so it is possible they may not be present at all. Particulates,
carbon monoxide, polycyclics, trace metals and hydrogen sulfide were observed
at concentrations that were small relative to stack amounts. Emissions from
the mixer are thus best treated as fugitive.
All emission factors for the typical facility are for controlled opera-
tion and are based either on average industry practice shown by survey or on
results of actual testing in a selected typical plant.
An industrial survey16 showed that over 66 percent of operating hot mix
asphalt plants use fuel oil for combustion. Possible sulfur oxide emissions
from the stack were calculated, assuming that all sulfur in the fuel oil is
oxidized to SO . . The amount of sulfur oxides actually released through the
stack may be attenuated by water scrubbers,, or even by the aggregate itself,
if limestone is being dried. Number 2 fuel oil has an average sulfur content
of 0.22 weight percent.
Emission factors for nitrogen oxides, nonmethane volatile organics, car-
bon monoxide, polycyclic organic material, and aldehydes were determined by
sampling stack gas at the representative asphalt hot mix plant.
8.1-14 EMISSION FACTORS 10/6
-------
TABLE 8.1-5. EMISSION FACTORS FOR SELECTED GASEOUS POLLUTANTS
FROM A CONVENTIONAL ASPHALTIC CONCRETE PLANT STACKa
Material emitted
Sulfur oxides (as S02)d'e
Nitrogen oxides (as N02)
Volatile organic compounds
Carbon monoxide
Polycyclic organic material
Aldehydes
Formaldehyde
2-Methylpropanal
( isobutyraldehyde )
1-Butanal
(n-butyraldehyde)
3-Methylbutanal
(isovaleraldehyde)
Emission
Factor
Rating
C
D
D
D
D
D
D
D
D
D
Emission
g/Mg
146S
18
14
19
0.013
10
0.075
0.65
1.2
8.0
factor
Ib/ton
0.292S
0.036
0.028
0.038
0.000026
0.02
0.00015
0.0013
0.0024
0.016
.Reference 16.
Particulates, carbon monoxide, polycyclics, trace metals and
hydrogen sulfide were observed in the mixer emissions at con-
centrations that were small relative to stack concentrations.
.Expressed as g/Mg and Ib/ton of asphaltic concrete produced.
rcean source test results of a 400 plant survey.
Reference 21. S = % sulfur in fuel. S02 may be attenuated
,.50% by adsorption on alkaline aggregate.
Based on limited test data from the single asphaltic concrete
plant described in Table 8.1-6.
10/86
Mineral Products Industry
8.1-15
-------
TABLE 8.1-6. CHARACTERISTICS OF A REPRESENTATIVE
ASPHALTIC CONCRETE PLANT SELECTED FOR SAMPLING3
Parameter
Plant sampled
Plant type
Production rate,
Mg/hr (tons/hr)
Mixer capacity,
Mg (tons)
Primary collector
Secondary collector
Fuel
Release agent
Stack height, m (ft)
Conventional, permanent,
batch plant
160.3 ± 16% (177 ± 16%)
3.6 (4.0)
Cyclone
Wet scrubber (venturi)
Oil
Fuel oil
15.85 (52)
Reference 16, Table 16.
References for Section 8.1
1. Asphaltic Concrete Plants Atmospheric Emissions Study, EPA Contract No.
68-02-0076, Valentine, Fisher, and Tomlinson, Seattle, WA, November 1971.
2. Guide for Air Pollution Control of Hot Mix Asphalt Plants, Information
Series 17, National Asphalt Pavement Association, Riverdale, MD, 1965.
3. R. M. Ingels, et al., "Control of Asphaltic Concrete Batching Plants in
Los Angeles County", Journal of the Air Pollution Control Association,
H)(l):29-33, January 1960.
4. H. E. Friedrich,. "Air Pollution Control Practices and Criteria for Hot
Mix Asphalt Paving Batch Plants", Journal of the Air Pollution Control
Association, 19_( 12):924-928, December 1969.
5. Air Pollution Engineering Manual, AP-40, U. S. Environmental Protection
Agency, Research Triangle Park, NC, 1973. Out of Print.
6. G. L. Allen, et al., "Control of Metallurgical and Mineral Dust and Fumes
in Los Angeles County, California", Information Circular 7627, U. S. De-
partment of Interior, Washington, DC, April 1952.
8.1-16
EMISSION FACTORS
10/86
-------
7. P. A. Kenline, Unpublished report on control of air pollutants from chem-
ical process industries, U. S. Environmental Protection Agency, Cincinnati,
OH, May 1959.
8. Private communication on particulate pollutant study between G. Sallee,
Midwest Research Institute, Kansas City, MO, and U. S. Environmental Pro-
tection Agency, Research Triangle Park, NC, June 1970.
9. J. A. Danielson, Unpublished test data from asphalt batching plants, Los
Angeles County Air Pollution Control District, Presented at Air Pollution
Control Institute, University of Southern California, Los Angeles, CA,
November 1966.
10. M. E. Fogel, et al., Comprehensive Economic Study of Air Pollution Con-
trol Costs for Selected Industries and Selected Regions. R-OU-455, U. S.
Environmental Protection Agency, Research Triangle Park, NC, February
1970.
11. Preliminary Evaluation of Air Pollution Aspects of the Drum Mix Process,
EPA-340/1-77-004, U. S. Environmental Protection Agency, Research Triangle
Park, NC, March 1976.
12. R. W. Beaty and B. M. Bunnell, "The Manufacture of Asphalt Concrete Mix-
tures in the Dryer Drum", Presented at the Annual Meeting of the Canadian
Technical Asphalt Association, Quebec City, Quebec, November 19-21, 1973.
13. J. S. Kinsey, "An Evaluation of Control Systems and Mass Emission Rates
from Dryer Drum Hot Asphalt Plants", Journal of'the Air Pollution Control
Association, 26(12):1163-1165 , December 1976.
14. Background Information for Proposed New Source Performance Standards,
APTD-1352A and B, U. S. Environmental Protection Agency, Research Triangle
Park, NC, June 1973.
15. Background Information for New Source Performance Standards, EPA 450/2-74-
003, U. S. Environmental Protection Agency, Research Triangle Park, NrC,
February 1974.
16. Z. S. Kahn and T. W. Hughes, Source Assessment: Asphalt Paving Hoc Mix,
EPA-600/2-77-107n, U. S. Environmental Protection Agency, Cincinnati, OH,
December 1977.
17. V. P. Puzinauskas and L. W. Corbett, Report on Emissions from Asphalt Hot
Mixes, RR-75-1A, The Asphalt Institute, College Park, MD, May 1975.
18. Evaluation of Fugitive Dust from Mining, EPA Contract No. 68-02-1321,
PEDCo Environmental, Inc., Cincinnati, OH, June 1976.
19. J. A. Peters and P. K..Chalekode, "Assessment of Open Sources", Presented
at the Third National Conference on Energy and the Environment, College
Corner, OH, October 1, 1975.
10/86 Mineral Products Industry 8.1-17
-------
20. Illustration of Dryer Drum Hot Mix Asphalt Plant, Pacific Environmental
Services, Inc., Santa Monica, CA, 1978.
21. Herman H. Forsten, "Applications of Fabric Filters to Asphalt Plants",
Presented at the 71st Annual Meeting of the Air Pollution Control Asso-
ciation, Houston, TX, June 1978.
22. Emission Of Volatile Organic Compounds From Drum Mix Asphalt Plants, EPA-
600/2-81-026, U. S. Environmental Protection Agency, Washington, DC,
February 1981.
23. J. S. Kinsey, Asphaltic Concrete Industry - Source Category Report, EPA-
600/7-86-038, U. S. Environmental Protection Agency, Cincinnati, OH,
October 1986.
8.1-18 EMISSION FACTORS 10/86
-------
8.3 BRICKS AND RELATED CLAY PRODUCTS
8.3.1 Process Description
The manufacture of brick and related products such as clay pipe, pottery
and some types of refractory brick involves the mining, grinding, screening and
blending of the raw materials, and the forming, cutting or shaping, drying or
curing, and firing of the final product.
Surface clays and shales are rained in open pits. Most fine clays are
found underground. After mining, the material is crushed to remove stones and
is stirred before it passes onto screens for segregation by particle size.
To start the forming process, clay is mixed with water, usually in a pug
mill. The three principal processes for forming brick are stiff mud, soft mud
and dry press. In the stiff mud process, sufficient water is added to give the
clay plasticity, and bricks are formed by forcing the clay through a die. Wire
is used in separating bricks. All structural tile and most brick are termed by
this process. The soft mud process is usually used with clay too wet tor the
stiff mud process. The clay is mixed with water to a moisture content of 20 to
30 percent, and the bricks are formed in molds. In the dry press process, clay
is mixed with a small amount of water and formed in steel molds by applying
pressure of 3.A3 to 10.28 megapascals (500 to 1500 pounds per square inch). A
typical brick manufacturing process is shown in Figure 8.3-1.
Wet.clay units that have been formed are almost completely dried before
firing, usually with waste heat from kilns. Many types of kilns are used for
firing brick, but the most common are the downdraft periodic kiln and the
tunnel kiln. The periodic kiln is a permanent brick structure with a number
of fireholes where fuel enters the furnace. Hot gases from the fuel are drawn
up over the bricks, down through them 'by underground flues, and out of the oven
to the chimney. Although lower heat recovery makes this type less efficient
than the tunnel kiln, the uniform temperature distribution leads to a good
quality product; In;most tunnel kilns, cars carrying about 1200 bricks travel
on rails through the kiln at the rate of one 1.83 meter (6 foot) car per hour.
The fire zone is located near the middle of the kiln and is stationary.
In all kilns, firing takes place in six steps: evaporation of free water,
dehydration, oxidation, vitrification, flashing, and cooling. Normally, gas or
residual oil is used for heating, but coal may be used. Total heating time
varies with the type of product, -for example, 22.9 centimeter (9 inch) refrac-
tory bricks usually require 50 to 100 hours of firing. Maximum temperatures of
about 1090°C (2000°F) are used in firing common brick.
10/86 Mineral Products Industry 8.3-1
-------
8.3.2 Emissions And Controlsl»3
Particulate matter is the primary emission in the manufacture of bricks.
The main source of dust is the materials handling procedure, which includes
drying, grinding, screening and storing the raw material. Combustion products
are emitted from the fuel consumed in the dryer and the kiln. Fluorides,
largely in gaseous form, are also emitted from brick manufacturing operations.
Sulfur dioxide may be emitted from the bricks when temperatures reach or exceed
1370°C (2500°F), but no data on such emissions are available.^
MINING
CRUSHING
Awn
STORAGE
(P)
PTTT VFTIT7TNP
(?)
cppppMTMr
(P)
FORMING
AND
CUTTING
FUEL
GLAZING
DRYING
(P)
HOT
GASES
i
KILN
STORAGE
AND
SHIPPING
(P).
Figure 8.3-1.
Basic flow diagram of brick manufacturing process,
(P = a major source of particulate emissions)
A variety of control systems may be used to reduce both particulate and
gaseous emissions. Almost any type of particulate control system will reduce
emissions from the material handling process, but good plant design and hooding
are also required to keep emissions to an acceptable level.
The emissions of fluorides can be reduced by operating the kiln at tem-
peratures below 1090°C (2000°F) and by choosing clays with low fluoride con-
tent. Satisfactory control can be achieved by scrubbing kiln gases with water,
since wet cyclonic scrubbers can remove fluorides with an efficiency of 95
percent or higher.
Table 8.3-1 presents emission factors for brick manufacturing without
controls. Table 8.3-2 presents data on particle size distribution and emission
factors for uncontrolled sawdust fired brick kilns. Table 8.3-3 presents data
on particle size distribution and emission factors for uncontrolled coal fired
tunnel brick kilns.
8.3-2
EMISSION FACTORS
10/86
-------
GO
ON
TABLE 8.3-1. EMISSION FACTORS FOR BRICK MANUFACTURING WITHOUT CONTROLS3
EMISSION FACTOR RATING: C
a
n
n
ta
O
D-
C
n
a
a
c
CO
00
.
u>
I
U)
Particulatea
Proceaa
R*w Material handling0
Drying
Grinding
Storage
Brick dryerd
Coal/ga» fired
Curing «nd firing6
Tunnel kiln
G«i fired
Oil fired
Coal fired
Coal/ga* fired
Sawduat fired
Periodic kiln
Ci* fired
Oil fired
Coil fired
kg/Mg
35
38
1?
0.006A
0.012
0.29
0.34A
0.16A
0.12
0.033
0.44
9.42
Ib/ton
70
76
34
0.012A
0.023
0.59
0.67A
0.31A
0.24
0.065
0.88
18.84'
Sulfur
kg/Mg
• -
-
-
0.55S
Ne8
1.9US
3.65S
0.3IS
-
Neg
2.93S
6.06S
oxide*
Ib/ton
-
-
-
1 .105
Neg
3.95S
7.3IS
0.62S
-
Neg
5.86S
12.I3S
Carbon monoxide
kg/Hg
-
-
-
-
0.03
0.06
0.71
-
-
0.075
0.095
1.19 •
Ib/ton
-
-
-
0.06
0.12
1.43
-
-
0.15
0.19
2.39
Volatile Organic Compounds
Nonmethane Methane
kg/Hg Ib/ton kg/Hg Ib/ton
- - - -
- - - -
_
- - - -
0.0015 0.003 0.003 0.006
0.0035 0.007 0.013 0.025
0.005 0.01 0.003 0.006
_
- - -
0.005 0.01 0.01 0.02
0.005 0.01 0.02 0.04
0.01 0.02 0.005 0.01
Nitrogen oxidei
kg/Hg
-
-
-
0.33
0.09
0.525
0.73
0.81
-
0.25
0.81
1.18
Ib/ton
-
-
-
0.66
0.18
1.05
1.45
1.61
-
0.50
1.62
2.35
fluoride*1*
kg/Mg
-
-
-
-
0.5
0.5
0.5
-
-
0.5
0.5
O.I
Ib/ton
-
-
-
-
1.0
1.0
1.0
-
-
1.0
1.0
1.0
•Expreaaed *a unite per unit weight of brick produced. One brick weigha about 2.95 kg (6.5 pounda). Daih - No data.
A • X a*h in coal. S - I aulfur in fuel. Nvg - negligible.
bReference* 1, 6-10.
ctaaed on data froo Section 8.7 on Ceramic Clay Manufacturing in tliia publication. Becauae of procea* variation
aoM itepa may be omitted. Storage lunaea apply only to that quantity of material atored.
dteference 12.
eReferencea 1, 5, 12-16.
-------
TABLE 8.3-2. PARTICLE SIZE DISTRIBUTION AND EMISSION FACTORS FOR
UNCONTROLLED SAWDUST FIRED BRICK KILNS3
EMISSION FACTOR RATING: E
Aerodynamic particle
diameter Cum)
2.5
6.0
10.0
Cumulative weight %
< stated size
36.5
63.0
82.5
?otal particulate emission
Emission factorb
(kg/Mg)
0.044
0.076
0.099
factor 0.12°
-
aReference 13.
^Expressed as cumulative weight of particulate <^ corresponding particle
size/unit weight of brick produced.
GTotal mass emission factor from Table 8.3-1.
.2 -
09 '
».
T3
« M
u
03
u -
0]
TO
XX «,
»* x>
. ••>
a o..
3
U 0.1
UNCONTROLLED
-•- U«lght percent
— Ealiiion factor
PI
3
a
O
o
-1
• 170
> « i > ; t t w
Particle diameter, pm
Figure 8.3-2. Cumulative weight percent of
particles less than stated particle diameters
for uncontrolled sawdust fired brick kilns.
8.3-4
EMISSION FACTORS
10/86
-------
TABLE 8.3-3. PARTICLE SIZE DISTRIBUTION AND EMISSION FACTORS FOR
UNCONTROLLED COAL FIRED TUNNEL BRICK KILNS3
EMISSION FACTOR RATING: E
Aerodynamic particle
diameter (um)
2.5
6.0
10.0
Cumulative weight %
<_ stated size
24.7
50.4
71.0
Total particulate emission
Emission factorb
(kg/Mg)
0.08A
0.17A
0.24A
factor 0.34AC
References 12, 17.
^Expressed as cumulative weight of particulate <_ corresponding particle
size/unit weight of brick produced. A = % ash in coal. (Use 10% if
ash content is not known).
GTotal mass emission factor from Table 8.3-1.
N
• IH4
CO
00
cu
3
4-1 >
OJ
3
E '
3 ,.,
UNCONTROLLED
Weight ocrcenc
Cslssion factor
CO
CD
CO
n
00
2
00
I t I* » »
Particle diameter, pm
Figure 8.3-3. Cumulative weight percent of
particles less than stated particle diameters
for uncontrolled coal fired tunnel brick kilns
10/86
Mineral Products Industry
1.3-5
-------
TABLE 8.3-4. PARTICLE SIZE DISTRIBUTION AND EMISSION FACTORS FOR
UNCONTROLLED SCREENING AND GRINDING OF RAW MATERIALS
FOR BRICKS AND RELATED CLAY PRODUCTSA
EMISSION FACTOR RATING: E
Aerodynamic particle
diameter (ura)
Cumulative weight %
< stated size
Emission factor^3
(kg/Mg)
2.5
6.0
10.0
0.2
0.4
7.0
0.08
0.15
2.66
Total particulate emission factor 38C
References 11, 18.
^Expressed as cumulative weight of particulate <_ corresponding
particle size/unit weight of raw material processed.
GTotal mass emission factor from Table 8.3-1.
9)
H
•o -
91
•u n
to
V
D
a •
3 i
UHcomtoiizD
Weight pcrcrac
Eals>lon factor
a
1.0 »
O
3
a
n
00
>>>>•• i* » »
Particle diameter,]
Figure 8.3-4. Cumulative weight percent of
particles less than stated particle diameters
for uncontrolled screening and grinding of raw
materials for bricks and related clay products.
8.3-6
EMISSION FACTORS
10/86
-------
References for Section 8.3
1. Air Pollutant Emission Factors, APTD-0923, U. S. Environmental Protection
Agency, Research Triangle Park, NC, April 1970.
2. "Technical Notes on Brick and Tile Construction", Pamphlet No. 9, Structural
Clay Products Institute, Washington, DC, September 1961.
3. Unpublished control techniques for fluoride emissions, U. S. Department Of
Health And Welfare, Washington, DC, May 1970.
4. M. H. Allen, "Report on Air Pollution, Air Quality Act of 1967 and Methods
of Controlling the Emission of Particulate and Sulfur Oxide Air Pollutants",
Structural Clay Products Institute, Washington, DC, September 1969.
5. F. H. Norton, Refractories, 3rd Ed, McGraw-Hill, New York, 1949.
6. K. T. Semrau, "Emissions of Fluorides from Industrial Processes: A Review",
Journal Of The Air Pollution Control Association, _7_( 2): 92-108 , August 1957.
7.. Kirk-Othmer Encyclopedia of Chemical Technology, Vol 5, 2nd Edition, John
Wiley and Sons, New York, 1964.
8. K. F. Wentzel, "Fluoride Emissions in the Vicinity of Brickworks", Staub,
25(3):45-50, March 1965.
9. "Control of Metallurgical.and Mineral Dusts and Fumes in Los Angeles
County", Information Circular No. 7627, Bureau Of Mines, U. S. Department .
Of Interior, Washington, DC, April 1952.
10. Notes on oral communication between Resources Research, Inc., Reston, VA
and New Jersey Air Pollution Control Agency, Trenton, NJ, July 20, 1969.
11. H. J. Taback, Fine Particle Emissions from Stationary and Miscellaneous
Sources in the South Coast Air Basin, PB 293 923/A.S, National Technical
Information Service, Springfield, VA, February 1979.
12. Building Brick and Structural Clay Industry - Lee Brick and Tile Co.,
Sanford, NC, EMB 80-BRK-l, U. S. Environmental Protection Agency,
Research Triangle Park, NC, April 1980.
13. Building Brick and Structural Clay Wood Fired Brick Kiln - Emission Test
Report - Chatham Brick and Tile Company, Gulf, North Carolina, EMB-80-
BRK-5, U. S. Environmental Protection Agency, Research Triangle Park, NC,
October 1980.
14. R. N. Doster and D. J. Grove, Stationary Source Sampling Report: Lee Brick
and Tile Co., Sanford. NC, Compliance Testing, Entropy Environmentalists,
Inc., Research Triangle Park, NC, February 1978.
15. R. N. Doster and D. J. Grove, Stationary Source Sampling Report: Lee Brick
and Tile Co., Sanford, NC, Compliance Testing, Entropy Environmentalists,
Inc., Research Triangle Park, NC, .June 1978.
10/86 Mineral Products Industry 8.3-7
-------
16. F. J. Phoenix and D. J. Grove, Stationary Source Sampling Report - Chatham
Brick and Tile Co., Sanford, NC, Partlculate Emissions Compliance Testing,
Entropy Environmentalists, Inc., Research Triangle Park, NC, July 1979.
17. Fine Particle Emissions Information System, Series Report No. 354, Office
Of Air Quality Planning And Standards, U. S. Environmental Protection
Agency, Research Triangle Park, NC, June 1983.
8.3-8 . EMISSION FACTORS 10/86
-------
8.6 PORTLAND CEMENT MANUFACTURING
8.6.1 Process Description1"^
Portland cement manufacture accounts for about 95 percent of the cement
production in the United States. The more than 30 raw materials used to make
cement may be divided into four basic components: line (calcareous), silica
(siliceous), alumina (argillaceous), and iron (ferriferous). Approximately
1575 kilograms (3500 pounds) of dry raw materials are required to produce 1
metric ton (2200 pounds of cement). Between 45 and 65 percent of raw material
weight is removed as carbon dioxide and water vapor. As shown in Figure 8.6-1,
the raw materials undergo separate crushing after the quarrying operation, and,
when needed for'processing, are proportioned, ground and blended by either a
dry or wet process. One barrel of cement weighs 171 kilograms (376 pounds).
In the dry process, moisture content of the raw material is reduced to less
than 1 percent, either before or during grinding. The dried materials are then
pulverized and fed directly into a rotary kiln. The kiln is a long steel cylin-
der with a refractory brick lining. It is slightly inclined, rotating about
the longitudinal axis. The pulverized raw materials are fed into the upper end,
traveling slowly to the lower end. Kilns are fired from the lower end, so that
the rising hot gases pass through the raw material. Drying, decarbonating and
calcining are accomplished as the material travels through the heated kiln and
finally burns to incipient fusion and forms the clinker. . The clinker is cooled,
mixed with about 5 weight, percent gypsum and ground to the desired fineness.
The product, cement, is then stored for later, packaging and shipment.
With the wet process, a slurry is made by adding water to the initial
grinding operation. Proportioning may take place before or after the grinding
step. After the materials are mixed, excess water is removed and final adjust-
ments are made to obtain a desired composition. This final homogeneous mixture
is fed to the kilns as a slurry of 30 to 40 percent moisture or as a wet fil-
trate of about 20 percent moisture. The burning, cooling, addition of gypsum,
and storage are then carried out, as in the dry process.
The trend in the Portland cement industry is toward the use of the dry
process of clinker production. Eighty percent of the kilns built since 1971
use the dry process, compared to 46 percent of earlier kilns. Dry process kilns
that have become subject to new source performance standards (NSPS) since 1979
commonly are either preheater or preheater/precalciner systems. Both systems
allow the sensible heat in kiln exhast gases to heat, and partially to calcine,
the raw feed before it enters the kiln.
Addition of a preheater to a dry process kiln permits use of a kiln one
half to two thirds shorter than those without a preheater, because heat transfer
to the dry feed is more efficient in a preheater than in the preheating zone of
the kiln.^ Also, because of the increased heat transfer efficiency, a preheater
kiln system requires less energy than either a wet kiln or a dry kiln without a
preheater to achieve the same amount of calcination. Wet raw feed (of 20 to 40
percent moisture) requires a longer residence time for preheating, which is
best provided in the kiln itself. Therefore, wet process plants do not use -.
10/86 Mineral Products Industry 8.6-1
-------
oo
K)
in
in
O
z
"3
H
O
QUARRYING
RAW
MATERIALS
PRIMARY AND
SECONDARY
CRUSHING
DRY MIXING
AND
BLENDING
OUST
COLLECTOR
4-
RAW
MATERIAL
PROPORTIONED
SLURRY MIXING
AND
BLENDING
-
STORAGE
KILN
FUEL
1
\-
CLINKER
COOLER
G'
STORAGE
OUST
COLLECTOR
AIR
SEPARATOR
STORAGE |—
GRINDER
Figgre 8.6-1. Basic How diagram of Portland cement manufacturing process.
O
oo
-------
preheater systems. A dry process kiln with a preheater system can us-: 50
percent less fuel than a wet process kiln.
8.6.2 Emissions And Controls1"2 »5
Particulate matter is the primary emission in the manufacture of Portland
cement. Emissions also include the normal combustion products of the fuel used
for heat in the kiln and in drying operations, including oxides of nitrogen and
small amounts of oxides of sulfur.
Sources of dust at cement plants are 1) quarrying and crushing, 2) raw
material storage, 3) grinding and blending (dry process only), 4) clinker pro-
duction and cooling, 5) finish grinding, and 6) packaging. The largest single
point of emissions is the kiln, which may be considered to have three units,
the feed system, the fuel firing system, and the clinker cooling and handling
system. The most desirable method of disposing of the dust collected by an
emissions control system is injection into the kiln burning zone for inclusion
in the clinker. If the alkali content of the raw materials is too high, how-
ever, some of the dust is discarded or treated before its return to the kiln.
The maximum alkali content of dust that can be recycled is 0.6 percent (calcu-
lated as sodium oxide). Additional sources of dust emissions are quarrying,
raw material and clinker, storage piles, conveyors, storage silos, loading/
unloading facilities, and paved/unpaved roads.
The complications of kiln burning and the large volumes of material handled
have led to the use of many control systems for dust collection. The cement
industry generally uses mechanical collectors, electric precipitators , fabric
filter (baghouse) collectors, or combinations of these to control emissions.
To avoid excessive alkali and sulfur buildup in the raw feed, some systems
have an alkali bypass exhaust gas system added between the kiln and the preheat-
er. Some of the kiln exhaust gases are ducted to the alkali bypass before the
preheater, thus reducing the alkali fraction passing through the feed. Particu-
late emissions from the bypass are collected by a separate control device.
Tables 8.6-1 through 8.6-4 give emission factors for cement manufacturing,
including factors based on particle size. Size distributions for particulate
emissions from, controlled and uncontrolled kilns and clinker coolers are also
shown in Figures 8.6-2 and 8.6-3. ,
Sulfur dioxide (SC>2) may come from sulfur compounds in the ores and in the
fuel combusted. The sulfur content of both will vary from plant to plant and
from region to region. Information on the efficacy of particulate control
devices on S02 emissions from cement kilns is inconclusive. This is because of
variability of factors such as feed sulfur content, temperature, moisture, and
feed chemical composition. Control extent will v-ary, of course, according to
the alkali and sulfur content of the raw materials and fuel. 6
Nitrogen oxides (NOx) are also formed during fuel combustion in rotary
cement kilns. The NO* emissions result from the oxidation of nitrogen in the
fuel (fuel NOx) as well as in incoming combustion air (thermal NOx). The quan-
tity of NOx formed depends on the type of fuel, its nitrogen content, combustion
temperature, etc. Like S02, a certain portion of the NC>x reacts with the alka-
line cement and thus is removed from the gas stream.
10/86 "Mineral Products Industry 8.6-3
-------
oo
1
TABLE 8.6-1. UNCONTROLLED EMISSION FACTORS FOR
EMISSION FACTOR RATING;
CEMENT MANUFACTURING3
E
Process
Partlculate" Mineral
kg/Mg ib/ton source*1
kg/Mg Ib/ton
Sulfur dloxidec
Gas 01 1
coufbustlon combustion
kg/Mg Ib/ton kg/Mg Ib/ton
Coal
combustion
kg/Mg Ib/ton
Nitrogen
oxides
kg/Mg Ib/ton
Lead
kg/Mg Ib/ton
Dry process kiln
Wet process kiln
Clinker cool ere
128
120
256
240
5.4
10.8
10.8
Neg
Ncg
2.2S 4.4S
3.6S
Neg Neg
2.2S 4. AS 3. 68
7.2S 1.4 2.8 0.06 0.12
7.2S 1:4 2.8 0.05 0.10
4.6
9.2
EMISSION FACTORS
Dryers, grinders, etc.*
Wet process 16.0 32.0 NA NA NA NA NA NA NA NA NA NA
Dry process 48.0 96.0 NA NA NA NA NA NA NA NA NA NA
"References 1-2. Expressed In terns of units of clinker produced, assuming 51 gypsum in finished .cement .
Includes fuel combustion emissions, which should not be calculated separately. Neg » negligible.
S » X sulfur In fuel. Dash » no data. NA - not applicable.
b£mlsslon Factor Rating: B .
cFactors account for reactions with alkaline dust, with no controls. One test series for gas and oil
fired wet process kilns, with limited data, suggests that 21-45Z of SCV; can be removed by reactions
with the alkaline filter, cake, if baghousea are used.
dpron sulfur In raw materials, which varies with their sources. Factors account for some residual
sulfur, because of Its alkalinity and affinity for SO^.
eKeference 8. Emission Factor Rating: D.
^Expressed In terms of units of cement produced.
0.01 0.02
0.02 0.04
O
^
oo
-------
TABLE 8.6-2. CONTROLLED PARTICIPATE EMISSION FACTORS FOR
CEMENT MANUFACTURING51
Type
of
source
Wet process kiln
Dry process kiln
Clinker cooler
Control
technology
Bag house
ESP
Mul ticlone
Mul ticyclone
+ ESP
Baghouse
Gravel bed
filter
ESP
Baghouse
Particulate
kg/Mg
clinker
0.57
0.39
130b
0.34
0.16
0.16
0.048
0.010
Ib/ton
clinker
l.l
0.78
260b
0.68
0.32
0.32
0.096
0.020
Emission
Factor
Rating
C
C
D
C
B
C
D
C
Primary limestone
crusher0 Baghouse
Primary limestone
screenc Baghouse
Secondary limestone
screen and crusherc Baghouse
Conveyor transfer0 Baghouse
Raw mill systemc»d Baghouse
.Finish mill system8 Baghouse
0.00051
0.00011
0.00.016
0.000020
0.034
0.017
0.0010
0.00022
0.00032
0.000040
0.068
0.034
D
D
D
C
aReference 8. Expressed as kg particulate/Mg (Ib particulate/ton) of clinker
produced, except as noted. ESP = electrostatic precipitator.
*>Based on a single test of a dry process kiln fired with a combination of
coke and natural gas. Not generally applicable to a broad cross section
of the cement industry.
cExpressed as mass of pollutant/mass of raw material processed.
dIncludes mill, air separator and weigh feeder.
elncludes mill, air separator(s) and one or more material transfer operations.
Expressed in terms of units of cement produced.
10/86
Mineral Products Industry
8.6-5
-------
oo
•
o>
I
TABLE 8.6-3. SIZE SPECIFIC PARTICULATE EMISSION FACTORS FOR CEMENT KILNS
EMISSION FACTOR RATING; D
a
Particle Cumulative anas X < staled slzeb
• lie
(ua) Uncontrolled Dry
Uet Dry process
Uet
process
process process kiln with kiln with
kiln kilo •ultlcloned ESP
ni
s
CO
§
"i
ft
H
O
po
to
2.5 7.0 18 3.8
5.0 20 NA 14
10.0 24 42 24
15.0 35 44 31
20.0 57 NA 38
Total aasa ealaslon factor
•Reference 8. ESP - electrostatic
bAerodynaalc dlaaeter. Percentages
64
83
85
91
98
preclpltator.
rounded to two
Baghouae
Uet Dry
process proccaa
kiln kiln
NA 45
NA 77
NA 84
NA 89
NA IUO
NA - not available.
significant figures
Cumil attve
Uncontrolled
Uet Dry
Process Process
kg/Mg-
8.4
24
29
43
68
120e
Dash - no
,
Ib/ton kg/Hg Ib/ton
17 23 46
48
58 54 108
86 57 114
136
240* 128" 256=
data.
ealsalon
factor < stated size0
Dry process
with
nul t Iclone
kg/Mg
5.0
19
32
41
49
I3U{
Ib/t
10
38
64
H2
98
260'
Wet process
with
d ESP
on kg/Mg
0.25
0.32
0.33
0.36
0.39
0.39f
Ib/ton
0.50
0.64
0.66
0.72
0.78
0.78f
Bag house
Uet Dry
process process
kg/Kg Ib/ton kg/Hg
NA NA 0.073
NA NA 0.13
NA NA 0.14
NA NA 0.15
NA NA 0.16
0.57* l.l' O.I6(
Ib/ton
0.1}
0.26
0.28
0.30
0.32
0.32f
CExpressed as unit weight of partlculate/unl t weight of clinker produced, aasualng 5X
d|a>ed on a single test, and ahould be used with csuttun.
•Proa Table 8.6-1.
(Proo Table 8.6-2.
O
^
oo
-------
IUUO.U
J
o
o
_ _
o c
IS
UJ
"
2
o 2
gu,
=» §
3
E
U
100.0
10.0
.0
0.1
i IT
1.0
Figure 8.6-2.
Uncontrolled Wef Process Kiln
Uncontrolled Dry Process Kiln
Dry Process Kiln wirh MulHclone
Wet Process Kiln wirh ESP
Dry Process Kiln wifh Baghouse
i i i
,. .1
100.0
10.0 jj
1.0
0.
0.01
O O)
"s 8
UJ
-o ^
~o 4-
w O
C
«3j
_B
I
U
10 100
Aerodynamic Particle Diameter (^tmA)
Size specific emission factors for cement kilns.
10/86
Mineral Products Industry
8.6-7
-------
10.0
10
100
o
o
g-s i.o
LU _*
w =
O —
o VJ
O en
«
~O "~
J 00
O V
i I o.i
O t/1
I-
0.01
I I I I I I
I 1 I I I I i
Uncontrolled Coolers
Coolers with Grovel Bed Filter
1 I II II!
10.0
1.0
o
o
a w
3 <0
cr -^
c \
O Ol
5 «
Uj N
TJ ^
.2 -o
— u
O •£
C
o
4)
u
l-° 10.0 " 100.0
Aerodynamic Particle Diameter (jirnA)
0.01
Figure 8.6-3. Size specific emission factors for clinker coolers.
8.6-8
EMISSION FACTORS
10/86
-------
TABLE 8.6-4. SIZE SPECIFIC EMISSION FACTORS FOR
CLINKER COOLERS3
EMISSION FACTOR RATING: E
Particle
sizeb
(um)
2.5
5.0
10.0
15.0
20.0
local mass
Cumulative mass Z
Cumulative emission
< stated sizec
Uncontrolled Gravel
0.54
1.5
8.6
21
34
emission factor
bed filter
40
64
76
84
89
factor
< stated size"
Uncontrolled
kg/Mg
0.025
0.067
0.40
0.99
1.6
4.6e
Ib/ton
0.050
0.13
0.80
2.0
3.2
9.2e
Gravel
kg/Mg
0.064
0.10
0.12
0.13
0.14
0.16f
bed filter
lb/ ton
0.13
0.20
0.24
0.26
0.28
0.32f
aReference 8.
^Aerodynamic diameter
cRounded to two significant figures.
dUnit weight of pollutant/unit weight of clinker
produced. Rounded to two significant figures.
eFrom Table 8.6-1.
fFrom Table 8.6-2.
References for Section 8.6
1. T. E. Kreichelt, ec al., Atmospheric Emissions from che Manufacture of
Portland Cement, 999-AP-17, U. S. Environmental Protection Agency,
Cincinnati, OH, 1967.
2. Background Information For Proposed New Source Performance Standards:
Portland Cement Plants, APTD-0711, U. S. Environmental Protection Agency,
Research Triangle Park, NC, August 1971.
3. A Study of the Cement Industry in the State of Missouri, Resources Research,
Inc., Reston, VA, December 1967.
4. Portland Cement Plants - Background Information for Proposed Revisions
to Standards. EPA-450/3-85-003a, U. S. Environmental Protection Agency,
Research Triangle Park, NC, May 1985.
5. Standards of Performance for New Stationary Sources, 36 FR 28476,
December 23, 1971.
6. Particulate Pollutant System Study. EPA Contract No. CPA-22-69-104, Midwest
Research Institute, Kansas City, MO, May 1971.
10/86
Mineral Products Industry
8.6-9
-------
7. Restriction of Emissions from Portland Cement Works, VDI Richtlinien,
Duesseldorf, West Germany, February 1967.
8. J. S. Klnsey, Lime and Cement Industry - Source Category Report, Vol. II,
EPA Contract No. 68-02-3891, Midwest Research Institute, Kansas City, MO,
August 14, 1986.
8.6-10 EMISSION FACTORS 10/86
-------
8.10 CONCRETE BATCHING
8.10.1 Process Description^"^
Concrete is composed essentially of water, cement, sand (fine aggregate)
and coarse aggregate. Coarse aggregate may consist of gravel, crushed stone
or iron blast furnace slag. Some specialty aggregate products could be either
heavyweight aggregate (of barite, magnetite, limonite, ilmenite, iron or steel)
or lightweight aggregate (with sintered clay, shale, slate, diatoraaceous shale,
perlite, veraiculite, slag, pumice, cinders, or sintered fly ash). Concrete
batching plants store, convey, measure and discharge these constituents into
trucks for transport to a job site. In some cases, concrete is prepared at a
building construction site or for the manufacture of concrete products such as
pipes and prefabricated construction parts. Figure 8.10-1 is a generalized
process diagram for concrete batching.
The raw materials can be delivered to a plant by rail, truck or barge.
The cement is transferred to elevated storage silos pneumatically or by bucket
elevator. The sand and coarse aggregate are transferred to elevated bins by
front end loader, clam shell crane, belt conveyor, or bucket elevator. From
these elevated bins, the constituents are fed by gravity or screw conveyor to
weigh hoppers, which combine the proper amounts of each material.
Truck mixed (transit mixed) concrete involves approximately 75 percent of
U. S. concrete batching plants. At these plants, sand, aggregate, cement and
water are all gravity fed from the weigh hopper into the mixer trucks. The
concrete is mixed on the way to the site where the concrete is to be poured.
Central mix facilities (including shrink mixed) constitute the other one fourth
of Che industry. With these, concrete is mixed and then transferred to either
an open bed dump truck or an agitator truck for transport to the job site.
Shrink mixed concrete is concrete that is partially mixed at the central mix
plant and then completely mixed in a truck mixer on the way to the job site.
Dry batching, with concrete is mixed and hauled to the construction site in dry
form, is seldom, if ever, used.
8.10-2 Emissions and Controls^"?
Emission factors for concrete batching are given in Table 8.10-1, with
potential air pollutant emission points shown. Particulate matter, consisting
primarily of cement dust but including some aggregate and sand dust emissions,
is the only pollutant of concern. All but one of the emission points are
fugitive in nature. The only point source is the transfer of cement to the
silo, and this is usually vented to a fabric filter or "sock". Fugitive sources
include the transfer of sand and aggregate, truck loading, mixer loading,
vehicle traffic, and wind erosion from sand and aggregate storage piles. The
amount of fugitive emissions generated during the transfer of sand and aggregate
depends primarily on the surface moisture content of these materials. The
extent of fugitive emission control varies widely from plant to plant.
10/86 . Mineral Products Industry 8.10-1
-------
o>
o
I
r-o
in
(H
O
•z.
o
H
o
70
\ BARGE /
FCCO
HOPPER
AGGREGATE
UNLOADING
ELEVATED STORAGE
BINS
SAND
AGGREGATE
PART ICULATE
EMISSIONS
TRUCK MIXED
PRODUCT
WEIGH
HOPPERS
WATER-
MIXER
CENTRAL MIXED
PRODUCT
PNEUMATIC
TRANSFER
J
^j
ELEVATED
CEMENT
SILO
X. S
~N
BUCKET
ELEVATOR
SCREW
\ 0«K
fe
• "•
[TRUO
^EF3
CEMENT
UNLOADING
o
CO
Figure 8.1-1. Typical concrete b;itcliing process.
-------
TABLE 8.10-1.
UNCONTROLLED PARTICULATE EMISSION FACTORS
FOR CONCRETE BATCHING
Source
Sand and aggregate transfer
Co elevated blnb
: Cement unloading Co elevated
storage silo
: Pneumatic0
Bucket elevator**
! Weigh hopper loading6
! Truck loading (truck mlx)e
: Mixer loading (central mlx)e
Vehicle traffic (unpaved road)^
. Wind erosion from sand
1 and aggregate storage pllesh
; Total process emissions
: (truck mix).)
1
kg/Mg
of
material
0.014
0.13
0.12
0.01
0.01
0.02
4.5 kg/VKT
3.9 kg/
hectare/day
0.05
Ib/ton
of
material
0.029
0.27
0.24
0.02
0.02
0.04
16 Ib/VMT
3.5 lb/
acre/day
0.10
Ib/yd3
of
concrete3
0.05
0.07
0.06
0.04
0.04
0.07
0.2«
o.ii
0.20
Emission
Factor
Rating
E
D
E
E
E
E
C
D
£
a8ased on a typical yd3 weighing 1.318 kg (4,000 lb) and containing 227 kg
(500 lb) cement, 564 kg (1,240 lb) sand, 864 kg (1,900 lb) coarse aggregate
and 164 kg (360 lb) water.
''Reference 6.
GFor uncontrolled emissions measured before filter. Based on two tests on
pneumatic conveying controlled by a fabric filter.
^Reference 7. From test of mechanical unloading to hopper and subsequent
transport of cement by enclosed bucket elevator to elevated bins with
fabric socks over bin vent.
Reference 5. Engineering judgement, based on observations and emission
cests of similar controlled sources.
fFrom Section 11.2.1, with k - 0.8, s - 12, S - 20, W - 20, vr - 14, and p -
100. VKT - vehicle kilometers traveled. VMT - vehicle miles traveled.
SBased on facility producing 23,100 m^/yr (30,000 yd3/yr), with average truck
load of 6.2m3 (B yd-3) and plant road length of 161 meters (1/10 mile).
11 From Section 3.19.1, for emissions <30 urn for Inactive storage piles.
'•Assumes 1,011 m- (1/4 acre) of sand and aggregate storage at plant with
production of 23,100 m3/yr (30,000 yd3/yr).
jBaaed on pneumatic conveying of cement at a truck mix facility. Does not
Include vehicle traffic or wind erosion from storage piles.
10/86
Mineral Products Industry
8.10-3
-------
Types of controls used may include water sprays, enclosures, hoods, cur-
tains, shrouds, movable and telescoping chutes, and the like. A major source
of potential emissions, the movement of heavy trucks over unpaved or dusty
surfaces in and around the plant, can be controlled by good maintenance and
wetting of the road surface.
Predictive equations which allow for emission factor adjustment based on
plant specific conditions are given in Chapter 11. Whenever plant specific
data are available, they should be used in lieu of the fugitive emission factors
presented in Table 8.10-1.
References for Section 8.10
1. Air Pollutant Emission Factors, APTD-0923, U. S. Environmental Protection
Agency, Research Triangle Park, NC, April 1970.
2. Air Pollution Engineering Manual, 2nd Edition, AP-40, U. S. Environmental
Protection Agency, Research Triangle Park, NC, 1974. Out of Print.
3. Telephone and written communication between Edwin A. Pfetzing, Pedco
Environmental., Inc., Cincinnati, OH, and Richard Morris and Richard
Meininger, National Ready Mix Concrete Association, Silver Spring, MD, May
1984.
4. Development Document for Effluent Limitations Guidelines and Standards of
Performance, The Concrete Products Industries, Draft, U. S. Environmental
Protection Agency, Washington, DC, August 1975.
5. Technical Guidance for Control of Industrial Process Fugitive Particulate
Emissions, EPA-450/3-77-010, U. S. Environmental Protection Agency,
Research Triangle Park, NC, March 1977.
6. Fugitive Dust Assessment at Rock and Sand Facilities in the South Coast
Air Basin, Southern California Rock Products Association and Southern
California Ready Mix Concrete Association, Santa Monica, CA, November
1979.
7. Telephone communication between T. R. Blackwood, Monsanto Research Corp.,
Dayton, OH, and John Zoller, Pedco Environmental, Inc., Cincinnati, OH,
October 18, 1976.
8.10-4 EMISSION FACTORS 10/86
-------
8.13 GLASS MANUFACTURING
8.13.1 General1"5
Commercially produced glass can be classified as soda-lime, lead, fused
silica, borosilicate, or 96 percent silica. Soda-lime glass, since it con-
stitutes 77 percent of total glass production, is discussed here. Soda-lime
glass consists of sand, limestone, soda ash, and cullet (broken glass). The
manufacture of such glass is in four phases: (1) preparation of raw material,
(2) melting in a furnace, (3) forming and (4) finishing. Figure 8.13-1 is a
diagram for typical glass manufacturing.
The products of this industry are flat glass, container glass, and press-
ed and blown glass. The procedures for manufacturing glass are the same for
all products except forming and finishing. Container glass and pressed and
blown glass, 51 and 25 percent respectively of total soda-lime glass pro-
duction, use pressing, blowing or pressing and blowing to form the desired
product. Flat glass, which is the remainder, is formed by float, drawing or
rolling processes.
As the sand, limestone and soda ash raw materials are received, they are
crushed and stored in separate elevated bins. These materials are then trans-
ferred through a gravity feed system to a weigher and mixer, where the mate-
' rial is mixed with cullet to ensure homogeneous melting. The mixture is con-
veyed to a batch storage bin where it is held until dropped into the feeder
to the melting furnace. All equipment used in handling and preparing the raw
material is housed separately from the furnace and is usually referred to as
the batch plant. Figure -8.13-2 is a flow diagram of a typical batch plant.
FINISHING
FINISHING
RAW
MATERIAL
MELTING
FURNACE
GLASS
FORMING
ANNEALING
INSPECTION
AND
TESTING
CULLET
CRUSHING
RECYCLE UNDESIRABLE
GLASS
PACKING
STORAGE
. OR
SHIPPING
10/86
Figure 8.13-1. Typical glass manufacturing process.
Mineral Products Industry
8.13-1
-------
CUUET
All MATERIALS
RECEIVING
HOPPER
V
SCREf
CONVEYOR
FILTER
VENTS
STORAGE 3INS
MAJOR RAI MATERIALS
MINOR
INGREDIENT
STORAGE
9INS
BELT CONVEYOR
9ATCH
STORAGE
BIN
FURNACE
FEEDER
Figure 8.13-2. General diagram of a batch plant.
The furnace most commonly used is a continuous regenerative furnace
capable of producing between 45 and 272 Mg (50 and 300 tons) of glass per
day. A furnace may have either side or end ports that connect brick checkers
to the inside .of the melter. The purpose of brick checkers (Figures 8.13-3
and 4) is to conserve fuel by collecting furnace exhaust gas heat which, when
the air flow is reversed, is used to preheat the furnace combustion air. As
material enters the melting furnace through the feeder, it floats on the top
of the molten glass already in the furnace. As it melts, it passes to the
front of the melter and eventually flows through a throat leading to the
refiner. In the refiner, the molten glass is heat conditioned for delivery
to the forming .process. Figures 8.13-3 and 8.13-4 show side port and end
.port regenerative furnaces.
After refining, the molten glass leaves the furnace through forehearths
(except in the float process, with molten glass moving directly to the tin
bath) and goes to be shaped by pressing, blowing, pressing and blowing, draw-
ing, rolling, or floating to produce the desired product. Pressing and blow-
ing are performed mechanically, using blank molds and glass cut into sections
(gobs) by a set of shears. In the drawing process, molten glass is drawn up-
ward in a sheet through rollers, with thickness of the sheet determined by the
speed of the draw and the configuration of the draw bar. The rolling process
is similar to the drawing process except that the glass is drawn horizontally
8.13-2
EMISSION FACTORS
10/86
-------
Figure 8.13-3. Side port continuous regenerative furnace,
ttri»ci IIBI tut
,«.*!! IttlftCt )• MM Mi
Figure 8.13-4. End port continuous regenerative furnace.
1Q/86 Mineral Products Industry 8.13-3
-------
on plain or patterned rollers and, for plate glass, requires grinding and
polishing. The float process is different, having a molten tin bath over
which the glass is drawn and formed into a finely finished surface requiring
no grinding or polishing. The end product undergoes finishing (decorating or
coating) and annealing (removing unwanted stress areas in the glass) as re-
quired, and is then inspected and prepared for shipment to market. Any
damaged or undesirable glass is transferred back to the batch plant to be
used as cullet.
8.13.2 Emissions and Controls^"^
The main pollutant emitted by the batch plant is particulates in the form
of dust. This can be controlled with 99 to 100 percent efficiency by enclos-
ing all possible dust sources and using baghouses or cloth filters. Another
way to control dust emissions, also with an efficiency approaching 100 percent,
is to treat the batch to reduce the amount of fine particles present, by pre-
sintering, briquetting, pelletizing, or liquid alkali treatment.
The melting furnace contributes over 99 percent of the total emissions
from a glass plant, both particulates and gaseous pollutants. Particulates
result from volatilization of materials in the melt that combine with gases
and form condensates. These either are collected in the checker work and gas
passages or are emitted to the atmosphere. Serious problems arise when the
checkers are not properly cleaned, in that slag can form, clog the passages
and eventually deteriorate the condition and efficiency of the furnace.
Nitrogen oxides form when nitrogen and oxygen react in the high temperatures
of the furnace. Sulfur oxides result from the decomposition of the sulfates
in the batch and sulfur in the fuel. Proper maintenance and firing of the
furnace can control emissions and also add to the efficiency of the furnace
and reduce operational costs. Low pressure wet centrifugal scrubbers have
been used to control particulate and sulfur oxides, but their inefficiency
(approximately 50 percent) indicates their inability to collect particulates
of submicron size. High energy venturi scrubbers are approximately 95 percent
effective in reducing particulace and sulfur oxide emissions. Their effect on
nitrogen oxide emissions is unknown. Baghouses, with up to 99 percent parti-
culate collection efficiency, have been used on small regenerative furnaces,
but fabric corrosion requires careful temperature control. Electrostatic pre-
cipitatoirs have an efficiency of up to 99 percent in the collection of par-
ticulates. Table 8.13-1 lists controlled and uncontrolled emission factors
for glass manufacturing. Table 8.13-2 presents particle size distributions
and corresponding emission factors for uncontrolled and controlled glass
melting furnaces.
Emissions from the forming and finishing phase depend upon the type of
glass being manufactured. For container, press, and blow machines, the ma-
jority of emissions results from the gob coming into contact with the machine
lubricant. Emissions, in the form of a dense white cloud which can exceed 40
percent opacity, are generated by flash vaporization of hydrocarbon greases
and oils. Grease and oil lubricants are being replaced by silicone emulsions
and water soluble oils, which may virtually eliminate this smoke. For flat
glass, the only contributor to air pollutant emissions is gas combustion in
the annealing lehr (oven), which is totally enclosed except for product entry
and exit openings. Since emissions are small and operational procedures are
efficient, no controls are used on flat glass processes.
8.1-3-4 EMISSION FACTORS 10/86
-------
O
CO
3
n>
O
rr
0)
a
c
(0
CD
CO
I
Ol
TABLE 8.13-1. EMISSION FACTORS FOR GLASS MANUFACTURING8
EMISSION FACTOR RATING: B
Procesa
(all types of glass)
Melting furnacec
Container
Uncontrolled
U/low energy scrubber1*
U/venturl scrubber6
U/baghouse'
Hartic
kg/Mg
N,g
0.7
(0.4-1). 9) (0
0.4
<0. 1
Nug
nlate
It/ton
Nug
1 .4
.9-1 .9)
0..7
O.I
Hug
U/electroatatlc preclpl taluriS Ntfg Nug
Flat
Uncontrolled
U/low-energy scrubber1*
U/venturi scrubber6
U/baghousef
I.I)
<0.4-l.u) (il
0,5
Nug
U/elect ros tat Ic preclpt tatoig Neg
Pressed and blown
Uncont rol led
U/low energy scrubber1*
U/vcnturl scrubber'
U/baghouse'
U/electroatattc preclpl tatorli
Forming and finishing
Container'1! J
.Flat
Pressed and blownl'ij
Lead glass manufacturing, all
processes'1
•Deferences 2-1, 5. Dash - no
8.7
(0.5-12.6) (1
4.2
0.5
O.I
O.I
Nug
Nug
Hug
_
l!.l)
.8-3.2)
1.0
Nug
Nug
Nug
17.4
.0-25.1)
B. 4
0.9
0.2
0.2
Neg
Neg
Neg
_
Sulfur oxldee
kg/Mg
0
1.?
( 1 .0-2.4)
0.9
O.I
1.7
1 .7
1.5
(1. 1-1.9)
u.8
O.I
1.5
1.5
2.8
(0.5-5.4)
1.3
O.I
2.8
2.8
Mug
Nug
Nug
^
Ib/ton
0
3.4
(2.0-4.U)
1.7
0.2
3.4
3.4
3.D
(2.2-3.8)
1.5
0.2
3.0
3.0
5.6
(1. 1-10.9)
2.7
0.3
5.6
5.6
Neg
Neg .
Neg
.
available data. Neg • negligible. Ranges In
parentheses, where available. CM
uNot separated into types of glass
utilize son* fora of control
^Control efficiencies for the
ualsulon factor.
Effect on nitrogen oildes Is
Effect on nitrogen oxides la
'Approximately 991 efficiency
pressed ss kg/Hg
(Ib/ton)
(I.e., bagtiouses, scrubbers,
unknown.
unknown.
of glass
cunt r 1 f u^ja
produced .
all plsnts
1 collectors)
Nitrogen oxides
kg/Mg
0
3.1
(1.6-4.5)
3.1
3.1
3.1
I.I
4.0
(2.8-5.2)
4.0 •
4.0
4.0
4.0
4.3
(0.4-10.0)
• 4.3
4.3
4.3
4.3
Neg
Neg
Neg
_
Ib/ton
0
6.2
O. 3-9.1)
6.2
6.2
6.2
6.2
b.ll
(5.6-10.4)
8.1)
8.0
8.0
8.0
8.5
(0.8-20.0)
8.5
8.5
8.5
8.5
Nug
Neg
Neg
_
voc
Carbon monoxide l.ead
kg/Mg Ib/ton kg/Mg
0
O.I
(0-0.
0.1
O.I
O.I
0. 1
-------
UNCOHTMU.EO
—•— Weight ptrcenc
Emission factor
CONTROLLED
-*— W«ighc p«rcenc
> » : • t 10 :o
P»rtlcl« dlaavcer, ua
Figure 8.13-5. Particle size distributions and emission factors for
glass melting furnace exhaust.
TABLE 8.13-2. PARTICLE SIZE DISTRIBUTIONS AND EMISSION FACTORS
FOR UNCONTROLLED AND CONTROLLED MELTING FURNACES
IN GLASS MANUFACTURING3
Emission Factor Rating:
Aerodynamic
particle
diameter, urn
Particle size distribution^
ESP
Uncontrolled Controlled^
Size specific emission
factor,
Uncontrolled
2.5
6.0
10
91
93
95
53
66
75
0.64
0.65
0.66
References 8-11.
^Cumulative weight % of particles < corresponding particle size.
cBased on mass partlculate emission factor of 0.7 kg/Mg glass produced, from
Table 8.13-1. Size specific emission factor = mass particulate emission
factor x particle size distribution, %/100. After ESP control, size specific
emission factors are negligible.
^Reference 8-9. Based on a single test.
8.13-6
EMISSION FACTORS
10/86
-------
References for Section 8.13
1. J. A. Danielson, (ed.), Air Pollution Engineering Manual, 2nd Ed.,
AP-40, U. S. Environmental Protection Agency, Research Triangle Park,
NC, May 1973. Out of Print.
2. Richard B. Reznik, Source Assessment: Flat Glass Manufacturing Plants,
EPA-600/20-76-032b, U. S. Environmental Protection Agency, Research
Triangle Park, NC, March 1976.
3. J. R. Schoor, et al., Source Assessment: Glass Container Manufacturing
Plants, EPA-600/2-76-269, U. S. Environmental Protection Agency,
Washington, DC, October 1976.
4. A. B. Tripler, Jr. and G. R. Smithson, Jr., A Review of Air Pollution
Problems and Control in the Ceramic Industries, Battelle Memorial Insti-
tute, Columbus, OH, presented at the 72nd Annual Meeting of the American
Ceramic Society, May 1970.
5. J. R. Schorr, et al., Source Assessment: Pressed and Blown Glass Manu-
facturing Plants, EPA-600/77-005, U. S. Environmental Protection Agency,
Washington, DC, January 1977.
6. Control Techniques for Lead Air Emissions, EPA-450/2-77-012, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, December 1977.
7. Confidential test data, Pedco-Environmental Specialists, Inc., Cincinnati,
OH.
8. H. J. Taback,' Fine Particle Emissions from Stationary.and Miscellaneous
Sources in the South Coast Air Basin, PB-293-923, National Technical
•Information Service, Springfield, VA, February 1979.
9. Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System (FPEIS), Series Report No. 219, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1983.
10. Environmental Assessment Data Systems, op. cit., Series No. 223.
11. Environmental Assessment Data Systems, op. cit., Series No. 225.
10/86 Mineral Products Industry 8.13-7
-------
8.15 LIME MANUFACTURING
8.15.1 General1'4
Lime is the high temperature product of the calcination of limestone.
There are two kinds, high calcium lime (CaO) and dolomitic lime (CaO • MgO).
Lime is manufactured in various kinds of kilns by one of the following
reactions:
CaC03 + heat ->• C02 + CaO (high calcium lime)
CaC03 • MgC03 + heat •* C02 + CaO • MgO (dolomitic lime)
In some lime plants, the resulting lime is reacted (slaked) with water to
form hydrated lime.
The basic processes in the production of lime are 1) quarrying raw
limestone; 2) preparing limestone for the kilns by crushing and sizing;
3) calcining limestone; 4) processing the lime further by hydrating; and
5) miscellaneous transfer, storage and handling operations. A general-
ized material flow diagram for a lime manufacturing plant is given in Fig-
ure 8.15-1. Note that some operations shown may not be performed in all
plants.
The heart of a lime plant is the kiln. The prevalent type of kiln is
the rotary kiln, accounting for about 90 percent of all lime production in
the United States. This kiln is a long, cylindrical, slightly inclined, re-
fractory lined furnace, through which the limestone and hot combustion gases
pass countercurrently. Coal, oil and natural gas may all be fired in rotary
kilns. Product coolers and kiln feed preheaters of various types are com-
monly used to recover heat from the hot lime product and hot exhaust gases,
respectively.
The next most common type of kiln in the United States is the vertical,
or shaft, kiln. This kiln can be described as an upright heavy steel cylin-
der lined with -refractory material. The limestone is charged at the top and
is calcined as it descends slowly to discharge at the bottom of the kiln. A
primary advantage of vertical kilns over rotary kilns is higher average fuel
efficiency. The primary disadvantages of vertical kilns are their rela-
tively low production rates and the fact that coal cannot be used without
degrading the quality of the lime produced. There have been few recent
vertical kiln installations in the United States because of high product
quality requirements.
Other, much less common, kiln types include rotary hearth and fluidized
bed kilns. Both kiln types can achieve high production rates, and neither
can operate with coal. The "calcimatic" kiln, or rotary hearth kiln, is a
circular shaped kiln with a slowly revolving donut shaped hearth. In fluid-
ized bed kilns, finely divided limestone is brought into contact with hot
combustion air in a turbulent zone, usually above a perforated grate. Be-
cause of the amount of lime carryover into the exhaust gases, dust collec-
tion equipment must be installed on fluidized bed kilns for process economy.
10/86 Mineral Products Industry 8.15-1
-------
I hign Caiciuxi and Ooiamitic U
| Guarry and Mix* Goarariam j ^_
i (Drilling. Having, and Canvarina, fW-dWco)
of Srown Linmrond )
J ^
I , . _. I IJ - 20 ei» U
-}_ Sen...*, and aaoif!«o,.« — f(X Vwtjeoj ,..,„
Ouning
0.9* - 4.* cm
Scrddmne and Clauificavion ••» uinairona ^ar -
horary <;int
i?
Cfltctnorion
j f -
J -^ —
I i i
: I ,'
I i !
T f t
Pwivwririno
0
! Scr««ntnd and Clauificarian
•©
| knvwcrion
1^
100)
"GDI
Max Sin 0.6* - 1.3 cr»
Nion Caiciwn 1 3oid«mric
.am Oaiamrle —Cuiculin* .
I?
u
-co)
and/o
Milllny ^V^-dMOO
Hidf. Caiciom and poiomiilc
Figure 8-. 15-1. Simplified flow diagram for lime and limestone products.
8.15-2
EMISSION FACTORS
10/86
-------
About 10 percent of all lime produced is converted to hydrated (slaked)
lime. There are two kinds of hydrators, atmospheric and pressure. Atmo-
spheric hydrators, the more prevalent type, are used in continuous mode to
produce high calcium and normal doloraitic hydrates. Pressure hydrators, on
the other hand, produce only a completely hydrated dolomitic lime and oper-
ate only in batch mode. Generally, water sprays or wet scrubbers perform
the hydrating process, to prevent product loss. Following hydration, the
product may be milled and then conveyed to air separators for further drying
and removal of coarse fractions.
In the United States, lime plays a major role in chemical and metal-
lurgical operations. Two of the largest uses are as steel flux and in
alkali production. Lesser uses include construction, refractory and agri-
cultural applications.
8.15.2 Emissions And Controls3'5
Potential air pollutant emission points in lime manufacturing plants
are shown in Figure 8.15-1. Except for gaseous pollutants emitted from
kilns, particulate is the only pollutant of concern from most of the opera-
tions .
The largest ducted source of particulate is the kiln. Of the various
kiln types, fluidized beds have the most uncontrolled particulate emissions,
because of the very small feed size combined with high air flow through
these kilns. Fluidized bed kilns are well controlled for maximum product
recovery. The rotary kiln is second worst in uncontrolled particulate emis-
sions, also because of the small feed size and .relatively high air veloci-
ties and dust entrainment caused by the rotating chamber. The calcimatic
(rotary hearth) kiln ranks third in dust production, primarily because of
the larger feed size and the fact that, during calcination, the limestone
remains stationary relative to the hearth. The vertical kiln has the lowest
uncontrolled dust emissions, due to the large lump feed and the relatively
low air velocities and slow movement of material through the kiln.
Some sort of particulate control is generally applied to most kilns.
Rudimentary fallout chambers and cyclone separators are commonly used for
control of the larger particles. 'Fabric'and gravel bed filters, wet (com-
monly venturi) scrubbers, and electrostatic precipitators are used for sec-
ondary control.
Nitrogen oxides, carbon monoxide and sulfur oxides are all produced in
kilns, although the last are the only .gaseous pollutant emitted in signifi-
cant quantities. Not all of the sulfur in the kiln fuel is emitted as sul-
fur oxides, since some fraction reacts with the materials in the kiln. Some
sulfur oxide reduction is also effected by the various equipment used for
secondary particulate control.
Product coolers are emission sources only when some of their exhaust
gases are not recycled through the kiln for use as combustion air. The
10/86 Mineral Products Industry 8.15-3
-------
trend is away from the venting of product cooler exhaust, however, to maxi-
mize fuel use efficiencies. Cyclones, baghouses and wet scrubbers have been
employed on coolers for particulate control.
Hydrator emissions are low, because water sprays or wet scrubbers are
usually installed to prevent product loss in the exhaust gases. Emissions
from pressure hydrators may be higher than from the more common atmospheric
hydrators, because the exhaust gases are released intermittently, making
control more difficult.
Other particulate sources in lime plants include primary and secondary
crushers, mills, screens, mechanical and pneumatic transfer operations,
storage piles, and roads. If quarrying is a part of the lime plant opera-
tion,' particulate may also result from drilling and blasting. Emission
factors for some of these operations are presented in Sections 8.20 and 11.2
of this document.
Controlled and uncontrolled emission factors and particle size data for
lime manufacturing are given in Tables 8.15-1 through 8.15-3. The size dis-
tributions of particulate emissions from controlled and uncontrolled rotary
kilns and uncontrolled product loading operations are shown in Figures
8.15-2 and 8.15-3.
8.15-4 EMISSION FACTORS 10/86
-------
o
oo
TABLE 8.15-1. EMISSION FACTORS FOR LIME MANUFACTURING"
EMISSION FACTOR RATING: B
Source
['articulate
kg/Hg " "Tb7ton
Nilrogrn oxides
kg/Hg Ih/lm.
Carbon •onoxide
kg/Hg Ib/lon
Suljur dioxide
kg/Hg ~ib/lon
H-
p
n
n
w
O
(X
n
OO
Ul
I
Ln
Crushers, screens, conveyors, storage
piles, unpaved roads, etc.
Rotary kilns
Uncontrolled'
Large diaaeter cyclone
Multiple cyclone
Electrostatic precipitalor'
Venluri scrubber
Crave1 bed filter8
Multiclone and venturi scrubber
Bagliouse
Cyclone and baghouse
Vertical kflns
Uncontrolled
Calcisutic kilns*
Uncontrolled
Multiple cyclone .
Secondary dust collection
Fluidized bed kilns
Product coolers
Uncontrolled
llydralora (atmospheric)1'
Vet scrubber
Crustier, screen, liauuerwi 11
Baghouse
Final screen
llaglioutie
Uncontrolled truck loading
Limestone
Oueo truck
Closed truck
Line - closed truck
Neg
Nt-g
Neg
NA
NA
NA
Neg
NA
Neg
NA
Neg
IHO
81
42
2.4
2.4 .
0.53'
0.44.
0.45J
0.055
350
160
83
4.8
4.8.
I.I1
0.87.
0.89J
0.11
.4
.4
.4
.4
.4
.4
.4
.4
.4
2.8
2.8
2.8
2.8
2.8
2.B
2.8
2.8
2.8
2
2
2
2
2
2
2
2
2
f
f
f
h
h
h
h
h
h
f
f
(
h
h
h
h
h
h
NA
25
3
NA .
in
20"
0.05
0.0005
0.0004
11.75
0. IB.
O.IS1
50
6
NA
•
40n
O.I
0.001
0.0008
1.5
0.76
O.JO1
0. 1
O.I
O.I
NA
Neg
Neg
Neg
N,g
N.:g
0.2
0.2
0.2
NA
Neg
N.-g
N.-g
Nrg
Nrg
Neg
N..'g
NA
NA
NA
NA
Neg
N.-g
Neg
Nrg
N.-g
N.-g
Nrg
NA
NA
NA
NA
Neg
N.rg
Neg
Neg
Nt-g
Neg
Neg
NA
NA
NA
NA
Neg
Neg
Neg
Neg
Neg
Neg
Neg
NA
NA
NA
NA
Neg
Neg
N.-g
Nrg
Neg
Neg
-------
oo
•-"
Cn
o
CD
TABLE 8.15-1 (cont.).
'Reference! 4-7. .Factor! (or kilns ami cooler! are per unit of line produced. Divide by two to obtain factora per unit of
limestone feed to the kiln. Factor! for liydraton are per unit of bydraled I la* produced. Multiply by 1.25 to obtain
.factor* per unit of I IBM; feed to the hydralor. Neg = ne|ll|ible. NA = not available.
rEmission Factor Rating = D.
.Factor* for tbeie operation! are presented in Section! 1.20 and 11.2 of thli document.
For coal fired rotary kilna only.
*No particulate control eicept for settling that May occur in Hark breeching and chimney bale.
*Sulfur dioxide nay be estimated by a material balance using tuel sulfur content.
jjCombiistloo coal/gai fired rotary fcilni only.
Mien acrubbera are uaed. < 5X of I lie fuel sulfur will be emitted *• SO, even with high sulfur coal. When other secondary
collection devices are uccd, abmil 201 of the fuel sulfur will be emitted as SO, with high sulfur fuels, and < inj with
.low sulfur fuel*.
3 .Emission Factor Rating = E.
£J /Emission Factor Rating - C.
Cslclmatic kilos generally have atone prehealrrs: Factora are for emissions after the kiln exhaust passei
g |tbrough • preheatef.
2» Fabric filter* *ad venturl scrubber! have been uied on calcinatlc kilns. No data are available on particulate
Demissions after secondary control.
•> Fluldized bed kilns must have sophisticated dust collection equipment for process economics, hence particulate
O fissions will depend on efficiency of the control equipment installed.
Q Some or all cooler exhaust typically is used in kiln as combustion sir. Emissions will result only from thsl
TO fraction not recycled to kiln.
"Typical particulate loading for atmospheric hydrstors following water ipriys or wet scrubber*. Limited data
suggest particulate emissions from pressure hydrator* pay he approximately I kg/Ng (2 Ib/ton) of hydrate pro-
duced, after wet collectors.
-------
o
^
oo
00
en
i
TABLE 8.15-2. SUMMARY OF SIZE SPECIFIC EMISSION FACTORS FOR ROTARY LIME KILNS
EMISSION FACTOR RATING: D
a:
H-
O
n
•i
(a
t- Particle
size
n (M«A)
0
0.
e
n 2.5
M
50
O
0- 10.0
(A
r» 15.0
•1
Cuaulative Bass 1 S staled particle size .
Uncontrolled
rotary kiln
1.4
2.9
12
31
Rotary
kiln wlthj
•u 1 1 i c 1 one
6.1
98
16
23
Roiary
kiln
with
tSPe
14
NA
50
62
Rotary kiln
with cyclone,
and baghbuse
27
NA
55
73
^
Total Bast ealsaion factor 8
Cumulative particulate emission factor S stated sizer
llncontrol led
rotary kilns
kg/Hg
2.6
5.2
21
56
ISO
Ib/ton
5.2
10
42
110
350
Rotary kiln
with d
nnlticlone
kg/Hg
2.6
4.1
6.9
9.7
42
Ib/ton
5.2
8.2
14
19
83
Rotary kiln
with ESP*
kg/Hg Ib/ton
0.34 0.68
NA NA
1.2 2.4
1.5 3.0
2.4 4.8
Rotary
kiln
with cyclone,
and baghouse
kg/Hg
0.02
NA
0.03
0.04
0.055
Ib/ton
0.03
NA
0.06
0.08
0.11
.Reference 7
Aerodynaaic
. Coal fired
diameter.
rotary kilns.
Numbers
rounded to two significant
figures.
F.SP = cli:
ct rostatlc
preclpitstor. NA
= not available.
eCMiision Factor Rating = E.
fFor cc»bination coal/natural gas fired rotary kilns.
For rotary kiln with cyclone collector followed by bughouse.
BpMiQ emission factor data is not available for baghouse, venturt scrubber, simple cyclone
and other control technologies used for rotary lime kilns.
-------
00
I—•
Ln
I
00
rz
M
CO
o
25
o
H
O
50
TABLE 8.15-3. UNCONTROLLED FUGITIVE PARTICIPATE EMISSION FACTORS FOR PRODUCT LOADING
, ........ . .... ...... , _ . . .
Type of loading operation
1'u Iveri zed limestone into ujien lied
trucks
Pulverized limestone into lank trucks
Glass line into tank trucks
Total . Inlulal.le
. u . , r
parliculate parliculate
kg/Hg
0.75
0 IB
0.15
Hi/ton kg/Hg Ih/lon
1.5 0.51 1.0
0.76 0.2V 0.5B
0.30 0.062 0.12
Fine
parl iculale
kg/Hg Ib/ton
O.IJ 0.26
0.04.1 0.086
0.0080 0.016
Emission
factor rat ing
1)
1)
E
.Reference 7. Factors are lor IIMSS u( jiol lulanl/iiiass of product loaded. Nmnliers rounded lo luo significant figures.
cHarliclf!8 < - 300 |imA (aeroilyiiainic
-------
o
oo
Cumulative Uncontrolled Emission Factor Equal to or Less Than Stated Size (kg/Mg)
H-
S
o
o.
n
o
a.
e
00,
H
m
co
Ln
Nl
N
(D
01
•d
n
n
H-
Ml
H-
O
(0
CO
H-
O
0
(a
n
rt
o
r|
(A
H-
g
n
o
•
i
3 _
i b
o*
TJ
Q
^»
0^
A
5'
1 5
" b
1
o
p
°;
<
— 0 O — _
— • o op o c
o bo o -^ c
1 1 1 1 1 III
-
-
*
j V
—
1 1 1 1 1 1 III
1 1 1 1 1 II
1 II 1 1 III
ca 10 —
ai yo yo 70 TO
a <£ o o o
_. Q Q Q O
S ^ ?• rir:
U J j -J
1 1 1 1
^ < i C
. n m ?- 8 ^
i\ i
• 0
v
\ P°
•^ \
'""V.
1 i 1 Mill
O """" • ^v
fo. \
s \
LI 1 1 Illl
1 1 1 1 INI
e
!\
, \
\ \
1 1 1 Mill
1 1 1 1 1 III
-
z
.
-
\
1 I i i I i iT
3 O o — — —
_ *_v * ' O O
30 — 0.0
~J — O
oo
Cumulative Controlled Emission Factor Equal to or Less Than Stated Size (kg/Mg)
I
vO
-------
lO.Ocr
0)
N
-o
4)
c
O
O
a
3
1.0
0 03
co
ve
u
o
o
0.001
0.1
1 . Limestone Loading - Open Trucks
2. Limestone Loading - Enclosed Trucks
3. Ume Loading - Enclosed Trucks
C*
! I
1.0 10.0
Aerodynamic Particle Diameter
i 1 i I i I I—'
100.0
H
J
I ' J 1 ' ' !
1(10)-
Figure 8.15-3. Size specific emission factors for product loading.
8.15-10
EMISSION FACTORS
10/86
-------
References for Section 8.15
1. C. J. Lewis and B. B. Crocker, "The Lime Industry's Problem Of Airborne
Dust", Journal Of The Air Pollution Control Association, 19(1):31-39,
January 1969.
2. Klrk-Othmer Encyclopedia Of Chemical Technology, 2d Edition, John Wiley
And Sons, New York, 1967.
3. Screening Study For Emissions Characterization From Lime Manufacture,
EPA Contract No. 68-02-0299, Vulcan-Cincinnati, Inc., Cincinnati, OH,
August 1974.
4. Standards Support And Environmental Impact Statement, Volume I: Proposed
Standards Of Performance For Lime Manufacturing Plants, EPA-450/2-77-
007a, U. S. Environmental Protection Agency, Research Triangle Park,
NC, April 1977.
5. Source test data on lime plants, Office Of Air Quality Planning And
Standards, U. S. Environmental Protection Agency, Research Triangle Park,
NC, 1976.
6. Air Pollutant Emission Factors, APTD-0923, U. S. Environmental Protection
Agency, Research Triangle Park, NC, April 1970.
7. J. S. Kinsey, Lime And Cement Industry - Source Category Report, Volume
I: Lime Industry, EPA-600/7-86-031, U. S. Environmental Protection
Agency, Cincinnati, OH, September 1986.
10/86 Mineral Products Industry 8.15-11
-------
o
CO
TABLE 8.19.2-2.
UNCONTROLLED PARTICULATE EMISSION FACTORS FOR OPEN DUST SOURCES
AT CRUSHED STONE PLANTS
9
ral Products 1
|
w
rt
Operation
Wet quarry
drilling
Batch drop
Truck unloading
Truck loading
Conveyor
Front end loader
Conveying
Tunnel belt
Unpaved haul roads
Material
Unfractured stonec
Fractured stone0
Crushed stone^
Crushed stone6
Crushed stonec
Emissions by particle size range
(aerodynamic diameter)3
TSP
< 30 urn
0.4 (0.0008)
0.17 (0.0003)
0.17 (0.0003)
29.0 (0.06)
1.7 (0.0034)
f
PM10
_< 10 urn
0.04 (0.0001)
0.008 (0.00002)
0.05 (0.0001)
NA
0.11 (0.0002)
f
Unitsb
g/Mg (Ib/ton)
g/Mg (Ib/ton)
g/Mg (Ib/ton)
g/Mg (Ib/ton)
g/Mg (Ib/ton)
Emission
Factor
Rating
E
D
E
E
E
aTotal suspended particulate (TSP) is that measured by a standard high volume sampler (See Section 11.2),
Use of empirical equations in Chapter 11 Is preferred to single value factors in this Table. Factors
in this Table are provided for convenience in quick approximations and/or for occasions when equation
variables can not be reasonably estimated. NA = not available.
•^Expressed as g/Mg (Ib/ton) of material through primary crusher, except for front end loading which Is
g/Mg (Ib/ton) of material transferred.
cReference 2.
^Reference 3.
eReference 6.
rSee Section 11.2 for empirical equations.
03
-------
specific source conditions, these equations should be used instead of those in
Table 8.19.2-2, whenever emission estimates applicable to specific stone quarry-
ing and processing facility sources are needed. Chapter 11.2 provides measured
properties of crushed limestone, as required for use in the predictive emission
factor equations.
References for Section 8.19.2
1. Air Pollution Control Techniques for Nonmetallic Minerals Industry,
EPA-450/3-82-014, U. S. Environmental Protection Agency, Research
Triangle Park, NC, August 1982.
2. P. K. Chalekode, et al., Emissions from the Crushed Granite Industry;
State of the Art, EPA-600/2-78-021, U. S. Environmental Protection
Agency, Washington, DC, February 1978.
3. T. R. Blackwood, et al., Source Assessment: Crushed Stone, EPA-600/2-78-
004L, U. S. Environmental Protection Agency, Washington, DC, May 1978.
4. F. Record and W. T. Harnett, Particulate Emission Factors for the
Construction Aggregate Industry, Draft Report, GCA-TR-CH-83-02, EPA
Contract No. 68-02-3510, GCA Corporation, Chapel Hill, NC, February L983.
5. Review Emission Data Base and Develop Emission Factors for the Con-
struction Aggregate Industry, Engineering-Science, Inc., Arcadia, CA,
September 1984.
6. C. Cowherd, Jr., et al., Development of Emission Factors for Fugitive Dust
Sources, EPA-450/3-74-037, U. S. Environmental Protection Agency, Research
Triangle Park, NC, June 1974.
7. R. Bohn, et al., Fugitive Emissions from Integrated Iron and Steel Plants,
EPA-600/2-78-050, U. S. Environmental Protection Agency, Washington, DC,
March 1978.
8.19.2-6 EMISSION FACTORS 9/85
-------
.8.22 TACONITE ORE PROCESSING
8.22.1 General 1~2
More than two thirds of the iron ore produced in the United States con-
sists of taconite, a low grade iron ore largely from deposits in Minnesota
and Michigan, but from other areas as well. Processing of taconite consists
of crushing and grinding the ore to liberate ironbearing particles, concen-
trating the ore by separating the particles from the waste material (gangue),
and pelletizing the iron ore concentrate. A simplified flow diagram of these
processing steps is shown in Figure 8.22-1.
Liberation - The first step in processing crude taconite ore is crushing and
grinding. The ore must be ground to a particle size sufficiently close to
the grain size of the ironbearing mineral to allow for a high degree of
mineral liberation. Most of the taconite used today requires very fine
grinding. The grinding is normally performed in three or four stages of dry
crushing, followed by wet grinding in rod mills and ball mills. Gyratory
crushers are generally used for primary crushing, and cone crushers are used
for secondary and tertiary fine crushing. Intermediate vibrating screens
remove undersize material from the feed to the next crusher and allow for
closed circuit operation of the fine crushers. The rod and ball mills are
also in closed circuit with classification systems such as cyclones. An
alternative is to feed some coarse ores directly to wet or dry semiautogenous
or autogenous (using larger pieces of the ore to grind/mill the smaller pieces)
grinding mills, then to pebble or ball mills. Ideally, the liberated particles
of iron minerals and barren gangue should be removed from the grinding circuits
as soon as they are formed, with larger particles returned for further grinding.
Concentration - As the iron ore minerals are liberated by the crushing steps,
the ironbearing particles must be concentrated. Since only about 33 percent
of the crude taconite becomes a shippable product for iron making, a large
amount of gangue is generated. Magnetic separation and flotation are most
commonly used for concentration of the taconite ore.
Crude ores in which most of the recoverable iron is magnetite (or, in
rare cases, maghemite) are normally concentrated by magnetic separation. The
crude ore may contain 30 to 35 percent total iron by assay, but theoretically
only about 75 percent of this is recoverable magnetite. The remaining iron
is discarded with the gangue.
Nonmagnetic taconite ores are concentrated by froth flotation or by a
combination of selective flocculation and flotation. The method is determined
by the differences in surface activity between the iron and gangue particles.
Sharp separation is often difficult.
Various combinations of magnetic separation and flotation may be used to
concentrate ores containing various iron minerals (magnetite and hematite, or
maghemite) and wide ranges of mineral grain sizes. Flotation is also often
used as a final polishing operation on magnetic concentrates.
10/86 Mineral Products Industry 8.22-1
-------
CD
OVERSIZE ORE
?• t ( ! ! \
M RAW PRIMARY
ORE CRUSHER
* SEC1n?J?r"V * ^rutFM ' . TE/nTr!£?V ^ -rnFFN (ADDITIONAL STAGES OF GRINDING
(FINE) - SCKEEN • (FINCI * SCREEN AND MAGNETIC SEPARATION
CRUSHER CRUSHER EMPLOYED!
CRUSHED AND SCREENED ORE 1 j
PRIMARY
MILL
MAGNETIC SECONDARY HYDRO- MAGNETIC
fcfiA^^iFiFn «_ •v|«^j|»i-»'v- mfliii k.riA^^incn _». «» • «" *-* i»n-tvji»».«iv^
. CLASSIFIER . SEPARATOR * '^*LJ-'. * CLASSIF|ER • SEPARATOR * SEPARATOR
OVERSIZE ORE OVERSIZE ORE
§
M
CO
CO
M
§
O
H
O
CO
TAILINGS TAILINGS, TAILINGS,
ORE
CONCENTRATE
TAILINGS 10
THICKENER O.CIM' (FUGITIVE EMISSIONS) '
BASIN rniMCENTHATE t DISC 4 CONCENTRATE .
STORAGE FILTERS ' THICKENER
I ORE
BENTONITE fc
STORAGE
L INDURATION f
r I ]
TRAVEL.NG PELLETS BALUNG BLENP(NG
GRAIt f ai-ncc« « DRUMS DLCIMUIIMU
C11'C1 | UNDERSIZE PELLETS
_J-..., . PMlP llMnf:Rc;i7FPFIIFTc;
4 " IIECilllND
1 I t
ROTARY PELLET
* i/i, M ' *" COOLER *• TRANSFER
KILN uAnini inij-
& HANDLING
I. _ 1
7
FUEl
O
co
Figure 8.22-1. Taconite ore processing plant. (Process emissions are indicated by i .)
-------
Palletization - Iron ore concentrates must be coarser than about No. 10
mesh to be acceptable as blast furnace feed without further treatment. The
finer concentrates are agglomerated into small "green" pellets. This is
normally accomplished by tumbling moistened concentrate with a balling drum
or balling disc. A binder, usually powdered bentonite, may be added to the
concentrate to improve ball formation and the physical qualities of the
"green" balls. The bentonite is lightly mixed with the carefully moistened
feed at 5 to 10 kilograms per megagram (10 to 20 Ib/ton).
The pellets are hardened by a procedure called induration, the drying
and heating of the green balls in an oxidizing atmosphere at incipient fu-
sion temperature of 1290 to 1400°C (2350 to 2550°F), depending on the compo-
sition of the balls, for several minutes and then cooling. Four general
types of indurating apparatus are currently used. These are the vertical
shaft furnace, the straight grate, the circular grate and grate/kiln. Mos-t
of the large plants and new plants use the grate/kiln. Natural gas is most
commonly used for pellet induration now, but probably not in the future.
Heavy oil is being used at a few plants, and coal may be used at future
plants.
In the vertical shaft furnace, the wet green balls are distributed
evenly over the top of the slowly descending bed of pellets. A rising
stream of hot gas of controlled temperature and composition flows counter to
the descending bed of pellets. Auxiliary fuel combustion chambers supply
hot gases midway between the top and bottom of the furnace. In the straight
grate apparatus, a continuous bed of agglomerated green pellets is carried
through various up arid down flows of gases at different temperatures. The
grate/kiln apparatus consists of a continuous traveling grate followed by
a rotary kiln. Pellets indurated by the straight grate apparatus are cooled
on an extension of the grate or in a separate cooler. The grate/kiln product
must be cooled in a separate cooler, usually an annular cooler with counter-
current airflow.
8.22.2 Emissions and Controlsl-4
Emission sources in taconite ore processing plants are indicated in
Figure 8.22-1. Particulate emissions also arise from ore mining operations.
Emission factors for the major processing sources without controls are pre-
sented in Table 8.22-1, and control efficiencies in Table 8.22-2. Table
8.22-3 presents data on particle size distributions and corresponding size-
specific emission factors for the controlled main waste gas stream from
taconite ore pelletizing operations.
The taconite ore is handled dry through the crushing stages. All
crushers, size classification screens and conveyor transfer points are major
points of particulate emissions. Crushed ore is normally wet ground in rod
and ball mills. A few plants, however, use dry autogenous or semi-autogenous
grinding and have higher emissions than do conventional plants. The ore
remains wet through the rest of the beneficiation process (through concentrate
storage, Figure 8.22-1) so particulate emissions after crushing are generally
insignificant.
The first source of emissions in the pelletizing process is the trans-
fer and blending of bentonite. There are no other significant emissions in
10/86 Mineral Products Industry 8.22-3
-------
TABLE 8.22-1. PARTICULATE EMISSION FACTORS FOR
TACONITE ORE PROCESSING, WITHOUT CONTROLS3
EMISSION FACTOR RATING: D
Emissions*5
Source kg/Mg Ib/ton
Ore transfer
Coarse crushing and screening
Fine crushing
Bentonite transfer
Bentonite blending
Grate feed
Indurating furnace waste gas
Grate discharge
Pellet handling
0.05
0.10
39.9
0.02
0.11
0.32
14.6
0.66
1.7
0.10
0.20
79.8
0.04
0.22
0.64
29.2
1.32
3.4
aReference 1. Median values.
^Expressed as units per unit weight of pellets produced.
the balling section, since the iron ore concentrate is normally too wet to
cause appreciable dusting. Additional emission points in the pelletizing
process include the main waste gas stream from the indurating furnace, pellet
handling, furnace transfer points (grate feed and discharge), and for plants
using the grate/kiln furnace, annular coolers. In addition, tailings basins
and unpaved roadways can be sources of fugitive emissions..
Fuel used to fire the indurating furnace generates low levels of sulfur
dioxide emissions. For a natural gas fired furnace, these emissions are about
0.03 kilograms of S02 per megagram of pellets produced (0.06 Ib/ton). High-
er S02 emissions (about 0.06 to 0.07 kg/Mg, or 0.12 to 0.14 Ib/ton) would
result from an oil or coal fired furnace.
Particulate emissions from taconite ore processing plants are controlled
by a variety of devices, including cyclones, multiclones, rotoclones, scrub-
bers, baghouses and electrostatic precipitators. Water sprays are also used
to suppress dusting. Annular coolers are generally left uncontrolled because
their mass loadings of particulates are small, typically less than 0.11 grams
per normal cubic meter (0.05 gr/scf).
The largest source of particulate emissions in taconite ore mines is
traffic on unpaved haul roads.^ Table 8.22-4 presents size specific emission
factors for this source determined through source testing at one taconite
mine. Other significant particulate emission sources at taconite mines are
wind erosion and blasting.^
As an alternative to the single valued emission factors for open dust
sources given in Tables 8.22-1 and 8.22-4, empirically derived emission
8.22-4 EMISSION FACTORS 10/86
-------
o
00
TABLE 8.22-2.
CONTROL EFFICIENCIES FOR COMBINATIONS OF
CONTROL DEVICES AND SOURCES3
3
n
o
a
n
o
a
c
(0
Control
Scrubber
Cyclone
Hulticlonr
Rotoclone
Bag collector
Eleclrostatlc
precipitstor
Dry mechanical
collector
Centrifugal
col lector
Coarse Ore • Fine Bentonlle
crushing transfer crushing transfer'
95(IO)f 99.5(18)1 99.5(5)f 98(l)f
91.6(4)1 99(5)f 99.6(6)f
99(2). 97(4)m 97(10).
99(1)- 97(l9)e
85(1)1 95(2)e
92(2)f
88(2)1
9l.6(4)f 98(l)f 99.7(7)f
98.3(4)1
99(2)m 99(8)e
99.9(2)ii
99(4)e
99.9(2)e
B5(l)f 85(l)f
Bentonite Grale Grate Waste Pellet
blending feed discharge gai handling
98.7(l)f 98.7(2)f 99.3(2)f 98.5(l)e 99.3(2)f
99.3(l)f 98(1)- 99(5)e 39(l)e 99.7(l)f
99(5)e 98(t)e 99(2)1
97.5(l)e
95-98(56)f
9.">-9B(2)f
98(l)e
99(2)f
99.7(l)f
98.9(2)f
9fi.8(l)e
88(l)f 88(l)f
98(l)e 99.4(l)e
99.4(l)e
Reference I. Control efficiencies are expressed as percent reduction. Number o in parentheses arr the number of
Indicated combinations with I lie slated efficiency. The letters si, f, e denote whether the slated efficiencies
were based upon Manufacturer's rating (m), field testing (f), or estimations (e). Blanks indicate thai no
such combinations of source and control technology are known to exist, or thai no dala on Ihe efficiency of
the combination ire available.
oo
N)
Cn
-------
:o 30 «o so M --o i
Parctel* dluectr, am
Figure 8.22-3. Particle size distributions and size specific emission
factors for indurating furnace waste gas stream from
taconite ore pelletizing.
TABLE 8.22-3.
PARTICLE SIZE DISTRIBUTIONS AND SIZE SPECIFIC EMISSION FACTORS
FOR CONTROLLED INDURATING FURNACE WASTE GAS STREAM FROM
TACONITE ORE PELLETIZING*
SIZE-SPECIFIC EMISSION FACTOR RATING: D
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Particle size
Cyclone
controlled
17.4
25.6
35.2
distribution^3
Cyclone/ESP
controlled
48.0
71.0
81.5
Size specific emission
factor,
Cyclone
controlled
0.16
0.23
0.31
kg/MgC
Cyclone/ESP
controlled
0.012
0.018
0.021
aReference 3. ESP = electrostatic precipitator. After cyclone control,
mass emission factor is 0.89 kg/Mg, and after cyclone/ESP control, 0.025
kg/Mg. Mass and size specific emission factors are calculated from data
in Reference 3, and are expressed as kg particulate/Mg of pellets produced.
^Cumulative weight % < particle diameter.
cSize specific emission factor = mass emission factor x particle size
distribution, %/100.
8.22-6
EMISSION FACTORS
10/86
-------
TABLE 8.22-4. UNCONTROLLED EMISSION FACTORS FOR HEAVY DUTY VEHICLE
TRAFFIC ON HAUL ROADS AT TACONITE MINES3
Surface Emission factor by aerodynamic
material
Crushed rock
and glacial
till
Crushed taconite
and waste
<30
3.1
11.0
2.6
9.3
I15
2.2
7.9
1.9
6.6
(urn)
I10
1.7
6.2
1.5
5.2
<5
1.1
3.9
0.9
3.2
diameter
<2.5
0.62
2.2
0.54
1.9
Units
kg/VKT
Ib/VMT
kg/VKT
Ib/VMT
Emission
Factor
Rating
C
C
D
D
aReference 4. Predictive emission factor equations, which provide
generally more accurate estimates, are in Chapter 11. VKT = vehicle
kilometers travelled. VMT = vehicle miles travelled.
factor equations are presented in Chapter 11 of this document. Each equation
has been developed for a source operation defined by a single dust generating
mechanism, common to many industries, such as vehicle activity on unpaved
roads. The predictive equation explains much of the observed variance in mea-
sured emission factors by relating emissions to parameters which characterize
source conditions. These parameters may be grouped into three categories,
1) measures of source activity or energy expended, i. e., the speed and weight
of a vehicle on an unpaved road; 2) properties of the material being disturbed,
i. e. , the content of suspendable fines in the surface material of an unpaved
road; and 3) climatic parameters, such as the number of precipitation free days
per year, when emissions tend to a maximum.
Because the predictive equations allow for emission factor adjustment to
specific source conditions, such equations should be used in place of the
single valued factors for open dust sources in Tables 8.22-1 and 8.22-4, when-
ever emission estimates are needed for sources in a specific taconite ore mine
or processing facility. One should remember that the generally higher quality
ratings assigned to these equations apply only if 1) reliable values of correc-
tion parameters have been determined for the specific sources of interest, and
2) the correction parameter values lie within the ranges tested in developing
the equations. In the event that site specific values are not available,
Chapter 11 lists measured properties of road surface and aggregate process
materials found in taconite mining and processing facilities, and these can be
used to estimate correction parameter values for the predictive emission factor
equations. The use of mean correction parameter values from Chapter 11 reduces
the quality ratings of the factor equations by one level.
10/86
Mineral Products Industry
8.22-7
-------
References for Section 8.22
1. J. P. Pilney and G. V. Jorgensen, Emissions from Iron Ore Mining,
Beneficiation and Pelletization, Volume 1, EPA Contract No. 68-02-2113,
Midwest Research Institute, Minnetonka, MN, June 1983.
2. A. K. Reed, Standard Support and Environmental Impact Statement for
the Iron Ore Beneficiation Industry (Draft), EPA Contract No. 68-02-
1323, Battelle Columbus Laboratories, Columbus, OH, December 1976.
3. Air Pollution Emission Test, Empire Mining Company, Palmer, MI, EMB-
76-IOB-2, U. S. Environmental Protection Agency, Research Triangle
Park, NC, November 1975.
4. T. A. Cuscino, e_t al., Taconite Mining Fugitive Emissions Study,
Minnesota Pollution Control Agency, Roseville, MN, June 1979.
8.22-8 EMISSION FACTORS 10/86
-------
Ul
(JO
3
re
o
o.
c
n
o.
e
Cfl
CO
N>
To Preparation and
Shipping FacilillM
haul toad
Figure 8.24-2. Operations at typical western surface coal mines.
-------
03
•
to
1
Operation
Truck loading
Bulldozing
TABLE 8.24-1. EMISSION FACTOR EQUATIONS FOR
AT WESTERN SURFACE COAL MINES
Material Emissions by particle size range
TSP < 30ura < ISura
Coal 0.580 0.0596
(M)I.2 (M)0.9
Coal 35.6 (s)l'^ 8.44 (a)1-5
(M)1-3 (M)1'4
Overburden 2.6 (s)'*2 0.45 (a)'-^
UNCONTROLLED OPEN DUST SOURCES
(METRIC UNITS)3
(aerodynamic diameter)b,c
Units
< 2.5 um/TSPd
0.019 kg/Mg
0.022 kg/hr
0.105 kg/hr
Emission
Factor
Rating
B
B
B
PI
Dragline
Overburden 0.0046 (d)1-1
0.0029 (d)°-7
0.017
in
M
o
•Z,
"d
o
H
O
Scraper
(travel node)
Grading
Vehicle traffic
(llght/nedlua duty)
Haul truck
Active storage pile
(wind erosion and
maintenance)
Coal
9.6 x 10-6 (s)
0.0034 (S)2-5
1:11
0.0019 (w]
1.8 u
(L)0'2
2.2 x 10"6 (a)l-* (W)2-5
0.0056 (S)2-°
1.05
0.0014
NA
0.026
0.031
0.040
0.017
NA
kg/VKT
kg/VKT
kg/VKT
kg/VKT
kg
(hect«re)(hr)
aAl 1 equations are from Reference I, except for coul storage pile equation from Reference 4. TSI* - lotnl suspended
partlculate. VKT - vehicle kilometers traveled. NA - not available.
bTSP denotes what is measured by a standard high volume sampler (see Section 11.2).
cSymbola for equations:
M - material moisture content (%) W - mean vehicle weight (Mg)
s - material silt content (2) S » mean vehicle speed (kph)
u - wind speed (m/sec) w - mean number of wheels
d - drop height (m) l< - road surface silt loading (g/ui?)
''Multiply the TSP predictive equation by tlila fraction to determine emissions In the <2.5 m size range.
eKatlng applicable to Mine Types I, U and IV (see Tables 8.24-5 and 8.24-6).
A
B
O
00
-------
o
oo
3
n>
2
'""'
•?
o
a
c
n
r»
(a
M
g.
C
CO
TABLE 8.24-2. EMISSION FACTOR EQUATIONS FOR UNCONTROLL
ED OPEN DUST SOURCES
AT WESTERN SURFACE COAL MINES (ENGLISH UNITS)3
Operation
Truck loading
Bulldozing
Dragline
Scraper
(travel nodel)
Grading
Vehicle traffic
(llght/aedlun duty)
Material Emissions by particle alze range (aerodynamic
TSH < 30um < 15um
Coal 1.16 0.119
(M)1'2 (M)0'9
Coal 78.4 (s)l>2 16.6 (s)''5
(M)1'3 (M)1-*
Overburden 5.7 (n)l-2 1.0 (a)l'-5
(H)1'3 (M)lt*
Overburden 0.0021 (d)l-l 0.0021 (d)0.7
(M)0.3 (M)0-3
2.7 x 10~5 (a)1-3 (W)2-* 6.2 x IO"6 (s)'-* (W)2-^
0.040 (S)2«5 • 0.051 (S)2'0
5.79 3.72
(M)*-0 (M)4-3
dlameter)b'c
Units
< 2.5un/TSPd
0.019 Ib/ton
0.022 Ib/hr
0.105 Ib/hr
0.017 lb/yd3
0.026 Ib/VMT
0.031 Ib/VMT
0.040 Ib/VMT
Emission
Factor
Rating
B
B
B
B
A
B
B
Haul truck
0.0067 (u)
0.0051
0.017
Ib/VMT
CD
•
NJ
Active storage pile
(wind erosion and
nalntenance)
Coal
1 .6 u
NA
NA
Ib
(acre)(hr)
• AJ1 equations are from Reference I, except for coal storage pile equation TrJiiT Reference 4~. ~~fi>Y - fotaT sliupenJeiT
partlculate. VMT " vehicle miles traveled. NA * not available.
° TSP denotes what la measured by a standard high volume sampler (sue Section 11.2).
c Symbols for equations:
M - material moisture content (X) W - mean vehicle weight (tons)
s -* material silt content (Z) S - IUL-.IM vehicle speed (inph)
u - wind speed (m/sec) w - mean number of uheels
d » drop height (ft) . I. = road surf ace. si 11 loading (g/m^)
d Multiply the TSP predictive equation by this fraction co determine emissions In the < 2.!)uiu size range.
e Hating applicable to Mine Types I, 11 and IV (see Tables 8.24-5 and 8.24-6).
C«
I
Ul
-------
The equations were developed through field sampling of various western surface
mine types and are thus applicable to any of the surface coal mines located in
the western United States.
In Tables 8.24-1 and 8.24-2, the assigned quality ratings apply within
the ranges of source conditions that were tested in developing the equations,
given in Table 8.24-3. However, the equations are derated one letter value
(e. g., A to B) if applied to eastern surface coal mines.
TABLE 8.24-3. TYPICAL VALUES FOR CORRECTION FACTORS APPLICABLE TO THE
PREDICTIVE EMISSION FACTOR EQUATIONS3
Number
Source Correction of test
factor samples
Coal loading
Bulldozers
Coal
Overburden
Dragline
Scraper
Grader
Light/medium
duty vehicle
Haul truck
Moisture
Moisture
Silt
Moisture
Silt
Drop distance
•• »•
Moisture
Silt .
Weight
Speed
Moisture
Wheels
Silt loading
7
3
3
8
8
19
7
10
15
7
7
29
26
Range Geometric
mean
6.6
4.0
6.0
2.2
3.8
1.5
5
0.2
7.2
33
36
8.0
5.0
0.9
6.1
3.8
34
- 38
- 22.0
- 11.3
- 16.8
- 15.1
- 30
- 100
- 16.3
- 25.2
- 64
- 70
- 19.0
- 11.8
- 1.7
- 10.0
- 254
- 2270
17.8
10.4
8.6
7.9
6.9
8.6
28.1
3.2
16.4
48.8
53.8
11.4
7.1
1.2
8.1
40.8
364
Units
7,
7,
7,
7,
7,
m •
ft
%
%
Mg
ton
kph ..
raph
7.
number
g/m2
Ib/ac
aReference
In using the equations to estimate emissions from sources found in a
specific western surface mine, it is necessary that reliable values for
correction parameters be determined for the specific sources of interest,
if the assigned quality ranges of the equations are to be applicable.
For example, actual silt content of coal or overburden measured at a facility
8.24-6
EMISSION FACTORS
10/86
-------
10.0 WOOD PRODUCTS INDUSTRY
Wood processing involves the conversion of raw wood to pulp, pulpboard or
types of wallboard such as plywood, particle board or hardboard. This chapter
presents emissions data on chemical wood pulping, on pulpboard and plywood manu-
facturing, and on woodworking operations. The burning of wood waste in boilers
and conical burners is discussed in Chapters 1 and 2 of this publication.
10/86 Wood Products Industry 10-1
-------
10.1 CHEMICAL WOOD PULPING
10.1.1 General
Chemical wood pulping involves the extraction of cellulose from wood by
dissolving the lignin that binds the cellulose fibers together. The four pro-
cesses principally used in chemical pulping are kraft, sulfite, neutral sulfite
semichemical (NSSC), and soda. The first three display the greatest potential
for causing air pollution. The kraft process alone accounts for over 80 per-
cent of the chemical pulp produced in the United States. The choice of pulping
process is determined by the desired product, by the wood species available,
and by economic considerations.
10.1.2 Kraft Pulping
Process Description^ - The kraft pulping process (See Figure 10.1-1)
involves the digesting of wood chips at elevated temperature and pressure in
"white liquor", which is a water solution of sodium sulfide and sodium hydroxide.
The white liquor chemically dissolves the lignin that binds the cellulose fibers
together.
There are two types of "digester systems, batch and continuous. Most kraft
pulping is done in batch digesters, although the more recent installations are
of continuous digesters. In a batch digester, when cooking is complete, the
contents of the digester are transferred to an atmospheric tank usually referred
to as a blow tank. The entire contents of the blow tank are sent to pulp
washers, where the spent cooking liquor is separated from the pulp. The pulp
then proceeds through various stages of washing, and possibly bleaching, after
which it is pressed and dried into the finished product. The "blow" of the
digester does not apply to continuous digester systems.'
The balance of the kraft process is designed to recover the cooking
chemicals and heat. Spent cooking liquor and the pulp wash water are combined
to form a weak black liquor which is concentrated in a multiple effect evaporator
system to about 55 percent solids. The black liquor is then further concentrated
to 65 percent solids in a direct contact evaporator, .by bringing the liquor
into contact with the flue gases from the recovery furnace, or in an indirect
contact concentrator. The strong black liquor is then fired in a recovery
furnace. Combustion of the organics dissolved in the black liquor provides
heat for generating process steam and for converting sodium sulfate to sodium
sulfide. Inorganic chemicals present in the black liquor collect as a molten
smelt at the bottom of the furnace.
The smelt is dissolved in water to form green liquor, which is transferred
to a causticizing tank where quicklime (calcium oxide) is added to convert the
solution back to white liquor for return to the digester system. A lime mud
precipitates from the causticizing tank, after which it is calcined in a lime
kiln to regenerate quicklime.
10/86 Wood Products Industry 10.1-1
-------
M
Crt
co
M
O
z
I
en
CHIPS
CHjSH.CHjSCH3.H2S
HzS.CHjSH.CfySCHj,
MO HIGHER COWOUKOS
RELIEF
I CH3SH, CHjSCH3l H2S
HEAT
EXCHANGER
NONCOHDEHSA
, 1
\
BLti
NONCONDENSABLES
TURPENTINE
CONTAMINATED WATER
STEAM. CONTAMINATED WATER.
CONTAMINATED
j, «.
AND CH3SH
PULP 13% SOLIDS
SPENT AIR. CH3SCHj.-»—
AND CHjSSCHj
OXIDATION
TOWER
BLACK LIQUOR
50% SOLIDS
DIRECT CONTACT
EVAPORATOR
IBLACK
LIQUOR 70% SOLIDS
CaO N»2S04-*
1,1
n
1
IATER
— •*
RECOVERY
FURNACE
OXIDIZING
ZONE
REDUCTION
ZONE
•AIR
\
Mjtrim
j 4
GREEN
LIQUOR
NJ2S t N*2CC
O
oo
Figure 10.1-1. Typical kraft sulfate pulping and recovery process.
-------
For process heating, for driving equipment, for providing electric power,
etc., many mills need more steam than can be provided by the recovery furnace
alone. Thus, conventional industrial boilers that burn coal, oil, natural gas,
or bark and wood are commonly used.
Emissions And Controls^"? - Particulate emissions from the kraft pro-
cess occur largely from the recovery furnace, the lime kiln and the smelt dis-
solving tank. These emissions are mainly sodium salts, with some calcium salts
from the lime kiln. They are caused mostly by carryover of solids and sublima-
tion and condensation of the inorganic chemicals.
Particulate control is provided on recovery furnaces in a variety of ways.
In mills with either a cyclonic scrubber or cascade evaporator as the direct
contact evaporator, further control is necessary, as these devices are generally
only 20 to 50 percent efficient for particulates. Most often in these cases,
an electrostatic precipitator is employed after the direct contact evaporator,
for an overall particulate control efficiency of from 85 to more than 99 percent,
Auxiliary scrubbers may be added at existing mills after a precipitator or a
venturi scrubber to supplement older and less efficient primary particulate-
control devices.
Particulate control on lime kilns is generally accomplished by scrubbers.
Electrostatic precipitators have been used in a few mills. Smelt dissolving
tanks usually are controlled by mesh pads, but scrubbers can provide further
control.
The characteristic odor of the kraft mill is caused by the emission of
reduced sulfur compounds, the most common of which are hydrogen sulfide, methyl
mercaptan, dimethyl sulfide and dimethyl disulfide, all with extremely low odor
thresholds. The major source of hydrogen sulfide is the direct contact evapo-
rator, in which the sodium sulfide in the black liquor reacts with the carbon
dioxide in the furnace exhaust. Indirect contact evaporators can significantly
reduce the emission of hydrogen sulfide. The lime kiln can also be a. potential
source of odor, as a similar reaction occurs with residual sodium sulfide in
the lime mud. Lesser amounts of hydrogen sulfide are emitted with the noncon-
densible offgasses from the digesters and multiple effect evaporators.
Methyl mercaptan and dimethyl sulfide are formed in reactions with the
wood component, lignin. Dimethyl disulfide is formed through the oxidation of
mercaptan groups derived from the lignin. These compounds are emitted from
many points within a mill, but the main sources are the digester/blow tank
systems and the direct contact evaporator.
Although odor control devices, per se, are not generally found in kraft
mills, emitted sulfur compounds can be reduced by process modifications and
improved operating conditions. For example, black liquor oxidation systems,
which oxidize sulfides into less reactive thiosulfates, can considerably reduce
odorous sulfur emissions from the direct contact evaporator, although the vent
gases from such systems become minor odor sources themselves. Also, noncon—
densible odorous gases vented from the digester/blow tank system and multiple
effect evaporators can be destroyed by thermal oxidation, usually by passing
them through the lime kiln. Efficient operation of the recovery furnace, by
avoiding overloading and by maintaining sufficient oxygen, residence time and
turbulence, significantly reduces emissions of reduced sulfur compounds from
10/86 Wood Products Industry 10.1-3
-------
this source as well. The use of fresh water instead of contaminated condensates
in the scrubbers and pulp washers further reduces odorous emissions.
Several new mills have incorporated recovery systems that eliminate the
conventional direct contact evaporators. In one system, heated combustion air,
rather than fuel gas, provides direct contact evaporation. In another, the
multiple effect evaporator system is extended to replace the direct contact
evaporator altogether. In both systems, sulfur emissions from the recovery
furnace/direct contact evaporator can be reduced by more than 99 percent.
Sulfur dioxide is emitted mainly from oxidation of reduced sulfur compounds
in the recovery furnace. It is reported that the direct contact evaporator
absorbs about 75 percent of these emissions, and further scrubbing can provide
additional control.
Potential sources of carbon monoxide emissions from the kraft process
include the recovery furnace and lime kilns. The major cause of carbon monoxide
emissions is furnace operation well above rated capacity, making it impossible
to maintain oxidizing conditions.
Some nitrogen oxides also are emitted from the recovery furnace and lime
kilns, although amounts are relatively small. Indications are that nitrogen
oxide emissions are on the order of 0.5 and 1.0 kilograms per air dried mega-
grams (1 and 2 Ib/air dried ton) of pulp produced from the lime kiln and
recovery furnace, respectively.5~6
A major source of emissions in a kraft mill is the boiler for generating
auxiliary steam and power. The fuels used are coal, oil, natural gas or-bark/
wood waste. See Chapter 1 for emission factors for boilers.
Table 10.1-1 presents emission factors for a conventional kraft mill.
The most widely used particulate control devices are shown, along with the odor
reductions through black liquor oxidation and incineration of noncondensible
offgases. Tables 10.1-2 through 10.1-7 present cumulative size distribution
data and size specific emission factors for particulate emissions from sources
within a conventional kraft mill. Uncontrolled and controlled size specific
emission factors' are presented in Figures 10.1-2 through 10.L-7. The particle
sizes presented are expressed in terms of the aerodynamic diameter.
10.1.3 Acid Sulfite Pulping
Process Description - The production of acid sulfite pulp proceeds
similarly to kraft pulping, except that different chemicals are used in the
cooking liquor. In place of the caustic solution used to dissolve the lignin
in the wood, sulfurous acid is employed. To buffer the cooking solution, a
bisulfite of sodium, magnesium, calcium or ammonium is used. A diagram of a
typical magnesium base process is shown in Figure 10.1-8.
Digestion is carried out under high pressure and high temperature, in
either batch mode or continuous digesters, and in the presence of a sulfurous
acid/bisulfite cooking liquid. When cooking is completed, either the digester
is discharged at high pressure into a blow pit, or its contents are pumped into
a dump tanjc at a lower pressure. The spent sulfite liquor (also called red
liquor) then drains through the bottom of the tank and is treated and discarded,
10.1-4 ' EMISSION FACTORS 10/86
-------
o
CO
TABU; 10.1-1. EMISSION FACTORS FOR SULFITE
EMISSION FACTOR RATING: A
o
o
10
•-(
o
a
e
o
c
(A
Source
Digester relief and blow tank
Brown stock waaher
Multiple effect evaporator
Recovery boiler acid direct
evaporator
Noncontact recovery boiler
without direct contact
evaporator
Snelt dissolving tank
Lime kiln
Turpentine condenser
Miscellaneous"
Type ut cuui rol
Untreated*1
Untreated6
Untreated1*
Untreated"1
Venturl
scrubber'
ESP
Aux 11 lary
scrubber
Untreated
ESF
Untreated
Mesh pad
Scrubber
Untreated
Scrubber or ESP
Untreated
Untreated
I'ari Iculate
kg/Mg
-
-
90
24
1
1.5-7. SB
115
1
3.5
0.5
O.I
2«
0.25
-
-
Ib/ton
_
-
180
48
2
3-158
230
2
7
I
0.2
56
0.5
-
-
Sulfur
dioxide (SO2)
kg/Mg
_
-
3.5
3.5
3.5
-
-
0.1
O.I
-
0.15
-
-
-
Ib/ton
_
-
-
7
7
7
-
-
0.2
0.2
-
0.3
-
-
-
Ca rbon
monoxide (CO)
kg/Mg
.
-
-
5.5
5.5
5.5
5.5
5.5
_
-
-
0.05
0.05
-
-
Ib/ton
.
-
-
11
11
11
11
II
_
-
-
O.I
O.I
-
-
Hydrogen
sulftde (S*)
kg/Mg
0.02
0.01
0.55
6e
6e
6e
6e
0.05h
0.05h
O.lJ
O.lJ
O.lJ
0.25"1
0.25"
0.005
-
Ib/ton
0.03
0.02
1.1
I2e
I2e
12«
I2e
O.I"
O.I"
0.2J
0.2J
0.2J
0.5™
0.5"
.01
-
RSH. RSR,
RSSR (S')
kg/Mg
0.6
0.2C
0.05
1.5e
l.5e
l.5«
l.5e
-
-
0.15J
0.151
0.15J
0.1°
O.lm
0.25
0.25
i
Ib/ton
1.2
0.4C
O.I
3e
3e
3e
3e
-
-
0.3J
0.3J
0.3J
0.2"
0.2"
0.5
0.5
"References 8-10. Factors expressed In unit weight of air dried unbleached pulp (AI)P). RSII - Methyl mercaptan. RSR -
Dimethyl sulflde. RSSR - Dimethyl dtsulflde. ESP - Electrostatic prectpl tator. Uuuli » No data.
''If noncondenslble gases from these sources are veined to lime kiln, recovery furnace or equivalent, tlie reduced sulfur
compounds are destroyed.
cApply with system using condensate an washing medium. When using .fresh water, emissions are 0.05 (O.I).
''Apply when cyclonic scrubber or cascade evaporator Is used for direct contact evaporation, with no further coin role.
cUsually reduced by 50X with black liquor oxidation un.l can be cut 95 - 99Z when oxidation Is complete and recovery
furnace is operated optimally.
'Apply when venturl scrubber Is used for direct contiicl evapuratIon, with no further controls.
BUse 7.5 (15) when auxiliary scrubber follows veniurl scrubber, and 1.5 (3) when it follows ESP.
."Apply when recovery furnace is operated optimally lo control total reduced sulfur (TKS) compounds.
JUsually reduced to 0.01 g/kg (0.02 Ib/tun) AI)P wliun water low In uulfldes is used in smelt dissolving tank and
associated scrubber.
""Usually reduced to 0.015 g/kg (0.03 Ib/ton) AI1P with efficient mud washing, optimal kiln operation and added caustic
in scrubbing water. With only efficient mud washing and optimal process control, TKS compounds reduced to 0.04 g/kg
(0.08 Ib/ton) ADP.
"Includes knotter vents, brownstock seal tanks, etc. When black liquor oxidation is Included, emissions are 0.3 (0.6).
-------
TABLE 10.1-2. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR A RECOVERY BOILER WITH A DIRECT
CONTACT EVAPORATOR AND AN ESPa
EMISSION FACTOR RATING: C
Particle size
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
Cumulative mass % <
stated size
Uncontrolled
95.0
93.5
92.2
83.5
56.5
45.3
26.5
100
Controlled
_
-
68.2
53.8
40.5
34.2
22.2
100
Cumulative emission factor
(kg/Mg of air dried pulp)
Uncontrolled
86
84
83
75
51
41
24
90
Controlled
.
-
0.7
0.5
0.4
0.3
0.2
1.0
aReference 7. Dash = no data
100
-,1.0
90 -
80 -
_ 70
60
50
40
5 30
20
10
0
0.1
Uncontrolled
Controlled
I LI 1 U
I I I I I I I
-0.9
-0.8
-0.7
-0.6
_ 0.5
_ 0.4
- 0.3
- 0.2
- 0.1
i.o 10
Particle diameter (urn)
100
Figure 10.1-2. Cumulative particle size distribution and
specific emission factors for recovery boiler
with direct contact evaporator and ESP.
size
10.1-6
EMISSION FACTORS
10/86
-------
TABLE 10.1-3. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR A RECOVERY BOILER WITHOUT A DIRECT
CONTACT EVAPORATOR BUT WITH AN ESPa
EMISSION FACTOR RATING: C
Particle size
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
Cumulative mass % <
stated size
Uncontrolled
—
-
-
78.0
40.0
30.0
17.0
100
Controlled
78.8
74.8
71.9
67.3
51.3
42.4
29.6
100
Cumulative emission factor
(kg/Mg of air dried pulp)
Uncontrolled
—
-
-
90
46
35
20
115
Controlled
0.8
0.7
0.7 .
0.6
0.5
0.4
0.3
1.0
aReference 7. Dash = no data.
ISO
~ 100
S 50
o.i
Controlled
I I I I
Uncontrolled
i i tin
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
1.0 10
Particle diameter (\m)
100
Figure 10.1-3. Cumulative particle size distribution and size
specific emission factors for recovery boiler without direct contact
evaporator but with ESP.
10/86
Wood Products Industry
10.1-7
-------
TABLE 10.1-4. .CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR A LIME KILN WITH A VENTURI SCRUBBER3
EMISSION FACTOR RATING: C
Particle size
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
Cumulative mass Z <
stated size
Uncontrolled
27.7
16.8
13.4
10.5
8.2
7.1
3.9
100
Controlled
98.9
98.3
98.2
96.0
85.0
78.9
54.3
100
Cumulative emission factor
(kg/Mg of air dried pulp)
Uncontrolled
7.8
4.7
3.8
2.9
2.3
2.0
1.1
28.0
Controlled
0.24
0.24
0.24
0.24
0.21
0.20
0.14
0.25
aReference 7.
30
j-s
.
•— o
20
10
Controlled
Uncontrolled
0.1
1.0 10
Particle diameter (i*n)
0.3
» i i i mi i 1—i i i i iin 1—i i M imo
Jo
100
Figure 10.1-4. Cumulative particle size distribution and size
specific emission factors for lime kiln with venturi scrubber.
10.1-8
EMISSION FACTORS
10/86
-------
TABLE 10.1-5. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR A LIME KILN WITH AN ESPa
EMISSION FACTOR RATING: C
Particle size
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
Cumulative mass % <
stated size
Uncontrolled
27.7
16.8
13.4
10.5
8.2
7.1
3.9
100
Controlled
91.2
88.5
86.5
83.0
70.2
62.9
46.9
100
Cumulative emission factor
(kg/Mg of air dried pulp)
Uncontrolled
7.8
4.7
3.8
2.9
2.3
2.0
1.1
28.0
Controlled
0.23
0.22
0.22
0.21
0.18
0.16
0.12
0.25
aRef erence 7 . . •
30
0.1
1.0 10
Particle diameter (vim)
Figure 10.1-5. Cumulative particle size distribution and size
specific emission factors for lime kiln with ESP.
10/86
Wood Products Industry
10.1-9
-------
TABLE 10.1-6. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR A SMELT DISSOLVING TANK WITH A
PACKED TOWER3
EMISSION FACTOR RATING: C
Particle size
(urn)
15
10
6
. 2.5
1.25
1.00
0.625
Total
Cumulative mass % <
stated size
Uncontrolled
90.0
88.5
87-.0
73.0
47.5
40.0
25.5
100
Controlled
95.3
95.3
94.3
85.2
63.8
54.2
34.2
100
Cumulative emission factor
(kg/Mg of air dried pulp)
Uncontrolled
3.2
3.1
3.0
2.6
1.7
1.4
0.9
3.5
Controlled
0.48
0.48
0.47
0.43
0.32
0.27
0.17
0.50
aReference 7.
»= S, 4
s-s
a.6
o.i
Controlled
Uncontrolled
\iit\\\
_LL 0
1.0 10
Particle diameter (v»)
0.5
2?
0.4 ^^
§•
0-2
0.1
100
Figure 10.1-6. Cumulative particle size distribution and size
specific emission factors for smelt dissolving tank with
packed tower.
10.1-10
EMISSION FACTORS
10/86
-------
TABLE 10.1-7. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR A SMELT DISSOLVING TANK WITH A
VENTURI SCRUBBER3
EMISSION FACTOR RATING: C
Particle size
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
Cumulative mass % <
stated size
Uncontrolled
90.0
88.5
87.0
73.0
47.5
54.0
25.5
100
Controlled
89.9
89.5
88.4
81.3
63.5
54.7
38.7
100
Cumulative emission factor
(kg/Mg of air dried pulp)
Uncontrolled
3.2
3.1
3.0
2.6
1.7 .
1.4
0.9
3.5
Controlled
0.09
0.09
0.09
0.08
0.06
0.06
0.04
0.09
aRef erence 7 .
° z
0.1
Controlled
Uncontrolled
1.0 10
Particle diameter
1.0
0.9
0.8
0.6
-
0.4 .2 o
0.3 Ji
0.2
0.1
0
100
Figure 10.1-7. Cumulative particle size distribution and size
specific emission factors for smelt dissolving tank with
venturi scrubber.
10/86
Wood Products Industry
10.1-11
-------
MICOVIHV lUHMCt/
AUOHMIONilfUAM
flHAUil
I
*-•
K)
UROMCRIOUOUOR
CO
CO
M
O
25
O
po
CO
SlfAMIOH
moctuMorowu
RicovfRYruMACi
UOUOR
NIMH
F^
nuiiirii IKICI
(VAPORAIOM
T
CO«0(IIS*II
•Ml
NfO
IIOUOK
Mil Ad HID IIOUOH
O
^
oo
Figure 10.1-8. Simplified process flow diagram of magnesium-base process
employing chemical and heat recovery.
-------
incinerated, or sent to a plant for recovery of heat and chemicals. The pulp
is then washed and processed through screens and centrifuges to remove knots,
bundles of fibers and other material. It subsequently may be bleached, pressed
and dried in papermaking operations.
Because of the variety of cooking liquor bases used, numerous schemes have
evolved for heat and/or chemical recovery. In calcium base systems, found most-
ly in older mills, chemical recovery is not practical, and the spent liquor is
usually discharged or incinerated. In ammonium base operations, heat can be
recovered by combusting the spent liquor, but the ammonium base is thereby con-
sumed. In sodium or magnesium base operations, the heat, sulfur and base all
may be feasibly recovered.
If recovery is practiced, the spent (weak) red liquor (which contains more
than half of the raw materials as dissolved organic solids) is concentrated in
a multiple effect evaporator and a direct contact evaporator to 55 to 60 per-
cent solids. This strong liquor is sprayed into a furnace and burned, pro-
ducing steam to operate the digesters, evaporators, etc. and to meet other
power requirements.
When magnesium base liquor is burned, a flue gas is produced from which
magnesium oxide is recovered in a multiple cyclone as fine white power. The
magnesium oxide is then water slaked and is used as circulating liquor in a
series of venturi scrubbers, which are designed to absorb sulfur dioxide from
the flue gas and to form a bisulfite solution for use in the cook cycle. When
sodium base liquor is burned, the inorganic compounds are recovered as a molten
smelt containing sodium sulfide and sodium carbonate. This smelt may be pro-
cessed further and used.to absorb sulfur dioxide from the flue gas and sulfur
burner. In some sodium base mills, however, the smelt may be sold to a nearby
kraft mill as raw material for producing green liquor.
If liquor recovery is not practiced, an acid plant is necessary of suf-
ficient capacity to fulfill the mill's total sulfite requirement. Normally,
sulfur is burned in a rotary or spray burner. The gas produced is then cooled
by heat exhangers and a water spray and Is then absorbed in a variety of dif-
ferent scrubbers containing either limestone or a solution of the base chemical.
Where recovery is practiced, fortification is accomplished similarly, although
a much smaller amount of sulfur dioxide must be produced to make up for that
lost in the process.
Emissions And Controls^ - Sulfur dioxide is generally considered the major
pollutant of concern from sulfite pulp mills. The characteristic "kraft" odor
is not emitted because volatile reduced sulfur compounds are not products of
the lignin/bisulfite reaction.
A major S02 source is the digester and blow pit (dump tank) system. Sul-
fur dioxide is present in the intermittent digester relief gases, as well as in
the gases given off at the end of the cook when the digester contents are dis-
charged into the blow pit. The quantity of sulfur dioxide evolved and emitted
to the atmosphere in these gas streams depends on the pH of the cooking liquor,
the pressure at which the digester contents are discharged, and the effective-
ness of the absorption systems employed for S02 recovery. Scrubbers can be
installed that reduce S02 from this source by as much as 99 percent.
10/86 Wood Products Industry 10.1-13
-------
Aaother source of sulfur dioxide emissions is the recovery system. Since
magnesium, sodium, and ammonium base recovery systems all use absorption systems
to recover S02 generated in recovery furnaces, acid fortification towers, mul-
tiple effect evaporators, etc., the magnitude of S02 emissions depends on the ,
desired efficiency of these systems. Generally, such absorption systems recover
better than 95 percent of the sulfur so it can be reused.
The various pulp washing, screening, and cleaning operations are also
potential sources of SC>2 • These operations are numerous and may account for a
significant fraction of a mill's SC>2 emissions if not controlled.
The only significant particulate source in the pulping and recovery pro-
cess is the absorption system handling the recovery furnace exhaust. Ammonium
base systems generate less particulate than do magnesium or sodium base systems.
The combustion productions are mostly nitrogen, water vapor and sulfur dioxide.
Auxiliary power boilers also produce emissions in the sulfite pulp mill,
and emission factors for these boilers are presented in Chapter 1.
Table 10.1-8 contains emission factors for the various sulfite pulping
operations.
10.1.4 Neutral Sulfite Semichemical (NSSC) Pulping
Process Description^' 12-14 _ jn this method, wood chips are cooked in a
neutral solution of sodium sulfite and sodium carbonate. Sulfite ions react
with the lignin in wood, and the sodium bicarbonate acts as a buffer to maintain
a neutral solution. The major difference between all semichemical techniques
and those of kraft and acid sulfite processes is that only a portion of the
lignin is removed during the cook, after which the pulp is further reduced by
mechanical disintegration. This method achieves yields as high as 60 to 80
percent, as opposed to 50 to 55 percent for other chemical processes.
The NSSC process varies from mill to mill. Some mills dispose of their
spent liquor, some mills recover the cooking chemicals, and some, when operated
in conjunction with kraft mills, mix their spent liquor with the kraft liquor
as a source of makeup cheincials. When recovery is practiced, the involved
steps parallel those of the sulfite process.
Emissions And Controls^>12-14 _ Particulate emissions are a potential prob-
lem only when recovery systems are involved. Mills that do practice recovery
but are not operated in conjunction with kraft operations often utilize fluid-
ized bed reactors to burn their spent liquor. Because the flue gas contains
sodium sulfate and sodium carbonate dust, efficient particulate collection may
be included for chemical recovery.
A potential gaseous pollutant is sulfur dioxide. Absorbing towers, diges-
ter/blower tank system, and recovery furnace are the main sources of S02, with
amounts emitted dependent upon the capability of the scrubbing devices installed
for control and recovery.
Hydrogen sulfide can also be emitted from NSSC mills which use kraft type
recovery furnaces. The main potential source is the absorbing tower, where a
10.1-14 EMISSION'FACTORS 10/86
-------
TABLE 10.1-8. EMISSION FACTORS FOR SULFITE PULPING3
Source
Dlgeacer/blow pic or
dump tankc
Recovery system6
Acid plant f
Other1*
Base
All
MgO
MgO
MgO
MgO
NH3
NH3
Na
Ca
MgO
NH3
Na
NH,
Na
Ca
All
Control
None
Process change**
Scrubber
Process change and
scrubber
All exhaust vented through
recovery system
Process change
Process change and
scrubber
Process change and
scrubber
Unknown
Multicyclone and venturl
scrubbers
Ammonia absorption and
mist eliminator
Sodium carbonate scrubber
Scrubber
Unknowns
Jeossen scrubber
Hone
Emission factor'9
Parclculate
kg/ADUMg
Meg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
1
0.35
2
Heg
Neg
Neg
Meg
Ib/ADUT
Neg
Neg
Neg
Neg
Neg
feg
Neg
Neg
Neg
2
0.7
Sulfur dioxide
kg/ADUMg
5 to 35
1 Co 3
0.5
0.1
0
12.5
0.2
1
33.5
i .5
3.5
4 j 1
1
Neg
Neg
Neg
Neg
0.2
0.1
4
6
Ib/ADUT
10 to 70
2 to 6
1 '
0.2
0
25
0.4
2
67
9
7
2
0.3
0.2
8
12
Emission
Factor
Rating
C
C
S
B
A
0
3
C
C
A
3
C
c
0
c
D
aReference 11. All factors represent long term average emissions. ADUMg * Air dried unbleached megagram.
ADUT » Air dried unbleached ton. Neg - negligible.
Expressed as kg (Ib) of pollutant/air dried unbleached ton (ag) of pulp.
e?actors represent emissions after cook Is completed and when digester contents are discharged Into blow pic or
dump tank. Some relief gases are vented from digester during cook cycle, but these are usually transferred Co
pressure accumulators and SO? therein ceabsorbed for use in cooking liquor. In some aills, actual emissions
will be Intermittent and for 3hort periods.
dXay include such measures as raising cooking liquor ?H (thereby lowering free 30,}, relieving digester
pressure before contents discharge, and pumping out digester contents Instead of blowing out.
'Recovery system at most mills is closed and includes recovery furnace, direct contact evaporator, multiple
effect evaporator, acid fortification cower, and 302 absorption scrubbers. Generally only one emission point
for entire system. Factors Include high S02 emissions during periodic purging of recovery systems.
^Necessary in mills with Insufficient or nonexistent recovery systems.
^Control is practiced, but -type of system is unknown.
"Includes miscellaneous pulping operations such as knotters, washers, screens, etc.
10/86
Wood Products Industry
10.1-15
-------
significant quantity of hydrogen sulfite is liberated as the cooking liquor is
made. Other possible sources, depending on the operating conditions, include
the recovery furnace, and in mills where some green liquor is used in the cook-
ing process, the digester/blow tank system. Where green liquor is used, it
is also possible that significant quantities of mercaptans will be produced.
Hydrogen sulfide emissions can be eliminated if burned to sulfur dioxide beforel
the absorbing system.
Because the NSSC process differs greatly from mill to mill, and because
of the scarcity of adequate data, no emission factors are presented for this
process.
References for Section 10.1
1. Review of New Source Performance Standards for Kraft Pulp Mills, EPA-450/
3-83-017, U. S. Environmental Protection Agency, Research Triangle Park,
NC, September 1983.
2. Standards Support and Environmental Impact Statement, Volume I; Proposed
Standards of Performance for Kraft Pulp Mills. EPA-450/2-76-014a, U. S.
Environmental Protection Agency, Research Triangle Park, NC, September
1976.
3. Kraft Pulping - Control of TRS Emissions from Existing Mills, EPA-450/78-
003b, U. S. Environmental Protection Agency, Research Triangle Park, NC,
March 1979.
4. Environmental Pollution Control, Pulp and Paper Industry, Part I: .Air,
EPA-625/7-76-001, U. S. Environmental Protection Agency, Washington, DC,
October 1976.
5. A Study of Nitrogen Oxides Emissions from Lime Kilns, Technical Bulletin
.Number 107, National Council of the Paper Industry for Air and Stream
Improvement, New York, NY, April 1980.
6. A Study of Nitrogen Oxides Emissions from Large Kraft Recovery Furnaces,
Technical Bulletin Number 111, National Council of the Paper Industry for
Air and Stream Improvement, New York, NY, January 1981.
7. Source Category Report for the Kraft Pulp Industry, EPA Contract Number
68-02-3156, Acurex Corporation, Mountain View, CA, January 1983.
8. Source test data, Office Of Air Quality Planning And Standards, U. S.
Environmental Protection Agency, Research Triangle Park, NC, 1972.
9. Atmospheric Emissions from the Pulp and Paper Manufacturing Industry,
EPA-450/1-73-002, U. S. Environmental Protection Agency, Research Triangle
. Park, NC, September 1973.
10. Carbon Monoxide Emissions from Selected Combustion Sources Based on Short-
Term Monitoring Records, Technical Bulleting Number 416, National Council
of the Paper Industry for Air and Stream Improvement, New York, NY,
January 1984.
10.1-16 EMISSION FACTORS 10/86
-------
11. Backgound Document; Acid Sulfit-? Pulping, EPA-450/3-77-005, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, January 1977.
12. E. R. Hendrickson, et al., Control of Atmospheric Emissions in the Wood
Pulping Industry, Volume I, HEW Contract Number CPA-22-69-18, U. S.
Environmental Protection Agency, Washington, DC, March 15, 1970.
13. M. Benjamin, et al., "A General Description of Commercial Wood Pulping and
Bleaching Processes", Journal of the Air Pollution Control Association, 19
(3):155-161, March 1969.
14. S. F. Galeano and B. M. Dillard, "Process Modifications for Air Pollution
Control in Neutral Sulfite Semi-chemical Mills", Journal of the Air Pollu-
tion Control Association, 22(3):195-199, March 1972.
10/86 Wood Products Industry 10.1-17
-------
11.2.6 INDUSTRIAL PAVED ROADS
11.2.6.1 General
Various field studies have indicated that dust emissions from industrial
paved roads are a major component of atmospheric particulate matter in the
vicinity of industrial operations. Industrial traffic dust has been found to
consist primarily of mineral matter, mostly tracked or deposited onto the
roadway by vehicle traffic itself when vehicles enter from an unpaved area or
travel on the shoulder of the road, or when material is spilled onto the paved
surface from haul truck, traffic.
11.2.6.2 Emissions And Correction Parameters
The quantity of dust emissions from a given segment of paved road varies
linearly with the volume of traffic. In addition, field investigations have
shown that emissions depend on correction parameters (road surface silt content,
surface dust loading and average vehicle weight) of a particular road and
associated vehicle traffic.l~2
Dust emissions from industrial paved roads have been found to vary in
direct proportion to the fraction of silt (particles <75 microns in diameter) in
the road surface material.^~^-. The silt fraction is determined by measuring the
proportion of loose dry surface dust that passes a 200 mesh screen, using the
ASTM-C-136 method. In addition, it has also been found that emissions vary in
direct proportion to the surface dust loading.1~2 The road surface dust loading
is that loose material which can be collected by broom sweeping and vacuuming of
the traveled portion of the paved road. Table 11.2.6-1 summarizes measured silt
and loading values for industrial paved roads.
11.2.6.3 Predictive Emission Factor Equations
The quantity of total suspended particulate emissions generated by vehicle
traffic on dry industrial paved roads, per vehicle kilometer traveled (VKT) or
vehicle mile traveled (VMT) may be estimated, with a rating of B or D (see
below), using the following empirical expression^:.
°-022 ' (I) (if) $) (r?) °'7
, , 0.077 I
n/ vio/ vioooy V3
(Ib/VMT)
'/ \iww/ v>;
where: E = emission factor
I = industrial augmentation factor (dimensionless) (see below)
n = number of traffic lanes
s = surface material silt content (%)
L = surface dust loading, kg/km (Ib/mile) (see below)
W = average vehicle weight, Mg (ton)
9/85 Miscellaneous Sources 11.2.6-1
-------
TABLE 11.2.6-1. TYPICAL SILT CONTENT AND LOADING VALUES FOR PAVED ROADS
AT INDUSTRIAL FACILITIES3
Industry
Copper aneltlng
Iron and steel
production
No. of
No. of No. of Silt (I. v/v) Travel Total loading x 1O~3
Sites Samples Range Mean lanes Range
1 3 (15.4-21.7) [19.0] 2 (12.9-19.5)
(45.8-69.2)
6 20 1.1-35.7 12.5 2 0.006-4.77
Mean
115.9]
(55.4)
0.495
Units"
Ib/ml
kg/ka
Silt loading
Range Mean
(188-400) (292]
0.09-79 12
Asphalt batching
(2.6-4.6) (3.3)
(12.1-18.0) (14.9| kg/ka (76-193) (120)
(43.0-64.0) (52.3) Ib/ni
Concrete batching 1
Sand and gravel
processing 1
3
3
[5
(6
.2-6.0)
.4-7.9!
(5
17
.5) 2
.1) 1
(1.4-1.8)
(5.0-6.4)
[2i8-5.5|
(9.9-19.4)
(1
(5
[3
(13
.7)
-91
.31
• 31
kg/ko
Ib/ml
kg/km
Ib/ml
[11-12]
[53-95]
112)
[70]
^References 1-5. Brackets Indicate values based on only one plant test.
bNultlply entries by 1,000 to obtain stated units.
The industrial road augmentation factor (I) in the Equation 1 takes into
account higher emissions from industrial roads than from urban roads. I = 7.0
for an industrial roadway which traffic enters from unpaved areas. I = 3.5 for
an industrial roadway with unpaved shoulders where 20 percent of the vehicles
are forced to travel temporarily with one set of wheels on the shoulder. I =
1.0 for cases in which traffic does not travel on unpaved areas. A value
between 1.0 and 7.0 which best represents conditions for paved roads at a
certain industrial facility should be used for I in the equation.
The equation retains the quality rating of B if applied to vehicles
traveling entirely on paved surfaces (I = 1.0) and if applied within the range
of source conditions that were tested in developing the equation as follows:
Silt
content
(%)
5.1 - 92
Surface loading
kg/km
42.0 - 2000
Ib/mile
149 - 7100.
*v
No. of
lanes
2-4
Vehicle weight
Mg tons
2.7 - 12 3 - 13
If I is >1.0, the rating of the equation drops to D because of the subjectivity
in the guidelines for estimating I.
The quantity of fine particle emissions generated by traffic consisting
predominately of medium and heavy duty vehicles on dry industrial paved roads,
per vehicle unit of travel, may be estimated, with a rating of A, using the
11.2.6-2
EMISSION FACTORS
9/85
-------
APPENDIX B
(Reserved for future use.)
Appendix B B-l
-------
APPENDIX C.I
PARTICLE SIZE DISTRIBUTION DATA AND SIZED EMISSION FACTORS
FOR
SELECTED SOURCES
C.l-1
-------
C.l-2
EMISSION FACTORS
-------
CONTENTS
AP-42
Section Page
Introduction C.1-5
1.8 Bagasse Boiler C.l-6
2.1 Refuse Incineration
Municipal Waste Mass Burn Incinerator C.l-8
Municipal Waste Modular Incinerator C.l-10
4.2 Automobile Spray Booth C.l-12
5.3 Carbon Black: Off Gas Boiler C.l-14
5.15 Detergent Spray Dryer TBA
5.17 Sulfuric Acid
Absorber C.1-18
Absorber, 20% Oleum C.l-20
Absorber, 32% Oleum C.l-22
Absorber, Secondary C.l-24
5.xx Boric Acid Dryer C.l-26
5.xx Potash Dryer
Potassium Chloride C.1-28
Potassium Sulfate C.l-30
6.1 Alfalfa Dehydrating - Primary Cyclone C.l-32
6.3 Cotton Ginning
Battery Condenser C.l-34
Lint Cleaner Air Exhaust C.l-36
Roller Gin Gin Stand . TBA
Saw Gin Gin Stand TBA
Roller Gin Bale Press .... TBA
Saw Gin Bale Press TBA
6.4 Feed And Grain Mills And Elevators
Carob Kibble Roaster C.l-44
Cereal Dryer C.l-46
Grain Unloading In Country Elevators C.l-48
Grain Conveying ; C.l-50
Rice Dryer C.l-52
6.18 Ammonium Sulfate Fertilizer Dryer ..." C.l-54
7.1 Primary Aluminum Production
Bauxite Processing - Fine Ore Storage C.l-56
Bauxite Processing - Unloading From Ore Ship C.l-58
7.13 Steel Foundries
Castings Shakeout C.l-60
Open Hearth Exhaust C.l-62
7.15 Storage Battery Production
Grid Casting C.l-64
Grid Casting And Paste Mixing C.l-66
Lead Oxide Mill C.l-68
Paste Mixing; Lead Oxide.Charging C.l-70
Three Process Operation C.l-72
7.xx Batch Tinner •. C.l-74
10/86 Appendix C.I . C.l-3
-------
CONTENTS (cont.)
AP-42
Section Page
8.9 Coal Cleaning
Dry Process C.l-76
Thermal Dryer C.l-78
Thermal Incinerator C.l-80
8.18 Phosphate Rock Processing
Calciner C.I-82
Dryer - Oil Fired Rotary And Fluidized Bed C.l-84
Dryer - Oil Fired Rotary C.l-86
Ball Mill C.l-88
Grinder - Roller And Bowl Mill C.l-90
8.xx Feldspar Ball Mill C.l-92
8.xx Fluorspar Ore Rotary Drum Dryer C.l-94
8.xx Lightweight Aggregate
Clay - Coal Fired Rotary Kiln C.l-96
Clay - Dryer C.l-98
Clay - Reciprocating Grate Clinker Cooler C.1-100
Shale - Reciprocating Grate Clinker Cooler C.1-102
Slate - Coal Fired Rotary Kiln C.1-104
Slate - Reciprocating Grate Clinker Cooler C.I-106
8.xx Nonmetallic Minerals - Talc Pebble Mill C.1-108
10.4 Woodworking Waste Collection Operations
Belt Sander Hood Exhaust C. 1-110
C.l-4 EMISSION FACTORS 10/86
-------
APPENDIX C.I
PARTICLE SIZE DISTRIBUTION DATA
AND
SIZED EMISSION FACTORS FOR SELECTED SOURCES
Introduction
This Appendix presents particle size distributions and emission factors
for miscellaneous sources or processes for which documented emission data were
available. Generally, the sources of data used to develop particle size
distributions and emission factors for this Appendix were:
1) Source test reports in the files of the Emission Measurement Branch
(EMB) of EPA's Emission Standards And Engineering Division, Office Of Air
Quality Planning And Standards.
2) Source test reports in the Fine Particle Emission Information System
(FPEIS), a computerized data base maintained by EPA's Air And Energy Engineer-
ing Research Laboratory, Office Of Research And Development.
3) A series of source tests titled Fine Particle Emissions From Station-
ary And Miscellaneous Sources In The South Coast Air Basin, by H. J. Taback.-*
4) Particle size distribution data reported in the literature by various
individuals and companies.
Particle size data from FPEIS were mathematically normalized into more
uniform and consistent data. Where EMB tests ana Taback report data were
filed in FPEIS, the normalized data were used in developing this Appendix.
Information on each source category in Appendix C.I is presented"in a two
page format. For a source category, a graph .provided on the first page presents
a particle size distribution expressed as the cumulative weight percent of
particles less than a specified aerodynamic diameter (cut point), in micro-
meters. A sized emission factor can be derived from the mathematical product,
of a mass emission factor and the cumulative weight percent of particles smaller
than a specific cut point in the graph. At the bottom of the page is a table
of numerical values for particle size distributions and sized emission factors,
in micrometers, at selected values of aerodynamic particle diameter. The
second page gives some information on the data used to derive the particle size
distributions.
Portions of the Appendix denoted TBA in the table of contents refer to
information which will be added at a later date.
Appendix C.I C.l-5
-------
EXTERNAL COMBUSTION -
1.8 BAGASSE FIRED BOILER
99.99
99.9
99
98
3 30
"
a
3
O
10
o.s.
0.1
0.01
CONTROLLED
Weight percent
Emission factor
1.5
CO
CD
o
3
1.0
CO
n
rr
O
n
0.5
0.0
5 6 7 3 9 10 20
Particle diameter, urn
30 40 50 60 70 80 90 100
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Wet scrubber controlled
46.3
70.5
97.1
Emission factor, kg/Mg
Wet scrubber controlled
0.37
0.56
0.78
C.l-6
EMISSION FACTORS
10/86
-------
EXTERNAL COMBUSTION - 1.8 BAGASSE FIRED BOILER
NUMBER OF TESTS: 2, conducted after wet scrubber control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 46.3 70.5 97.1
Standard deviation (Cum. %): 0.9 0.9 1.9
Min (Cum. %): 45.4 69.6 95.2
Max (Cum. %): 47.2 71.4 99.0
TOTAL PARTICULATE EMISSION FACTOR: -Approximately 0.8 kg particulate/Mg bagasse
charged to boiler. This factor is derived from AP-42, Section 1.8, 4/77,' which
states that the particulate emission factor from an uncontrolled bagasse fired
boiler is 8 kg/Mg and that wet scrubbers typically provide 90% particulate
control.
SOURCE OPERATION: Source is a Riley Stoker Corp. vibrating grate spreader
stoker boiler rated at 120,000 Ib/hr but operated during this testing at 121%
of rating. Average steam temperature and pressure were 579°F and 199 psig
respectively. Bagasse feed rate could not be measured, but was estimated to be
about 41 (wet) tons/hr.
SAMPLING TECHNIQUE: Anderson Cascade irapactor.
EMISSION FACTOR RATING: D
REFERENCE:
Emission Test Report, U. S. Sugar Company, Bryant, Fl, EMB-80-WFB-6,
U. S. Environmental Protection Agency» Research Triangle Park, NC,
May 1980.
10/86 Appendix C.I C.l-7
-------
TJ
V
.o
-------
2.1 REFUSE INCINERATION: MUNICIPAL WA2T£ MASS BURN INCINERATOR
NUMBER OF TESTS: 7, conducted before control
STATISTICS: Aerodynamic Particle Diameter (urn): 2.5 6.0 . 10.0
Mean (Cum. %): 26.0 30.6 38.0
Standard deviation (Cum. %): 9.5 13.0 14.0
Min (Cum. %): 18 22 24
Max (Cum. %): 40 49 54
TOTAL PARTICULATE EMISSION FACTOR: 15 kg of particulate/Mg of refuse charged.
Emission factor from AP-42 Section 2.1.
SOURCE OPERATION: Municipal incinerators reflected in the data base include
various mass burning facilities of typical design and operation.
SAMPLING TECHNIQUE: Unknown.
EMISSION FACTOR RATING: D
REFERENCE:
Determination Of Uncontrolled Emissions, Product 2B, Montgomery County,
Maryland, Roy F. Weston, Inc., West Chester, PA, August 1984.
10/86 Appendix C.I
C.l-9
-------
2.1 REFUSE INCINERATION: MUNICIPAL WASTE MODULAR INCINERATOR
99.99
99.9
99
9t
— Weight percent
— Emission factor
10.0
8.0 CD
0)
o
3
n
rr
O
6.0
OQ
OQ
4.0
2.0
3 * 3 6 7 8 9 10 20 30 40 50 M 70 80 M IOC
Particle diameter, urn
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
54.0
60.1
67.1
Emission factor, kg/Mg
Uncontrolled
8.1
9.0
10.1
C.l-10
EMISSION FACTORS
10/86
-------
2.1 REFUSE INCINERATION: MUNICIPAL WASTE MODULAR INCINERATOR
NUMBER OF TESTS: 3, conducted before control
STATISTICS: Aerodynamic Particle Diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 54.0 60.1 67.1
Standard deviation (Cum. %): 19.0 20.8 23.2
Min (Cum. Z): 34.5 35.9 37.5
Max (Cum. 7.): 79.9 86.6 94.2
TOTAL PARTICULATE EMISSION FACTOR: 15 kg of particulate/Mg of refuse charged.
Emission factor from AP-42.
SOURCE OPERATION: Modular incinerator (2 chambered) operation was at 75.9% of
the design process rate (10,000 Ib/hr) and 101.21 of normal steam production
rate. Natural gas is required to start the incinerator each week. Average
waste charge rate was 1.983T/hr. Net heating value of garbage 4200-4800 BTU/lb
garbage charged.
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING: C
REFERENCE:
Emission Test Report, City of Salem, Salem, Va, EMB-80-WFB-1., U. S. Envi-
ronmental Protection Agency, Research Triangle Park, NC, February 1980.
10/86 Appendix C.I C.l-11
-------
4.2.2.8 AUTOMOBILE & LIGHT DUTY TRUCK SURFACE COATING OPERATIONS:
AUTOMOBILE SPRAY BOOTHS (WATER BASE ENAMEL)
cu
N
CO
•a
-------
4.2.2.8 AUTOMOBILE AND LIGHT DUTY TRUCK SURFACE COATING OPERATIONS:
AUTOMOBILE SPRAY BOOTHS (WATER BASE ENAMEL)
NUMBER OF TESTS: 2, conducted after water curtain control.
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 28.6 38.2 46.7
Standard deviation (Cum. %): 14.0 16.8 20.6
Min (Cum. %): 15.0 21.4 26.1
Max (Cum. %): 42.2 54.9 67.2
TOTAL PARTICULATE EMISSION FACTOR: 4.84 kg particulate/Mg of water base
enamel sprayed. From References a and b.
SOURCE OPERATION: Source is a water base enamel spray booth in an automotive
assembly plant. Enamel spray rate is 568 Ibs/hour, but spray gun type is not
identified. The spray booth exhaust rate is 95,000 scfm. Water flow rate to
the water curtain control device is 7181 gal/min. Source is operating at 84%
of design rate.
SAMPLING TECHNIQUE: SASS and Joy trains with cyclones.
EMISSION FACTOR RATING: D
REFERENCES:
a. H. J. Taback, Fine Particle Emissions from Stationary and Miscellaneous
Sources in the South Coast Air Basin, PB 293 923/AS, National Technical
Information Service, Springfield, VA, February 1979.
b. Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System, Series Report No. 234, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C.I C.l-13
-------
5.3 CARBON BLACK: OIL FURNACE PROCESS OFF GAS BOILER
99.99
99.9
99
98
73
10 80
00
70
** 60
" 50
a
10
2
I
0.3
0.1
0.01
. UNCONTROLLED
9— Weight percent
— Emission factor
1.75
CO
to
1.50
01
n
o
n
QQ
1.25
1.00
4)671910 10
Particle diameter, um
30 *0 50 60 70 80 90 100
Aerodynamic
particle
diameter, um
2.5
6.0'
10.0
Cumulative wt . % < stated size
Uncontrolled
87.3
95.0
97.0
Emission factor,
Uncontroll
1.40
1.52
1.55
kg/Mg
ed
C.l-14
EMISSION FACTORS
10/86
-------
5.3 CARBON BLACK: OIL FURNACE PROCESS OFF GAS BOILER
NUMBER OF TESTS: 3, conducted at off gas boiler outlet
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 87.3 95.0 97.0
Standard Deviation (Cum. %): 2.3 3.7 8.0
Min (Cum. %): 76.0 90.0 94.5
Max (Cum. %): 94.0 99 100
TOTAL PARTICULATE EMISSION FACTOR: 1.6 kg particulate/Mg carbon black produced,
from reference.
SOURCE OPERATION: Process operation: "normal" (production rate = 1900 kg/hr).
Product is collected in fabric filter, but the off gas boiler outlet is
uncontrolled.
SAMPLING TECHNIQUE: Brinks Cascade Impactor
EMISSION FACTOR RATING: D
REFERENCE:
Air Pollution Emission Test, Phillips Petroleum Company, Toledo, OH, EMB-
73-CBK-l, U. S. Environmental Protection Agency, Research Triangle Park,
NC, September 1974.
10/86 Appendix C.I
C.l-15
-------
5.17 SULFURIC ACID: ABSORBER (ACID ONLY)
01
N
TJ
01
CO
J_l
CO
so
-*
10
20
30
40 50 60 70 iO 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt . % < stated size
Uncontrolled
51.2
100
100
Emission factor, kg/Mg
Uncontrolled
(0.2) (2.0)
0.10
0.20
0.20
1.0
2.0
2.0
C.l-18
EMISSION FACTORS
10/86
-------
5.17 SULFURIC ACID: ABSORBER (ACID ONLY)
NUMBER OF TESTS: Not available
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 51.2 100 100
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 0.2 to 2.0 kg acid mist/Mg sulfur charged,
for uncontrolled 98% acid plants burning elemental sulfur. Emission factors
are from AP-42.
SOURCE OPERATION: Not available
SAMPLING TECHNIQUE: Brink Cascade Impactor
EMISSION FACTOR RATING: E
REFERENCES: " .
a. Final Guideline Document: Control of Sulfuric Acid Mist Emissions from
Existing Sulfuric Acid Production Units, EPA-450/2-77-019, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, September 1977.
b. R. W. Kurek, Special Report On EPA Guidelines For State Emission Stand-
ards For Sulfuric Acid Plant Mist, E. I. du Pont de Nemours and Company,
Wilmington, DE, June 1974.
c. J. A. Brink, Jr., "Cascade Impactor For Adiabatic Measurements", Indus-
trial and Engineering Chemistry, _50_:647, April 1958.
10/86 Appendix C.I C.l-19
-------
5.17 SULFURIC ACID: ABSORBER, 20% OLEUM
-------
5.17 SULFURIC ACID: ABSORBER, 20% OLEUM
NUMBER OF TESTS: Not available
STATISTICS: Aerodynamic particle diameter (urn)*: 1.0 1.5 2.0
Mean (Cum. %): 26 50 73
Standard deviation (Cum. .%):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: Acid mist emissions from sulfuric acid
plants are a function of type of feed as well as oleum content of product.
See AP-42 Section 5.17, Table 5.17-2.
SOURCE OPERATION: Not available
SAMPLING TECHNIQUE: Brink Cascade Impactor
EMISSION FACTOR RATING: E
REFERENCES.:
a. Final Guideline Document: Control of Sulfuric Acid Mist Emissions from
Existing Sulfuric Acid Production Units, EPA-450/2-77-019, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, September 1977.
b. R. W. Kurek, Special Report On EPA Guidelines For State Emission Stand-
ards For Sulfuric Acid Plant Mist, E. I. du Pont de Nemours and Company,
Wilmington, DE, June 1974.
c. J. A. Brink, Jr., "Cascade Impactor For Adiabatic Measurements", Indus-
trial and Engineering Chemistry, 50:647, April 1958.
100% of the partlculate is less than 2.5 urn in diameter.
10/86 Appendix C.I C.l-21
-------
5.17 SULFURIC ACID: ABSORBER, 32% OLEUM
99.99
99.9
V
N
4)
<0
09
V
JZ
60
•H
g
>
3
O
95
90
10
3.1
0.01
UNCONTROLLED
Weight percent
3 <• 5 6 7 a 9 LO :o .
Particle diameter, urn
30 iO 50 60 70 30 90 1.00
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt . % < stated size
Uncontrolled
100
100
100
Emission factor, kg/Mg
Uncontrolled
See Table 5.17-2
C.l-22
EMISSION FACTORS
10/86
-------
5.17 SULFURIC ACID: ABSORBER, 32% OLEUM
NUMBER OF TESTS: Not available
STATISTICS: Aerodynamic particle diameter (um)*: 1.0 1.5 2.0
Mean (Cum. %): 41 63 84
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: Acid mist emissions from sulfuric acid
plants are a function of type of feed as well as oleum content of product. See
AP-42 Section 5.17, Table 5.17-2.
SOURCE OPERATION: Not available
SAMPLING TECHNIQUE: Brink. Cascade Impactor
EMISSION FACTOR RATING: E
REFERENCES:
a. Final Guideline Document: Control of Sulfuric Acid Mist Emissions from
Existing Sulfuric Acid Production Units, EPA-450/2-77-019, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, September 1977.
b. R. W. Kurek, Special Report On EPA Guidelines For State Emission Stand-
ards For Sulfuric Acid Plant Mist, E. I. du Pont de Nemours and Company,
Wilmington, DE, June 1974.
c. J. A. Brink, Jr., "Cascade Impactor For Adiabatic-Measurements", Indus-
trial and Engineering Chemistry, 50:647, April 1958.
100% of the particulate is less than 2.5 um In diameter.
10/86 Appendix C.I C.l-23
-------
5.17 SULFURIC ACID: SECONDARY ABSORBER
99.9
99
98
0)
N 9)
T3 9°
V
i_>
2 8°
03
V, 70
*« 60
2 30
00
-< 40
0)
3 30
0>
> :o
3
o.;
0.01
UNCONTROLLED
Weight percent
36789 10 „> 20
Particle diameter, urn
iO 50 60 70 SO 90 10O
Aerodynamic
particle
diameter , urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
48
78
87
Emission factor , kg/Mg
Uncontrolled
Not Available
Not Available
Not Available
C.l-24
EMISSION FACTORS-
10/86
-------
5.17 SULFURIC ACID: SECONDARY ABSORBER
NUMBER OF TESTS: Not available
STATISTICS: Particle Size (urn): 2.5 6.0 10.0
Mean (Cum. %): 48 78 87
Standard Deviation (Cum. %):
Min (Cum. %):
Max (Cum. X):
TOTAL PARTICULATE EMISSION FACTOR: Acid mist emission factors vary widely
according to type of sulfur feedstock. See AP-42 Section 5.17 for guidance.
SOURCE OPERATION: Source is the second absorbing tower in a double absorption
sulfuric acid plant. Acid mist loading is 175 - 350 mg/m3.
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING: E . '
REFERENCE:
G. E. Harris and L. A. Rohlack, "Particulate Emissions from Non-fired
Sources in Petroleum Refineries: A Review of Existing Data", Publica-
tion No. 4363, American Petroleum Institute, Washington, DC, December
1982*
10/86 Appendix C.I C.l-25
-------
5.xx CHEMICAL PROCESS INDUSTRY: BORIC ACID DRYER
99.99
99.9
99
98
-------
5.xx BORIC ACID DRYER
NUMBER OF TESTS: a) 1, conducted before controls
b) 1, conducted after fabric filter control
STATISTICS: (a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 0.3 3.3 6.9
Standard Deviation (Cum. %):
Man (Cum. %):
Max (Cum. %):
(b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 3.3 6.7 10.6
Standard Deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: Before control, 4.15 kg particulate/Mg
boric acid dried. After fabric filter control, 0.11 kg particulate/Mg boric
acid dried. Emission factors from Reference a.
SOURCE OPERATION: 100% of design process' -race.
SAMPLING TECHNIQUE: a) Joy train with cyclones
b) SASS train with cyclones
EMISSION FACTOR RATING: E
REFERENCES:
a. H. J. Taback, Fine Particle Emissions from Stationary and Miscellaneous
Sources in the South Coast Air Basin, PB 293 923/AS, National-Technical
Information Service, Springfield, VA, February 1979.
b. Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System, Series Report No. 236, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C.I C.l-27
-------
5.xx POTASH (POTASSIUM CHLORIDE) DRYER
99.99
99.9
99
98
95
N
•3 9°
-o
— Weight percent
— Emission factor
CONTROLLED
k— Wt. £ high pressure
5.0
4.0
3.0
PI
CO
CD
o
3
O
i-t
OQ
z"
TO
2-.0
1.0
0.0
5 6 7 3 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, um
Aerodynamic
particle
diameter (um)
2.5
6.0
10.0
Cumulative wt. I < stated size
Uncontrolled
0.95
2.46
4.07
High pressure
drop venturl
scrubber
5.0
7.5
9.0
Emission factor
(kg/Mg)
-Uncontrolled
0.31
0.81
1.34
C.l-28
EMISSION FACTORS
10/86
-------
5.xx POTASH (POTASSIUM CHLORIDE) DRYER
NUMBER OF TESTS: a) 7, before control
b) 1, after cyclone and high pressure drop venturi scrubber
control
STATISTICS: a) Aerodynamic particle diameter (um): 2.5 6.0 10.0
Mean (Cum. %): 0.95 2.46 4.07
Standard deviation (Cum. %): 0.68 2.37 4.34
Min (Cum. %): 0.22 0.65 1.20
Max (Cum. %): 2.20 7.50 13.50
b) Aerodynamic particle diameter (um): 2.5 6.0 10.0
Mean (Cum. %): 5.0 7.5 9.0
Standard deviation (Cum. %):
Min (Cum. 7.):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: Uncontrolled emissions of 33 kg particu-
late/Mg of potassium chloride product from dryer, from AP-42 Section 5.16. It
is assumed that particulate emissions-from rotary gas fired dryers'.for pdtassium
chloride are similar to particulate emissions from rotary steam tube dryers for
sodium carbonate.
SOURCE OPERATION: Potassium chloride is dried in a rotary gas fired dryer.
SAMPLING TECHNIQUE: a) Andersen Impactor
b) Andersen Impactor
EMISSION FACTOR RATING: C
REFERENCES:'
a) Emission Test Report, Kerr-Magee, Trooa, CA, EMB-79-POT-4, U. S.
Environmental Protection Agency, Research Triangle Park, NC, April 1979.
b) Emission Test Report, Kerr-Magee, Trona, CA, EMB-79-POT-5,. U. S.
Environmental Protection Agency, Research Triangle Park, NC April 1979.
10/86 Appendix C.I C.l-29
-------
5.xx POTASH (POTASSIUM SULFATE) DRYER
0)
N
OJ
at
u
00
V
X
bo
99.99
99.9
99
98
9S
90
30
70
60
50
40
30
20
10
3
O
2
I
0.5
0.1
0.01
CONTROLLED
Weight percent
•Emission factor
0.02}
3.020
0.015
CD
00
o
3
09
n
7f
OQ
TO
0.010
0.005
4 56789 10 20 30
Particle diameter, um
40 50 6O 70 80 90 100
Aerodynamic
particle
diameter (um)
2.5
6.0
10.0
Cumulative wt. Z < stated size
Controlled with fabric filter
18.0
32.0
43.0
Emission factor,
kg/Mg
Controlled with fabric
filter
0.006
0.011
0.014
C.l-30
EMISSION FACTORS
10/86
-------
5.xx POTASH (POTASSIUM SULFATE) DRYER
NUMBER OF TESTS: 2, conducted after fabric filter
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 18.0 32.0 43.0
Standard deviation (Cum. 2): 7.5 11.5 14.0
Min (Cum. %): 10.5 21.0 29.0
Max (Cum. %): - 24.5 44.0 14.0
TOTAL PARTICULATE EMISSION FACTOR: After fabric filter control, 0.033 kg
of particulate per Mg of potassium sulfate product from the dryer. Calculated
from an uncontrolled emission factor of 33 kg/Mg and control efficiency of
99.9 %. From Reference a and AP-42 Section 5.16. It is assumed that
particulate emissions from rotary gas fired dryers are similar to those from
rotary steam tube dryers.
SOURCE OPERATION: Potassium sulfate is dried in a rotary gas fired dryer.
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING:
REFERENCES:
a) Emission Test Report, Kerr-McGee, Trona, CA, EMB-79-POT-4, Office Of Air
Quality Planning And Standards, U. S. Environmental Protection Agency,
Research Triangle Park, NC, April 1979.
b) Emission Test Report, Kerr-McGee, Trona, GA, EMB-79-POT-5, Office Of Air
Quality Planning And Standards, U. S. Environmental Protection Agency,
Research Triangle Park, NC, April 1979.
10/86
Appendix C.I
C.l-31
-------
6.1 ALFALFA DEHYDRATING: DRUM DRYER PRIMARY CYCLONE
99.9
99
98
01 95
N
•O
Ol
9
3)
90
90
•a
2 30
D :c
>
:a
E
o
D-:
-. •>:
UNCONTROLLED
Weight percent
Emission factor
i i iii
0.4
31
n
75
0.4
o.o
r •> • s ? :o :; :o -o 10
Particle diameter, urn
Aerodynamic
Particle
diameter, urn
2.5
6.0
10.0
Cum. wt. % < stated size
Uncontrolled
70.6
82.7
90.0
Emission factor, kg/Mg
Uncontrolled
3.5
4.1
4.5
C.l-32
EMISSION FACTORS
10/86
-------
6.1 ALFALFA DEHYDRATING: DRUM DRYER PRIMARY CYCLONE
NUMBER OF TESTS: 1, conducted before control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 70.6 82.7 90.0
Standard deviation (Cum. %)
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 5.0 kg particulate/Mg alfalfa pellets
before control. Factor from AP-42.
SOURCE OPERATION: During this test, source dried 10 tons of alfalfa/hour in a
direct fired rotary dryer.
SAMPLING TECHNIQUE: Nelson Cascade Impactor
EMISSION FACTOR RATING: E
REFERENCE:
Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System, Series Report No. 152, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1983: *
10/86 Appendix C.I C.l-33
-------
6.3 COTTON GINNING: BATTERY CONDENSER
».9»
99.9
99
98
9}
4)
(4
•H M
to
•XJ
•" 10
CO
1 3
3
2
1
O.J
0.1
a.ai
^
•
•
•
~
~ y^
/ *
/A
s s
/ //
Jt f /
S^M '
/^^ y
" .^^"^ /
^^^ /
ms""/^ /'
* ./^ *
s
* - - s
s
m • 9
^ 9
*
..• *
CYCLONE
• • Weight percent
— — — Emission factor
CYCLONE AND WET SCRUBBER
• Weight percent
• • • Emission factor
•
-
-
•£
—
_
1 I
0.100
9
H»
91
0)
O
"*
i-h
0)
f«
0.050 Q
^1
*
oq
"^•x
0*
H»
fD
0.006
0.003
0
3 4 5 6 7 3 9 10 20 30 40 50 40 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter (um)
2.5
6.0
10.0
Cumulative we. Z < stated size
With
cyclone
8
33
62
With cyclone &
wet scrubber
11
26
52
Emission factor (kg/bale)
With
cyclone
0.007
0.028
0.053
With cyclone
& wet scrubber
0.001
0.003
0.006
C.l-34
EMISSION FACTORS
10/86
-------
6.3 COTTON GINNING: BATTERY CONDENSER
NUMBER OF TESTS: a) 2, after cyclone
b) 3, after wet scrubber
STATISTICS: Aerodynamic particle diameter (urn):
a) Mean (Cum. %):
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %.):
b) Mean (Cum. %):
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
2.5
8
11
6.0
33
10.0
62
26
52
TOTAL PARTICIPATE EMISSION FACTOR: Particulate emission factor for battery
condensers with typical controls is 0.09 kg (0.19 lb)/bale of cotton. From
AP-42. Factor with wet scrubber after cyclone is 0.012 kg (0.026 lb)/bale.
Scrubber efficiency is 867.. From Reference b.
SOURCE. OPERATION: During tests, source was operating at 100% of design capa-
city. No other information on source is available.
SAMPLING TECHNIQUE: UW Mark 3 Impact or
EMISSION FACTOR RATING:
REFERENCES:.
a) Emission cesc daca from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System (FPEIS), Series Report No. 27, U". S.
Environmental Protection Agency, Research Triangle Park, NC, June 1983.
b) Robert E. Lee, Jr., et al. , "Concentration And Size Of Trace Metal Emis-
sions From A Power Plant, A Steel Plant, And A Cotton Gin", Environmental
Science And Technology, 9(7):643-7, July 1975.
10/86
Appendix C.I
C.l-35
-------
6.3 COTTON GINNING: LINT CLEANER AIR EXHAUST
M
-4
CO
TJ
o.t
3 4 5 6 7 8 9 10 20 30 40 50 6O 70 80 9O IOC
Particle diameter, um
Aerodynamic
particle
diameter (um)
2.5
6.0
10.0
Cumulative wt. 7. < stated size
After
cyclone
1
20
54
After cyclone
& wet scrubber
11
74
92
Emission factor
(kg/bale)
After cyclone
0.004
0.07
0.20
C.-1-36
EMISSION FACTORS
10/86
-------
6.3 COTTON GINNING: LINT CLEANER AIR EXHAUST
NUMBER OF TESTS: a) 4, after cyclone
b) 4, after cyclone and wet scrubber
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. 7.): 1 20 54
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. Z):
b) Aerodynamic particle diameter (am): 2.5 6.0 10.0
Mean (Cum. Z): 11 74 92
Standard deviation (Cum. Z):
Min (Cum. Z):
Max (Cum. 7.):
TOTAL PARTICULATE EMISSION FACTOR: 0.37 kg particulate/bale of cotton
processed, with typical controls. Factor is from AP-42.
SOURCE OPERATION: Testing was conducted while processing both machine picked
and ground harvested upland cotton, at a production rate of about 6.8
bales/hr.
SAMPLING TECHNIQUE: Coulter counter.
EMISSION FACTOR RATING: E
REFERENCE:
S. E. Hughs, et al., "Collecting Particles From Gin Lint Cleaner Air
Exhausts", presented at the 1981 Winter Meeting of the American Society of
Agricultural Engineers, Chicago, IL, December 1981.
10/86 Appendix C.I C.l-37
-------
99.99
99.9
99
98
0)
N ,
95
90
•o
0)
80
CO
« 70
^ 60
AJ 5°
•g, ^o
•rt
« 30
0, 20
••-(
ij
n
OQ
TO
0.25
0.0
5 6 7 3 9 LO 20
Particle diameter, urn
30 4O 50 60 70 30 90 IOC
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
3.0
3.2
9.6
Emission factor, kg/Mg
Uncontrolled
0.11
0.12
0.36
C.l-44
EMISSION FACTORS
10/86
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS: CAROB KIBBLE ROASTER
NUMBER OF TESTS: 1, conducted before controls
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 3.0 3.2 9.6
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 3.8 kg/Mg carob kibble roasted. Factor
from Reference a, pg. 4-175.
SOURCE OPERATION: Source roasts 300 kg carob pods per hour, 100% of the design
rate. Roaster heat input is 795 kj/hr of natural gas.
SAMPLING TECHNIQUE: Joy train with 3 cyclones,
EMISSION FACTOR RATING: E
REFERENCES:
a. H. J. Taback, Fine Particle Emissions from Stationary and Miscellaneous
Sources in the South Coast Air Basin, PB 293 923/AS, National Technical
Information Service, Springfield, VA, February 1979.
b. Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System Series, Report No. 229, U. S. Environ-
mental Protection Agency, Research Triangle Park,-NC, June 1983.
10/86 Appendix C.I C.l-45
-------
99.99
99.9
99
98
« 80
tJ
00
V 70
;N> 60
5 50
-S? »o
n
€
OT
0.25
0.0
5 6 7 g 9 10 20 30
Particle diameter, urn
40 SO 6O 70 80 90 100
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
27
37
44
Emission factor, kg/Mg
Uncontrolled
0.20
0.28
0.33
C.l-46
EMISSION FACTORS
10/86
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS: CEREAL DRYER
NUMBER OF TESTS: 6, conducted before controls
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 27 37 44
Standard deviation (Cum. %): 17 18 20
Min (Cum. %): 13 20 22
Max (Cum. %): 47 56 58
TOTAL PARTICULATE EMISSION FACTOR: 0.75 kg particulate/Mg cereal dried.
Factor taken from AP-42.
SOURCE OPERATION: Confidential.
SAMPLING TECHNIQUE: Andersen Mark III Impactor
EMISSION FACTOR RATING: C
REFERENCE:
Confidential test data from a major grain processor, PEI Associates,
Inc., Golden, CO, January 1985.
10/86 Appendix C.I C.l-47
-------
99.99
99.9
99
98
CO 9}
N
90
CO
TJ
V
« M
«J
u
" 70
60
u 30
.C
&0 40
S 30
J> 20
3
S
10
2
1
0.3
0.1
0.01
6.4 FEED AND GRAIN MILLS AND ELEVATORS:
GRAIN UNLOADING IN COUNTRY ELEVATORS
y
UNCONTROLLED j
•— Weight percent
Emission factor
1.5
1.0
CO
CO
o
3
01
n
rt
O
n
0.3
0.0
* 5 4 7 t 9 10 20
Particle diameter, um
30 40 50 60 70 90 90 IOC
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wgt. %
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS:
GRAIN UNLOADING IN COUNTRY ELEVATORS
NUMBER OF TESTS: 2, conducted before control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 13.8 30.5 49.0
Standard deviation (Cum. %): 3.3 2.5
Min (Cum. %): 10.5 28.0 49.0
Max (Cum. %): 17.0 33.0 49.0
TOTAL PARTICULATE EMISSION FACTOR: 0.3 kg particulate/Mg of grain unloaded,
without control. Emission factor from AP-42.
SOURCE OPERATION: During testing, the facility was continuously receiving
wheat of low dockage. The elevator is equipped with a dust collection system
which serves the dump pit boot and leg.
SAMPLING TECHNIQUE: Nelson Cascade Impactor
EMISSION FACTOR RATING: D.
REFERENCES:
a. Emission test data from Environmental Assessment Data Systems, Fine
Particle Emission Information System (FPEIS), Series Report No. 154, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1983.
b. Emission Test Report, Uniontown Co-op, Elevator No. 2, Uniontown, WA,
Report No. 75-34, Washington State Department Of Ecology, Olympia, WA,
October 1975.
10/86 Appendix C.I C.l-49
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS: CONVEYING
99.99
99.9
99
98
95
90
80
70
60
50
40
30
20
V
«
•o
as
to
60
•H
V
3
(U
S 10
I—I
3 5
° 2-
1
0.5
0.1
0.01
UNCONTROLLED
• Weight percent
—— Emission factor
1 t I I
0.4
PI
a
0.3 H-
CO
CD
)-••
o
3
B>
O
rr
O
rl
0.2 7?
OQ
O.I
5 6 7 3 9. 10 20
Particle diameter, urn
30 40 50 .60 70 80 90 IOC
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt . % < stated size
Uncontrolled
16.8
41.3
69.4
Emission factor, kg/Mg
Uncontrolled
0.08
0.21
0.35
C.l-50
EMISSION FACTORS
10/86
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS: CONVEYING
NUMBER OF TESTS: 2, conducted before control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 16.8 41.3 69.4
Standard deviation (Cum. %): 6.9 16.3 27.3
Min (Cum. %): 9.9 25.0 42.1
Max (Cum. %): 23.7 57.7 96.6
TOTAL PARTICIPATE EMISSION FACTOR: 0.5 kg particulate/Mg of grain processed,
without control. Emission factor from AP-42.
SOURCE OPERATION: Grain is unloaded from barges by "marine leg" buckets lifting
the grain from the barges and discharging it onto an enclosed belt conveyer,
which transfers the grain to the elevator. These tests measured the combined
emissions from the "marine leg" bucket unlqader and the conveyer transfer
points. Emission rates averaged 1956 Ibs particulate/hour (0.67 kg/Mg grain
unloaded). Grains are corn and soy beans.
SAMPLING TECHNIQUE: Brinks Model B Cascade Impactor
EMISSION FACTOR RATING: D
REFERENCE:
Air Pollution Emission Test, Bunge Corporation, Destrehan, LA, EMB-74-
GRN-7, U. S. Environmental Protection Agency, Research Triangle Park,
NC, January 1974.
10/86 Appendix C.I C.l-51
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS: RICE DRYER
01
99.99
99.9
99
98
95
CO
._ 90
~
01
ij
03 go
CO
v 70
M 60
J= 5°
00
01
•* 30
> 20
a
s
o
10
5
2
1
0.5
0.1
0.01
UNCONTROLLED
Weight percent
Emission factor
0.015
PI
5
IB
CO
t-*
o
3
0.010 03
n
o
n
oq
oq
0.00}
0.00
3 4 5 6 7 8 ? 10 20
Particle diameter, urn
30 40 50 60 70 80 90 100
Aerodynamic
Particle
diameter, um
2.5
6.0
10.0
Cumulative wt . % < Stated Size
Uncontrolled
2.0
8.0
19.5
Emission Factor (kg/Mg)
Uncontrolled
0.003
0.01
0.029
C.l-52
EMISSION FACTORS
10/86
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS: RICE DRYER
NUMBER OF TESTS: 2, conducted on uncontrolled source.
STATISTICS: Aerodynamic Particle Diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 2.0 8.0 19.5
Standard Deviation (Cum. %): - 3.3 9.4
Min (Cum. %): 2.0 3.1 10.1
Max (Cum. %): 2.0 9.7 28.9
TOTAL PARTICULATE EMISSION FACTOR: 0.15 kg particulate/Mg of rice dried.
Factor from AP-42, Table 6.4-1, footnote b for column dryer.
SOURCE OPERATION: Source operated at 100% of rated capacity, drying 90.8 Mg
rice/hr. The dryer is heated by four 9.5 kg/hr burners.
SAMPLING TECHNIQUE: Sass train with cyclones.
EMISSION FACTOR RATING: D
REFERENCES:
a. H. J. Taback, Fine Particle Emissions from Stationary and Miscellaneous
Sources in the South Coast Air Basin, PB 293 923/AS, National Technical
Information Service, Springfield, VA, February 1979.
b. Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System, Series Report No. 228, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C.I C.l-53
-------
6.18 AMMONIUM SULFATE FERTILIZER: ROTARY DRYER
99.99
99.9
99
98
95
20
T-l
l_l
03
~* 10
I 5
2
I
0.5
O.I
0.01
UNCONTROLLED
Weight percent
Emission factor
30
CO
09
o
a
20
OQ
10
4 5 6 7 8 9 10 20 30
* " •
Particle diameter, urn
40 50 60 70 M 90 LOO
Aerodynamic
particle
diameter, urn
. 2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
10.8
49.1
98.6
Emission factor, kg/Mg
Uncontrolled
2.5
11.3
22.7
C.l-54
Appendix C.I
10/86
-------
6.18 AMMONIUM SULFATE FERTILIZER: ROTARY DRYER
NUMBER OF TESTS: 3, conducted before control.
STATISTICS: Aerodynamic particle diameter (urn) 2.5 6.0 10.0
Mean (Cum. %): 10.8 49.1 98.6
Standard Deviation (Cum. %): 5.1 21.5 1.8
Min (Cum. %): 4.5 20.3 96.0
Max (Cum. %): 17.0 72.0 100.0
TOTAL PARTICULATE EMISSION FACTOR: 23 kg particulate/Mg of ammonium sulfate
produced. Factor from AP-42.
SOURCE OPERATION: Testing was conducted at three ammonium sulfate plants
operating rotary dryers within the following production parameters:
Plant ; A C D
% of.design process rate 100.6. 40.1 100 :
production rate, Mg/hr 16.4 6.09 8.4
SAMPLING TECHNIQUE: Andersen Cascade Irapactors
EMISSION FACTOR RATING: C
REFERENCE:
Ammonium Sulfate Manufacture - Background Information For Proposed
Emission Standards, EPA-450/3-79-034a, U. S. Environmental Protection
Agency, Research Triangle Park, NC, December 1979.
10/86 Appendix C.I' C.l-55
-------
7.1 PRIMARY ALUMINUM PRODUCTION: BAUXITE PROCESSING
FINE ORE STORAGE
99.99
99.9
99
98
0) 95
N
CO
90
80
™ 70
60
ij 50
00 40
i-l
SI »
-------
7.1 PRIMARY ALUMINUM PRODUCTION: BAUXITE PROCESSING
FINE ORE STORAGE
NUMBER OF TESTS: 2, after fabric filter control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 50.0 62.0 68.0
Standard deviation (Cum. %): 15.0 19.0 20.0
Min (Cum. %): 35.0 43.0 48.0
Max (Cum. %): 65.0 81.0 88.0
TOTAL PARTICULATE EMISSION FACTOR: 0.0005 kg particulate/Mg of ore filled,
with fabric filter control. Factor calculated from emission and process data
in reference.
SOURCE OPERATION: The facility purifies bauxite to alumina. Bauxite ore,
unloaded from ships, is conveyed to storage bins from which it is fed to the
alumina refining process. These tests measured the emissions from the bauxite
ore storage bin filling operation (the ore drop from the conveyer .into the bin),
after fabric filter control. Normal bin filling rate is between 425 and 475
tons per hour.
SAMPLING TECHNIQUE: Andersen Irapactor
EMISSION FACTOR RATING: E
REFERENCE:
Emission Test Report, Reynolds Metals Company, Corpus Christi, TX, EMB-
80-MET-9, U. S. Environmental Protection Agency, Research Triangle Park,
NC, May 1980. :
10/86 Appendix C.I C.l-57
-------
7.1 PRIMARY ALUMINUM PRODUCTION: BAUXITE PROCESSING
UNLOADING ORE FROM SHIP
99.99
99.9
99
98
1)
N 95
i-t
CO
T3 90
20
•H
LJ
SJ
1
1
0.5
0.1
0.01
CONTROLLED
•— Weight percent
— Emission factor
0.0075
0.0050
03
CO
rr
O
OQ
2
0.0025
0.00
4 3 6 7 3 9 10 20 30
Particle diameter, um
40 JO 60 70 80 90 I.OC,
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt . % < stated size
Wet
scrubber controlled
60.5
67.0
70.0
Emission factor, kg/Mg
Wet scrubber
controlled
0.0024
0.0027
0.0028
C.l-58
EMISSION FACTORS
10/86
-------
7.1 PRIMARY ALUMINUM PRODUCTION: BAUXITE PROCESSING
UNLOADING ORE FROM SHIP
NUMBER OF TESTS: 1, after venturi scrubber control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 60.5 67.0 70.0
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 0.004 kg particulate/Mg bauxite ore unloaded
after scrubber control. Factor calculated from emission and process data
contained in reference.
SOURCE OPERATION: The facility purifies bauxite to alumina. Ship unloading
facility normally operates at 1500-1700 tons/hr, using a self contained
extendable boom conveyor that interfaces with a dockside conveyor belt through
an accordion chute. The emissions originate at the point of transfer of the
bauxite ore from the ship's boom conveyer as the ore drops through the the
chute onto the dockside conveyer. Emissions are ducted to a dry cyclone! and
then to a Venturi scrubber. Design pressure drop across scrubber is 15 inches,
and efficiency during test was 98.4 percent.
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING: E
REFERENCE:
Emission Test Report, Reynolds Metals Company, Corpus Christi, TX, EMB-
80-MET-9, U. S. Environmental Protection Agency, Research Triangle Park,
NC, May 1980.
10/86 Appendix C.I C.l-59
-------
7.13 STEEL FOUNDRIES: CASTINGS SHAKEOUT
*9.9» p
99.9
99
98
00
T3
rr
O
3 4 56789 10 20
Particle diameter, urn
30 40 50 60 70 30 9O LOO
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt . % < stated size
Uncontrolled
72.2
76.3
82.0
Emission factor, kg/Mg
Uncontrolled
11.6
12.2
13.1
C.l-60
' EMISSION FACTORS
10/86
-------
7.13 STEEL FOUNDRIES: CASTINGS SHAKEOUT
NUMBER OF TESTS: 2, conducted at castings shakeout exhaust hood before controls
STATISTICS: Aerodynamic particle diameter (um): 2.5 6.0 10.0
Mean (Cum. %): 72.2 76.3 82.0
Standard deviation (Cum. %): 5.4 6.9 4.3
Min (Cum. %): 66.7 69.5 77.7
Max (Cum. %): 77.6 83.1 86.3
TOTAL PARTICULATE EMISSION FACTOR: 16 kg particulate/Mg metal melted, without
controls. Although no nonfurnace emission factors are available for steel
foundries, emissions are presumed to be similar to those in iron foundries.
Nonfurnace emission factors for iron foundries are presented in AP-42.
SOURCE OPERATION: Source is a steel foundry casting steel pipe. Pipe molds
are broken up at the castings shakeout operation. No additional information is
available.
SAMPLING TECHNIQUE: Brinks Model BMS-11 Impactor
EMISSION FACTOR RATING: D
REFERENCE:
Emission test data from Environmental Assessment Data Systems, Fine
Particle Emission Information System, Series Report No. 117, U. S. Envi-
ronmental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C.I C.l-61
-------
7.13 STEEL FOUNDRIES: OPEN HEARTH EXHAUST
99.99
99.9
99
98
95
90
80
70
60
50
40
30 .
20
10
5
2
1
0.5
0.1
n.m
UNCONTROLLED
— •— Weight percent
Emission factor
CONTROLLED
-•— Weight Percent
. • • Emission factor
»
_
^^^^ —
• *~ — "
*
^^M
^^i**^
^— -*^"
^ "
" ^^'^^"^ --•***'*
— — — — ~ — "* —
.
* _
^
~~
* _ ^
^ • •
-
••»••***"*
-
i i iiiiiii i j iiiiii
8.0
7.0
6.0
PI
3
01
5.0 J2.
O
3
i-h
0)
n
4.0 rr
0
n
7?
OQ
3.0 ^
-_. OQ
^^~
0.5
0.4
0.3
0.2
0.1
0.0
5 6 7 3 9 10 20 30 40 50 60 70 30 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt . % < stated size
Uncontrolled
79.6
82.8
85.4
ESP
49.3
58.6
66.8
Emission Factor (kg/Mg)
Uncontrolled
4.4
4.5
4.7
ESP
0.14
0.16
0.18
C.l-62
EMISSION FACTORS
10/86
-------
7.13 STEEL FOUNDRIES: OPEN HEARTH EXHAUST
NUMBER OF TESTS: a) 1, conducted before control
b) 1, conducted after ESP control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 79.6 82.8 85.4
Standard Deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %):• 49.3 58.6 66.8
Standard Deviation (Cum. %):
Min (Cum. 7.):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 5.5 kg particulate/Mg metal processed,
before control. Emission factor from AP-42. AP-42 gives an ESP control
efficiency of 95 to 98.5%. At 95% efficiency, factor after ESP control is'
0.275 kg particulate/Mg metal processed.
SOURCE OPERATION: Source produces steel castings by melting, alloying, and
casting pig iron and steel scrap. During these tests, source was operating at
100% of rated capacity of 3260 kg metal scrap feed/hour, fuel oil fired, and 8
hour heats.
SAMPLING TECHNIQUE: a) Joy train with 3 cyclones
b) Sass train with cyclones
EMISSION FACTOR RATING: E
REFERENCE:
Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System, Series Report No. 233, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C.I C.l-63
-------
eu
•H
a
ai
60
4)
3
a
u
7.15 STORAGE BATTERY PRODUCTION: GRID CASTING
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
1
0.3
0.1
0.01
UNCONTROLLED
• Weight percent
Emission factor
i i I i.
j_
1 ' '
z.o
s
09
09
01
O
1.0
cr
0)
.5
3 4 5 6 7 8 9 10 20 30 40 50 60 70 30 90 100
Particle diameter, urn
Aerodynamic
particle
diameter (um)
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
87.8
100
100
Emission factor
(kg/103 batteries)
Uncontrolled
1.25
1.42
1.42
C.l-64
EMISSION FACTORS
10/86
-------
7.15 STORAGE BATTERY PRODUCTION: GRID CASTING
NUMBER OF TESTS: 3, conducted before control
STATISTICS: Aerodynamic particle diameter (um): 2.5 6.0 10.0
Mean (Cum. %): 87.8 100 100
Standard deviation (Cum. %): 10.3 " -
Min (Cum. %): 75.4 100 100
Max (Cum. %): 100 100 1.00
Impactor cut points ware so small that most data points had to be
extrapolated.
TOTAL PARTICIPATE EMISSION FACTOR: 1.42 kg particulate/103 batteries
produced, without controls. Factor from AP-42.
SOURCE OPERATION: During tests, plant was operated at 39% of design process
rate. Six of nine of the grid casting machines were operating during the test.
Typically, 26,500 to 30,000 pounds of lead per 24 hour day are charged to the
grid casting operation.
SAMPLING TECHNIQUE: Brinks Impactor
EMISSION FACTOR RATING: E
REFERENCE:
Air Pollution Emission Test, Globe Union, Inc., Canby, OR, EMB-76-BAT-4,
U. S. Environmental Protection Agency, Research Triangle Park, NC,
October 1976.
10/86 Appendix C.I C.l-65
-------
7.15 STORAGE BATTERY PRODUCTION: GRID CASTING AND PASTE MIXING
v
N
•o
0)
as
u
CO
JZ
00
0)
3
3
O
99.99
99.9
99
98
95
9O
SO
70
60
SO
40
30
20
LO
2
I •
0.5
0.1
O.Ot
UNCONTROLLED
—•— Weight percent
Emission factor
o
3
CD
n
OQ
t—t
O
er
n
oo
5 6 7 3 9 10 20
Particle diameter, urn
30 40 50 60 70 80 90 LOO
Aerodynamic
particle
diameter (urn)
2.5
6.0
10.0
Cumulative wt. Z < stated size
Uncontrolled
65.1
90.4
100
Emission factor
(kg/103 batteries)
Uncontrolled
2.20
3.05
3.38
C.l-66
EMISSION FACTORS
10/86
-------
7.15 STORAGE BATTERY PRODUCTION: GRID CASTING AND PASTE MIXING
NUMBER OF TESTS: 3, conducted before control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 65.1 . 90.4 100
Standard deviation (Cum. %): 24.8 7.4
Min (Cum. %): 44.1 81.9 100
Max (Cum. %): 100 100 100
TOTAL PARTICULATE EMISSION FACTOR: 3.38 leg particulate/103 batteries,
without controls. Factor is from AP-42, and is the sum of the individual
factors for grid casting and paste mixing.
SOURCE OPERATION: During tests, plant was operated at 39% of the design
process rate. Grid casting operation consists of 4 machines. Each 2,000 Ib/hr
paste mixer is controlled for product recovery by a separate low energy impinge-
ment type wet collector designed for an 8 - 10 inch w. g. pressure drop at
2,000 acfra.
SAMPLING TECHNIQUE: Brinks Irapactor
EMISSION FACTOR RATING:
REFERENCE: ' "
Air Pollution Emission Test, Globe Union, Inc., Canby, OR, EMB-76-BAT-4,
U. S. Environmental Protection Agency, Research Triangle Park, NC,
October 1976.
10/86 Appendix C.I • C.l-67
-------
7.15 STORAGE BATTERY PRODUCTION: LEAD OXIDE MILL
99.99
99.9
99
98
95
01
N
— * 90
CO
0) 30
4»l
09
AJ 70
CO
v 60
»•< 50
j- iO
no
•H 30
01
•* :o
01
-H
iJ 10
to
1— 1
I" 3
3
CJ
2
1
0.5
• O.I
0.01
—
/
/
*
'
" /
1
/ f
" ' / ^r
S^
f .S
™ //
v»
" ^X/
jr /
"" x^^
- /^^ ^
" M^^^ ^
" /
/
/
/
/
" /
/
_ /
—
~
> i i i i i i i i
'. Z 3 4 5 6 7 g 9 10
^M
^^
—
_
—
CONTROLLED
•*— Weight percent:
— Emission factor
0.05
PI
9
0.0* °°
CO
H-
O
3
i-h
to
n
rr
0
1
0.03 *
P~
cre
^^
o
u>
cr
(B
0.02 fl
^.
ft
CO
0.01
0
20 30 40 50 60 70 30 90 100
Particle diameter, um
Aerodynamic
Cumulative wt. Z < stated size
particle
diameter (um) After fabric filter
2.5 32.8
6.0 64.7
10.0 83.8
Emission factor
(kg/103 batteries)
After fabric filter
0.016
0.032
0.042
C.l-68
EMISSION FACTORS
10/86
-------
7.15 STORAGE BATTERY PRODUCTION: LEAD OXIDE MILL
NUMBER OF TESTS: 3, conducted after fabric filter
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 32.8 64.7 83.8
Standard deviation (Cum. %): 14.1 29.8 19.5
Min (Cum. %): 17.8 38.2 . 61.6
Max (Cum. %): 45.9 97.0 100
TOTAL PARTICULATE EMISSION FACTOR: 0.05 kg particulate/103 batteries, after
typical fabric filter control (oil to cloth ratio of 4:1). Emissions from a
well controlled facility (fabric filters with an average air to cloth ratio of
3:1) were 0.025 kg/103 batteries (Table 7.15-1 of AP-42) .
SOURCE OPERATION: Plant receives metallic lead and manufactures lead oxide by
the ball mill process. There are 2 lead oxide production lines, each with a
typical feed rate of 15 one hundred pound lead pigs per hour. Product is
collected with a cyclone and baghouses with 4:1 air to cloth ratios.
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING: E
REFERENCE:
Air Pollution Emission Test, ESB Canada Limited, Mississouga, Ontario,
EMB-76-BAT-3, U. S. Environmental Protection Agency, Research Triangle
Park., NC, August 1976.
10/86 Appendix C.I C.l-69
-------
7.15 STORAGE BATTERY PRODUCTION: PASTE MIXING & LEAD OXIDE CHARGING
W.99
99.9
99
98
95
V
N
-« 90
CO
•o
(0
j_l
a>
NX
60
80
70
60
50
1.0
30
20
-------
7.15 STORAGE BATTERY PRODUCTION: PASTE MIXING & LE»D OXIDE CHARGING
NUMBER OF TESTS: a) 1, conducted before control
b) 4, conducted after fabric filter control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 80 100 100
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Aerodynamic particle diameter (um): 2.5 6.0 10.0
Mean (Cum. %): 47 87 99
Standard deviation (Cum. %): 33.4 14.5 0.9
Min (Cum. %): 36 65 98
Max (Cum. %): 100 100 100
Impactor cut points were so small that many data points had to be extra-
polated. Reliability of particle size distributions based on a single test
is questionable.
TOTAL PARTICULATE EMISSION FACTOR:- 1.96 kg.particulate/103 batteries,
without controls. Factor from AP-42.
SOURCE OPERATION: During test, plant was operated at 39% of the design
process rate. Plant has normal production rate of 2,400 batteries per day and
maximum capacity of 4,000 batteries per day. Typical amount of lead oxide
charged to the mixer is 29,850 lb/8 hour shift. Plant produces wet batteries,
except formation is carried out at another plant.
SAMPLING TECHNIQUE: a) Brinks Impactor
b) Andersen
EMISSION FACTOR RATING:
REFERENCE:
Air Pollution Emission Test, Globe Union, Inc., Canby, OR, EMB-76-BAT-4,
U. S. Environmental Protection Agency, Research Triangle Park, NC,
October 1976.
10/86 Appendix C.I ' C.l-71
-------
7.15 STORAGE BATTERY PRODUCTION: THREE PROCESS OPERATION
41
N
•o
-------
7.15 STORAGE BATTERY PRODUCTION: THREE PROCESS OPERATION
NUMBER OF TESTS: 3, conducted before control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean-(Cum. %): 93.4 100 100
Standard deviation (Cum. %): 6.43
Min (Cum. %): 84.7
Max (Cum. %): 100
Impactor cut points were so small that data points had to be
extrapolated.
TOTAL PARTICULATE EMISSION FACTOR: 42 kg particulate/103 batteries, before
controls. Factor from AP-42.
SOURCE OPERATION: Plant representative stated that the plant usually operated
at 35% of design capacity. Typical production rate is 3,500 batteries per day
(dry and wet), but up to 4,500 batteries per day can be produced. This is
equivalent to normal and maximum daily element production of 21,000 and 27,000
battery elements, respectively. .
SAMPLING TECHNIQUE: Brinks Impactor
EMISSION FACTOR RATING: E
REFERENCE:
Air Pollution Emission Test, ESB Canada Limited, Mississouga, Ontario,
EMB-76-BAT-3, U. S. Environmental Protection Agency, Research Triangle
Park, NC, August 1976.
10/86 Appendix C.I C.l-73
-------
7.xx BATCH TINNER
N
•H
00
99.99
99.9
99
98
9J
90
-------
7.xx BATCH TINNER
NUMBER OF TESTS: 2, conducted before controls
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 37.2 45.9 55.9
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICIPATE EMISSION FACTOR: 2.5 kg particulate/Mg tin consumed, without
controls. Factor from AP-42, Section 7.14.
SOURCE OPERATION: Source is a batch operation applying a lead/tin coating to
tubing. No further source operating information is available.
SAMPLING TECHNIQUE: Andersen Mark. Ill Impactor
EMISSION FACTOR RATING: D
REFERENCE:
Confidential test data, PEI Associates, Inc., Golden, CO, January 1985.
10/86 Appendix C.I C.l-75
-------
8.9 COAL CLEANING: DRY PROCESS
i 1111111 i i iiiiii
0.004
m
0.003 g.
r^
00
CO
• h*
0
3
09
O
CT
O
l-l
"
0.002 *"
V)
J-
"
0.001
0.00
1 2 J 4 5 6 7 8 9 10 20 30 4O 50 60 70 80 90 LOO
Particle diameter, um
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative we . % < stated size
After fabric filter control
16
26
31
Emission factor, kg/Mg
After fabric filter control
0.002
0.0025
0.003
C.l-76
EMISSION FACTORS
10/86
-------
8.9 COAL CLEANING: DRY PROCESS
NUMBER OF TESTS: 1, conducted after fabric filter control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 16 26 31
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 0.01 kg particulate/Mg of coal processed.
Emission factor is calculated from data in AP-42, assuming 99% particulate
control by fabric filter.
SOURCE OPERATION: Source cleans coal with the dry (air table) process.
Average coal feed rate during testing was 70 tons/hr/table.
SAMPLING TECHNIQUE: Coulter counter
EMISSION FACTOR RATING: E
REFERENCE:
R. W. Kling, Emissions from the Florence Mining Company Coal Process-
ing Plant at Seward, PA, Report No. 72-CI-4, York Research Corporation,
Stamford, CT, February 1972.
10/86 Appendix C.I C.l-77
-------
SECTION 8.9 COAL CLEANING: THERMAL DRYER
N
•H
00
99.99
99.9
99
98
93
90
CO SO
CO
70
»•< *°
50
40
30
:o
£2.
60
T-l
0)
0)
e
3
10
5
2.
I
0.5
0.1
0.01
UNCONTROLLED
- Weight percenc
• Emission factor
CONTROLLED
- Weight percent
5.0
PI
9
M-
o>
01
f-h
3.0 0)
O
1.0
0.0
5 4 7 8 9 10 . 20
Particle diameter, um
30 40 50 *O 70 SO 90 100
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
42
86
96
After
wet scrubber
53
85
91
Emission factor, kg/Mg
Uncontrolled
1.47
3.01
3.36
After
wet scrubber
0.016
0.026
0.027
C.l-78
EMISSION FACTORS
10/86
-------
8.18 PHOSPHATE ROCK PROCESSING: CALCINER
0)
N
CO
•o
-------
SECTION 8.9 COAL CLEANING: THERMAL DRYER
NUMBER OF TESTS: a) 1, conducted before control
b) 1, conducted after wet scrubber control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 42 86 96
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 53 85 91
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 3.5 kg particulate/Mg of coal processed,
(after cyclone) before wet scrubber control. After wet scrubber control, 0.03
kg/Mg. These are site specific emission factors and are calculated from, process
data measured during source testing.
SOURCE OPERATION: Source operates a thermal dryer to dry coal cleaned by wee
cleaning process. Combustion zone in the thermal dryer is about 1000°F, and
the air temperature at the dryer exit is about 125°F. Coal processing rate is
about 450 tons per hour. Product is collected in cyclones.
SAMPLING TECHNIQUE: a) Coulter counter
. b) Each sample was dispersed with aerosol OT, and further
dispersed using an ultrasonic bath. Isoton was the
electrolyte used.
EMISSION FACTOR RATING: E
REFERENCE:
R. W. Kling, Emission Test Report, Island Creek Coal Company Coal Pro-
cessing Plant, Vansant, Virgina, Report No. Y-7730-H, York Research
Corporation, Stamford, CT, February 1972.
10/86 Appendix C.I C.l-79,
-------
8.18 PHOSPHATE ROCK PROCESSING: CALCINER
NUMBER OF TESTS: 6, conducted after wet scrubber control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. Z): 94.0 97.0 98.0
Standard deviation (Cum. %): 2.5 1.6 1.5
Min (Cum. %): 89.0 95.0 96.0
Max (Cum. %): 98.0 99.2 99.7
TOTAL PARTICULATE EMISSION FACTOR: 0.0685 kg particulate/Mg of phosphate
rock calcined, after collection of airborne product in a cyclone, and wet
scrubber controls. Factor from reference cited below.
SOURCE OPERATION: Source is a phosphate rock calciner fired with #2 oil,
with a rated capacity of 70 tons/hour. Feed to the calciner is beneficiated
rock.
SAMPLING TECHNIQUE: Andersen Impactor.
EMISSION FACTOR RATING: C
REFERENCE: Air Pollution Emission Test, Beker Industries, Inc. , Conda, ID,
EMB-75-PRP-4, U. S. Environmental Protection Agency, Research Triangle Park,
NC, November 1975.
10/86 Appendix C.I C.l-83
-------
8.18 PHOSPHATE ROCK PROCESSING: OIL FIRED ROTARY AND
FLUIDIZED BED TANDEM DRYERS
10
-------
8.18 PHOSPHATE ROCK PROCESSING:
OIL FIRED ROTARY AND FLUIDIZED BED TANDEM DRYERS
NUMBER OF TESTS: 2, conducted after wet scrubber and electrostatic pre-
cipitator control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 78.0 88.8 93.8
Standard deviation (Cum. %): 22.6 9.6 2.5
Min (Cum. %): 62 82 92
Max (Cum. %): 94 95 95
TOTAL PARTICULATE EMISSION FACTOR: 0.0125 kg particulate/Mg phosphate rock
processed, after collection of airborne product in a cyclone and wet scrubber/
ESP controls. Factor from reference cited below..
SOURCE OPERATION: Source operates a rotary and a fluidized bed dryer to dry
various types of phosphate rock. Both dryers are fired with No. 5 fuel.oil.,
and exhaust into a common duct. The rated capacity of the rotary dryer is
300 tons/hr, and that of the fluidized bed dryer is 150-200 tons/hr. During
testing^source was operating at 67.7% of rated capacity.
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING: C
REFERENCE: Air Pollution Emission Test, W. R. Grace Chemical Company, Bartow,
FL, EMB-75-PRP-1, U. S. Environmental Protection-Agency, Research Triangle
Park, NC, January 1976.
10/86 Appendix C.I C.l-85
-------
8.18 PHOSPHATE ROCK PROCESSING: OIL FIRED ROTARY DRYER
41
N
•H
CD
T3
O)
JJ
«
.U
00
oo
-------
8.18 PHOSPHATE ROCK PROCESSING: OIL FIRED ROTARY DRYER
NUMBER OF TESTS: a) 3, conducted after cyclone
b) 2, conducted after wet scrubber control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): • • 15.7 41.3 58.3
Standard deviation (Cum. %): 5.5 9.6 13.9
Min (Cum. %): 12 30 43
Max (Cum. %): 22 48 70
b) Aerodynamic particle diaraetet (urn): 2.5 6.0 10.0
Mean (Cum. %): 89.0 92.3 96.6
Standard Deviation (Cum. %): 7.1 6.0 3.7
Min (Cum. %): . 84 88 94
Max (Cum. %): 94 96 99
Impactor cut points for the tests conducted before control are small, and
many of the data points are extrapolated. These particle size distributions
are related to specific equipment and source operation, and are most appli-
cable to. partlculate emissions from similar sources operating similar equip-
ment. Table 8.18-2, Section 8.18, AP-42 presents particle size distributions
for generic phosphate rock dryers. •'••.'•
TOTAL PARTICULATE EMISSION FACTORS: After cyclone, 2.419 kg particulate/Mg
rock processed. After wet scrubber control, 0.019 kg/Mg. Factors from
reference cited below.
SOURCE OPERATION: Source dries phosphate rock in #6 oil fired rotary dryer.
During these tests, source operated at 69% of rated dryer capacity of 350 ton/
day, and processed coarse pebble rock.
SAMPLING TECHNIQUE: a) Brinks Cascade Impactor
b) Andersen Impactor
EMISSION FACTOR RATING: D
REFERENCE: Air Pollution Emission Test, Mobil Chemical. Nichols, FL, EMB-75-
PRP-3, U. S. Environmental Protection Agency, Research Triangle Park, NC,
January 1976.
10/86 Appendix C.I C.l-87
-------
8.18 PHOSPHATE ROCK PROCESSING: BALL MILL
cu
N
tx>
•H
cu
99.9
99
98
95
90
80
70
60
50
40
30
:o
jj LO
CO
O
2
I
0.5
0.1
1.01
CYCLONE
• Weight percent
———Emission factor
0.4
m
9
to
CO
o
a
a>
o
OQ
2
0.2
4 5 6 7 3 9 10 20
Particle diameter, urn
JO 40 50 60 70 30 90 LOO
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. 7, < stated size
After cyclone*
6.5
19.0
30.8
Emission factor, kg/Mg
After cyclone3
0.05
0.14
0.22
aCyclones are typically used in phosphate rock processing as product collectors.
Uncontrolled emissions are emissions in the air exhausted from such cyclones.
C.l-88
EMISSION FACTORS
10/86
-------
8.18 PHOSPHATE ROCK PROCESSING: BALL MILL
NUMBER OF TESTS: 4, conducted after cyclone
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 6.5 19.0 30.8
Standard deviation (Cum. Z): 3.5 0.9 2.6
Min (Cum. 2): 3 18 28
Max (Cum. %): 11 20 33
Impactor cutpoints were small, and most data points were extrapolated.
TOTAL PARTICULATE EMISSION FACTOR: 0.73 kg particulate/Mg of phosphate rock
milled, after collection of airborne product in cyclone. Factor from
reference cited below.
SOURCE OPERATION: Source mills western phosphate rock. During testing,
source was operating at 101Z of rated capacity, producing 80 tons/hour.
SAMPLING TECHNIQUE: Brinks Impactor
EMISSION FACTOR RATING: C
REFERENCE: Air Pollution Emission Test, Beker Industries, Inc., Conda, ID,
EMB-75-PRP-4, U. S. Environmental Protection Agency, Research Triangle
Park, NC, November 1975.
10/86 Appendix C.I C.l-89
-------
8.18 PHOSPHATE ROCK PROCESSING:
— Weight percent
— Emission factor
CYCLONE AND FABRIC FILTER
i— Weight percent
1.5
1.0
PI
IB
03
O*
3
i-n
B>
n
n
O
n
OQ
0.5
• 5 ' 6 7 fc » 10 , 20
Particle diameter, urn
30 40 50 60 70 80 90 100
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. Z < stated- size
After
cyclone3
21
45
62
After fabric filter
25
70
90
Emission factor, kg/Mg
After
cyclone3
0.27
0.58
0.79
After fabric filter
Negligible
Negligible
Negligible
a Cyclones are typically used in phosphate rock processing as product collectors.,
Uncontrolled emissions are emissions in the air exhausted from such cyclones.
C.l-90
EMISSION FACTORS
10/86
-------
8.18 PHOSPHATE ROCK PROCESSING: ROLLER MILL AND BOWL MILL GRINDING
NUMBER OF TESTS: a) 2, conducted after cyclone
b) 1, conducted after fabric filter control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 21.0 45.0 62.0
Standard deviation (Cum. Z): 1.0 1.0 0
Min (Cum. Z): 20.0 44.0 62.0
Max (Cum. Z): 22.0 46.0 62.0
b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. Z): 25 70 90
Standard deviation (Cum. Z):
Min (Cum. Z):
Max (Cum. Z):
TOTAL PARTICULATE EMISSION FACTOR: 0.73 kg particulate/Mg of rock pro-
cessed, after collection of airborne product in a cyclone. After fabric
filter control, 0.001 kg particulate/Mg rock processed. Factors calculated
from data in reference cited below. AP-42 (2/80) specifies a range of
emissions from phosphate rock grinders (uncontrolled)* See Table 8•18-1
for guidance.
SOURCE OPERATION: During testing, source was operating at 100Z of design
process rate. Source operates } roller mill with a rated capacity of 25
tons/hr of feed, and 1 bowl mill with a rated capacity of 50 tons/hr of
feed. After product has been collected in cyclones, emissions from each
mill are vented to a common baghouse. Source operates 6 days/week, and
processes Florida rock.
SAMPLING TECHNIQUE: a) Brinks Cascade Impactor
b) Andersen Impactor
EMISSION FACTOR RATING: D
REFERENCE: Air Pollution Emission Test, The Royster Company, Mulberry,
FL, EMB-75-PRP-2, U. S. Environmental Protection Agency, Research Triangle
Park, NC, January 1976.
10/86 Appendix C.I . C.l-91
-------
8.xx NONMETALLIC MINERALS: FELDSPAR BALL MILL
99.99
99.9
99
98
09
V
30
70
60
^ 50
Si
SO 40
o> :o
£
0.5
0.1
0.01
6.0
UNCONTROLLED
Weight percent
Emission factor
i |_
a.o
o
3
01
O
4.0
OQ
2.0
0.0
3 - 5 6 7 8 9 10 20 30 40 50 60 70 SO 90 LOO
Particle diameter, urn
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. % < stated size
Before controls
11.5
22.8
32.3
Emission factor, kg/Mg
Before controls
1.5
2.9
4.2
C.l-92
EMISSION FACTORS
10/86
-------
8.xx NONMETALLIC MINERALS: FELDSPAR BALL MILL
NUMBER OF TESTS: 2, conducted before controls
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 11.5 22.8 32.3
Standard deviation (Cum. %): 6.4 7.4 6.7
Min (Cum. %): 7.0 17.5 27.5
Max (Cum. %): 16.0 28.0 37.0
TOTAL PARTICULATE EMISSION FACTOR: 12.9 kg particulate/Mg feldspar produced.
Calculated from data in reference and related documents.
SOURCE OPERATION: After crushing and grinding of feldspar ore, source produces
feldspar powder in a ball mill.
SAMPLING TECHNIQUE: Alundum thimble followed by 12 inch section of stainless
steel probe followed by 47 mm type SGA filter contained in a stainless steel
Gelman filter holder. Laboratory analysis methods: microsieve and electronic
particle counter.
EMISSION FACTOR RATING: D
REFERENCE:
Air Pollution Emission Test, International Minerals and Chemical Company.
Spruce Pine, NC, EMB-76-NMM-1, U. S. Environmental Protection Agency,
Research Triangle Park, NC, September 1976.
10/86 'Appendix C.I C.l-93
-------
8.xx NONMETALLIC MINERALS: FLUORSPAR ORE ROTARY DRUM DRYER
99.99
99.9
99
98
IV 95
N
CO
CO
90
SO
70
u 50
jr
SO 40
iH
$ 30
-------
8.xx NONMETALLIC MINERALS: FLUORSPAR ORE ROTARY DRUM DRYER
NUMBER OF TESTS: 1, conducted after fabric filter control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 10 30 48
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 0.375 kg particulate/Mg ore dried, after
fabric filter control. Factors from reference.
SOURCE OPERATION: Source dries fluorspar ore in a rotary drum dryer at a feed
rate of 2 tons/hour.
SAMPLING TECHNIQUE: Andersen Mark III Impactor
EMISSION FACTOR RATING: E
REFERENCE:
Confidential test data from a major fluorspar ore processor, PEI
Associates, Inc., Golden, CO, January 1985.
10/86 Appendix C.I C.l-95
-------
8.xx LIGHTWEIGHT AGGREGATE (CLAY): COAL FIRED ROTARY KILN
99.99
99.9
99
98
91 95
N
00
T3
-------
8.xx LIGHTWEIGHT AGGREGATE (CLAY): COAL FIRED ROTARY KILN
NUMBER OF TESTS: a) 4, conducted after wet scrubber control
b) 8, conducted after settling chamber and wet scrubber
control
STATISTICS: a) Aerodynamic particle diameter, (urn): 2.5 6.0 10.0
Mean (Cum. %): 55 75 84
Standard Deviation (Cum. %):
Min (Cum. %) :
Max (Cum. %):
b) Aerodynamic particle diameter, (urn): 2.5 6.0 10.0
Mean (Cum. Z): 55 65 81
Standard Deviation (Cum. Z):
Min (Cum. Z):
Max (Cum. Z):
TOTAL PARTICULATE EMISSION FACTOR: 1.77 kg particulate/Mg of clay processed,
after control by settling chamber and wet scrubber. Calculated from data in
Reference c.
SOURCE OPERATION: Sources produce lightweight clay aggregate in pulverized
coal fired rotary kilns. Kiln capacity for Source b is 750 tons/day, and
operation is continuous. .
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING: C
REFERENCES: .
a. Emission Test Report. Lightweight Aggregate Industry, Texas Industries,
Inc., EMB-80-LWA-3, U. S. Environmental Protection Agency, Research
Triangle Park, NC, May 1981.
b. Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System, Series Report No. 341, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1983.
c. Emission Test Report, Lightweight Aggregate Industry, Arkansas Light-
weight Aggregate Corporation, EMB-80-LWA-2, .U. S. Environmental
Protection Agency, Research Triangle Park, NC, May 1981.
10/86 Appendix C.I C.l-97
-------
8.xx LIGHTWEIGHT AGGREGATE (CLAY): DRYER
99.94
99.9
99
98
tt, 95
eg
TJ
V
CO
„,
80
™ 70
M "
iJ 50
JS ,„
60 *<>
§j M
O) 20
3! 10
I 3
O
2
I
O.J
O.I
0.01
/
UNCONTROLLED
Weight percent
Emission factor.
40
n
H-
CD
00
H-
O
3
0)
O
OQ
OQ
20
3 .* 3 6 7 8 9 10 20
Particle diameter, urn
30
4» 50 60 70 80 9O IOC
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
37.2
74.8
89.5
Emission factor, kg/Mg
Uncontrolled
13.0
26.2
31.3
C.l-98
EMISSION FACTORS
10/86
-------
8.xx LIGHTWEIGHT AGGREGATE (CLAY): DRYER
NUMBER OF TESTS: 5, conducted before controls
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 37.2 74.8 89.5
Standard deviation (Cum. %): 3.4 5.6 3.6
Min (Cum. %): 32.3 68.9 85.5
Max (Cum. %): 41.0 80.8 92.7
TOTAL PARTICULATE EMISSION FACTOR: 35 kg/Mg clay feed to dryer. From
AP-42, Section 8.7.
SOURCE OPERATI-ON: No information on source operation is available
SAMPLING TECHNIQUE: Brinks impactor
EMISSION FACTOR RATING: C
REFERENCE:
Emission test data from Environmental Assessment Data Systems, Fine Par-
ticle Emission Information System, Series Report No. 88, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C-l C.l-99
-------
8.xx LIGHTWEIGHT AGGREGATE (CLAY): RECIPROCATING GRATE CLINKER COOLER
99.9»
OJ
(4
CO
99.9
99
98
95
t3 ^
0)
u
S3 30
CO
70
V
*< 60
4_) 50
§ «
-------
8.xx LIGHTWEIGHT AGGREGATE (CLAY): RECIPROCATING GRATE CLINKER COOLER
NUMBER OF TESTS: a) 12, conducted after Multiclone control
b) 4, conducted after Multiclone and fabric filter control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 19.3 38.1 56.7
Standard deviation (Cum. %): 7.9 14.9 17.9
Min (Cum. %): 9.3 18.6 29.2
Max (Cum. %): 34.6 61.4 76.6
b) Aerodynamic particle diameter (um): 2.5 6.0 10.0
Mean (Cum. %): 39 . 48 54
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 0.157 kg particulate/Mg clay processed,
after multiclone control. Factor calculated from data in Reference b. After
fabric filter control, particulate emissions are negligible.
SOURCE.OPERATION: Sources produce lightweight clay aggregate in a coal fired
rotary kiln and reciprocating grate clinker cooler.
SAMPLING TECHNIQUE: a) Andersen Impactor
b) Andersen Impactor
EMISSION FACTOR RATING: C
REFERENCES:
a. Emission Test Report, Lightweight Aggregate Industry, Texas Industriesr
Inc., EMB-80-LWA-3, U. S. Environmental Protection Agency, Research
Triangle Park, NC, May 1981.
b. Emission Test Report, Lightweight Aggregate Industry, Arkansas Light-
weight Aggregate Corporation, EMB-80-LWA-2, U. S. Environmental
Protection Agency, Research Triangle Park, NC, May 1981.
c. Emission test data from Environmental Assessment Data Systems, Fine
Particle Emission Information System, Series Report No. 342, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C.I C.1-101
-------
8.xx LIGHTWEIGHT AGGREGATE (SHALE): RECIPROCATING GRATE CLINKER COOLER
99.99
99.9
99
98
95
90
N
•H
CO
•o
0)
CO 80
CO
70
V
K 60
u JO
-------
8.xx LIGHTWEIGHT AGGREGATE (SHALE): RECIPROCATING GRATE CLINKER COOLER
NUMBER OF TESTS: 4, conducted after settling chamber control
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 8.2 17.6 25.6
Standard deviation (Cum. %): 4.3 2.8 1.7
Min (Cum. %): 4.0 15.0 24.0
Max (Cum. %): 14.0 21.0 28.0
TOTAL PARTICULATE EMISSION FACTOR: 0.08 kg particulate/Mg of aggregate
produced. Factor calculated from data in reference.
SOURCE OPERATION: Source operates two kilns to produce lightweight shale
aggregate, which is cooled and classified on a reciprocating grate clinker
cooler. Normal production rate of the tested kiln is 23 tons/hr, about 66% of
rated capacity. Kiln rotates at 2.8 rpm. Feed end temperature is 1100°F.
SAMPLING TECHNIQUE: Andersen Impactor
EMISSION FACTOR RATING: B
REFERENCE:
Emission Test Report, Lightweight Aggregate Industry, Vulcan Materials
Company, EMB-80-LWA-4, U. S. Environmental Protection Agency, Research
Triangle Park, NC, March 1982.
10/86 • Appendix" C.I C. 1-103
-------
8.xx LIGHTWEIGHT AGGREGATE (SLATE): COAL FIRED ROTARY KILN
99.99
99.9
99
98
0)
IM
90
4)
i-l
to SO
JJ
CO
70
JJ 50
0)
S 30
3
e
u
10
2
I
0.5
0.1
0.01
UNCONTROLLED
- Weight percent
- Emission factor
CONTROLLED
- Weight percent
&o
00
09
03
n
oq
20
3 * 5 6 7 8 9 10
20
30 40 50 60 70 80 90
0
IOC
Aerody nami c
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. % < stated size
Without
controls
13
29
42
After wet
scrubber control
33
36
39
Emission factor, kg/Mg
Without
controls
7.3
16.2
23.5
After wet
scrubber control
0.59
0.65
0.70
C.1-104
EMISSION FACTORS
10/86
-------
8.xx LIGHTWEIGHT AGGREGATE (SLATE): COAL FIRED ROTARY KILN
NUMBER OF TESTS: a) 3, conducted before control
b) 5, conducted after wet scrubber control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 13.0 29.0 42.0
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 33.0 36.0 39.0
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: For. uncontrolled source, 56.0 kg parti-
culate/Mg of feed. After wet scrubber control, 1.8 kg particulate/Mg of feed.
Factors are calculated from data in reference.
SOURCE OPERATION: Source produces light weight aggregate from slate in coal
fired rotary kiln and reciprocating grate clinker cooler. During testing
source was operating at a feed rate of 33 tons/hr., 83% rated capacity. Firing
zone temperatures are about 2125°F and kiln rotates at 3.25 RPM.
SAMPLING TECHNIQUE: a. Bacho
b. Andersen Impactor
EMISSION FACTOR RATING: C
REFERENCE:
Emission Test Report, Lightweight Aggregate Industry, Galite Corporation,
EMB-80-LWA-6, U. S. Environmental Protection Agency, Research Triangle
Park, NC, February 1982.
10/86 Appendix C.I C.I-105
-------
8.xx LIGHTWEIGHT AGGREGATE (SLATE): RECIPROCATING GRATE CLINKER COOLER
99.99
99.9
99
V «
N
•H
09
9O
JO
y *•
4)
3 30
2 20
10
2
1
0.5
0.1
0.01
CONTROLLED
•— Weight percent
— Emission factor
• » i" "
0.2
m
05
0
3
o
l-l
0.1
i 3 * 7 < » 10 20 30 40 50 60 70 SO »0 100
Particle diameter, um
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. Z < stated size
After settling chamber control
9.8
23.6
41.0
Emission factor, kg/Mg
After
settling chamber control
0.02
0.05
0.09
C.1-106
EMISSION FACTORS
10/86
-------
8.xx LIGHTWEIGHT AGGREGATE (SLATE): RECIPROCATING GRATE CLINKER COOLER
UMBER OF TESTS: 5, conducted after settling chamber control
TATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean .(Cum. %): 9.8 23.6 41.0
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
:OTAL PARTICULATE EMISSION FACTOR: 0.22 kg particulate/Mg of raw material
:eed. Factor calculated from data in reference.
SOURCE OPERATION: Source produces lightweight slate aggregate in a cool fired
d.ln and a reciprocating grate clinker cooler. During testing, source was
operating at a feed rate of 33 tons/hr, 83% of rated capacity. Firing zone
:emperatures are about 2125°F, and kiln rotates at 3.25 rpm.
SAMPLING TECHNIQUE: Andersen Impactors
EMISSION FACTOR RATING: C
REFERENCE:
Emission Test Report, Lightweight Aggregate Industry, Galite Corporation,
EMB-80-LWA-6, U. S. Environmental Protection Agency, Research Triangle
Park, NC, February 1982.
10/86 Appendix C.I
C.1-107
-------
8.xx NONMETALLIC MINERALS: TALC PEBBLE MILL
99.99
99.9
99
98
-------
8.xx NONMETALLIC MINERALS: TALC PEBBLE MILL
NUMBER OF TESTS: 2, conducted before controls
STATISTICS: Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 30.1 42.4 56.4
Standard deviation (Cum. %): 0.8 0.2 0.4
Min (Cum. %): 29.5 42.2 56.1
Max (Cum. %): 30.6 42.5 56.6
TOTAL PARTICULATE EMISSION FACTOR: 19.6 kg particulate/Mg ore processed.
Calculated from data in reference.
SOURCE OPERATION: Source crushes talc ore then grinds crushed ore in a pebble
mill. During testing, source operation was normal, according to the operators.
An addendum.to reference indicates throughput varied between 2.8 and 4.4
tons/hour during these tests.
SAMPLING TECHNIQUE:- Sample was collected in an.alundum thimble and analyzed
with a Spectrex Prototron Particle Counter Model ILI 1.000.
EMISSION FACTOR RATING: E
REFERENCE:
Air Pollution Emission Test, Pfizer, Inc., Victorville, CA, EMB-77-NMM-5,
U. S. Environmental Protection Agency, Research Triangle Park, NC, July
1977.
10/86 Appendix C.I C.1-109
-------
99.99
99.9
99
98
4)
N 95
90
80
60
ao
•H 10
0)
3 30
41
> 20
-3 10
O S
2
1
0.5
0.1
0.01
10.4 WOODWORKING WASTE COLLECTION OPERATIONS:
BELT SANDER HOOD EXHAUST CYCLONE
CYCLONE CONTROLLED
-•- Weight percent
—•- Emission factor
FABRIC FILTER
—•- Weight percent
3.0
01
CO
O
3
2.0
O
i-l
1.0
3 4 3 6 7 8 9 10 .20 3O 40 SO 60 70 80 90 1OO
Particle diameter, um
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt . % < stated size
Cyclone
29.5
42.7
52.9
After cyclone
and fabric filter
14.3
17.3
32.1
Emission factor, kg/hour
of cyclone operation
After
cyclone collector
0.68
0.98
1.22
C.1-110
EMISSION FACTORS
10/86
-------
10.4 WOODWORKING WASTE COLLECTION OPERATIONS:
BELT SANDER HOOD EXHAUST CYCLONE
NUMBER OF TESTS: a) 1, conducted after cyclone control
b) 1, after cyclone and fabric filter control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 29.5 42.7 52.9
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 14.3 17.3 32.1
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICULATE EMISSION FACTOR: 2.3 kg particulate/hr of cyclone operation.
For cyclone controlled source, this emission factor applies to typical large
diameter cyclones into which wood waste is fed directly, not to cyclones .that
handle waste .previously collected in cyclones. If baghouses are used for waste
collection, partieulate emissions will be negligible. Accordingly, no emission
factor is provided for the fabric filter controlled source. Factors from AP-42.
SOURCE OPERATION: Source was sanding 2 ply panels of mahogany veneer, at 100%
of design process rate of 1110 ra^/hr.
SAMPLING TECHNIQUE: a) Joy train with 3 cyclones
b) Sass train with cyclones
EMISSION FACTOR RATING: E
REFERENCE:
Emission test data from Environmental Assessment Data Systems, Fine
Particle Emi'ssion Information System, Series Report No. 238, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1983.
10/86 Appendix C.I C.1-111
-------
APPENDIX C.2
GENERALIZED PARTICLE SIZE DISTRIBUTIONS
10/86 Appendix C.2 C.2-1
-------
CONTENTS
Page
C.2.1 Rationale For Developing Generalized Particle
Distributions C.2-3
C.2.2 How To Use The Generalized Particle Size Distributions
For Uncontrolled Processes . C.2-3
C.2.3 How To Use The Generalized Particle Size Distributions
For Controlled Processes . C.2-17
C.2.4 Example Calculation . . C.2-17
Tables
C.2-1 Particle Size Cateogry By AP-42 Section C.2-5
C.2-2 Description.of Particle Size Categories C.2-8
C.2-3 Typical Collection Efficiencies of Various Particulate
Control Devices (percent) C.2-17
Figures
C.2-1 Example Calculation for Determining Uncontrolled and
Controlled Particle Size Specific Emissions C.2-4
C.2-2 Calculation Sheet C.2-7
References C.2-18
C.2-2 EMISSION FACTORS 10/86
-------
APPENDIX C.2
GENERALIZED PARTICLE SIZE DISTRIBUTIONS
C.2.1 Rationale For Developing Generalized Particle Size Distributions
The preparation of size specific particulate emission inventories
requires size distribution information for each process. Particle size
distributions for many processes are contained in appropriate industry
sections of this document. Because particle size information for many
processes of local impact and concern are unavailable, this Appendix provides
"generic" particle size distributions applicable to these processes. The
concept of the "generic particle size distribution is based on categorizing
measured particle size data from similar processes generating emissions from
similar materials. These generic distributions have been developed from
sampled size distributions from about 200 sources.
Generic particle size distributions are approximations. They should be
used only in the absence of source-specific particle size distributions for
areawide emission inventories.
C.2.2 How To Use The Generalized Particle Size Distributions For
Uncontrolled Processes •
Figure C.2-1 provides an example calculation to assist the analyst in.
preparing particle size specific emission estimates using generic size
distributions.
The following instructions for the calculation apply to each particulate
emission source for which a particle size distribution is desired and for
which no source specific particle size information is given elsewhere in this
document:
1. Identify and review the AP-42 Section dealing with that process.
2. Obtain the uncontrolled particulate emission factor for the process
from the main text of AP-42, and calculate uncontrolled total
particulate emissions.
3. Obtain the category number of the appropriate generic particle size
distribution from Table C.2-1.
4. Obtain the particle size distribution for the appropriate category
from Table C.2-2. Apply the particle size distribution to the
uncontrolled particulate emissions.
Instructions for calculating the controlled size specific emissions are
given in C.2.3 and illustrated in Figure C.2-1. -
10/86 Appendix C.2
C.2-3
-------
Figure C.2-1. EXAMPLE CALCULATION FOR DETERMINING UNCONTROLLED
AND CONTROLLED PARTICLE SIZE SPECIFIC EMISSIONS.
SOURCE IDENTIFICATION
Source name and address: ABC Brick Manufacturing
Process description:
AF-42 Section:
Uncontrolled AP-42
emission factor:
Activity parameter:
Uncontrolled emissions:
24 Dusty Way
Anywhere, USA
Dryers/Grinders
8.3, Bricks And Related Clay Products
96 Ibs/ton
63.700 tons/year
3057.6 tons/year
/units)
_(units)
(units)
UNCONTROLLED SIZE EMISSIONS
Category name: Mechanically Generated/Aggregate. Unprocessed Ores
Category number: 3
Particle size (ym)
Generic distribution, Cumulative
percent equal to or less than the size:
Cumulative mass _<_ particle size emissions
(tons/year):
1 2.5
15
458.6
< 6
34
1039.6
< 10
51
1559.4
CONTROLLED SIZE EMISSIONS*
Type of control device: Fabric Filter
Collection efficiency (Table C.2-3):
Mass in size range** before control
(tons/year):
Mass in size range after control
(tons/year):
Cumulative mass (tons/year):
Particle size (urn)
0-2.5 2.5-6 6 - 10
99.0
458.6
4.59
4.59
99.5
581.0
2.91
7.50
99.5
519.8
2.60
10.10
* These data do not include results for the greater than 10 um particle size range.
** Uncontrolled size data are cumulative percent equal to or less than the size.
Control efficiency data apply only to size range and are not cumulative.
C.2-4
EMISSION FACTORS
10/86
-------
TABLE C.2-1. PARTICLE SIZE CATEGORY BY AP-42 SECTION
AP-42
Section
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
2.1
2.3
3.2
5.4
5.3
5.10
5. a
5.12
5.15
5.17
a. I
6.2
6.3
6.4
Source Category
External combustion
Bituminous coal combustion
Anthracite coal combustion
Fuel oil combustion
Utility, residual oil
Industrial, residual oil
Utility, distillate oil
Commercial, residual oil
Commercial, distillate
Residential, distillate
Natural gas combustion
Liquefied petroleum gas
Wood waste combustion in
boilers
Lignite, combustion
Bagasse Combustion
Residential fireplaces
Wood stoves
Waste oil combustion
Solid waste disposal
Refuse Incinerators
Conical burners (wood waste)
Internal combustion engine
j
Highway vehicles
Off highway
Chemical process
Charcoal production
Hydrofluoric acid
Spar drying
Spar handling
Transfer
Paint
Phosphoric acid (thermal
process)
Phthalic anhydride
Sodium carbonate
Sulforic acid
rood and agricultural
Alfalfa dehydrating
Primary cyclone
Meal collector cyclone
Pellet cooler cyclone
Pellet regrlnd cyclone
Coffee roasting
Cotton ginning
Feed and grain mills and
elevators
Unloading
Category
Number
a
a
b
a
a
2
b
2
a
1.
9
3
3
3
*
a
9
a
b
b
7
7 -
7
6
b
b
AP-42
Section
6.5
6.7
6.8
6.10
6.10.3
6.11
6.14
6.16
6.17
6.18
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
7.9
7.10
C
Source Category
Food and agricultural (cont.)
Grain elevators
Grain processing
Fermentation
Meat smokehouses
Ammonium nitrate fertilizers
Phosphate fertilizers
Ammonium phosphates
Reactor/amnoniator-
granulator
Dryer/cooler
Starch manufacturing
Ured manufacturers
Defoliation and harvesting
of cotton
Trailer loading
Transport
Harvesting of grain
Harvesting machine
Truck loading
Field transport
Ammonium sulfate manufacturing
Rotary dryer
Fluidized-bed dryer
Metallurgical industry
Primary aluminum production
Bauxite grinding
Aluminum hydroxide calcining
Anode baking furnace
Prebake cell
Vertical Soderberg
Horizontal Soderberg
Coke manufacturing
Primary copper smelting
Ferroalloy production
Iron and steel production
Blast furnace
Slips
Cast house
Sintering
Windbox
Sinter discharge
Basic oxygen furnace
Electee arc furnace
Primary lead smelting
Zinc smelting
Secondary aluminum . -
Sweating furnace
Smelting
Crucible furnace
Reverberatory furnace
Secondary copper smelting
and alloying
Gray iron foundries
ategorv
Number
6
7
6&7
9
a
3
4
4
7
3
6
6
S
5
6
b
b
4
.5
9
a •
8
a
a
a
t.
a
a
a
a
a
a
'a
8
8
8
a
8
a
a. Categories with particle size data specific to process Included in the main body of the text.
b. Categories with particle size data specific to process included in Appendix C.I.
c. Data for each numbered category are shown in Table C.2-2.
d. Highway vehicles data are reported in AP-42 Volume II: Mobile Sources.
Id/86
Appendix C.2
C.2-5
-------
TABLE C.2-1 (continued).
AP-42
Section
Source Category
Category
Number
AP-42
Section
Source Category
Category
Number
Metallurgical Industry (cone.)
7.11 Secondary lead proceaalng a
7.12 Secondary magnesium smelting 8
7.13 Steel foundarles
nelting ' b
7.14 Secondary tine smelting 9
7.15 Storage battery production b
7.13 Leadbearing ore crushing and
grinding 4
Mineral products
S.I Asphaltic concrete plants
Process a
3.3 Brick* and related clay
products
Raw materials handling
Dryers, grinders, etc. b
Tunnel/periodic kilns
Gas fired a
Oil fired a
Coal fired a
3.5 Castable refractories
Raw material dryer 3
Raw material crushing and
screening 3
Electric arc Belting 8
Curing oven ' 3
3.6 Portland cement manufacturing
Dry process
Kilns a
Dryers, grinders, etc. 4
'Jet process
Kilns a
Dryers, grinders, etc. 4
3.7 Ceramic clay manufacturing
Drying 3
Grinding 4
Storage 3
3.8 Clay and fly ash sintering
Fly ash sintering, crushing,
screening and yard storage 5
Clay mixed with coke
Crushing, screening, and
yard storage 3
3.9 Coal cleaning 3
8.10 Concrete batching 3
8.11 Glass fiber manufacturing
Unloading and conveying 3
Storage bine 3
Mixing and weighing 3
Class furnace - vool
Class furnace - textile
8.13 Glass manufacturing
8.14 Grpsua manufacturing
Rotary ore dryer
Roller mill
8.15
8.16
8.18
8.19.L
8.19.2
8.22
3.23
3.24
10.1
Mineral products (cont.)
Impact mill
Flash calciner
Continuous kettle calciner
Line manufacturing
Mineral vool manufacturing
Cupola
Reverberator? furaace
Blow chamber
Curing oven
Cooler
Phosphate rock processing
Drying
Calcining
Grinding
Transfer and storage
Sand and gravel processing
Continuous drop
Transfer station
Pile formation - stacker
Batch drop
Active storage piles
Vehicle traffic unpaved road
Crushed stone processing
Dry crushing
Primary crushing
Secondary crushing
and screening
Tertiary crushing
and screening
Recrushlng and screening
Fines mill
Screening-, conveying,
and handling
Taconite are processing
Fine crushing
tfaste gas
Pellet handling
Grate discharge
Grate feed
Bentonlte blending
Coarse crushing
Ore transfer
Bentonlte transfer
Unpaved roads
Metallic minerals processing
Western surface coal mining
Wood processing
Chemical wood pulping
Miscellaneous sources
11.2 Fugitive dust
a. Categories with particle size data specific to process Included in the main body of the text.
b. Categories with particle size data specific to process Included in Appendix C.I.
<-. Data for each numbered category are shown in Table C.2-2.
C.2-6
EMISSION FACTORS
10/
oo
-------
Figure C.2-2. CALCULATION SHEET.
SOURCE IDENTIFICATION
Source name and address:
Process description:
AP-42 Section:
Uncontrolled AP-42
emission factor:
Activity parameter:
Uncontrolled emissions:
_(units)
_(units)
(units)
UNCONTROLLED SIZE EMISSIONS
Category name:
Category number:
Particle size (urn)
< 2.5 < 6
< 10
Generic distribution, Cumulative
percent equal to or less than the size:
Cumulative mass _< particle size emissions
(tons/year):
CONTROLLED. SIZE EMISSIONS*
Type of-control device:
0 - 2.5
Particle size (um)
2.5 - 6
6-10
Collection efficiency (Table C.2-3):
Mass in size range** before control
(tons/year):
Mass in size range after control:
(tons/year):
Cumulative mass (tons/year):
* These data do not include results for the greater than 10 um particle size range.
** Uncontrolled size data are cumulative percent equal to or less than the size.
Control efficiency data apply only to size range and are not cumulative.
10/86
Appendix C.2
C.2-7
-------
TABLE C.2-2. DESCRIPTION OF PARTICLE SIZE CATEGORIES
Category: 1
Process: Stationary Internal Combustion Engines
Material: Gasoline and Diesel Fuel
Category 1 covers size specific emissions from stationary internal
combustion engines. The particulate emissions are generated from fuel
combustion.
REFERENCE: 1„ 9
99
UJ "
IXI
Z 98
v 90
^-
£ 80
IAJ
o.
u, 70
£ 60
I 50
§ 40
_J L L 1 1 i L L
2 3 4 S 10
PARTICLE DIAMETER. Mg
Cumulative %
less than or equal
Particle to stated size Minimum Maximum Standard
size, pm (uncontrolled) Value Value Deviation
1.0a 82
2.0a 88
2.5 90 78 99 11
3.0a 90
4.0a 92
5.0a 93
6.0 93 86 99 7
10.0 96 92 99 4
Value calculated from data reported at 2.5, 6.0, and 10.0 um. No
statistical parameters are given for the calculated value-.
C.2-8
EMISSION FACTORS
10/86
-------
TABLE C.2-2 (continued).
Category: 2
Process: Combustion
Material: Mixed Fuels
Category 2 covers boilers firing a mixture of fuels, regardless of the
fuel combination. The fuels include gas, coal, coke, and petroleum.
Particulate emissions are generated by firing these miscellaneous fuels,
REFERENCE: 1
95
90
80
70
60
50
40
30
20
10
ir IllIri
J 1 I I I I I L I
2345
PARTICLE DIAMETER,
10
Cumulative %
less than or equal
Particle to stated size Minimum
size, um (uncontrolled) Value
1.0a 23
2.0a 40
2.5 45 32
3.03 50
4.0a 58
5.03 64
6.0 70 49
10.0 79 56
Maximum Standard
Value Deviation
70
84
87
17
14
12
Value calculated from data reported at 2.5, 6.0, and 10.0 um. No
statistical parameters are given for the calculated value.
10/86
Appendix C.2
C.2-9
-------
TABLE C.2-2 (continued).
Category: 3
Process: Mechanically Generated
Material: Aggregate, Unprocessed Ores
Category 3 covers material handling and processing of aggregate and
unprocessed ore. This broad category includes emissions from milling,
grinding, crushing, screening, conveying, cooling, and drying of material.
Emissions are generated through either the movement of the material or the
interaction of the material with mechanical devices.
REFERENCE: 1-2, 4, 7
90
SJ 80
a 70
S 60
" 50
V
2 40
UJ
£ 30
UJ
°- 20
LU .
< 10
I 5
2
lit I i i i r
2 • 3 4 5 - 10
PARTICLE DIAMETER, \fn
Particle
size, ym
2.0
4.0
5.0
6.0
10.0
a
Cumulative %
less than or equal
to stated size Minimum Maximum
(uncontrolled) Value Value
4
11
15 3 35
18
25
30
34 15 65
51 23 81
Standard
Deviation
13
14
Value calculated from data reported at 2.5, 6.0, and 10.0 urn. No
statistical parameters are given for the calculated value.
C.2-10
EMISSION FACTORS
10/86
-------
TABLE C.2-2 (continued).
Category: 4
Process: Mechanically Generated
Material: Processed Ores and Non-metallic Minerals
Category 4 covers material handling and processing of processed ores and
minerals. While similar to Category 3, processed ores can be expected to have
a greater size consistency than unprocessed ores. Particulate emissions are
a result of agitating the materials by screening or transfer, during size
reduction and beneficiation of the materials by grinding and fine milling, and
by drying.
REFERENCE: 1
95
90
80
r>si
"Z 70
2 60
£ 50
v 40
5 30
o
£ 20
khf
»
^ 10
_l
I 5
0.5
I 345
PARTICLE DIAMETER,
Particle
size, um
2.0e
2.5
3.0!
4.0£
5.0*
6.0
10.0
Cumulative %
less than or equal .
to stated size Minimum
(uncontrolled) Value
6
21
30 1
36
48
58
62 17
85 70
10
Maximum
Value
51
83
93
Standard
Deviation
19
17
7
Value calculated from data reported at 2.5, 6.0, and 10.0
statistical parameters are given for the calculated value.
No
10/86
Appendix C:2
C.2-11
-------
TABLE C.2-2 (continued).
Category:
Process:
Material:
Calcining and Other Heat Reaction Processes
Aggregate, Unprocessed Ores
Category 5 covers the use of calciners and kilns in processing a variety
of aggregates and unprocessed ores. Emissions are a result of these high
temperature operations.
REFERENCE: 1-2, 8
90
80
70
60
50
40
30
20
10
5
•>
I I 1 I I T
I
I I I 1 I I I
2345 10
'ARTICLE DIAMETER, ytn
Cumulative %
less than or equal
Particle to stated size Minimum Maximum Standard
size, urn (uncontrolled) Value Value Deviation
1.0a 6
2.0a .13 . .
2.5 18 3 42 11
3.0a 21
4.0a 28
5.0a 33
6.0 37 13 74 19
10.0 53 25 84 19
Value calculated from data reported at 2.5, 6.0, and 10.0 urn.
statistical parameters are given for the calculated value.
No
C.2-12
EMISSION FACTORS
10/86
-------
TABLE C.2-2 (continued).
Category:
Process:
Material:
Grain Handling
Grain
Category 6 covers various grain handling (versus grain processing)
operations. These processes could include material transfer, ginning and
other miscellaneous handling of grain. Emissions are generated by mechanical
agitation of the material.
REFERENCE: 1, 5
30
£ 20
2 io
i/i 5
V
2 2
<_>
oe 1
uj '
^ 0.5
^ 0.2
1 0,1
§ 0.05
<_)
0.01
2345 10
PARTICLE DIAMETER, \en
Cumulative %
less than or equal
Particle to stated size
size, ym (uncontrolled)
l.O3 .07
2.0a .60
2.5 1
3.0a 2
4.0a 3
5.0a 5
6.0 7
10.0 15
Minimum
Value
3
6
Maximum
Value
Standard
Deviation
12
25
3
7
Value calculated from data reported at 2.5, 6.0, and 10.0 urn.
statistical parameters are given for the calculated value.
No
10/86
Appendix C.2
C.2-13
-------
TABLE C.2-2 (continued).
Category:
Process:
Material:
Grain Processing
Grain
Category 7 covers grain processing operations such as drying, screening,
grinding and milling. The particulate emissions are generated during
forced air flow, separation or size reduction.
REFERENCE: 1-2
80
70
60
50
40
30
20
10
i i i r IT
2 345
PARTICLE DIAMETER, pm
10
Cumulative %
less than or equal'
Particle to stated size Minimum
size, ]im (uncontrolled) Value
l.O3 8
2.0a 18 .
2.5 23 17
3.0a 27 -
4.0a 34
5. Oa 40
6.0 43 35
10.0 61 56
Maximum Standard
Value Deviation
34
48
65
7
5
Value calculated from data reported at 2.5, 6.0, and 10.0 ym.
statistical parameters are given for the calculated value.
No
C.2-14
EMISSION FACTORS
10/86
-------
TABLE C.2-2 (continued).
Category: 8
Process: Melting, Smelting, Refining
Material: Metals, except Aluminum
Category 8 covers the melting, smelting, and refining of metals (in-
cluding glass) other than aluminum. All primary and secondary production
processes for these materials which involve a physical or chemical change are
included in this category. Materials handling and transfer are not included.
Particulate emissions are a result of high temperature melting, smelting, and
refining.
REFERENCE: 1-2
99
98
95
90
80
70
60
50
2345 10
PARTICLE DIAMETER, um
Cumulative %
less than or equal
Particle to stated size Minimum Maximum Standard
size, um (uncontrolled) Value Value Deviation
1.0a 72
2.0a 80
2.5 82 63 99 12
3.0a 84
4.03 86
5.0a 88
6.0 89 75 99 9
10.0 92 80 99 7
Value calculated from data reported at 2.5, 6.0, and 10.0 um.
statistical parameters are given for the calculated value.
- -10/86 Appendix C.2
No
C.2-15
-------
TABLE C.2-2 (continued).
Category:
Process:
Material:
Condensation, Hydration, Absorption, Prilling and Distillation
All
Category 9 covers condensation, hydration, absorption, prilling, and
distillation of all materials. These processes involve the physical separa-
tion or combination of a wide variety of materials such as sulfuric acid and
ammonium nitrate fertilizer. (Coke ovens are included since they can be con-
sidered a distillation process which separates the volatile matter from coal
to produce coke.)
REFERENCE: 1, 3
2345
ARTICLE DIAMETER,
Cumulative %
less than or equal
Particle to stated size Minimum
size, urn (uncontrolled) Value
1.0a 60
2.0a 74
2.5 78 59
3.0a 81
4.0a 85
5.0a 88
6.0 91 61
10.0 94 71
Maximum Standard
Value Deviation
99
99
99
17
12
9
Value calculated from data reported at 2.5, 6.0, and 10.0 ym.
statistical parameters are given for the calculated value.
Mo
C.2-16
EMISSION FACTORS
10/86
-------
C.2.3 How To Use The Generalized Particle Size Distributions For
Controlled Processes
To calculate the size distribution and the size specific emissions for a
source with a particulate control device, the user first calculates the
uncontrolled size specific emissions. Next, the fractional control efficiency
for the control device is estimated, using Table C.2-3. The Calculation Sheet
provided (Figure C.2-2) allows the user to record the type of control device
and the collection efficiencies from Table C.2-3, the mass in the size range
before and after control, and the cumulative mass. The user will note that
the uncontrolled size data are expressed in cumulative fraction less than the
stated size. The control efficiency data apply only to the size range
indicated and are not cumulative. These data do not include results for the
greater than 10 ym particle size range. In order to account for the total
controlled emissions, particles greater than 10 ym in size must be included.
C.2.4 Example Calculation
An example calculation of uncontrolled total particulate emissions,
uncontrolled size specific emissions, and controlled size specific emission is
shown on Figure C.2-1. A blank Calculation Sheet is provided in Figure C.2-2.
TABLE C.2-3 TYPICAL COLLECTION EFFICIENCIES OF VARIOUS
PARTICULATE CONTROL DEVICES.a'b
(percent)
Type of collector
Baffled settling chamber
Simple (high-chroughput) cyclone
High-efficiency and multiple cyclones
Electrostatic precipitator (ESP)
Packed-bed scrubber
Vencuri scrubber
Wet -impingement scrubber
Fabric filter
Part
0 - 2.5
NR
50
80
95
90
90
25
99
icle size,
2.5 - 6
5
75
95
99
95
95
85
99.5
urn
6-10
15
85
95
99.5
99
99
95
99.5
The data shown represent an average of actual efficiencies. The efficien-
cies are representative of well designed and well operated control equipment.
Site specific factors (e.g., type of particulate being collected, varying
pressure drops across scrubbers, maintenance of equipment, etc.) will affect
the collection efficiencies. The efficiencies shown are intended to provide
guidance for estimating control equipment performance when source-specific
data are not available.
Reference: 10
NR = Not reported.
10/86
Appendix C.2
C.2-17
-------
References for Appendix C.2
1. Fine Particle Emission Inventory System, Office of Research and
Development, U. S. Environmental Protection Agency, Research Triangle
Park, NC, 1985.
2. Confidential test data from various sources, PE1 Associates, Inc.,
Cincinnati, OH, 1985.
3. Final Guideline Document: Control of Sulfuric Acid Production Units,
EPA-450/2-77-019, U. S. Environmental Protection Agency, Research
Triangle Park, NC, 1977.
4. Air Pollution Emission Test, Bunge Corp., Destrehan, LA., EMB-74-GRN-7,
U. S. Environmental Protection Agency, Research Triangle Park, NC, 1974.
5. I. W. Kirk, "Air Quality in Saw and Roller Gin Plants", Transactions of
the ASAE. 20:5, 1977.
6. Emission Test Report, Lightweight Aggregate Industry, Galite Corp.,
EMB-80-LWA-6, U. S. Environmental Protection Agency, Research Triangle
Park, NC, 1982.
7. Air Pollution Emission Test, Lightweight Aggregate Industry, Texas
Industries. Inc., EMB-80-LWA-3, U. S. Environmental Protection Agency,
Research Triangle Park, NC, 1975.
3. Air Pollution Emission Test. Empire Mining Company, Palmer. Michigan,
EMB-76-IOB-2, U. S. Environmental Protection Agency, Research Triangle
Park, NC, 1975.
9. H. Taback , et al., Fine Particulate Emission from Stationary Sources in
che South Coast Air Basin, KVB, Inc., Tustin, CA 1979.
10. K.. Rosbury, Generalized Particle Size Distributions for Use in Preparing
Particle Size Specific Emission Inventories, U. S. Environmental
Protection Agency, Contract No. 68-02-3890, PEI Associates, Inc., Golden,
CO, 1985.
°'J.S. 30VERNKENT PRINTING CFFICE: 1- t6-"2£-6l I
C.2-18 EMISSION FACTORS 10/86-.
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reicrsr before complctmiij
REPORT NO.
AP-42, Supplement A
2.
3. RECIPIENT'S ACCESSION NO.
TITLE AND SUBTITLE
Supplement A to Compilation Of Air Pollutant Emission
Factors, AP-42, Fourth Edition
5. REPORT DATE
October 1986
6. PERFORMING ORGANIZATION CODE
AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
PERFORMING ORGANIZATION NAME AND ADDRESS
U. S. Environmental Protection Agency
Office Of Air And Radiation
Office Of Air Quality Planning And Standards
Research Triangle, NC 27711
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
2. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
5. SUPPLEMENTARY NOTES
EPA Editor: Whitmel M. Joyner
6. ABSTRACT
In this Supplement to the Fourth Edition of AP-42, new or revised emissions
data are presented for Bituminous And Subbituminous Coal Combustion; Anthracite Coal
Combustion; Fuel Oil Combustion; Natural Gas Combustion; Wood Waste Combustion In
Boilers; Lignite Combustion; Sodium Carbonate; Primary Aluminum Production; Coke
Production; Primary Copper Smelting; Ferroalloy Production; Iron And Steel Production
Primary Lead Smelting; Zinc Smelting; Secondary Aluminum Operations; Gray Iron
Foundries; Secondary Lead Smelting; Asphaltic Concrete Plants; Bricks And Related
Clay Products; Portland Cement Manufacturing; Concrete Batching; Glass Manufacturing;
Lime Manufacturing; Construction Aggregate Processing; Taconite Ore Processing;
Western Surface Coal Mining; Chemical Wood Pulping; Appendix C.I, 'Particle Size
Distribution Data And Sized Emission Factors For Selected Sources"; and Appendix C.2,
"Generalized Particle Size Distributions".
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b. IDENTIFIERS/OPEN ENDED TERMS
c. COSATI I-'iclU/ClOup
Stationary Sources
Point Sources
Area Sources
Emission Factors
Emissions
18. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
21. NO. OF PAGES
460
20. SbCURiTY CLASS (This page I
22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS EDITION is OBSOLETE
------- |