AP421A
AP-42
Supplement A
October 1986
SUPPLEMENT A
TO
COMPILATION
OF
AIR POLLUTANT
EMISSION FACTORS
Volume I:
Stationary Point
And Area Sources
-------
AP-42
Supplement A
October 1986
j$ SUPPLEMENT A
TO
t
COMPILATION
OF
AIR POLLUTANT
EMISSION FACTORS
Volume I:
Stationary Point
And Area Sources
U.S. Environmental Protectl
Reg/on V, Library
230 South Dearborn Street
Chicago, WJnois 60604
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office Of Air And Radiation
Office Of Air Quality Planning And Standards
Research Triangle Park, North Carolina 27711
-------
INSTRUCTIONS FOR INSERTING SUPPLEMENT A
INTO AP-42
Pp. iii and iv (blank) replace same. New Publications In Series.
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Add Appendix C.I. New Information.
Add Appendix C.2. New Information.
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PUBLICATIONS 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.I
Appendix C.2
10/86
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
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 Cleaning 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 Black 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
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 8.1-1
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 Castable Refractories 8.5-1
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 megagram 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 usijig this information with respect to any specific
1 10/86
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1.1 BITUMINOUS AND SUBBITUMINOUS COAL COMBUSTION
1.1.1 General 1
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 the 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 partlculate, flyash rein-
jection from mechanical collectors is commonly employed to improve boiler
efficiency. Ash residue 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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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.^~6
Sulfur Oxides?~9 _ Gaseous sulfur oxides from external coal combustion
are largely sulfur dioxide (802) and much less quantity of sulfur trioxide
(803) 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 subbiturn!nous 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
-------
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 combustion, 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 handfired 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.
10/86 External Combustion Sources 1.1-7
-------
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
Cunulative mass % <_ stated size
Uncontrolled
40
37
33
21
6
It
2
100
Controlled
Multiple
cyclone
99
93
84
61
31
19
e
100
ESP
83
75
63
40
17
8
e
100
Cumulative emission factor0 [kg/Mg (Ib/ton) coal, as fired]
Uncontrolled
1.4A (2.8A)
1.30A (2.6A)
1.16A (2.32A)
0.74A U.48A)
0.21A (0.42A)
0.14A (0.28A)
0.07A (0.14A)
3.5A (7.0A)
Controlled11
Multiple cyclone
0.69A (1.38A)
0.65A (1.3A)
0.59A (1.18A)
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)
O.OHA (0.022A)
0.005A (0.01A)
0.002A (0.004A)
e
0.028A (0.056A)
aReference 61.ESP » electrostatic precipltator.
^Expressed as aerodynamic equivalent diameter.
CA - coal ash weight Z, as fired.
dE>tlMted control efficiency for multiple cyclone, 80Z; ESP, 99.23:.
*lnsuffIclent data.
3.bA
2 8A
2.1A
1.4A
0.70A
ESP
i I i i I I I
l.OA
Q.9A
0 8A
0 7A
0 6A
0.5A
0.4A
0 3A
0.2A
0.1A
0
1A
06A
04A £„
T3
02A I £
0.01A
r- O
006Ap °
.2 .4 .6 1 24 6 10
Particle diameter (ym)
20
40 60 100
0.002A
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 1.1-6.
CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR SPREADER STOKERS BURNING BITUMINOUS COALa
EMISSION FACTOR RATING:
C (uncontrolled and controlled for
multiple cyclone without flyash
reinjection, and with baghouse)
E (multiple cyclone controlled with
flyash reinjection, and ESP
controlled)
P.rtlcle ill**
(»•>
IS
10
6
2.5
1.25
1.00
0.425
TOTAL
Cm
Uncontrolled
28
20
It
7
5
5
4
100
Controlled
Multiple
cyclonec
16
73
51
8
2
2
1
100
Multiple
cyclone1*
7*
65
52
27
16
U
9
100
ESP
97
90
82
61
46
41
•
100
••ghouie
72
60
46
26
18
15
7
100
Uncontrolled
8.4
(16.8)
6.0
(12.0)
4.2
(».4>
2.1
(4.2)
1.5
(3.0)
1.5
(3.0)
1.2
(2.4)
30.0
(60.0)
M| (Ib/ton) co.1, u fired]
Controlled
Multiple
cyclone*
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)
8.5
(I'.O)
Multiple
cyclone**
4.4
(8.8)
3.9
(7.8)
3.1
(6.2)
1.6
(3.2)
1.0
(2.0)
O.t
(1.6)
0.5
(1.0)
6.0
(12.0)
ESP
0.23
(0.46)
0.22
(0.44)
0.20
(0.40)
0.15
(0.30)
0.11
(0.22)
0.10
(0.20)
c
0.24
(0.48)
bghou.e
0.043
(0.086)
0.0)6
(0.072)
0.028
(0.056)
0.016
(0.032)
0.011
(0.022)
0.009
(0.018)
0.004
(0.008)
0.06
(0.12)
btiprjiied •• «erodyn«alc equivalent dlMeter.
cvitn fly.th reinjection.
'Without fly.ch reinjection.
•Inefficient die..
fE.tU.ted control efficiency for CSP, 99.21; beghou.e, 99.at.
c >-
o £
10
9
8
7
6
5
4
3
2
1
0
.1
Multiple cyclone with
flyash reinjection
Multiple cyclone without
flyash reinjection
Baghouse
Uncontrolled
-ESP
10. Q
.2
.4 .6 1
10
20
40 60 100
2.0
1.0
0.6
0.4
0.2
0.1
.
i
ir
2 4 6
Particle diameter (pm)
Figure 1.1-4. Cumulative size specific emission factors for
stokers burning bituminous coal
o.io
0.06
0.04 3
u
<9
0.02 .§'
i/i
£'
0.01 "
0.006 o
4->
0.004 S:
0.002 f>
0.001
spreader
10/86
External Combustion Sources
1.1-11
-------
TABLE 1.1-8. CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC EMISSION
FACTORS FOR UNDERFEED STOKERS BURNING BITUMINOUS COALa
EMISSION FACTOR RATING: C
Particle stzeb
(jm)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass % < stated size
50
41
32
25
22
21
18
100
Uncontrolled cumulative
[kg/Mg (Ib/ton) coal
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)
emission factorc
, as fired]
aReference 61.
''Expressed as aerodynamic equivalent diameter.
cMay also be used for uncontrolled hand fired units.
10
9
8
7
6
'€ 3
i ?
, L
\
o
.1
Uncontrolled
I I I i i 11 I
.4 .6 1 2 4 6 10
Particle diameter (urn)
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
-------
15. Field Testing: Application of Combustion Modifications To Control NCy
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-600/7-78-036a, 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, Plezer, SC, EMB-71-CI-01, U. 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, jK9):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, 9(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
-------
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 Desulfurization 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/ 7-80-111, 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 clinkering, 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 Controls2'1'4
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.
10/86 External Combustion Sources 1.2-1
-------
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 1.2-4. 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 %
< stated size
Uncontrolled0
64
52
42
27
24
23
d
100
Cumulative emission factor
[kg/Mg (Ib/ton) coal, as fired]
Controlled
2.9
2.4
1.9
1.2
1.1
1.1
d
4.6
(5.8)
(4.8)
(3.8)
(2.4)
(2.2)
(2.2)
(9.2)
aReference 19.
^Expressed as aerodynamic equivalent diameter.
cMay also be used for uncontrolled hand fired units.
dInsufficient data.
*-> *-> o
OJ O 2
^ cr>
2^
*J 01
C -X.
O —'
.1 .2 .4 .6 1 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
-------
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 Report, 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 NOjj 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 asphaltene, 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
-------
low loads from boilers firing any of the lighter grades, however. At too low a
load condition, proper combustion conditions cannot be maintained, and partic-
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 _ Tota} gg^ 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 803 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 1 »* ' 17»23>27 - TWO mechanisms form NO , oxidation of
fuelbound nitrogen and thermal fixation of the nitrogen in combustion air.
Fuel NOjf 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 NOjj
will generally account for over 50 percent of the total NOX generated. Thermal
fixation, on the other hand, 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 NOx reductions are not nearly so significant.
Other Pollutantsl8-21 - 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 1,3-3. 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 slzeb
(urn)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass I < 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 (Ib/lo3 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
controlled6
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 aerodynamic equivalent diameter.
cPartlculate emission 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(8) + 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.
So
«
l.OA
0.9A
0.8A
0.7A
0.6A
0.5A
0.4A
0.3A
0.2A
0.1A
OA
.1 .2 .4 .6 1 2 46 10
Particle diameter (pm)
20
0.2QA
0.18A
0.16A ^ _
01 _
0.14A i"°
0.12A
0.10A
0.08A
| S
^ u
v .1
0.06A .2-
-
0.04A z
0.02A
OA
40 60 100
Figure 1.3-2. Cumulative size specific emission factors for industrial
boilers firing residual oil.
10/86
External Combustion Sources
1.3-5
-------
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
(urn)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass % < stated size
Uncontrolled with
residual oil
78
62
44
23
16
14
13
100
Uncontrolled with
distillate oilc
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)
0.1 3A (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.
cp«rticulate emission 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 (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
0.80A
0.70A
0.60A
0.50A
0.40A
0.30A
0.20A
0.10A
0
Distillate oil
t i i i i i
I
Residual oil
0.25
0.15
0.10
0.05 S
0
.1 .2 .4 .6 1 2 46 10
Particle diameter (ym)
20
40 60 100
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
-------
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, U. 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., Field 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 NOy Emissions from Utility Boilers, EPA-650/2-74-066,
U. S. Environmental Protection Agency, Washington, DC, June 1974.
10/86
External Combustion Sources 1.3-9
-------
23. K. J. Lira, et al., Technology Assessment Report for Industrial Boiler
Applications; NOx 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 liquefiable const! tutents and removal of hydrogen
sulfide (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/scra (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 mercaptan 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 are 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
stoichlometric 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 recirculation. 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 recirculated. Flue gas recirculation is best suited for new
boilers. Retrofit application would require extensive burner modifications.
10/86 External Combustion Sources 1.4-1
-------
Studies indicate that low NOjj 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, NC^ 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 particulate has been estimated to be less
than 1 micrometer in size. 27 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
Nonmethane
C
C
D
D
Methane
C
C
D
D
10/86
External Combustion Sources
1.4-3
-------
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, H_;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, TX, August 1972.
8. R. E. Barrett, et al . , Field Investigation of Emissions from Combustion
Equipment for Space Heating, EPA-R2-73-084, 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 NOx 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 NO, 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
-------
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
-------
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 Controls^"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 reinjection, 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 using 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
-------
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
extensively 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
-------
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10/86
External Combustion Sources
1.6-7
-------
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. Bosserman, "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, NCy 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. Nonfossll Fueled Boilers - Emission Test Report; Weyerhaeuser Company,
Longview, 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
-------
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
-------
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 S02, 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 partlculate 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 1.7-4 CUMULATIVE PARTICLE SIZE DISTRIBUTION AND SIZE SPECIFIC
EMISSION FACTORS FOR LIGNITE FUELED SPREADER STOKERS3
EMISSION FACTOR RATING: E
Particle sizeb
Cy»)
15
10
6
2.5
1.25
1.00
0.625
TOTAL
Cumulative mass I < stated size
Uncontrolled
28
20
14
7
5
5
4
100
Multiple cyclone
controlled
55
41
31
26
23
22
e
100
Cumulative emission factor*1
[kg/Kg (Ib/ton) coal, a* flr«dj
Uncontrolled
0.95A (1.9A)
0.68A (1.36A)
0.48A (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)
0.150A (0.300A)
e
0.68A (1.36A)
•Reference 13.
^Expressed as aerodynamic equivalent diameter.
cCoal ash weight I content, as fired.
dEstlmated control efficiency for multiple cyclone, 80Z.
'Insufficient data.
l.OA
0.9A
2
ts~ °'8A
«u?
«££ 0.7A
5-cC
^S*, 0.6A
ri «/» «
*i g" o-5*
••po
t*g 0.4A
i£«
g^i 0.3A
¥ o
§ u
g 0.2A
0.1A
0
Uncontrolled
Multiple cyclone
iL
.4 .6 1 2 4 6 10
Particle diameter
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
-------
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 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 1.7-7
-------
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.^ 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 $1
million or more) to submit operating and financial data on an annual basis. Sawyer and Farmer3 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
-------
Different values for time at base and peak loads are obtained by changing the total time at lower loads (0
through 75 percent) or by changing the distribution of 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 tuibme operation. Note that the
cycle determines onlr the importance of each load condition in computing composite emission factors for each
type of turbine, not overall operating houis.
The top portion of Table 3.1-2 gives separate factors foi gas-fired and oil-fired 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 be 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. //:>(! I): 522-531. November 1971.
2. Hare. C. T. and K. J. Springer, Exhaust Emissions from Uncontrolled Vehicles and Related Equipment Using
Internal Combustion Engines. Final Report. Part 6: Gas Turbine Electric Utility Powei Plants. Southwest
Research Institute. San Antonio. Tex. Prepared for Envnonmental Piotcction Agency. Research Tuangle Paik.
N.C.. under Contract No. EHS 70-108. February 1974.
3. Sawyer, V. W. and R. C. Farmer. 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 the 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
-------
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 by the 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
9/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
-------
3.4 STATIONARY LARGE BORE DIESEL AND DUAL FUEL ENGINES
3.4.1 General
The primary domestic use of large bore diesel engines, i.e., those
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 NC^ 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.
Stationary Internal Combustion Sources 3.4-1
-------
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 gases 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
Chemical class Total
Compound Vapor emissions
pressure Viscosity g/truck Ib/truck
Acetone
Perchl oroethyl ene
Methyl methacrylate
Phenol
Propylene glycol
high
high
medium
low
low
low
low
medium
low
high
311
215
32.4
5.5
1.07
0.686
0.474
0.071
0.012
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
-------
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,
Na2C03* NaHC03* 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 (Na2C02 ' H20) 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
-------
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Chemical Process Industry
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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 precipitators (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
-------
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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 (A1203) 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
(Al^Oo * 3^0) 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 Al2C>3 is put through the Hall-
Heroult process, an electrolytic reduction of alumina dissolved in a molten salt
bath of cryolite (Na3AlF^) 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
-------
prebake cells. 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
-------
TABLE 7.1-2. EMISSION FACTORS FOR PRIMARY ALUMINUM PRODUCTION PROCESSES3.b
EMISSION FACTOR RATING: A
Operation
Total
partlculatec
kg/Mg Ib/ton
Gaseous
fluoride
kg/Mg Ib/ton
Particulate
fluoride
kg/Mg Ib/ton
Reference
Bauxite grinding
Uncontrolled 3.0
Spray tower 0.9
Floating bed scrubber 0.85
Quench tower and spray screen 0.5
Aluminum hydroxide calcining
Uncontrolled11 100.0
Spray tower 30.0
Floating bed scrubber 28.0
Quench tower 17.0
ESP 2.0
Anode baking furnace
Uncontrolled 1.5
Fugitive NA
Spray tower 0.375
ESP 0.375
Dry alumina scrubber 0.03
Prebake cell
Uncontrolled 47.0
Fugitive 2.5
Emissions to collector 44.5
Multiple cyclones 9.8
Dry alumina scrubber 0.9
Dry ESP plus spray tower 2.25
Spray tower 8.9
Floating bed scrubber 8.9
Coated bag filter dry scrubber 0.9
Cross flow packed bed 13.15
Dry plus secondary scrubber 0.35
Vertical Soderberg stud cell
Uncontrolled 39.0
Fugitive 6.0
Emissions to collector 33.0
Spray tower 8.25
Venturl scrubber 1.3
Multiple cyclones 16.5
Dry alualna scrubber 0.65
Scrubber plus ESP plus spray
screen and scrubber 3.85
Horizontal Soderberg stud cell
Uncontrolled 49.0
Fugitive 5.0
Emissions to collector 44.0
Spray tower 11.0
Floating bed scrubber 9.7
Scrubber plus wet ESP 0.9
Wet ESP 0.9
Dry alunlna scrubber 0.9
6.0
1.8
1.7
1.0
200.0
60.0
56.0
34.0
4.0
3.0
NA
0.75
0.75
0.06
94.0
5.0
89.0
19.6
1.8
4.5
17.8
17.8
1.8
26.3
0.7
78.0
12.0
66.0
16.5
2.6
33.0
1.3
7.7
98.0
10.0
88.0
22.0
19.4
1.8
1.8
1.8
Neg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
NA
NA
NA
NA
NA
NA
NA
NA
NA
0.45
NA
0.02
0.02
0.0045
0.9
NA
0.04
0.04
0.009
12.0
0.6
11.4
11.4
0.1
0.7
0.7
0.25
1.7
3.25
0.2
16.5
2.45
14.05
0.15
0.15
14.05
0.15
0.75
11.0
1.1
9.9
3.75
0.2
0.1
0.5
0.2
24.0
1.2
22.8
22.8
0.2
1.4
1.4
0.5
3.4
6.7
0.4
33.0
4.9
28.1
0.3
0.3
28.1
0.3
1.5
22.0
2.2
19.8
7.5
0.4
0.2
1.0
0.4
0.05
NA
0.015
0.015
0.001
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
6.0
0.6
5.4
1.35
1.2
0.1
0.1
0.1
0.1
NA
0.03
0.03
0.002
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
12.0
1.2
10.8
2.7
2.4
0.2
0.2
0.2
1,3
1,3
1,3
1.3
1.3
1,3
1,3
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
2,10
2,10
2,10
2,10
2
2,10
10
10
*For bauxite grinding, expressed as kg/Mg (Ib/ton) of bauxite processed. For aluminum hydroxide calcining,
expressed as kg/Mg (Ib/ton) of alumina produced. All other factors are/Mg (ton) of molten aluminum product.
ESP- electrostatic preclpitator. NA * not available. Neg - negligible.
''Sulfur oxides may be estimated, with an Emission Factor Rating of C, by the following calculations.
Anode baking furnace, uncontrolled S02 Emissions (excluding furnace fuel combustion emissions):
20(C)(S)(1-0.01 K) kg/Mg [40(C)(S)(1-0.01 K) Ib/ton)
Prebake (reduction) cell, uncontrolled S02 emissions:
0.2(C)(S)(K) kg/Mg (0.4(C)(S)(K) Ib/ton]
Where: C - Anode consumption* during electrolysis, Ib anode consumed/lb Al produced
S - J sulfur in anode before baking
K - I of total Sc>2 emitted by prebake (reduction) cells.
* Anode consumption weight Is weight of anode paste (coke * pitch) before baking.
clncludes particulate fluorides.
dAfter multicyclone.
10/86
Metallurgical Industry
7.1-5
-------
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 %
1.5
o c
ro O
M- (_>
c
C 3
O
1/1
I/)
1.0
0.5
I
I
Figure 7.1-3.
0.625 1.25 2.5 6.0 10.0
Particle size (pm)
Emission factors less than stated particle size
for fugitive emissions from HSS aluminum cells.
10/86
Metallurgical Industry
7.1-7
-------
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 S02 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
-------
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
-------
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
-------
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
Pushing emissions
harging emissions
oor emissions
(3) Topside emissions
(§) Battery underfire emissions
(Courtesy of the Western
Pennsylvania Air Pollution
Control Association)
10/86
Metallurgical Industry
7.2-5
-------
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10/86
Metallurgical Industry
7.2-7
-------
TABLE 7.2-2 (continued)
Particulate
emission Particle
factor size
Process rating (urn)
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
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
Cumulative mass emission
mass % factors
< stated
size kg/Mg Ib/ton
28. CT
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
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
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 rQ £. ">« PARTICIPATE
EMISSION RATE ' ton COAL CHARGED
99.950
99.90
99.60
99.50
99
98
95
UJ
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UJ $0
h-
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to
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£ 50
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u
c
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10"' 10° 10' I02
PARTICLE DIAMETER, micrometers
Note: Extrapolated to the 15 ym size, using engineering estimates,
Figure 7.2-4. Coal preheating (controlled with scrubber).
10/86
Metallurgical Industry
7.2-11
-------
Ibs PARTICIPATE
EMISSION RATE ''" ton COAL CHARGED
no ion >
yy.yy\j
99.950
99.90
99.80
99.50
99
98
95
Ul
S 9°
0
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H 70
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PARTICLE DIAMETER, micrometers
Note: Extrapolated to the 15 ym size, using engineering estimates.
Figure 7.2-6. Pushing (uncontrolled) average of 6 sites.
10/86
Metallurgical Industry
7.2-13
-------
TOTAL PARTICULATE _ Q Q72
EMISSION RATE " '
Ibs PARTICULATE
ton COAL CHARGED
UJ
N
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99.950
99.90
99.80
99.50
99
98
95
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PARTICLE DIAMETER, micrometers
Figure 7.2-8. Mobile scrubber cars,
10/86
Metallurgical Industry
7.2-15
-------
Ibs PARTICIPATE
99.930
99.90
99.80
99.50
99
98
95
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w 80
£ 70
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v 60
2 50
8 40
£ 30
a
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< 10
D
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EMISSION RATE ton COAL CHARGED
-
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Figure 7.2-10. Quenching (uncontrolled) clean water <1,500 mg/L IDS.
10/86
Metallurgical Industry
7.2-17
-------
TOTAL PARTICIPATE _?5>1 lbs PARTICIPATE
EMISSION RATE " ton COAL CHARGED
99.930
99.90
99.80
99.50
99
98
95
UJ
- 90
a
UJ 80
£ 70
in
v 60
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PARTICLE DIAMETER, micrometers
10'
Figure 7.2-12. Quenching (controlled with baffles) clean water <1,500 mg/L IDS,
10/86
Metallurgical Industry
7.2-19
-------
References for Section 7.2
1. John Fitzgerald, et al., Inhalable Participate 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
-------
7.3 PRIMARY COPPER SMELTING
7.3.1 Process Description^'^
In the 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 (802). 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
-------
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 SOo 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
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 S02, and the FeO blowing
and slag skimming are repeated until an adequate amount of relatively pure C^S,
called "white metal", accumulates in the bottom of the converter. A renewed air
blast oxidizes the copper sulfide sulfur to SOoj leaving blister copper in the
10/86 Metallurgical Industry 7.3-3
-------
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 Fierce-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
Remaining smelter processes handle material that contains very little
sulfur, hence SC>2 emissions from these processes are relatively insignificant.
Particulate 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 S02 concentration be main-
tained. Practical limitations have usually restricted sulfuric acid plant
application to gas streams that contain at least 3 percent SC^. Table 7.3-1
shows typical average S02 concentrations for the various smelter unit offgases.
Currently, converter gas effluents at most smelters are treated for SC>2 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 SC>2 content gas effluents from reverberatory furnace opera-
tions are usually released to the atmosphere with no reduction of SC>2. 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
SC>2 to acid, with approximately 2000 parts per million SC>2 remaining in the acid
plant effluent gas. Double contact acid plants collect from 98 to more than 99
percent of the SC>2 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 SC^.
10/86 Metallurgical Industry 7.3-5
-------
TABLE 7.3-2. EMISSION FACTORS FOR PRIMARY COPPER SMELTERSa»b
EMISSION FACTOR RATING: B
Patticulate
Sulfur dloxided
Configuratlonc
References
Reverberatory furnace (RF)
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 (SS) 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
Ce
CD
NR
C
kg/Mg
25
18
22
25
18
NA
25
18
5
50
18
NA
50
18
5
70
5
NAH
5
NA
NA
Ib/ton
50
36
45
50
36
NA
50
36
10
100
36
NA
100
36
10
140
10
NA£
10
NA
NA
kg/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
1
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
•Expressed as units/unit weight of concentrated ore processed by the smelter. Approximately 4
unit weights of concentrate are required to produce 1 unit weight of blister copper. NA - not
available.
bFor 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 particulate removal in hot ESPs may range 20 to 80Z and in cold ESPs
may be 99%. Converter gas effluents and, at some smelters, roaster gas effluents are treated in
single contact acid plants (SCAP) or double contact acid plants (DCAP) for S02 removal. Typical
SCAPs are about 96Z efficient, and DCAPs are up to 99.8X efficient in S02 removal. They also
remove over 99X of particulate matter. Noranda and flash furnace offgases are also processed
through acid plants and are subject to the same collection efficiencies as cited for
converters and some roasters.
cln addition to sources indicated, each smelter configuration contains fire refining anode
furnaces after the converters. Anode furnaces emit negligible S02- No particulate emission
data are available for anode furnaces.
^Factors for all configurations except reverberatory furnace followed by converters have been
developed by normalizing test 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.
fused 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 smelters with multiple hearth roasters, reverberatory furnace and
converters.
10/86
Metallurgical Industry
7.3-7
-------
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^ (urn) 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.
GNominal particulate removal efficiency is 99%.
^T= 4
Ol
I
I
0.24
0.20
0.16
0.12
0.08
0.04
c* n
3C+
o
0.625
1.25
2.5 5
Particle Size (um)
10
15
Figure 7.3-3.
Size specific emission factors for
reverberatory smelting.
10/86
Metallurgical Industry
7.3-9
-------
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 SMELTERS*
EMISSION FACTOR RATING: B
Particulate S02
Source of emission
kg/Mg Ib/ton kg/Mg Ib/ton
Roaster calcine discharge
Smelting furnace*5
Converter
Converter slag return
Anode furnace
Slag cleaning furnace0
1.3
0.2
2.2
NA
0.25
4
2.6
0.4
4.4
NA
0.5
8
0.5
2
65
0.05
0.05
3
1
4
130
0.1
0.1
6
aReferences 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.
cUsed to treat slags from smelting furnaces and converters at the flash
furnace smelter.
10/86 Metallurgical Industry 7.3-11
-------
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;
15
10
5
2.5
1.25
0.625
Total
s suaueu sj.ze
33
28
25
22
20
17
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.
-o
CD
o
-------
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 SMELTERS3
EMISSION FACTOR RATING: C
Operation
Roasting
Smelting
Converting
Refining
Emission
kg/Mg
0.075
0.036
0.13
MA
factorb
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.
bFor 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
-------
11. R. M. Statnick, Measurements of Sulfur Dioxide, Partlculate 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. Environmenal 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.
10/86 Metallurgical Industry 7.3-17
-------
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, ferromanganese, and ferrochrome, con-
stitute approximately 85 percent of domestic production. Subgroups of these
alloys include siliconmanganese, sij'iqon metal and ferrochromium. 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. Others
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
-------
TABLE 7.4-1. FERROALLOY PROCESSES AND RESPECTIVE PRODUCT GROUPS
Process
Submerged arc furnace3
Exothermic**
Silicon reduction
Aluminum reduction
Mixed aluminothermal/
silicothermal
Electrolytic0
Vacuum furnace**
Induction furnace6
Product
Silvery iron (15 - 22% Si)
Ferrosilicon (50% Si)
Ferrosilicon (65 - 75% Si)
Silicon metal
Silicon/manganese/zirconium (SMZ)
High carbon (HC) ferromanganese
Si1iconmanganese
HC ferrochrome
Ferrochrome/silicon
FeSi (90% Si)
Low carbon (LC) ferrochrorae, LC
ferromanganese, Medium carbon (MC)
ferromanganese
Chromium metal, Ferrotitanium,
Ferrocolumbium, Ferrovanadium
Ferromolybdenum, 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 exthermic reaction,
by addition of silicon, aluminum or combination of the two.
GProcess by which simple ions of a metal, usually chromium or manganese
in an electrolyte, are plated on cathodes by direct low voltage current.
^Process by which carbon is removed from solid state high carbon
ferrochrome 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
-------
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 chlorinatlon, 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 SiC^, CaO and MgO, if present in the charge.
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
-------
NOTES
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Metallurgical Industry
7.4-11
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10/86
Metallurgical Industry
7.4-13
-------
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EMISSION RATE '°'z*° Mg
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PARTICLE DIAMETER, micrometers
Figure 7.4-5. Controlled (baghouse),
size distribution
FeMn producing, open furnace
10/86
Metallurgical Industry
7.4-15
-------
99.990
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TOTAL PARTICIPATE kg PARTlCULATE
EMISSION RATE ~lb U
Mg ALLOY
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PARTICLE DIAMETER, micrometers
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10/86
Metallurgical Industry
7.4-17
-------
99.950
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- EMISSION RATE •L ^u .. A1 . ._v 1
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/-
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-
.
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—
-
-
-
.
-
-
I 1
111 Illllll 1 1 Illllll 1 1 1 1 1 1 1 1
UJ
N
w
O
UJ
1.08 <
CO
0.96 y
0.80 u
H
0.56 ^
o
0.40 p
cc
<
a.
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JC
UJ
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P
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O
i
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f 10° 10 ' I02
PARTICLE DIAMETER, micrometers
Figure 7.4-9. Controlled (ESP), FeCr (HC) producing, open furnace
particle size distribution
10/86
Metallurgical Industry
7.4-19
-------
99.990
99.950
99.90
99.80
99.50
99
98
95
j
4
90
()
O
ID
in
H-
Z
UJ
o
-------
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
-------
9. M. Szabo and R. Gerstle, Operations and Maintenance of Partlculate 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, ^3(4):l7-29, 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
-------
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
-------
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 casthouse, 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/ft^). 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
/ • -)"" J
-------
pounds, aliphatic hydrocarbons, and chlorides. At the discharge end, emissions
are mainly iron and calcium oxides. Sinter strand windbox 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 EOF 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
-------
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/10^ ft3) having an
average heat value of 83 BTU/ft3.
Emissions for combustion of coke oven gas can be estimated in the same
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 Ib/lO^1 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 factors for procfe3'3es 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 (cont.). PARTICULATE EMISSION FACTORS FOR IRON AND STEEL MILLS3
Source
BOF Charging
At source
At building monitor
Controlled by baghouse
BOF Tapping
At source
At building monitor
Controlled by baghouse
Hot metal transfer
At source
At building monitor
BOF monitor (all sources)
Q-BOP melting and refining
Controlled by scrubber
Electric arc furnace
Melting and refining
Uncontrolled carbon
steel
Charging, tapping and
slagging
Uncontrolled emissions
escaping monitor
Melting, refining,
charging, tapping
and slagging
Uncontrolled
Alloy steel
Carbon steel
Controlled by:6
Building evacuation
to baghouse for
alloy steel
Direct shell
evacuation (plus
charging hood)
vented to common
baghouse for
carbon steel
Units
kg/Mg (Ib/ton) hot metal
kg/Kg (Ib/ton) steel
kg/Mg (Ib/ton) hot metal
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
Emission 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)
0.095 (0.19)
0.028 (0.056)
0.25 (0.5)
0.028 (0.056)
19.0 (38.0)
0.7 (1.4)
5.65 (11.3)
25.0 (50.0)
0.15 (0.3)
0.0215 (0.043)
Emission
Factor
Rating
D
B
B
D
B
B
A
B
B
B
C
c
A
C
A
E
Particle
Size
Data
Yes
Yes
Yes
Yes
Yes
Yes
Yes
10/86
Metallurgical Industry
7.5-9
-------
TABLE 7.5-2. SIZE SPECIFIC EMISSION FACTORS
Source
Sintering
Wind box
Uncontrolled
Leaving grate
Controlled by wet
ESP
Controlled by
venturi scrubber
Controlled by
cyclone6
Controlled by
baghouse
Emission
Factor
Rating
D
C
C
C
C
Particle
Size yma
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 (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 sou rce^
Controlled by
baghouse
BOF Tapping
At source^
Emission
Factor
Rating
C
E
D
E
Particle
Size yma
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)
9.0x10-6 1.8xlO-5
3.0x10-5 6.0xlO-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
Open hearth furnace
Melting and refining
Uncontrolled
Open Hearth Furnaces
Controlled by
ESPP
Emission
Factor
Rating
E
E
Particle
Size urn*
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
10b
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 (pm) 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.
krorpedo ladle desulfurization with CaC2 and CaC03.
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
-------
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10/86
Metallurgical Industry
7.5-17
-------
TABLE 7.5-3. UNCONTROLLED CARBON MONOXIDE EMISSION FACTORS
FOR IRON AND STEEL MILLSa
EMISSION FACTOR RATING: C
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,
°kg/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 iron 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
-------
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
-------
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 (862) 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 the
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 + PbS— » 3Pb + S02 (6)
» 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 sulf ides) , 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
-------
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
The remainder is captured by the slag. The concentration of this 862
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 Sulfur dioxide
Process
kg/Mg Ib/ton kg/Mg Ib/ton
Ore crushing^
Sintering (updraft)c
Blast furnace^
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.
^Reference 2. Based on quantity of ore crushed. Estimated from similar
nonferrous metals processing.
cReferences 1, 5-7.
dReferences 1-2, 8.
eReference 2.
^Reference 2. Based on quantity of materials handled.
10/86 Metallurgical Industry 7.6-5
-------
TABLE 7.6-2. LEAD EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION FOR
BAGHOUSE CONTROLLED BLAST FURNACE FLUE GASES3
EMISSION FACTOR RATING: C
Particle
size"
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
< stated size
98
86.3
71.8
56.7
54.1
53.6
52.9
100.0
Cumulative
kg/Mg
1.17
1.03
0.86
0.68
0.65
0.64
0.63
1.20
emission 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.
1.20
1.00
OJ
o
o
o
0.80 ^
o
0.60 °
00
1/1
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 7.6-4. UNCONTROLLED LEAD FUGITIVE EMISSION FACTORS AND
PARTICLE SIZE DISTRIBUTION FOR SINTER MACHINE3
EMISSION FACTOR RATING: D
Particle
c-i T ob
(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
kg/Mg
0.10
0.10
0.09
0.08
0.07
0.07
0.07
0.10
emission 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
OJ
c
o
o
c
r:
o
t>
LO
1/1
0.10 -
0.09
0.08
0.07
J L
Figure 7.6-4.
0.625 1.0 1.25 2.5 6.0 10.0 15.0
Particle size (ym)
Size specific fugitive emission factors for
uncontrolled sinter machine.
10/86
Metallurgical Industry
7.6-9
-------
TABLE 7.6-6.
UNCONTROLLED LEAD FUGITIVE EMISSION FACTORS AND PARTICLE
SIZE DISTRIBUTION FOR DROSS KETTLE3
EMISSION FACTOR RATING: D
Particle
0 j _ AH
size"
(urn)
15
10
6
2.5
1.25
1.00
0.625
Total
< 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.
Ol
c
o
o
s-
o
o
(T3
C
O
0.18
0.15
0.12
0.09
0.06 ~
j I
0.625 1.0 1.25 2.5 6.0 10.0 15.0
Particle size (vim)
Figure 7.6-6. Size specific lead fugitive emission factors for
uncontrolled dross kettle.
10/86
Metallurgical Industry
7.6-11
-------
TABLE 7.6-8. UNCONTROLLED FUGITIVE EMISSION FACTORS FOR
PRIMARY LEAD SMELTING PROCESSESSa»b
P*TTl -J c Q -f f\ f\ _
Cjlll J. o o J_ \J L I
points
Ore storage**
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 buildingb
Blast furnace
Lead pouring to ladle, transferring
slag pouring0
Slag cooling1*
Zinc fuming furnace vents
Dross kettleb
Reverberatory furnace leakageb
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
culate
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
1? a r* t" r\ y
r a.cL,o L
Rating
D
E
E
E
E
E
E
E
D
D
E
E
D
D
E
E
aExpressed 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
-------
4. Environmental Assessment of the Domestic Primary Copper, Lead and Zinc
Industries (Prepublication), 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 AISI
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
-------
In a fluidized 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 SC>2 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 + H2S04 -» Zn+2(aq) + S04~2(aq) + H20 (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
-------
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 S02 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
-------
TABLE 7.7-2. UNCONTROLLED FUGITIVE PARTICULATE EMISSION FACTORS FOR
PRIMARY SLAB ZINC PROCESSING3
EMISSION FACTOR RATING: E
Emission factor*5
Process
(kg/Mg) (Ib/ton)
Roasting Negligible Negligible
Sinter plant0
Wind box 0.12 - 0.55 0.24 - 1.10
Discharge and screens 0.28 - 1.22 0.56 - 2.44
Retort buildingd 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.
cFrom 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
-------
7.8 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 removal, and air classification separates the
insulation.
10/86 Metallurgical Industry 7.8-1
-------
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
-------
30. J. M. Kane, "Equipment For Cupola Control", American Foundryman's Society
Transactions, £4:525-531, 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
-------
TABLE 7.8-1. PARTICULATE EMISSION FACTORS FOR SECONDARY
ALUMINUM OPERATIONS3
Uncontrolled
Operation
Sweating furnace''
Smelting
Crucible furnace*5
Reverberatory furnacec
Chlorine demagging"
kg/Mg
7.25
0.95
2.15
500
Ib/ton
14.5
1.9
4.3
1000
Electrostatic
Baghouse precipitator
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
B
aReference 2. Emission factors for sweating and smelting furnaces expressed as units per unit
weight of metal processed. For chlorine demagging, emission factor Is kg/Mg (Ib/ton) of
chlorine used.
*>Based on averages of two source tests.
cUncontrolled, 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/Mg (0.3 Ib/ton).
dfiased 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).
eThis 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 steps. 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
-------
J *
i .
Particle Size Distributions and Size Specific Emission
Factors for Uncontrolled Reverberatory Furnaces
UNCONTROLLED
Weight percent
"article dlanefe
UNCOOTROLLED
Emission factor
xi *o o ic *o x
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 distribution15
Aerodynamic
particle
diameter, urn
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, urn.
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, TX, 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
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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 metal, 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
-------
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EMISSION FACTORS
10/86
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Metallurgical Industry
7.10-3
-------
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
3
1
0
1
.0
.0
.0
.25
.0
1.8 -
0.5 -
0.25 -
0.06 -
0.06 -
3
1
0
0
0
.6
.9
.80
.20
.18
3.0 -
1.4 -
0.5 -
<0.
<0.
4.0
2.0
0.8
12
15
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0.2
0.5
<0
<0
.Ob
- 0
- 1
.06
.05
.8
.0
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 (bentonite) 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 contamination, 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 brittleness. At times, the molten metal
may be inoculated with graphite to adjust carbon content. The treated molten
iron is then ladled into molds and transported to 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 grid to shake the mold and core sand loose from the casting. In the
simpler foundries, molds, core sand and castings are separated manually, and
the sand from the 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 through the slag hole located above the level of the molten iron.
Electric arc and 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
Cupola
Electric arc furnace
Control
device
Uncontrolled'3
Scrubber0
Venturi scrubber^
Electrostatic
precipitator6
Baghouse^
Single wet capS
Impingement scrubberS
High energy scrubberS
Uncontrolled*1
BaghouseJ
Total Emission
particulate Factor
Rating
kg/Mg
6.9
1.6
1.5
0.7
0.3
4.0
2.5
0.4
6.3
0.2
Ib/ton
13.8
3.1
3.0
1.4
0.7
8.0
5.0
0.8
12.7
0.4
C
c
C
E
C
B
B
B
C
C
Electric induction
furnace
Reverberatory
Uncontrolled^
Baghouse™
Uncontrolled11
Baghousem
0.5
0.1
1.1
0.1
0.9
0.2
2.1
0.2
D
E
D
E
aExpressed as weight of pollutant/weight of gray iron produced.
bReferences 1,7,9-10.
cReferences 12,15. Includes averages for wet cap and other scrubber types not
already listed.
References 12,17,19.
eRef erences 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.
mReference 4.
nReference 1.
7.10-8
EMISSION FACTORS
10/86
-------
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EMISSION FACTORS
10/86
-------
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7.10-10
EMISSION FACTORS
10/86
-------
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10/86
Metallurgical Industry
7.10-11
-------
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7.10-12
EMISSION FACTORS
10/86
-------
z
UJ
o
(T
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Q.
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99.990
99.950
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99.80
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0.2
0.15
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0.0
TOTAL PARTI CULATE
EMISSION RATE
_ 6-9 Kg PARTICIPATE
Mg METAL
MELTED (PRODUCED)
i i i i 11
i i i 11
6.2
5.9
5.5
4.8
10° I01 I02
PARTICLE DIAMETER, micrometers
UJ
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tn
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V
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3.1 p
or
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Figure 7.10-3. Particle size distribution for uncontrolled cupola.21-22
10/86
Metallurgical Industry
7.10-13
-------
99.950
99.90
99.80
99.50
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PARTICLE DIAMETER, micrometers
7.10-14
Figure 7.10-4. Particle size distribution for
baghouse controlled cupola.13
EMISSION FACTORS
10/86
-------
I-
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UJ
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QL
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TOTAL PARTI CUL ATE , ^ kg PARTICIPATE
- EMISSION RATE LD Mg METAL
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PARTICLE DIAMETER, micrometers
ui
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2
ui
H
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2
a
o
Figure 7.10-5. Particle size distribution for venturi scrubber
controlled cupola.21-22
10/86
Metallurgical Industry
7.10-15
-------
UJ
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99.99U
99.950
99.90
99.80
99.50
99
98
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5
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0.5
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TOTAL PARTlCULATE = 2.1 Kg PARTlCULATE
. EMISSION RATE Mg M£TAL
MELTED (PRODUCED)
•
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PARTICLE DIAMETER, micrometers
Figure 7.10-7,
Particle size distribution for uncontrolled
pouring and cooling.25
10/86
Metallurgical Industry
7.10-17
-------
99.990
99.990
99.90
99.80
99.50
99
98
95
90
z
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70
60
50
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10
5
2
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0.5
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O.IS
O.I
TOTAL PARTICIPATE = 1.60
EMISSION RATE
0.0
10
kg PARTICIPATE
Mg METAL
P
MELTED/ (PRODUCED)
.0° 10 '
PARTICLE DIAMETER, micrometers
1.60
1.12
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N
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a
ui
UJ
0.70 O
0.67 p
0.66
u
UJ
10'
Figure 7.10-8. Particle size distribution for uncontrolled shakeout.26
7.10-18
EMISSION FACTORS
10/86
-------
REFERENCES FOR SECTION 7.10
1, Summary of Factors Affecting Compliance by Ferrous Foundries, Volume I;
Text, EPA-340/1-80-020, U. S. Environmental Protection Agency,
Washington, DC, January 1981.
2. Air Pollution Aspects of the Iron Foundry Industry, APTD-0806, U. S.
Environmental Protection Agency, Research Triangle Park, NC, February 1971.
3. Systems Analysis of Emissions and Emission Control in the Iron Foundry
Industry, Volume II; Exhibits, APTD-0645, U. S. Environmental Protection
Agency, Research Triangle Park, NC, February 1971.
4. J. A. Davis, et al., Screening Study on Cupolas and Electric Furnaces in
Gray Iron Foundries, EPA Contract No. 68-01-0611, Battelle Laboratories,
Columbus, OH, August 1975.
5. R. W. Hein, et al., Principles of Metal Casting, McGraw-Hill, New York,
1967.
6. P. Fennelly and P. Spawn, Air Pollution Control Techniques for Electric Arc
Furnaces in the Iron and Steel Foundry Industry^EPA-450/2-78-024, U. S.
Environmental Protection Agency, Research Triangle Park, NC, June 1978.
7. R. D. Chmielewski and S. Calvert, Flux Force/Condensation Scrubbing for
Collecting Fine Particulate from Iron Melting Cupola,EPA-600/7-81-148,
U. S. Environmental Protection Agency, Research Triangle Park, NC,
September 1981.
8. W. F. Hammond and S. M, Weiss, "Air Contaminant Emissions From Metallurgi-
cal Operations In Los Angeles County", Presented at the Air Pollution Con-
trol Institute, Los Angeles, CA, July 1964.
9. Particulate Emission Test Report On A Gray Iron Cupola at Cherryville
Foundry Works, Cherryville, NC, Department Of Natural And Economic Re-
sources, Raleigh, NC, December 18, 1975.
10. J. N. Davis, "A Statistical Analysis of the Operating Parameters Which
Affect Air Pollution Emissions From Cupolas", November 1977. Further
information unavailable.
11. Air Pollution Engineering Manual, Second Edition, AP-40, U. S, Environ-
mental Protection Agency, Research Triangle Park, NC, May 1973. Out of
Print.
12. Written communication from Dean Packard, Department Of Natural Resources,
Madison, WI, to Douglas Seeley, Alliance Technology, Bedford, MA, April
15, 1982.
13. Particulate Emissions Testing At Opelika Foundry, Birmingham, AL, Air
Pollution Control Commission, Montgomery, AL, November 1977 - January 1978.
14. Written communication from Minnesota Pollution Control Agency, St. Paul,
MN, to Mike Jasinski, Alliance Technology, Bedford, MA, July 12, 1982.
10/86 Metallurgical Industry 7.10-19
-------
15. Stack Test Report, Dunkirk 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 Paxton-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, Talladega, 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
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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 (Pb304 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 nonmetal 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 megagratns 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
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O
w
c
•H
4-1
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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 drossing 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 Controls*»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
Sweating1" Leaching0
Reverberatory
Smelting
Blast (cupola)d
Kettle Kettle Casting
refining oxidation
Partlculate6
Uncontrolled (kg/Mg)
tlb/ton)
Controlled (kg/Mg)
(Ib/ton)
Lead6
Uncontrolled (kg/Mg)
(Ib/ton)
Controlled (kg/Mg)
(Ib/ton)
Sulfur dioxide8
Uncontrolled (kg/Mg)
(Ib/ton)
Emission Factor Rating
16-35
32-70
4-8P
7-1&P
Neg*
N«g
Neg
Neg
Neg
Neg
Neg
Neg
Neg
162 (87-242)8 153 (92-207)h 0.02J
323 (173-483)«-8 307 (184-413)h O.Oii
0.50 (0.26-0.77)"
1.01 (0.53-1.55)"
32 (17-48)1
65 (35-97)1
1.12 (0.11-2.44)" Neg
2.24 (0.22-4.88)" Neg
52 (31-70)r 0.006J
104 (64-140)r O.OlJ
0.15 (0.02-0.32)8 Neg
0.29 (0.03-0.64)8 Neg
40 (36-44)» 27 (9-55)8
80 (71-88)" 53 (18-110)8
<40k
0.02J
0.04J
Neg
Neg
0.007J
O.OlJ
Neg
Neg
•Neg - negligible. Dash - not available. Ranges in parentheses.
''Reference 1. Estimated from sweating furnace emissions from nonlead secondary nonfetrous processing
industries. Based on quantity of material charged to furnace.
cReference 1.
''Blast furnace emissions are combined flue gases and associated ventilation hood streams (charging
and tapping).
eParticulate and lead factors baaed on quantity of lead product produced, except as noted.
fDetermined negligible, based on average baghouse control efficiency >99Z.
8References 8-11.
"References 8,11-12.
JReference 13. Lead content of kettle refining emissions is 40X
and of casting emissions is 36Z.
^References 1-2. Essentially all product lead oxide is entrained In an air stream and subsequently
recovered by baghouse with average collection efficiency >99Z. Factor represents emissions of
lead oxide that escape a baghouse used to collect the lead oxide product. Based on the amount of lead
produced and represents approximate upper limit for emissions.
•inferences 6,8-H.
"References 6,8,11-12,14-15.
PRaferences 3,5. Based on assumption that uncontrolled reverberatory furnace flue emissions are 23Z lead.
^Reference 13. Uncontrolled reverberatory furnace flue emissions assumed to be 23Z lead. Blast furnace
emissions have lead content of 341, based on single uncontrolled plant test.
rReference 13. Blase furnace emissions have lead content of 26Z, based on single controlled plant test.
•Based on quantity of material charged to furnaces.
7.11-4
EMISSION FACTORS
10/86
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TABLE 7.11-2. FUGITIVE EMISSION FACTORS FOR SECONDARY LEAD PROCESSINGa
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
L(
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.
References 3,5. Assumes 23% lead content of uncontrolled blast furnace
flue emissions.
dReference 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 (802)* 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
nitrogen. 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 %
O
O
t/i
oo
0.05 '£
0.625 1.0 1.25 2.50 6-0 10.0 15.0
Particle size (ym)
Figure 7.11-2. Emission factors less than stated particle size
for baghouse controlled blast furnace flue gases.
7.11-6
EMISSION FACTORS
10/86
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TABLE 7.11-4.
EMISSION FACTORS AND PARTICLE SIZE DISTRIBUTION FOR UNCONTROLLED
AND BAGHOUSE CONTROLLED BLAST FURNACE VENTILATION3
EMISSION FACTOR RATING: D
Particle
size*3
(urn)
Cumulative
< stated
mass %
size
15
10
6
2.5
1.25
1.00
0.625
Total
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.
°Expressed as equivalent aerodynamic particle diameter.
OJ
o
o
(_)
c
25
20
cn
S
^ 15
s_
o
o
ro
C
O
10
I I
_L
0.5
0.4
0.3
o.;
0.1
s_
o
1/1
I/I
0.625 1.0 1.25 2.5 6.0
Particle size (ym)
10.0 15.0
Figure 7.11-3.
Emission factors less than stated particle size for uncontrolled
and baghouse controlled blast furnace ventilation.
10/86
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 filter*3 Reverberatory 99.7
Settling chamber plus dry
cyclone plus fabric filter0 Reverberatory 99.8
Venturi scrubber plus demister^ Blast 99.3
aReference 8.
bReference 9.
cReference 10.
^Reference 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. Environ-
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 Particulace
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.-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
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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 (% 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 radiation, 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
-------
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00
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8.1-2
EMISSION FACTORS
10/86
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10/86
Mineral Products Industry
8.1-3
-------
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
-------
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Mineral Products Industry
8.1-5
-------
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.
8.1.2 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 of 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 10/86
-------
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 8.1-1 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 8.1-2
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
b c
Uncontrolled '
Precleaner
High efficiency cyclone
Spray tower
Baffle spray tower
Multiple centrifugal scrubber
Orifice scrubber
Venturi scrubber
Baghouse
22.5
7.5
0.85
0.20
0.15
0.035
0.02
0.02
0.01
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.
Reference 16. These factors differ from those given
in Table 8.1-6 because they are for uncontrolled
.emissions and are from an earlier survey.
Reference 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
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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 organics 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-
, cess.
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 mass $ stated
Cumulative particulate emission factors
S stated size
(pmA) Uncontrolled
2.5 5.5
10.0 23
15.0 27
Total mass
emission
factor
Condensable
e
organics
^* - TTnnnni-rrvl 1 oH fnnl- ml 1 ff\^
— •^— — uncontroj-ieu uon.troi.Lcu
Controlledf kg/Mg Ib/ton 10"3 kg/Mg 10"3 Ib/ton
11 0.14 0.27 0.53 1.1
32 0.57 1.1 1.6 3.2
35 0.65 1.3 1.7 3.5
2.5 4.9 4.9 9.8
3.9 7.7
.Reference 23, Table 3-35. Rounded to two significant figures.
Aerodynamic diameter.
Expressed in terms of emissions per unit weight of asphaltic concrete produced. Not
.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 99.8% 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
-------
3
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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 STACK4
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-butyr aldehyde)
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.
f+
.Expressed as g/Mg and Ib/ton of asphaltic concrete produced.
Mean 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 Conventional, permanent,
batch plant
Production rate,
Mg/hr (tons/hr) 160.3 ± 16% (177 ± 16%)
Mixer capacity,
Mg (tons) 3.6 (4.0)
Primary collector Cyclone
Secondary collector Wet scrubber (venturi)
Fuel Oil
Release agent Fuel oil
Stack height, m (ft) 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,
10(1):29-33, January I960.
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, NC,
February 1974.
16. Z. S. Kahn and T. W. Hughes, Source Assessment: Asphalt Paving Hot 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 mined 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 formed by
this process. The soft mud process is usually used with clay too wet for 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.4
CRUSHING
Awr»
STORAGE
(P)
PITT VPR T 7 TNP
(?)
SCREENING
(P)
FORMING
AND
CUTTING
FUEL
GLAZING
DRYING
(P)
HOT
GASES
~T
KILN
(P)
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
-------
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-------
TABLE 8.3-2. PARTICLE SIZE DISTRIBUTION AND EMISSION FACTORS FOR
UNCONTROLLED SAWDUST FIRED BRICK KILNS3
EMISSION FACTOR RATING: E
Aerodynamic particle
diameter (urn)
2.5
6.0
10.0
r
Cumulative weight %
<^ stated size
36.5
63.0
82.5
?otal particulate emission
Emission factor^
(kg/Mg)
0.044
0.076
0.099
factor 0.12C
aReference 13.
^Expressed as cumulative weight of particulate <^ corresponding particle
size/unit weight of brick produced.
cTotal mass emission factor from Table 8.3-1.
(U M
N «
V
1)
E
UNCONTROLLED
«— Weight percent
— Enis«ion factor
P)
3
H-
CO
CO
o
3
o.io Hi
to
O
rr
O
11
OQ
005 00
M to SO «O 70 M M 100
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 (^m)
2.5
6.0
10.0
r
Cumulative weight %
< stated size
24.7
50.4
71.0
'otal particulate emission
Emission factor^
(kg/Mg)
0.08A
0.17A
0.24A
factor 0.34AC
aReferences 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).
cTotal mass emission factor from Table 8.3-1.
0)
N
05
•d
«
to
•0
V
•
00
• H
-------
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 (yra)
2.5
6.0
10.0
T<
Cumulative weight %
£ stated size
0.2
0.4
7.0
Emission factor*5
(kg/Mg)
0.08
0.15
2.66
Dtal particulate emission factor 38C
1
References 11, 18.
^Expressed as cumulative weight of particulate £^ corresponding
particle size/unit weight of raw material processed.
cTotal mass emission factor from Table 8.3-1.
V
N
V »
K ™
*J "
J= M
.? -
»
«0 i
3 ,
B '
3 i
UNCONTROLLED
—•- Weight pcretnc
Eaission factor
PI
3
o
3
P>
n
00
OQ
40 M M 79 10 w :or
Particle diameter,pm
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/AS, 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 Description^"-'
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
-------
oc
o
o
to-I
SO
00
oc
o
<-> I
v>
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u
s
^
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3
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3
c
c
ox
0)
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CD
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2
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(0
U)
(0
CO
CO
CO
O)
8.6-2
EMISSION FACTORS
10/86
-------
preheater systems. A dry process kiln with a preheater system can use 50
percent less fuel than a wet process kiln.
8.6.2 Emissions And Controlsl~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 (862) 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 SC>2 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 vary, 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 NOx 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 NOx reacts with the alka-
line cement and thus is removed from the gas stream.
10/86 Mineral Products Industry 8.6-3
-------
tO
o
H
Pi
U
P-l
f^J
\f.
,
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01 M J3 01
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to oi -ni o
a, z M eu UH
X 01 M
00 CO U
. 01 C
n rH 01 O
01 01 C U
oo ^ u to cj
c to u to
•rt M 01
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co oi en o
a oo u
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•a u ox
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01 JS -H -C 4J CM
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8.6-4
EMISSION FACTORS
10/86
-------
TABLE 8.6-2. CONTROLLED PARTICULATE EMISSION FACTORS FOR
CEMENT MANUFACTURING3
Type
of
source
Wet process kiln
Dry process kiln
Clinker cooler
Control
technology
Baghouse
ESP
Multiclone
Multicyclone
+ 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
1.1
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
crusherc
Primary limestone
screen0
Secondary limestone
screen and crusherc
Conveyor transfer0
Raw mill system0»d
Finish mill systeme
Baghouse
Baghouse
Baghouse
Baghouse
Baghouse
Baghouse
0.00051
0.0010
0.00011 0.00022
0.00016
0.000020
0.034
0.017
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.
°Expressed as mass of pollutant/mass of raw material processed.
^Includes 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
-------
cfl
to
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r^
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ft
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U
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0
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<
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to H
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W PC
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< H
fJ CJ
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S3 S
PH CO
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CJ H
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(D
4)
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I
u
«
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c
1
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v4
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-^ <*J CN m PO rn
O O O O O O
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8.6-6
EMISSION FACTORS
10/86
-------
1000.0
.3
S
o
*
1°
o
•« "x
.2 5>
S
§1
_o
3
u
100.0
10.0
1.0
0.1
1.0
Figure 8.6-2.
Uncontrolled Wet Process Kiln
Uncontrolled Dry Process Kiln
^3) Dry Process Kiln with Multiclone'
ffi Wet Process Kiln with ESP
Dry Process Kiln with Baghouse
i i i til i i i ILI LI
100.0
10.0
O i.
3 V
o o>
1.0 1~
•S3
-O is*
.2 ~o
"2 o
0.1
0.01
10 100
Aerodynamic Particle Diameter (^tmA)
Size specific emission factors for cement kilns,
10/86
Mineral Products Industry
1.6-7
-------
10.0
5
o
§•* i.o
LU _*
O —
o <->
* x
-o —
O «
I I 0.1
O t/l
Ij
« ^~
ja
I
U
0.01
10
T
100
i I i i i r r
JO Uncontrolled Coolers
Coolers with Gravel Bed Filter
I I I I I I 11
I I i l i i i i
10.0
1.0 | «
o U
c
O O)
E 41
UJ N
J) T3
"o IT
o.i *
c
o
u
-------
TABLE 8.6-4. SIZE SPECIFIC EMISSION FACTORS FOR
CLINKER COOLERSa
EMISSION FACTOR RATING: E
Particle
sizeb
(urn)
2.5
5.0
10.0
15.0
20.0
Total mass
Cumulative mass %
< stated sizec
Cumulative emission factor
< stated sized
Uncontrolled Gravel bed filter Uncontrolled
0.54
1.5
8.6
21
34
emission factor
40
64
76
84
89
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 bed filter
kg/Mg
0.064
0.10
0.12
0.13
0.14
0.16f
Ib/ton
0.13
0.20
0.24
0.26
0.28
0.32f
aReference 8.
bAerodynamic diameter
CRounded to two significant figures.
<*Unit 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, et al., Atmospheric Emissions from the 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 Rlchtlinien,
Duesseldorf, West Germany, February 1967.
8. J. S. Kinsey, 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 Description1"^
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, limonlte, ilmenite, iron or steel)
or lightweight aggregate (with sintered clay, shale, slate, diatomaceous shale,
perlite, vermiculite, 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 the 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 Controls5"7
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
-------
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8.10-2
EMISSION FACTORS
10/86
-------
TABLE 8.10-1.
UNCONTROLLED PARTICULATE EMISSION FACTORS
FOR CONCRETE BATCHING
Source
Sand and aggregate transfer
to elevated bin''
Cement unloading to elevated
storage silo
Pneumatic0
Bucket elevator"1
Weigh hopper loading6
Truck loading (truck mix)6
Mixer loading (central mix)6
Vehicle traffic (unpaved road)£
Wind erosion from sand
and aggregate storage piles"
Total process emissions
(truck mix)J
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
0.28
O.li
0.20
Emission
Factor
Rating
E
D
E
E
E
E
C
D
E
aBased on a typical yd^ weighing 1.818 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.
bReference 6.
cFor 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
tests of similar controlled sources.
£From Section 11.2.1, with k - 0.8, s - 12, S - 20, W - 20, v - 14, and p -
100. VKT - vehicle kilometers traveled. VMT - vehicle miles traveled.
SBased on facility producing 23,100 mVyr (30,000 yd^/yr), with average truck
load of 6.2m^ (8 yd^) and plant road length of 161 meters (1/10 mile).
hFrom Section 8.19.1, for emissions <30 urn for inactive storage piles.
1Assumes 1,011 ra2 (1/4 acre) of sand and aggregate storage at plant with
production of 23,100 m3/yr (30,000 yd3/yr).
iBaaed 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 Oust 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 General!~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
1
ANNEALING
INSPECTION
AND
TESTING
CULLET
CRUSHING
RECYCLE UNDESIRABLE
GLASS
u
PACKING
STORAGE
OR
SHIPPING
10/86
Figure 8.13-1. Typical glass manufacturing process.
Mineral Products Industry
8.13-1
-------
GULLET
RAI MATERIALS
RECEIVING
HOPPER
V
SCREI
CONVEYOR
STORAGE BINS
MAJOR RAW MATERIALS
BATCH
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
-------
MFiMC* SlDt f»Ui
CLASS SUflFACf I* KlflMt
Figure 8.13-3. Side port continuous regenerative furnace,
ItFINCR SIOC till
/ 81111 tUIFACI IN
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 particulate 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-
cipitators 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.
8.13-4 EMISSION FACTORS 10/86
-------
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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. Most
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 and 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^
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.
bExpressed 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
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10/86
Mineral Products Industry
8.22-5
-------
s
g
5 » r I » 10 20 10 kO SO M '0 H 40 100
Particle dlawC*r, an
Figure 8.22-3. Particle size distributions and size specific emission
factors for indurating furnace waste gas stream from
taconite ore palletizing.
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 TAGONITE MINES3
Surface
material
Crushed rock
and glacial
till
Crushed taconite
and waste
Emission factor by aerodynamic
po
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, et al., Taconite Mining Fugitive^Emissions Study,
Minnesota Pollution Control Agency, Roseville, MN, June 1979.
8.22-8 EMISSION FACTORS 10/86
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10/86
Mineral Products Industry
8.24-5
-------
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
II M
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
%
%
%
%
%
m
ft
%
%
Mg
ton
kph
mph
"/
/a
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 latch 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
-------
CO
en
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10.1-2
EMISSION FACTORS
10/86
-------
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.-*~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 10.1-7. 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 tank 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
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10/86
Wood Products Industry
10.1-5
-------
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
90 -
80
fe~ 70
tJi
£s
= -0 60
OJ u_
^ o 40
Si 30
c
3
20
10
0
0.1
Uncontrolled
Controlled
1.0 10
Particle diameter (pm)
1.0
0.9
0.8
°-7 S-Z
I*
°'6 13
0.5 -2 I
0.4 | °
£^>
0.3 Ji
0.2
0.1
_LL
100
Figure 10.1-2. Cumulative particle size distribution and size
specific emission factors for recovery boiler
with direct contact evaporator and ESP.
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
Uncontroll ed
_
-
-
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.
150
S-5 100
*• a.
^3 O
50
Controlled
I I I I I I I I I
Uncontrolled
I I I I I I I II
I I I I I I I I
1.0
0.9
O.S
0.7 o-
•g.
«•-
0.6 =
0.1
1.0 10
Particle diameter (pm)
100
0.3
0.2
0.1
0
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 % <
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
Reference 7.
30
.§?
S 5
I.!:
i:
~ o
20
10
Controlled
Uncontrolled
0.3
2|
0.2-2 S-
Particle diameter (urn)
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 LO.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
aReference 7.
30
20
•£•8
I/I •«-
"3°
in
10
0.1
Controlled
i i i i i ill
Uncontrolled
i i i i t i i i
1.0 10
Particle diameter (urn)
i i i ii il o
0.3
0.1
100
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.
.2 *
0.1
Controlled
Uncontrolled
0.6
I I I I I I II
1.0 10
Particle diameter (urn)
I I I I I I 11
0.5
0.4
100
§1
0-2 If
0.1
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 SCRUBBER21
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
aReference 7.
4 _
0.1
Controlled
I I I I I 11II
Uncontrolled
J I I I I I 111
1.0 10
Particle diameter (pm)
1.0
0.9
0.8
0.7 >-_
2 a-
0.6
§2
0.5 I .
•a»4_
0.4 ^ °
"if
0.3 oi
<_i
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
-------
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CO
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10.1-12
EMISSION FACTORS
10/86
-------
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 SC>2 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 S(>2 from this source by as much as 99 percent.
10/86 Wood Products Industry 10.1-13
-------
Another 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 SC>2 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 S02- 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 chemcials. 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 PULPINGa
Source
Digester/blow pit or
dump tankc
Recovery system6
Acid plantf
Otherh
Base
All
MgO
MgO
MgO
MgO
NH3
NH3
Na
Ca
MgO
NH3
Ma
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
Multlcyclone and venturi
scrubbers
Ammonia absorption and
mist eliminator
Sodium carbonate scrubber
Scrubber
Unknown^
Jenssen scrubber
None
Emission factorb
Particulate
kg/ADUMg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
1
0.35
2
Neg
Neg
Neg
Neg
Ib/ADUT
Neg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
Neg
2
0.7
4
Neg
Neg
Neg
Neg
Sulfur dioxide
kg/ADUMg
5 to 35
1 to 3
0.5
0.1
0
12.5
0.2
1
33.5
4.5
3.5
1
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
1
Emission
Factor
Rating
C
C
B
B
A
D
B
C
C
A
B
C
C
D
C
D
•Reference 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 (tag) of pulp.
c?actors represent emissions after cook is completed and when digester contents are discharged into blow pit or
dump tank. Some relief gases are vented from digester during cook cycle, but these are usually transferred to
pressure accumulators and SO2 therein reabsorbed for use in cooking liquor. In some mills, actual emissions
will be Intermittent and for short periods.
dMay include such measures as raising cooking liquor pH (thereby lowering free S02), 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 tower, and S02 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 before
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 Sulflte 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, JL9_
(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.1~2 xhe 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.^"^ 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^:
7
(kg/VKT) (1)
E = 0.077 I gj UM (T^ m "" (Ib/VMT)
where: E = emission factor
I = industrial augmentation factor (dimension!ess) (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 smelting
Iron and steel
production
No. of No. of Silt (Z, v/w)
Sites Samples Range Mean
1 3 [15.4-21.7] [19.0]
6 20 1.1-35.7 12.5
No. of
Travel
lanes
2
2
Silt loading
Total loading x 10~3
Range
[12.9-19.5]
145.8-69.2]
0.006-4.77
Mean
[15.9]
[55.4]
0.495
UnitsO
kg/km
Ib/mi
kg/km
(g/m2)
Range
[188-400]
0.09-79
Mean
[292]
12
Asphalt batching
Concrete batching
Sand and gravel
processing
[2.6-4.6] 13.3]
[5.2-6.0] [5.5]
[6.4-7.9] [7.1]
[12.1-18.0] [14.9] kg/km
[43.0-64.0] [52.8] Ib/mi
[1.4-1.8]
(5.0-6.4]
[1.7] kg/km
[5.9] Ib/mi
[2.8-5.5] [3.8] kg/km
[9.9-19.4] [13.3] Ib/mi
[76-193] [120]
[11-12] [12]
[53-95] [70]
"References 1-5. Brackets Indicate value* based on only one plant test.
^Multiply 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
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.l-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.l-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.1-30
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 Gi n Gin Stand TBA
Roller Gin Bale Press TBA
Saw Gin Bal e 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.1-52
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.1-72
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.1-82
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 Nomnetallic 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 and 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
0)
N
90
80
0)
V
*•«
70
50
jC
_ j 40
•M
§30
2 20
10
2
1
0.5
0.1
0.01
CONTROLLED
-•— Weight percent
Emission factor
1.5
M
H-
03
0)
O
a
1.0 CD
O
rr
O
i-l
(ff
0.5
* 5 6 7 8 9 10 20 30
Particle diameter, urn
0.0
40 50 60 70 80 90 100
Aerodynamic
particle
diameter, um
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 impactor.
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
-------
2.1 REFUSE INCINERATION: MUNICIPAL WASTE MASS BURN INCINERATOR
01
N
0)
13
01
jj
CO
CO
V
X
4J
A
bo
g
01
•H
a
r-t
|
o
99.99
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
1
0.5
0.1
Om
UNCONTROLLED
• Weight percent
— — — Emission factor
w
»
-
-
»
^^j*
^- — •*
• — "
/
/
/
t
^s
^ '
^ ** —
»
b
10.0
w
8.0 H-
CO
03
H-
0
9
^*
(B
o
ft
o
"^
6-° JT
J
4.0
2.0
1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt . % < stated size
Uncontrolled
26.0
30.6
38.0
Emission factor, kg/Mg
Uncontrolled
3.9
4.6
5.7
C.l-8
EMISSION FACTORS
10/86
-------
2.1 REFUSE INCINERATION: MUNICIPAL WASTE 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
M.9
99
9*
0)
N 95
•O 90
V
V 70
»* w
£ 50
bo
"aj *°
* 30
0)
> 20
4J
cd
J"
2
1
0.5
0.1
0.01
y
UNCONTROLLED
-•— Weight percent
Emission factor
10.0
M
8.0 CD
03
H-
O
a
PI
o
o
1-1
6.0 ?r
4.0
2.0
45678910 20 30
Particle diameter, urn
40 MM 70 MM IOC
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. %): 34.5 35.9 37.5
Max (Cum. %): 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 101.2% 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.I-11
-------
4.2.2.8 AUTOMOBILE & LIGHT DUTY TRUCK SURFACE COATING OPERATIONS:
AUTOMOBILE SPRAY BOOTHS (WATER BASE ENAMEL)
9)
N
oo
-o
0)
4J
03
iJ
00
V
x
4J
M
•H
s
>
«
*2
3
a
s
O
99.99
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
1
0.5
0.1
On i '
•
.M
-
m
_
X
/
'
• ' •
X
" X ^^
/^^^^^
•^^^^^
/'
/
^
~
-
CONTROLLED
-•- Weight percent
Emission factor
ft 1 1 1 1 1 i 1 ft I 1 Illlil
3.0
M
g.
0)
tn
H-
O
a
2.0
£»
O
rr
O
^
?r
00
E<
Oq
1.0
0.0
1 " 2 3 4 5 6 7 a 9 10 20 30 40 50 60 70 80 90 IOC
Particle diameter, um
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. % < stated size
Water curtain controlled
28.6
38.2
46.7
Emission factor, kg/Mg
Water curtain controlled
1.39
1.85
2.26
C.l-12
EMISSION FACTORS
10/86
-------
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
99.9
99
98
co
•B 90
4J
CO 80
4J
CO
70
I,"
cu
* 30
£20
H 10
0 5
2
1
O.S
0.1
0.01
S
UNCONTROLLED
—•— Weight percent
Emission factor
1.75
1.50
M
B.
CO
CO
O
3
03
r>
00
1.25
1.00
4 5 4 7 » 9 10 10 30
Particle diameter, urn
40 50 W 70 80 90 100
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
87.3
95.0
97.0
Emission factor, kg/Mg
Uncontrolled
1.40
1.52
1.55
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)
99.99
99.9
99
98
N
» 90
•o
0)
J-l 80
U
tO 70
V 60
50
1 4°
CU 30
3
r>
f^
o
1.0 ^
c?
0.5
0.0
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 particulate 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
99
98
95
N
W 90
•O
« 80
CO
V
4J
bo
•H
$
>
•H
JJ
«
70
60
50
40
30
20
0.1
0.01
UNCONTROLLED
Weight percent
3 4 56789 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
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 (urn)*: 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 urn in diameter.
10/86 Appendix C.I C.l-23
-------
5.17 SULFURIC ACID: SECONDARY ABSORBER
».99
99.9
99
98
0)
N 95
90
4)
4J
2
GO
60
50
40
s
* 30
V
> 20
60
10
1
0.5
0.1
0.01
UNCONTROLLED
Weight percent
4 5 6 7 8 9 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
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. %):
TOTAL PARTICIPATE 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/m^.
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
0) 95
N
•H
co
90
V
4J
CO 80
4J
00
70
V
kg 60
•U 50
JS
*H
2 30
^
•H
U
cd
rH 10
3
B
3 ,
0 5
2
1
0.3
0.1
Orti
UNCONTROLLED
— •— Weight percent
Emission factor
CONTROLLED
— •- Weight percent
-
•
•«
m
"
—
/
[ /
/
1
I ^
_
** / j*^*^
^^*^
^^9ff _^r
^ "/x^
/r
;/ '
.s / _
jr
* j' ^
* /
/
1 1 lltlllt 1 I 1 1 1 1 1 1
0.5
0.4
M
a
CO
CD
H-
0
9
Hi
0.3 £
rr
O
OQ
J
0.2
0.1
0.0
1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 IOC
Particle diameter, urn
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
0.3
3.3
6.9
Fabric filter
3.3
6.7
10.6
Emission factor, kg/Mg
Uncontrolled
0.01
0.14
0.29
Fabric filter
controlled
0.004
0.007
0.011
C.l-26
EMISSION FACTORS
10/86
-------
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. %):
Min (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 rate.
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
n
pf
o
i-t
2.0
1.0
56789 10
20
0.0
30 40 50 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter (urn)
2.5
6.0
10.0
Cumulative wt. TL < stated size
Uncontrolled
0.95
2.46
4.07
High pressure
drop venturi
scrubber
5.0
7.5
9.0
Emission factor
(kg/Kg)
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 (urn): 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 (urn): 2.5 6.0 10.0
Mean (Cum. %): 5.0 7.5 9.0
Standard deviation (Cum. %):
Min (Cum. %):
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 potassium
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, Trona, 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
99.99
99.9
99
98
95
0)
N
•H 90
CO
V 80
CO
W 70
00
V *°
X 50
j- *0
•H1 30
a
20
0)
>
±J 10
<0
3
8 5
9
0
2
1
0.5
0.1
w
-
m
.
B
"
.s*
^*^s
.*^ /
^^^ /
fc ^^^^ s
*^ ^
/
• /
/
/
*
'
/
/
lfc
•
-
CONTROLLED
• Weight percent
Emission factor
•>/>
Particle diameter, um
Aerodynamic Cumulative wt. % < stated size
particle
diameter (um) Controlled with fabric filter
2.5 18.0
6.0 32.0
10.0 43.0
30 40 50 oO 70
_
.
-
-.
0 . 025
0.020
w
PL
00
00
H-
O
a
H>
0.015 »
n
rt
O
^
7f
OP
^
j?
w
0.010
0.005
0
BO 90 1.00
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. %): 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: E
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, CA, 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
•H
00
90
•O
5 so
30
« ,0
«*H
at
3 30
« :c
§
O
0.',
UNCONTROLLED
—•- Weight percent
Emission factor
o
3
n
rr
O
o.o
.0 :0 sC '0 3C ^0 100
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
00
W.M
99.9
99
98
95
90
01 80
4J
«
tt 7°
v to
K SO
je *o
bo
1 "
* 20
2
1
0.5
0.1
0.01
CYCLONE
—•— Weight percent
Emission factor
CYCLONE AND WET SCRUBBER
• Weight percent
• • • Emission factor
o.ioo
B
CO
co
H-
O
9
o
0.050 o
€
o-
(to
.006
0.003
5 6 7 8 9 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
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): 2.5 6.0 10.0
a) Mean (Cum. %): 8 33 62
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Mean (Cum. %): 11 26 52
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
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 86%. 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 Impactor
EMISSION FACTOR RATING: E
REFERENCES:
a) Emission test data 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
o>
N
01
4-1
(0
4J
00
V
§
V
•H
4J
0)
r-{
3
99.99
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.1
0.01
CYCLONE
• Weight percent
Ealidon factor
CYCLONE AND WET SCRUBBER
—•—Weight percent
0.3
ff
H-
0)
01
H-
o
9
0.2 n
rr
O
Q>
M
fl>
O.i
5 6 7 8 9 10
20
30 40 50 60 70 80 90 IOC
Particle diameter, urn
Aerodynamic
particle
diameter (urn)
2.5
6.0
10.0
Cumulative wt. % < 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.l-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. %): 1 20 54
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 11 74 92
Standard deviation (Cum. %):
Min (Cum, %):
Max (Cum. %):
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
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS:
CAROB KIBBLE ROASTER
99.99
99.9
99
98
N
-.- 1
» 90
-o
01
•u 80
W 70
M 6°
50
jj
§ 40
S 30
0) 20
•H
n) 10
rH
3
O
2
1
0.5
0.1
0.01
-
^™
-
"
'
\
.
/
/
/
^f
1
1
1 r
~ "" ~ UNCONTROLLED
-•— Weight percent
Emission factor
0.75
Emissd
o
3
HI
0.50 0>
0
0
*
OP
£
0.25
0.0
3 4 5 6 7 8 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
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
-------
6.4 FEED AND GRAIN MILLS AND ELEVATORS:
CEREAL DRYER
99.9
99
98
3 95
CO
•0 90
^J
SO go
4J
co
v 70
»•* 60
g 4°
* 30
£20
•H
Cumula t
»—
Ln O
2
1
0.5
0.1
0.01
-
~~
^
-
~
; ^^^~^
'
•
^ '
.
O
ft
O
rl
10
cw
0.25
0.0
3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, urn
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
01 95
N
CO
TJ
0)
90
70
V
jj 50
JS
B
o
10
2
1
0.5
0.1
0.01
6.4 FEED AND GRAIN MILLS AND ELEVATORS:
GRAIN UNLOADING IN COUNTRY ELEVATORS
y
UNCONTROLLED
—•— Weight percent
Emission factor
1.5
S"
H-
w
CO
H-
O
9
1.0 Hi
P)
n
pr
O
0.5
0.0
3 4 5 6 7 8 9 10 20 30
Particle diameter, urn
40 50 60 70 80 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
0)
N
•H
CO
TJ
CO
CO
V
•H3
Q>
CU
I
U
99.99
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
1
0.5
0.1
0.01
UNCONTROLLED
• Weight percent
———Emission factor
0.4
0.3
CO
CO
s-
3
Hi
0)
rr
O
i-t
Jf
0.1
4 5 6 7 8 9 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
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);
Mean (Cum. %):
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
2.5
6.0 10.0
16.8
6.9
9.9
23.7
41.3
16.3
25.0
57.7
69.4
27.3
42.1
96.6
TOTAL PARTICULATE 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 unloader 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
99.99
99.9
99
98
8 •>
•^
CO
"S 9°
4J
R) 80
M
v 70
X 60
i: 50
bo
•H 40
* 30
CU
> 20
•H
U
CO
•3 10
3
•3
O 5
2
1
0.5
0.1
0. 01
/
t
I
'
/ ^
/
'
/
/
'
/
/
/
/
/
^
f ~*
1
\ •
i
i
t •
/ ^
i /
t s
* i /
i /
i ^^
i^^^ —
^^t^
- IT f
1
1
4
UNCONTROLLED
-•— Weight percent
Emission factor
2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90
0.015
M
B
en
(B
0
a
It!
0.010 0)
f)
rr
0
"
ff
^^
rio
TO
0.005
0.00
100
Particle diameter, urn
Aerodynamic
Particle
diameter, urn
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 PARTICIPATE 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
70
0.1
0.01
UNCONTROLLED
Weight percent
Emission factor
30
M
5
H-
0)
CO
H-
o
3
20
O
i-t
10
S 6 7 8 9 10 20 30
Particle diameter, urn
40 SO 60 70 80 9O 100
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 Impactors
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
-------
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 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-57
-------
7.1 PRIMARY ALUMINUM PRODUCTION: BAUXITE PROCESSING
UNLOADING ORE FROM SHIP
99.99
99.9
99
98
01
N 95
90
8°
v
70
*4 60
2 5°
bO
1
3 30
0)
> 20
•H
JJ
*
7J 10
0.1
0.01
CONTROLLED
—•- Weight percent
Emission factor
0.0075
0
H-
05
9)
H«
O
0.0050 *
€
sc
TO
0.0025
0.00
4 5 6 7 8 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
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
*9.99
99.9
99
98
90
g
•H
CO
13
01
CO 80
u
0)
V
70
•u SO
0)
3 30
» ,0
1
U
10
3
2
1
0.5
0.1
0.01
UNCONTROLLED
-•— Weight percent
Emission factor
15
B
h*
01
O
3
HI
10 B)
O
5 6 7 8 9 10 20 30
Particle diameter, um
40 SO 60 70 80 90 100
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 (urn): 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
99.9
99
98
95
•H 9°
CO
T3 80
01
1 J
«0 70
JaJ
to
60
V
50
• I 40
_£.
bO 30 .
«1
9 20
q)
•H 10
4J
<
-------
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. %):
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 8260 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
-------
7.15 STORAGE BATTERY PRODUCTION: GRID CASTING
CO
«
4J
03
V
t>0
•H
(U
0)
99.9
99
98
95
90
"S 80
70
60
50
40
30
20
jj 10
i-t
I '
2
1
0.5
0.1
0.01
UNCONTROLLED
—*~~ Weight percent
Emission factor
J—t_j_
j_
j.
2.0
m
00
0)
o
1.0
(0
1
A
00
.5
3 * 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter (urn)
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 (urn): 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. %): 100 100 100
Impactor cut points were so small that most data points had to be
extrapolated.
TOTAL PARTICULATE 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:
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
99.99
99.9
99
98
95
N
« 90
X)
-------
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 kg 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 acfm.
SAMPLING TECHNIQUE: Brinks Impactor
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
0)
N
•H 90
00
0) 80
±J
(0
4J 70
00
\x 6°
»* 50
JS 40
bO
•H 30
4)
* 20
SI
•H
JJ 10
<0
*"H
3 5
0
2
1
0.5
0.1
Oni
• Ul
Aerodynamic
particle
diameter (u
2.5
6.0
10.0
.
_
/
1
^ '
/
1
1 V*
/ /
1 :/
" Js
jf
" /I
/
" J/ ^
I/ 1
/
i
^
I
1
M /
/
„
"
2 3 4 56789 10
Particle dlamet*
Cumulative wt. % < stated size
m) After fabric filter
32.8
64.7
83.8
-
-
—
—
_
CONTROLLED
*— Weight percent
— Emission factor
20 30 40 50 60 70 80 90
sr, urn
Emission factor
(kg/103 batteries)
After fabric filte
0.016
0.032
0.042
0.05
M
9
0.0* »
L^
o
9
i-h
BJ
n
rt
0
i-i
0.03 -
£
"^
^•*
0
cr
09
rt
0.02 (?
H-
00
0.01
0
100
r
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
0)
N
•O
0)
4-1
(0
4_l
CO
V
bo
•H
V
99.99
99.9
99
98
95
90
80
70
60
50
40
30
20
10
0.1
0.01
UNCONTROLLED
—•—Weight percent
Emission factor
CONTROLLED
—•—Weight percent
JL
-I L
_L
M
H-
2.0 CO
CO
p.
o
01
o
rt
o
l-i
-------
7.15 STORAGE BATTERY PRODUCTION: PASTE MIXING & LEAD 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 (urn): 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, InctJ 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
01
N
•H
oo
TJ
0)
4-1
CO
V
43
bO
•H
-------
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
99.9
99
98
Ol 95
•H
03
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 PARTICULATE 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 III 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
cy
N
00
TJ
01
4-1
CO
co
V
»•*
f.
bo
01
>
•H
jj
0)
1-t
0
99.99
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
1
0.5
0.1
n ni
-
_
.
-
.
-
^
f
- y
f
/
X
X
X
x ^m
' ^^^^ ~
m^*~^
-
-
" ^^
^
CONTROLLED
— •- Weight percent
Emission factor
i i i i i i i i i i i i i i i i i
0.004
tfl
0.003 9,
CO
CO
H-
O
a
l"t)
o>
O
rr
O
•
0.002 ff
0?
0.001
0.00
3 4 5 6 7 8 9 10 20 30 40 SO 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt . % < 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
99.99
99.9
99
98
n
rr
O
n
JT
1.0
3 4 5 6 7 8 9 10 20 30
Particle diameter, um
40 50 60 70 80 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
-------
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 wet
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
-------
8.9 COAL PROCESSING: THERMAL INCINERATOR
rt.99
99.9
99
98
20
CO
10
3
O 5
2
1
0.5
0.1
0.01
UNCONTROLLED
- Weight percent
- Emission factor
CONTROLLED
- Weight percent
0.4
W
CO
H-
O
3
0)
n
00
0.2
0.0
3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. % < stated size
Uncontrolled
9.6
17.5
26.5
Cyclone
controlled
21.3
31.8
43.7
Emission factor, kg/Mg
Uncontrolled
0.07
0.12
0.19
C.l-80
EMISSION FACTORS
10/86
-------
8.9 COAL PROCESSING: THERMAL INCINERATOR
NUMBER OF TESTS: a) 2, conducted before controls
b) 2, conducted after multicyclone control
STATISTICS: a) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 9.6 17.5 26.5
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
b) Aerodynamic particle diameter (um): 2.5 6.0 10.0
Mean (Cum. %): 26.4 35.8 46.6
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICIPATE EMISSION FACTOR: 0.7 kg particulate/Mg coal dried, before
multiclone control. Factor from AP-42.
•SOURCE OPERATION: Source is a thermal incinerator controlling gaseous emissions
from a rotary kiln drying coal. No additional operating data are available.
SAMPLING TECHNIQUE: Andersen Mark III Impactor
EMISSION FACTOR RATING: D
REFERENCE:
Confidential test data from a major coal processor, PEI Associates, Inc.,
Golden, CO, January 1985.
10/86 Appendix C.I C.l-81
-------
8.18 PHOSPHATE ROCK PROCESSING: CALCINER
0)
N
00
99.9
99
98
95
90
"S 80
id
GO
v
bo
•H
01
4J
eg
70
60
50
40
30
20
1.0
2
1
0.5
0.1
0.01
CYCLONE AND WET SCRUBBER
• Weight percent
Emission factor
0.075
pa
CD
01
O
a
0.050
O
o
1-1
£
0.025
3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
After cyclone8 and
wet scrubber
94.0
97.0
98.0
Emission factor, kg/Mg
After cyclone3 and
wet scrubber
0.064
0.066
0.067
aCyclones are typically used in phosphate rock processing as product collectors.
Uncontrolled emissions are emissions in the air exhausted from such cyclones.
C.l-82
EMISSION FACTORS
10/86
-------
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. %): 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
4)
N
•H
00
0)
JJ
(0
on
V
K
4=
00
•H
91
3
>
4J
i-H
O
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
1
0.5
0.1
0.01
-
-
"
^^f^
*s^^
* y*^
^^^
^^"^ ^ '
' —^***'^ "^
Wi ,/
**
* -"
^. ^* *"
*""" —
•
*m
-
^
IM>
WET SCRUBBER AND ESP
_ • Weight percent
Emission factor
» • ..,,!,. , . . 1 , , . ,
0.015
rt
3
H*
CO
CO
H-
o
3
Hi
0.010 CO
n
0
l-t
«.
yf
00
CM
0.005
0
3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
After wet scrubber and
ESP control
78.0
88.8
93.8
Emission factor, kg/Mg
After wet scrubber and
ESP control
0.010
0.011
0.012
C.l-84
EMISSION FACTORS
10/86
-------
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 PARTICIPATE 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
cu
(4
99.9
99
98
95
90
•O
CU 80
U
CO
% ?°
V
bC
V
81
JJ
<0
60
50
40
30
20
10
5
2
1
0.5
0.1
0.01
CYCLONE
-•— Weight percent
Enigsion factor
CYCLONE AND WET SCRUBBER
-•—Weight percent
• • • Enlaalon factor
1.5
,
i.o
«
H-
CO
00
H-
o
9
O
rr
O
OQ
0.5
0.02
HO.01
3 4 56789 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
After
cyclone3
15.7
41.3
58.3
After
wet scrubber
89
92.3
96.6
Emission factor, kg/Mg
After
cyclone3
0.38
1.00
1.41
After
wet scrubber
0.017
0.018
0.018
aCyclones are typically used in phosphate rock processing as product collectors.
Uncontrolled emissions are emissions in the air exhausted from such cyclones.
C.l-86
EMISSION FACTORS
10/86
-------
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 diameter (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 particulate 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
99.9
99
98
95
D
N
•H 90
CO
"S 8°
10
4J 70
co
v 60
»-? 50
£ 40
$ 30
0)
* 20
cu
>
JJ 10
te
1 5
o
2
1
0.5
0.1
In i
. U 1
-
-
.
^
.s^
.s^
~>^ /
^^^ f
^>^ /
^^ /
/
s
/ CYCLONE
• Weight percent
Emission factor
2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90
0.4
M
(L
CO
CO
o
3
P)
n
pr
0
n
K
Oq
00
0.2
Q
100
Particle diameter, urn
Aerodynamic
particle
diameter , urn
2.5
6.0
10.0
Cumulative wt. % < stated size
After cyclone3
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-J
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. %): 3.5 0.9 2.6
Min (Cum. %): 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 101% 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: ROLLER MILL AND BOWL MILL GRINDING
99.99
0)
N
CO
•o
CO
v
f.
00
•H
0)
I
CJ
99.9
99
98
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.1
0.01
CYCLONE
>— Weight percent
— Emission factor
CYCLONE AND FABRIC FILTER
I—Weight percent
1.5
PL
(D
CO
O
3
1.0 tt
O
iff
0?
0.5
3 4 56789 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
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. %): 1.0 1.0 0
Min (Cum. %): 20.0 44.0 62.0
Max (Cum. %): 22.0 46.0 62.0
b) Aerodynamic particle diameter (urn): 2.5 6.0 10.0
Mean (Cum. %): 25 70 90
Standard deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
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 100% of design
process rate. Source operates 1 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
-------
99.99
99.9
99
98
01 95
N
•H
50 90
80
70
V
60
*S
4j 50
4=
bO 40
i> 30
<1) 20
I0
3
O
1
0.5
0.1
0.01
8.xx NONMETALLIC MINERALS: FELDSPAR BALL MILL
UNCONTROLLED
—•- Weight percent
Emission factor
8.0
M
9
6.0
O
3
i-h
0)
O
rr
O
*.o
&
2.0
3 4 56789 10 20
Particle diameter, um
0.0
30 40 50 60 70 80 90 100
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
V 95
N
•O
0)
4_l
CO
V
90
80
70
60
4j 50
f,
bO 40
S 30
H 10
i
0.5
0.1
0.01
CONTROLLED
-•— Weight percent
Emission factor
ft II
0.4
M
0)
CO
H-
o
3
i-h
01
n
Jf
0.2
0.0
5 6 7 8 9 10 20 30 40 50 60 70 80 90 100
Particle diameter, urn
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. % < stated size
After fabric filter control
10
30
48
Emission factor, kg/Mg
After fabric filter control
0.04
0.11
0.18
C.l-94
EMISSION FACTORS
10/86
-------
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
S 95
01
4-1
90
80
09
V
70
o 60
U 50
C
bp 40
"rH
S 30
J> :o
10
I
0.5
O.J
0.01
WET SCRUBBER and
SETTLING CHAMBER
-•— Weight percent
— Emission factor
WET SCRUBBER
-•— Weight percent
2.0
W
a
H-
O
1.0
3 4 5 6 7 8 9 10 20
Particle diameter, urn
30
0.0
40 50 60 70 SO 90 100
Aerodynamic
particle
diameter (um)
2.5
6.0
10.0
Cumulative wt. % < stated size
Wet scrubber
and settling chamber
55
65
81
Wet
scrubber
55
75
84
Emission factor (kg/Mg)
Wet scrubber
and settling chamber
0.97
1.15
1.43
C.l-96
EMISSION FACTORS
10/86
-------
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. %): 55 65 81
Standard Deviation (Cum. %):
Min (Cum. %):
Max (Cum. %):
TOTAL PARTICIPATE 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
99.99
99.9
99
98
0) 95
N
t^J
w 90
T3
01
« 80
<0
4-1
» 70
V
60
8s?
4J 5°
"§> 40
•H
* 30
*
0) 20
•H
« 10
9
§ 5
O
2
1
0.5
0.1
0.01
1
-
-
jf
/
/
" /
^/
f
/
/ /
" / /
/ /
/ /
^ ^/ s
/
/
/
/
/
/
X
/
/
. /
„
„
UNCONTROLLED
— •— Weight percent
Emission factor
2 J 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90
40
W
g
H-
co
CO
H-
O
3
l-h
0)
0
rt
O
1-1
7T
00^
TO
20
0
IOC
Particle diameter, urn
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 OPERATION: 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
99.99
99.9
99
98
V Qt
N "
CO
•O '°
01
4J
1C 80
CO
V
70
50
» 30
£ 20
iH 10
3
U 5
7
1
0.5
0.1
0.01
MULTICLONE CONTROLLED
-•— Weight percent
Emission factor
FABRIC FILTER
—•- Weight percent
0.15
W
a
CO
CO
H-
O
D
0.10 (tt
n
rt
O
n
OQ
0?
0.05
0.0
4 5 6 7 8 9 10 20
Particle diameter, urn
30 40 50 60 70 30 90 100
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt . % < stated size
Multi clone
19.3
38.1
56.7
Fabric filter
39
48
54
Emission factor, kg/Mg
Multi clone
0.03
0.06
0.09
C.1-100
EMISSION FACTORS
10/86
-------
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 (urn): 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 Industries,
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
96
4J
10 80
CO
70
V
X 60
u 50
|*o
» 30
£ 20
•H
4J
CD
r-l 10
0 5
2
1
0.5
0.1
0.01
CONTROLLED
-*- Weight percent
Emission factor
i i
§ § • i • i
i i i
0.05
0.03
M
H-
CO
09
0.01
3 4 5 6 7 8 9 10 20 30
Particle diameter, urn
o.o
40 50 60 70 80 90 100
Aerodynami c
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. % < stated size
Settling chamber control
8.2
17.6
25.6
Emission factor, kg/Mg
Settling chamber control
0.007
0.014
0.020
C.1-102
EMISSION FACTORS
10/86
-------
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
9t
•o "
t)
iJ
(0 80
u
09
70
60
V
*•!
JJ so
§40
V
» 30
£20
r-l 10
O 5
2
1
0.5
0.1
0.01
UNCONTROLLED
—•— Weight percent
Emission factor
CONTROLLED
-*- Weight percent
40
09
05
to
o
rt
o
rt
(ff
20
5 6 7 8 9 10
20
30 40 SO 60 70 80 90 IOC
Aerodynamic
particle
diameter, urn
2.5
6.0
10.0
Cumulative wt. 7, < 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 (um): 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.1-105
-------
8.xx LIGHTWEIGHT AGGREGATE (SLATE): RECIPROCATING GRATE CLINKER COOLER
99.99
N
•H
CO
CO
99
98
95
90
M
70
»*e *°
4-1 50
•H *°
V
» 30
« 20
3 10
g
2
1
0.5
0.1
0.01
CONTROLLED
•— Weight percent
— Emission factor
llift
0.2
M
H
CO
CO
H-
O
9
O
i-t
Oq
0.1
0.0
3 4 5 6 7 • 9 10 20 30 40 50 60 70 W 90 100
Particle diameter, um
Aerodynamic
particle
diameter, um
2.5
6.0
10.0
Cumulative wt. % < 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
NUMBER OF TESTS: 5, conducted after settling chamber control
STATISTICS: 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. %):
TOTAL PARTICIPATE EMISSION FACTOR: 0.22 kg particulate/Mg of raw material
feed. Factor calculated from data in reference.
SOURCE OPERATION: Source produces lightweight slate aggregate in a cool fired
kiln 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
temperatures 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
-------
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 1000.
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
-------
•H
30
20
73 10
O 5
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
-9~ Weight percent
3.0
M
9
H>
-------
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. 7=) :
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, particulate 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 m^/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 Emission 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:
AP-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 (urn)
Generic distribution, Cumulative
percent equal to or less than the size:
Cumulative mass _< particle size emissions
(tons/year):
< 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 urn 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
Sectio
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
5.8
5.10
5.11
5.12
5.16
5.17
6.1
6.2
6.3
6.4
a.
b.
c.
d.
n 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 peticlcum gas
Wood waste combustion 1n
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 add (thermal
process)
Phthalic anhydride
Sodium carbonate
Sulfurlc add
Food 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
Categories with particle size data
Categories with particle size data
Data for each numbered category are
Highway vehicles data are reported
Category
Number
a
a
a
a
b
a
a
2
b
2
a
1
9
3
3
3
4
a
9
a
b
b
7
7
7
6
b
b
specific
specific
shown in
in AP-42
AP-42
Section
6.5
6.7
6.8
6.10
6.10.
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
to process
to process
Table C.2-
Volume II:
Source Category
Food and agricultural (cont.)
Grain elevators
Grain processing
Fermentation
Meat smokehouses
Ammonium nitrate fertilizers
Phosphate fertilizers
3 Ammonium phosphates
Reactor/ammoniator-
granulator
Dryer/cooler
Starch manufacturing
Urea manufacturing
Defoliation and harvesting
of cotton
Trailer loading
Transport
Harvesting of grain
Harvesting machine
Truck loading
Field transport
Ammonium sulfate manufacturing
Rotary dryer
Fluid1zed-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
Electric arc furnace
Primary lead smelting
Z1nc smelting
Secondary aluminum
Sweating furnace
Smelting
Crucible furnace
Reverberatory furnace
Secondary copper smelting
and alloying
Gray iron foundries
included in the main body of the t
included in Appendix C.I.
2.
Mobile Sources.
Category
Number*
6
7
6&7
9
a
3
4
4
7
a
6
6
6
6
6
b
b
4
5
9
a
8
a
a
a
a
a
a
a
a
a
a
a
8
8
8
a
8
a
!Xt.
10/86
Appendix C.2
C.2-5
-------
TABLE C.2-1 (continued).
AF-42
Section
Source Category
Category
Number
AP-42
Section
Source Category
Category
Number
Metallurgical industry (cont.)
7.11 Secondary lead processing a
7.12 Secondary magnesium smelting 8
7.13 Steel foundaries
melting b
7.14 Secondary zinc smelting 8
7.15 Storage battery production b
7.18 Leadbearing ore crushing and
grinding 4
Mineral products
8.1 Asphaltic concrete plants
Process a
8.3 Bricks and related clay
products
Raw materials handling
Dryers, grinders, etc. b
Tunnel/periodic kilns
Cas fired a
Oil fired a
Coal fired a
8.5 Castable refractories
Raw material dryer 3
Raw material crushing and
screening 3
Electric arc melting 8
Curing oven 3
8.6 Portland cement manufacturing
Dry process
Kilns a
Dryers, grinders, etc. 4
Wet process
Kilns a
Dryers, grinders, etc. 4
8.7 Ceramic clay manufacturing
Drying 3
Grinding 4
Storage 3
8.8 Clay and fly ash sintering
Fly ash sintering, crushing,
screening and yard storage 5
Clay mixed with coke
Crushing, screening, and
yard storage 3
8.9 Coal cleaning 3
8.10 Concrete batching 3
8.11 Glass fiber manufacturing
Unloading and conveying 3
Storage bins 3
Mixing and weighing 3
Class furnace - wool a
Glass furnace - textile a
8.13 Glass manufacturing a
8.14 Gypsum manufacturing
Rotary ore dryer a
Roller mill 4
Mineral products (cont.)
Impact mill
Flash calciner
Continuous kettle calciner
8.15 Lime manufacturing
8.16 Mineral wool manufacturing
Cupola
Reverberatory furnace
Blow chamber
Curing oven
Cooler
8.18 Phosphate rock processing
Drying
Calcining
Grinding
Transfer and storage
8.19.1 Sand and gravel processing
Continuous drop
Transfer station
Pile formation - stacker
Batch drop
Active storage piles
Vehicle traffic unpaved road
8.19.2 Crushed stone processing
Dry crushing
Primary crushing
Secondary crushing
and screening
Tertiary crushing
and screening
Recrushing and screening
Fines mill
Screening, conveying,
and handling
8.22 Taconite ore processing
Fine crushing
Waste gas
Pellet handling
Grate discharge
Grate feed
Bentonite blending
Coarse crushing
Ore transfer
Bentonite transfer
Unpaved roads
8.23 Metallic minerals processing
8.24 Western surface coal mining
Wood processing
10.1 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.
r. Data for each numbered category are shown in Table C.2-2.
C.2-6
EMISSION FACTORS
10/86
-------
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 (ym)
< 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:
Particle size (ym)
0-2.5 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 ym 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
yy
98
95
90
80
70
60
50
40
-
-
i
-
1 T I
i—*
- -^
iii'
^^*~**
-
.
-
-
i i ii iii
2345 10
PARTICLE DIAMETER,
Particle
size, vim
1.0
2.0£
2.5
3.0£
4.0£
5.0£
6.0
10.0
a
Cumulative %
less than or equal
to stated size Minimum
(uncontrolled) Value
82
88
90 78
90
92
93
93 86
96 92
Maximum Standard
Value Deviation
99
99
99
11
7
4
Value calculated from data reported at 2.5, 6.0, and 10.0 ym. 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
o
UJ
t—
ce.
UJ
a.
95
90
80
70
60
50
40
30
20
10
l1IIIIITT
I I i I i I I I I
2345 10
PARTICLE DIAMETER, \m\
Particle
size, ym
i.oa
2.0a
2.5
4.0
5.0
6.0
10.0
a
Cumulative %
less than or equal
to stated size Minimum
(uncontrolled) Value
23
40
45 32
50
58
64
70 49
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 ym. 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
l/l
V
h-
Z
UJ
u
90
80
70
60
50
40
30
20
10
5
2
r i i iiiiri
2345 10
PARTICLE DIAMETER, \sn
Cumulative %
less than or equal
Particle to stated size Minimum
size, urn (uncontrolled) Value
1.0a 4
2.0a 11
2.5 15 3
3.0a 18
a
25
30
6.0 34 15
10.0 51 23
a
Maximum Standard
Value Deviation
35
65
81
13
14
Value calculated from data reported at 2.5, 6.0, and 10.0 ym. 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
Particle
size, ym
i.oe
2.0
2.5
3.0*
4.0£
5.0£
6.0
10.0
a
IS!
V
95
90
80
70
60
50
40
30
20
10
5
2
1
0.5
i i i i i
2 345
PARTICLE 'DIAMETER, \m
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 ym. No
statistical parameters are given for the calculated value.
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 r i i i
i
i i i i i
2 345
PARTICLE DIAMETER,
10
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 ym. No
statistical parameters are given for the calculated value.
C.2-12
EMISSION FACTORS
10/86
-------
TABLE C.2-2 (continued).
Category: 6
Process: Grain Handling
Material: 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
o
UJ
*—
-------
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
o
UJ
*—
ft
80
70
60
50
40
30
20
10
1I1IIT
I 1 I I I I
2 345
PARTICLE DIAMETER, pm
10
Cumulative %
less than or equal
Particle to stated size Minimum Maximum
size, ym (uncontrolled) Value Value
1.0a 8
2.0a 18
2.5 23 17 34
3.0a 27
4.0a 34
5.0a 40
6.0 43 35 48
10.0 61 56 65
Standard
Deviation
7
5
Value calculated from data reported at 2.5, 6.0, and 10.0 pm.
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
40
2345 10
PARTICLE DIAMETER, \tm
Particle
size, pm
i.oa
2.0a
2.5
3.0
4.0*
5.0£
6.0
10.0
a
Cumulative %
less than or equal
to stated size Minimum Maximum Standard
(uncontrolled) Value Value Deviation
72
80
82 63 99 12
84
86
88
89 75 99 9
92 80 99 7
Value calculated from data reported at 2.5, 6.0, and 10.0 ym.
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
Q
LiJ
t—
<
99
98
95
90
80
70
60
50
40
IT
I
2 345
PARTICLE DIAMETER,
I I i l l l I
10
Particle
size, ym
1.0'
2.0*
2.5
3.0''
4.0
5.0a
6.0
10.0
a
a
Cumulative %
less than or equal
to stated size Minimum
(uncontrolled) Value
60
74
78 59
81
85
88
91 61
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.
No
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 pm particle size range. In order to account for the total
controlled emissions, particles greater than 10 pm 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.3'
(percent)
Type of collector
Baffled settling chamber
Simple (high-throughput) cyclone
High-efficiency and multiple cyclones
Electrostatic precipitator (ESP)
Packed-bed scrubber
Venturi scrubber
Wet-impingement scrubber
Fabric filter
Particle size, ym
0 - 2.5
NR
50
80
95
90
90
25
L "
2.5 - 6
5
75
95
99
95
95
85
99.5
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, PEI 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.
8. 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
the 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.
"U.S. GOVERNMENT PRINTING OFFICE:1986-726-611
C.2-18 EMISSION FACTORS 10/86
-------
TECHNICAL REPORT DATA
(Please read Instructions un the re\ ersi before completing
1 REPORT NO.
AP-42, Supplement A
3. RECIPIENT'S ACCESSION NO.
4 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
7 AUTHOR(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. 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.
12. SPONSORING AGENCY NAME AND ADDRESS
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
EPA Editor: Whitmel M. Joyner
16. 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".
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATl Field/Group
Stationary Sources
Point Sources
Area Sources
Emission Factors
Emissions
18. DISTRIBUTION STATEMENT
19. SECURITY CLASS (This Report)
21. NO. OF PAGES
460
20 SECURITY CLASS (This page)
22. PRICE
EPA Form 2220-1 (R«v. 4-77) PREVIOUS EDITION is OBSOLETE
-------
|