-------
Emissions from anode bake ovens include the products of fuel
combustion; high boiling organics from the cracking, distillation and oxid-
ation of paste binder pitch; sulfur dioxide from the carbon paste; fluorides
from recycled anode butts; and other particulate matter. The concentrations
of uncontrolled SC>2 emissions from anode baking furnaces range from 5 to 47
ppm (based on 3 percent sulfur in coke.)^
Casting emissions are mainly fumes of aluminum chloride, which may
hydrolyze to HC1 and
A variety of control devices has been used to abate emissions from
reduction cells and anode baking furnaces. To control gaseous and partic-
ulate fluorides and particulate emissions, one or more types of wet scrub-
bers (spray tower and chambers, quench towers, floating beds, packed beds,
Venturis, and self induced sprays) have been applied to all three types of
reduction cells and to anode baking furnaces. Also, particulate control
methods such as electrostatic precipitators (wet and dry) , multiple
cyclones and dry alumina scrubbers (fluid bed, injected, and coated filter
types) have been employed 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 off-
gases through the entering alumina feed, on which the fluorides are absored.
This technique has an overall control efficiency of 98 to 99 percent. Bag-
houses are then used to collect residual fluorides entrained in the alumina
and to recycle them to the reduction cells. Wet electrostatic precipitators
approach adsorption in particulate removal efficiency but must be coupled to
a wet scrubber or coated baghouse to catch hydrogen fluoride.
Scrubber systems also remove a portion of the SC-2 emissions. These
emissions could be reduced by wet scrubbing or by reducing the quantity of
sulfur in the anode coke and pitch, i. e., calcinating the coke.
In the aluminum hydroxide calcining, bauxite grinding and materials
handling operations, various dry dust collection devices (centrifugal
collectors, multiple cyclones, or electrostatic precipitators 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 particle size distributions similar to those presented in Table 7.1-3.
References for Section 7.1
1 . Engineering and Cost Effectiveness Study of Fluoride Emissions Control,
Volume I, APTD-0945, U. S. Environmental Protection Agency, Research
Triangle Park, NC, January 1972.
2. Air Pollution Control in the Primary Aluminum Industry, Volume I,
EPA-450/3-73-004a, U. S. Environmental Protection Agency, Research
Triangle Park, NC, July 1973.
4/81 Metallurgical Industry 7.1-7
-------
3. Particulate Pollutant System Study, Volume I, APTD-0743, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, May 1971.
4. Emissions from Wet Scrubbing System, Report Number Y-7730-E, York
Research Corp., Stamford, CT, May 1972.
5. Emissions from Primary Aluminum Smelting Plant, Report Number Y-7730-B,
York Research Corp., Stamford, CT, June 1972.
6. Emissions from the Wet Scrubber System, Report Number Y-7730-F, York
Research Corp., Stamford, CT, June 1972.
7. T. R. Hanna and M. J. Pilat, "Size Distribution of Particulates Emitted
from a Horizontal Spike Soderberg Aluminum Reduction Cell", Journal of
the Air Pollution Control Association, 22j 533-536, July 1972.
8. Background Information for Standards of Performance; Primary Aluminum
Industry, Volume 1; Proposed Standards, EPA-450/2-74-020a, U. S.
Environmental Protection Agency, Research Triangle Park, NC, October
1974.
9. Primary Aluminum: Guidelines for Control of Fluoride Emissions from
Existing Primary Aluminum Plants, EPA-450/2-78-049b, U. S. Environmental
Protection Agency, Research Triangle Park, NC, December 1979.
10. Written communication from T. F. Albee, Reynolds Aluminum, Richmond, VA,
to A. A. MacQueen, U. S. Environmental Protection Agency, Research
Triangle Park, NC, October 20, 1982.
7.1-8 EMISSION FACTORS 4/81
-------
7.5 IRON AND STEEL PRODUCTION
1-2
7.5.1 Process Description and Emissions
Iron and steel manufacturing may be grouped into eight generic process
operations: 1) coke production, 2) sinter production, 3) iron production,
4) steel production, 5) semifinished product preparation, 6) finished prod-
uct preparation, 7) heat and electricity supply and 8) handling and trans-
port of raw, intermediate and waste materials. Figure 7.5-1, a general
flow diagram of the iron and steel industry, interrelates these categories.
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.
Sinter Production - The sintering process converts fine raw materials like
fine iron ore, coke breeze, fluxstone, mill scale and flue dust into an ag-
glomerated product of suitable size for charging into a blast furnace. The
materials are mixed with water to provide cohesion in a mixing mill and are
placed on a continuous moving grate called the sinter strand. A burner
hood above the front third of the sinter strand ignites the coke in the
mixture. Once ignited, combustion is self supporting and provides suffi-
cient heat, 1300 to 1480°C (2400 to 2700°F), to cause surface melting and
agglomeration of the mix. On the underside of the sinter machine lie wind-
boxes that draw the combusted air through the material bed into a common
duct to a particulate control device. The fused sinter is discharged at
the end of the sinter machine, where it is crushed and screened, and any
undersize portion is recycled to the mixing mill. The remaining sinter is
cooled in open air by water spray or by mechanical fan to draw off the heat
from the sinter. The cooled sinter is screened a final time, with the
fines being recycled and the rest being sent to charge the blast furnaces.
Emissions occur at several points in the sintering process. Points of
particulate generation are the windbox, the discharge (sinter crusher and
hot screen), the cooler and the cold screen. In addition, inplant transfer
stations generate emissions which can be controlled by local enclosures.
All the above sources except the cooler normally are vented to one or two
control systems.
Iron Production - Iron is produced in blast furnaces, which are large re-
fractory lined chambers into which iron (as natural ore or as agglomerated
products such as pellets or sinter, coke and limestone) is charged and al-
lowed to react with large amounts of hot air to produce molten iron. Slag
and blast furnace gases are byproducts of this operation. The average
charge to produce one unit weight of iron requires 1.7 unit weights of iron
bearing charge, 0.55 unit weights of coke, 0.2 unit weights of limestone,
and 1.9 unit weights of air. Average blast furnace byproducts consist of
0.3 unit weights of slag, 0.05 unit weights of flue dust, and 3.0 unit
weights of gas per unit of iron produced. The flue dust and other iron ore
fines from the process are converted into useful blast furnace charge by
the sintering operation.
5/83 Metallurgical Industry 7.5-1
-------
CO
3
13
0)
0)
T3
G
a
C
o
t-l
cu
&
4J
O
14-1
60
rt
o
iH
M-i
0)
c
cu
o
60
7.5-2
EMISSION FACTORS
5/83
-------
Because of its high carbon monoxide content, this blast furnace gas
has a low heating value, about 2790 to 3350 joules per cubic 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 re-
move about 60 percent of the particulate. Next, the gases undergo a one or
two stage cleaning operation. The primary cleaner is normally a wet scrub-
ber, which removes about 90 percent of the remaining particulate. The sec-
ondary cleaner is a high energy wet scrubber (usually a venturi) or an
electrostatic precipitator, either of which can remove up to 90 percent of
the particulate that eludes the primary cleaner. Together these control
devices provide a clean fuel of less than 0.05 grams per cubic meter (0.02
gr/ft3) for use in the steel plant.
•
Emissions occur during the production of iron when there is a blast
furnace "slip" and during hot metal transfer operations in the cast house.
All gas generated in the blast furnace is normally cleaned and used for
fuel. Conditions such as "slips", however, can cause instant emissions of
carbon monoxide and particulates. Slips occur when a stratum of the mate-
rial charged to a blast furnace does not settle with the material below it,
thus leaving a gas filled space between the two portions of the charge.
When this unsettled stratum of charge collapses, the displaced gas may
cause the top gas pressure to increase above the safety limit, thus opening
a counter weighted bleeder valve to the atmosphere.
Steel Production (Basic Oxygen Furnace) - The basic oxygen process is used
to produce steel from a furnace charge typically composed of 70 percent
molten blast furnace metal and 30 percent scrap metal by use of a stream of
commercially pure oxygen to oxidize the impurities, principally carbon and
silicon. Most of the basic oxygen furnaces (BOF) in the United States have
oxygen blown through a lance in the top of the furnace. However, the
Quelle Basic Oxygen Process (QBOP), which is growing in use, has oxygen
blown through tuyeres in the bottom of the furnace. Cycle times for the
basic oxygen process range from 25 to 45 minutes.
The large quantities of carbon monoxide (CO) produced by the reactions
in the BOF can be combusted at the mouth of the furnace and then vented to
gas cleaning devices, as with open hoods, or the combustion can be sup-
pressed at the furnace mouth, as with closed hoods. The term "closed hood"
is actually a misnomer, since the opening at the furnace mouth is large
enough to allow approximately 10 percent of theoretical air to enter. Al-
though most furnaces installed before 1975 are of the open hood design,
nearly all the QBOPs in the United States have closed hoods, and most of
the new top blown furnaces are being designed with closed hoods.
There are several sources of emissions in the basic oxygen furnace
steel making process, 1) the furnace mouth during refining - with collec-
tion by local full (open) or suppressed (closed) combustion hoods, 2) hot
metal transfer to charging ladle, 3) charging scrap and hot metal, 4) dump-
ing slag and 5) tapping steel.
Steel Production (Electric Arc Furnaces) - Electric arc furnaces (EAF) are
used to produce carbon and alloy steels. The charge to an EAF is nearly
5/83 . Metallurgical Industry 7.5-3
-------
always 100 percent scrap. Direct arc electrodes through the roof of the
furnace melt the scrap. An oxygen lance may or may not be used to speed
the melting and refining process. Cycles range from 1-1/2 to 5 hours for
carbon steel and from 5 to 10 hours for alloy steel.
Sources of emissions in the electric arc furnace steel making process
are 1) emissions from melting and refining, often vented through a hole in
the furnace roof, 2) charging scrap, 3) dumping slag and 4) tapping steel.
In interpreting and using emission factors for EAFs, it is important to
know what configuration one is dealing with. For example, if an EAF has a
building evacuation system, the emission factor before the control device
would represent all melting, refining, charging, tapping and slagging emis-
sions which ascend to the building roof. Reference 2 has more details on
various configurations used to control electric arc furnaces.
Steel Production (Open Hearth Furnaces) - In the open hearth furnace (OHF),
a mixture of iron and steel scrap and hot metal (molten iron) is melted in
a shallow rectangular basin or "hearth". Burners producing a flame above
the charge provide the heat necessary for melting. The mixture of scrap
and hot metal can vary from all scrap to all hot metal, but a half and half
mixture is a reasonable industry average. The process may or may not be
oxygen lanced, with process cycle times approximately 8 hours and 10 hours,
respectively.
Sources of emissions in the open hearth furnace steel making process
are 1) transferring hot metal, 2) melting and refining the heat, 3) charg-
ing of scrap and/or hot metal, 4) dumping slag and 5) tapping steel.
Semifinished Product Preparation - After the steel has been tapped, the
molten metal is teemed into ingots which are later heated to form blooms,
billets or slabs. (In a continuous casting operation, the molten metal may
bypass this entire process.) The product next goes through a process of
surface preparation of semifinished steel (scarfing). A scarfing machine
removes surface defects before shaping or rolling of the steel billets,
blooms and slabs by applying jets of oxygen to the surface of the steel,
which is at orange heat, thus removing a thin layer of the metal by rapid
oxidation. Scarfing can be performed by machine on hot semifinished steel
or by hand on cold or slightly heated semifinished steel. Emissions occur
during teeming as the molten metal is poured, and when the semifinished
steel products are manually or machine scarfed to remove surface defects.
Miscellaneous Combustion Sources - Iron and steel plants require energy
(heat or electricity) for every plant operation. Some energy operations on
plant property that produce emissions are boilers, soaking pits and slab
furnaces which burn coal, No. 2 fuel oil, natural gas, coke oven gas or
blast furnace gas. In soaking pits, ingots are heated until the tempera-
ture 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). The
emissions from the combustion of natural gas, fuel oil or coal for boilers
7.5-4 EMISSION FACTORS 5/83
-------
can be found in Chapter 1 of this document. Estimated emissions from these
same fuels used in soaking pits or slab furnaces can be the same as those
for boilers, but since it is estimation, the factor rating drops to D.
Emission factor data for blast furnace gas and coke oven gas are not
available and must be estimated. There are three facts available for mak-
ing 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 emission factor for combustion of blast furnace gas is equal to the
particulate loading of that fuel, 0.05 grams per cubic meter (2.9 lb/106
ft3).
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 meth-
ane, the main component of natural gas, it is assumed that the combustion
of this methane in coke oven gas generates 0.06 grams per cubic meter (3.3
lb/106 ft3) of particulate. 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/106 ft3).
Open Dust Sources - Like process emission sources, open dust sources con-
tribute to the atmospheric particulate burden. Open dust sources include
1) vehicle traffic on paved and unpaved roads, 2) raw material handling
outside of buildings and 3) 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 deliver-
ables, steel products 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 sta-
tions, 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 7.5-1. 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 7.5-1, empirically derived emission factor equations are
presented in Chapter 11 of this document. Each equation was developed for
a source operation defined on the basis of a single dust generating mecha-
nism 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 charac-
terize source conditions. These parameters may be grouped into three cate-
gories: 1) measures of source activity or energy expended (e.g., the speed
5/83 Metallurgical Industry 7.5-5
-------
TABLE 7.5-1. UNCONTROLLED PARTICULATE EMISSION FACTORS FOR
OPEN DUST SOURCES AT IRON AND STEEL MILLS3
Operation
Continuous drop
Conveyor transfer station
Sinter
Pile formation -
stacker
Pellet ore
Lump ore
ri
Coal"
Batch drop
Front end loader/truck0
High silt slag
Low silt slag
Vehicle travel on
unpaved roads ,
Light duty vehicle
j
Median duty vehicle
u
Heavy duty vehicle
Vehicle travel on
paved roads
Light/heavy vehicle mixc
Predictive emission factor
, sented in Chapter 11.
Emissions by
< 30 |jm
13
0.026
1.2
0.0024
0.15
0.00030
0.055
0.00011
13
0.026
4.4
0.0088
0.51
1.8
2.1
7.3
3.9
14
0.22
0.78
equations
c Units/unit of material transferred.
, Reference 3. Interpolation to other
Reference 4. Interpolation to other
<
9-
0.
0.
0.
0.
0.
0.
0.
8.
0.
2.
0.
0.
1.
1.
5.
2.
9.
particle
15 \m
0
018
75
0015
095
00019
034
000069
5
017
9
0058
37
3
5
2
7
7
0.16
0.56
size range
(aerodynamic
< 10 \m
6
0
0
0
0
0
0
0
6
0
2
0
0
1
1
4
2
7
0
0
, which generally
Units/unit of
particle sizes
particle sizes
.5
.013
.55
.0011
.075
.00015
.026
.000052
.5
.013
.2
.0043
.28
.0
.2
.1
.1
.6
.12
.44
provide
4
0
0
0
0
0
0
0
4
0
1
0
0
0
0
2
1
4
0
.0
more
< 5 Mm
.2
.0084
.32
,00064
.040
.000081
.014
.000029
,0
.0080
.4
.0028
.18
.64
.70
.5
.4
.8
.079
.28
accurate
diameter)
< 2
2.
0.
0.
.5 M»
3
0046
17
0.00034
0.
0.
0.
0.
2.
0.
0.
0.
0.
0.
0.
1.
0.
2.
0.
0.
022
000043
0075
000015
3
0046
80
0016
10
37
42
5
76
7
042
15
estimates of
Unitsb
g/Mg
Ib/T
8/Mg
Ib/T
g/Mg
Ib/T
g/Mg
Ib/T
g/Mg
Ib/T
g/Mg
Ib/T
kg/VKT
Ib/VMT
kg/VKT
Ib/VMT
kg/VKT
Ib/VMT
kg/VKT
Ib/VMT
emissions.
Emission
Factor
Rating
D
D
B
B
C
C
E
E
C
C
C
C
C
C
C
C
B
B
C
C
are pre-
distance traveled.
will be approximate.
will be approxinate.
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., num-
ber 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, the equations should be used in place of the
factors in Table 7.5-1, 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 correction 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. Chapter 11 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 spe-
cific values are not available. Use of mean correction parameter values
from Chapter 11 reduces the quality ratings of the emission factor equation
by one level.
7.5-6
EMISSION FACTORS
5/83
-------
Particulate emission factors for iron and steel plant processes are in
Table 7.5-2. These emission factors are a result of an extensive investi-
gation by EPA and the American Iron and Steel Institute.2 Carbon monoxide
emission factors are in Table 7.5-3.5
TABLE 7.5-2. PARTICULATE EMISSION FACTORS FOR IRON AND STEEL MILLS3
Source
Blast furnaces
Slips
Uncontrolled cast house emissions
Monitor
Tap hole and trough (not runners)
Sintering
Windbox emissions
Uncontrolled
Leaving grate
After coarse particulate removal
Controlled by dry ESP
Controlled by wet ESP
Controlled by scrubber
Controlled by cyclone
Sinter discharge (breaker and hot
screens)
Uncontrolled
Controlled by baghouse
Controlled by orifice scrubber
Windbox and discharge
Controlled by bagbouse
Basic oxygen furnaces
Top blown furnace melting and refining
Uncontrolled
Controlled by open hood vented to:
ESP
Scrubber
Controlled by closed hood vented to:
Scrubber
QBOP melting and refining
Controlled by scrubber
Charging
At source
At building monitor
Tapping
At source
At building monitor
Hot metal transfer
At source
At building monitor
EOF monitor (all sources)
Electric arc furnaces
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
Units
kg (lb)/slip
kg/Mg (Ib/ton) hot metal
kg/Mg (Ib/ton) finished
sinter
kg/Mg (Ib/ton) finished
sinter
kg/Mg (Ib/ton) finished
sinter
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) hot metal
kg/Mg (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
Emissions Emission Factor
Rating
39.5
0.3
0.15
5.56
A. 35
0.8
0.085
0.235
0.5
3.4
0.05
0.295
0.15
14.25
0.065
0.045
0.0034
0.028
0.3
0.071
0.46
0.145
0.095
0.028
0.25
19
0.7
5.65
25
(87)
(0.6)
(0.3)
(11.1)
(8.7)
(1.6)
(0.17)
(0.47)
(1)
(6.8)
(0.1)
(0.59)
(0.3)
(28.5)
(0.13)
(0.09)
(0.0068)
(0.056)
(0.6)
(0.142)
(0.92)
(0.29)
(0.19)
(0.056)
(0.5)
(38)
(1.4)
(11-3)
(50)
D
B
B
B
A
B
B
B
B
B
B
A
A
B
A
B
A
A
A
B
A
B
A
B
B
C
C
A
C
Controlled by:
Configuration 1
(building evacuation to bagbouse
for alloy steel)
Configuration 2
(DSE plus charging hood vented
to common baghouse for carbon
steel)
0.15 (0.3)
0.0215 (O.OA3)
(continued)
5/83
Metallurgical Industry
7.5-7
-------
TABLE 7.5-2.
PARTICULATE EMISSION FACTORS FOR IRON AND
STEEL MILLS3 (continued)
Source Units
Open hearth furnaces
Melting and refining kg/Mg (Ib/ton) steel
Uncontrolled
Controlled by ESP
Teeming
Leaded steel kg/Mg (Ib/ton) steel
Uncontrolled (as measured at the
source)
Controlled by side draft hood vented
to baghouse
Unleaded steel
Uncontrolled (as measured at the
source)
Controlled by side draft hood vented
to baghouse
Machine scarfing
Uncontrolled kg/Mg (Ib/ton) metal
through scarfer
Controlled by ESP
Miscellaneous combustion sources
Boilers, soaking pits and slab reheat kg/109 J (lb/106 BTU)
furnaces
Blast furnace gas
Coke oven gas
Emissions Emission Factor
Rating
10.55
0.14
Onoj.
. UOH
0.405
0.0019
0.035
0.0008
0.05
0.0115
0.015
0.0052
(21.1)
(0.28)
fn l£Ol
V U > 1 DO )
(0.81)
(0.0038)
(0.07)
(0.0016)
(0.1)
(0.023)
(0.035)
(0.012)
A
A
A
A
A
A
B
A
D
D
, Reference 2. ESP = electrostatic precipitator. DSE = direct shell evacuation.
For fuels such as coal, fuel oil and natural gas, use the emission factors presented in Chapter 1. of
this document. The factor rating for these fuels in boilers is A, and in soaking pits and slab re-
heat furnaces is D.
TABLE 7.5-3. UNCONTROLLED CARBON MONOXIDE
EMISSION FACTORS FOR IRON
AND STEEL MILLS3
EMISSION FACTOR RATING: C
Source
kg/Mg
Ib/ton
Sintering windbox
Basic oxygen furnace
Electric arc furnace
22
69
9
44
138
18
, Reference 5.
of finished sinter.
7.5-8
EMISSION FACTORS
5/83
-------
References for Section 7.5
1. H. E. McGannon, ed., The Making, Shaping and Treating of Steel, U. S.
Steel Corporation, Pittsburgh, PA, 1971.
2. T. A. Cuscino, Jr., Particulate Emission Factors Applicable to the
Iron and Steel Industry, EPA-450/4-79-029, U. S. Environmental Protec-
tion Agency, Research Triangle Park, NC, September 1979.
3. R. Bonn, 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.
4. C. Cowherd, Jr., et al. , Iron and Steel Plant Open Source Fugitive
Emission Evaluation, EPA-600/2-79-103, U. S. Environmental Protection
Agency, Research Triangle Park, NC, May 1979.
5. Control Techniques for Carbon Monoxide Emissions from Stationary
Sources, AP-65, U. S. Department of Health, Education and Welfare,
Washington, DC, March 1970.
5/83 Metallurgical Industry 7.5-9
-------
8.14 GYPSUM MANUFACTURING
1-2
8.14.1 Process Description
Gypsum is calcium sulfate dihydrate (CaSO • 2H 0) , a white or gray
naturally occurring mineral. Raw gypsum ore is processed into a variety of
products such as a Portland cement additive, soil conditioner, industrial
and building plasters, and gypsum wallboard. To produce plasters or
wallboard, gypsum must first be partially dehydrated or calcined to produce
calcium sulfate hemihydrate (CaSO, • %H 0) , commonly called stucco.
A flow diagram for a typical gypsum process producing both crude and
finished gypsum products is shown in Figure 8.14-1. In this process, gypsum
is crushed, dried, ground and calcined. Some of the operations shown in
Figure 8.14-1 are not performed at all gypsum plants. Some plants produce
only wallboard, and many plants do not produce soil conditioner.
Gypsum ore, from quarries and/or underground mines, is crushed and
stockpiled near a plant. As needed, the stockpiled ore is further crushed
and screened to about 50 millimeters (2 inches) in diameter. If the
moisture content of the mined ore is greater than about 0.5 weight percent,
the ore must be dried in a rotary dryer or a heated roller mill. Ore dried
in a rotary dryer is conveyed to a roller mill where it is ground to
90 percent less 149 micrometers (100 mesh). The ground gypsum exits the
mill in a gas stream and is collected in a product cyclone. Ore is
sometimes dried in the roller mill by heating the gas stream, so that drying
and grinding are accomplished simultaneously and no rotary dryer is needed.
The finely ground gypsum ore is known as landplaster, which may be used as
soil conditioner.
In most plants, landplaster is fed to kettle calciners or flash
calciners, where it is heated to remove three quarters of the chemically
bound water to form stucco. Calcination occurs at approximately 120 to
150°C (250 to 300°F), and 0.908 megagrams (Mg) (one ton) of gypsum calcines
to about 0.77 Mg (0.85 ton) of stucco.
In kettle calciners, the gypsum is indirectly heated by hot combustion
gas passed through flues in the kettle, and the stucco product is discharged
into a "hot pit" located below the kettle. Kettle calciners may be operated
in either batch or continuous modes. In flash calciners, the gypsum is
directly contacted with hot gases, and the stucco product is collected at
the bottom of the calciner. A major gypsum manufacturer holds a patent on
the design of the flash calciner.
At some gypsum plants, drying, grinding and calcining are performed in
heated impact mills. In these mills, hot gas contacts gypsum as it is
ground. The gas dries and calcines the ore and then conveys the stucco to a
product cyclone for collection. The use of heated impact mills eliminates
the need for rotary dryers, calciners and roller mills.
5/83
Mineral Products Industry 8.14-1
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8.14-2
EMISSION FACTORS
5/83
-------
Gypsum and stucco usually are transferred from one process to another
in screw conveyors or bucket elevators. Storage bins or silos are normally
located downstream of roller mills and calciners but may also be used
elsewhere.
In the manufacture of plasters, stucco is ground further in a tube or
ball mill and then batch mixed with retarders and stabilizers to produce
plasters with specific setting rates. The thoroughly mixed plaster is fed
continuously from intermediate storage bins to a bagging operation.
In the manufacture of wallboard, stucco from storage is first mixed
with dry additives such as perlite, starch, fiberglass or vermiculite. This
dry mix is combined with water, soap foam, accelerators and shredded paper
or pulpwood in a pin mixer at the head of a board forming line. The slurry
is then spread between two paper sheets that serve as a mold. The edges of
the paper are scored, and sometimes chamfered, to allow precise folding of
the paper to form the edges of the board. As the wet board travels the
length of a conveying line, the calcium sulfate hemihydrate combines with
the water in the slurry to form solid calcium sulfate dihydrate or gypsum,
resulting in rigid board. The board is rough cut to length, and it enters a
multideck kiln dryer where it is dried by direct contact with hot combustion
gases or by indirect steam heating. The dried board is conveyed to the
board end sawing area and is trimmed and bundled for shipment.
2
8.14.2 Emissions and Controls
Potential emission sources in gypsum manufacturing plants are shown in
Figure 8.14-1. Although several sources may emit gaseous pollutants,
particulate emissions are of greatest concern. The major sources of
particulate emissions include rotary ore dryers, grinding mills, calciners
and board end sawing operations. Particulate emission factors for these
operations are shown in Table 8.14-1. All these factors are based on output
production rates. Particle size data for ore dryers, calciners and board
end sawing operations are shown in Tables 8.14-2 and 8.14-3.
The uncontrolled emission factors presented in Table 8.14-1 represent
the process dust entering the emission control device. It is important to
note that emission control devices are frequently needed to collect the
product from some gypsum processes and, thus, are commonly thought of by the
industry as process equipment and not added control devices.
Emissions sources in gypsum plants are most often controlled with
fabric filters. These sources include:
- rotary ore dryers - board end sawing
- roller mills - scoring and chamfering
- impact mills - plaster mixing and bagging
- kettle calciners - conveying systems
- flash calciners - storage bins
Uncontrolled emissions from scoring and chamfering, plaster mixing and
bagging, conveying systems, and storage bins are not well quantified.
5/83 Mineral Products Industry 8.14-3
-------
TABLE 8.14-1. PARTICULATE EMISSION FACTORS FOR GYPSUM PROCESSING3
EMISSION FACTOR RATING: B
Process Uncontrolled
kg/Mg Ib/ton
With
fabric
filter0
kg/Mg Ib/ton
With
electrostatic
precipitator
kg/Mg Ib/ton
Crushers, screens,
stockpiles, roads
Rotary ore dryers
Roller mills1
,Impact mills6*
Flash calcinerse>m
Continuous kettle
calciners
e.f.g
0.0042(FFF)
1.77
1.3
j
50
19
.g.j
0.16(FFF)
1.77
2.6
37
^
0.02"
0.06
0.01
0.02
0.04"
0.12
0.02
0.04
0.003P 0.006P
NA
0.05k 0.09k
NA
NA
0.05J
0.09J
Board end sawing*'
2.4 m (8 ft) boards
3.7 m (12 ft) boards
kg/m2
0.04
0.03
lb/100 ft2
0.8
0.5
kg/106 m2
36
36
lb/106 ft2
7.5
7.5
nased on process output production rate. Rating applies to all factors except where otherwise noted.
Dash - not applicable. NA - not available.
Factors represent any dust entering the emission control device.
References 3-6, 8-11. Factors for sources controlled with fabric 'filters are based on pulse jet fabric
filters with actual air/cloth ratios ranging from 2.3:1 - 7.0:1, mechanical shaker fabric filters with
ratios from 1.5:1 - 4.6:1, and a reverse flow,fabric filter with a ratio of 2.3:1.
Factors for these operations are in Sections 8.19 and 11.2.
elncludes particulate matter from fuel combustion.
References 3-4, 8, 11-12. Equation is for emission rate upstream of any process cyclones and is
applicable only to concurrent rotary ore dryers with flowrates of 7.5 m /s (16,000 acfm) or less.
FFF in the uncontrolled emission factor equation is "flow feed factor", the ratio of gas mass
rate per unit dryer cross sectional area to the dry mass feed rate, in the following units:
2 2
kg/hr - m of gas flow Ib/hr - ft of gas flow
Mg/hr dry feedton/hr dry feed
Measured uncontrolled emission factors for 4.2 and 5.7 m /s (9000 and 12,000 acfm) range from 5 -
60 kg/Mg (10 - 120 Ib/ton).
gEMISSION FACTOR RATING: C.
Applicable to rotary dryers with and without process cyclones upstream of the fabric filter.
References 11-14. Factors apply to both heated and unheated roller mills.
^Factors represent emissions downstream of the product cyclone.
Factor is for combined emissions from roller mills and kettle calciners, based on the sum of the roller
mill and kettle calciner output production rates.
References 9,15. As used here, an impact mill is a process unit with process cyclones and is
used to dry, grind and calcine gypsum simultaneously.
References 3, 6, 10. A flash calciner is a process unit used to calcine gypsum through direct contact
with hot gas. No grinding is performed in this unit.
"References 4-5, 11, 13-14.
Based on emissions from both the kettle and the hot pit. Not applicable to batch kettle calciners.
References 4-5, 16. Based on 13 mm (>s in.) board thickness and 1.2 m (4 ft)
board width. For other board thicknesses, multiply the appropriate emission factor by 0.079 times
board thickness in millimeters, or by 2 times board thickness in inches.
8.14-4
EMISSION FACTORS
5/83
-------
TABLE 8.14-2. UNCONTROLLED PARTICLE SIZE DATA
FOR GYPSUM PROCESSING
Process Weight Percent
10 ym 2 ym
Rotary ore dryer , ,
. ' n J a . cb . Ob
with cyclones 45 12
without cyclones 8 1
d e e
Continuous kettle calciners 63 17
Flash calcinersf 38b 10b
3.
.Reference 4.
Aerodynamic diameter, Andersen analysis.
.Reference 3.
References 4-5.
^Equivalent diameter, Bahco and Sedigraph analyses,
References3, 6.
TABLE 8.14-3. PARTICLE SIZE DATA FOR GYPSUM PROCESSING
OPERATIONS CONTROLLED WITH FABRIC FILTERS3
Process
Rotary ore dryer.
with cyclones ,
without cyclones
g
Flash calciners
Board end sawing
Weight Percent
10 ym 2 ym
c 9
26 9
84 52
76 49
O
.Aerodynamic diameters, Andersen analysis.
Reference 4.
c
.Not available
Reference 3.
^References 3, 6.
References 4-5.
5/83 Mineral Products Industry 8.14-5
-------
Emissions from some gypsum sources are also controlled with
electrostatic precipitators (ESP). These sources include rotary ore dryers,
roller mills, kettle calciners and conveying systems. Although rotary ore
dryers may be controlled separately, emissions from roller mills and
conveying systems are usually controlled jointly with kettle calciner
emissions. Moisture in the kettle calciner exit gas?improves the ESP
performance by lowering the resistivity of the dust.
Other sources of particulate emissions in gypsum plants are primary and
secondary crushers, screens, stockpiles and roads. If quarrying is part of
the mining operation, particulate emissions may also result from drilling
and blasting. Emission factors for some of these sources are presented in
Sections 8.19 and 11.2.
Gaseous emissions from gypsum processes result from fuel combustion and
may include nitrogen oxides, carbon monoxide and sulfur oxides. Processes
using fuel include rotary ore dryers, heated roller mills, impact mills,
calciners and board drying kilns. Although some plants use residual fuel
oil, the majority of1the industry uses clean fuels such as natural gas or
distillate fuel oil. Emissions from fuel combustion may be estimated
using emission factors presented in Sections 1.3 and 1.4.
References for Section 8.14
1. Kirk-Othmer Encyclopedia of Chemical Technology, Volume 4, John Wiley &
Sons, Inc., New York, 1978.
2. Gypsum Industry - Background Information for Proposed Standards
(Draft), U. S. Environmental Protection Agency, Research Triangle Park,
NC, April 1981.
3. Source Emissions Test Report, Gold Bond Building Products, EMB-80-
GYP-1, U. S. Environmental Protection Agency, Research Triangle Park,
NC, November 1980.
4. Source Emissions Test Report, United States Gypsum Company, EMB-80-
GYP-2, U. S. Environmental Protection Agency, Research Triangle Park,
NC, November 1980.
5. Source Emission Tests, United States Gypsum Company Wallboard Plant,
EMB-80-GYP-6, U. S. Environmental Protection Agency, Research Triangle
Park, NC, January 1981.
6. Source Emission Tests, Gold Bond Building Products, EMB-80-GYP-5, U. S.
Environmental Protection Agency, Research Triangle Park, NC,
December 1980.
7. S. Oglesby and G. B. Nichols, A Manual of Electrostatic Precipitation
Technology, Part II; Application Areas, APTD-0611, U. S. Environmental
Protection Agency, Cincinnati, OH, August 25, 1970.
8. Official Air Pollution Emission Tests Conducted on the Rock Pryer
£ind #3 Calcidyne Unit, Gold Bond Building Products, Report No. 5767,
Rosnagel and Associates, Medford, NJ, August 3, 1979.
8.14-6 EMISSION FACTORS 5/83
-------
9. Particulate Analysis of Calcinator Exhaust at Western Gypsum Company,
Kramer, Callahan and Associates, Rosario, NM, April 1979. Unpublished.
10. Official Air Pollution Tests Conducted on the #1 Calcidyner Baghouse
Exhaust at the National Gypsum Company, Report No. 2966, Rossnagel and
Associates, Atlanta, GA, April 10, 1978.
11. Report to United States Gypsum Company on Particulate Emission
Compliance Testing, Environmental Instrument Systems, Inc., South
Bend, IN, November 1975. Unpublished.
12. Particulate Emission Sampling and Analysis, United States Gypsum
Company, Environmental Instrument Systems, Inc., South Bend, IN,
July 1973. Unpublished.
13. Written communication from Wyoming Air Quality Division, Cheyenne, WY,
to Michael Palazzolo, Radian Corporation, Durham, NC, 1980.
14. Written communication from V. J. Tretter, Georgia-Pacific Corporation,
Atlanta, GA, to M. E. Kelly, Radian Corporation, Durham, NC,
November 14, 1979.
15. Telephone communication between Michael Palazzolo, Radian Corporation,
Durham, NC, and D. Louis, C. E. Raymond Company, Chicago, IL, April 23,
1981.
16. Written communication from Michael Palazzolo, Radian Corporation,
Durham, NC, to B. L. Jackson, Weston Consultants, West Chester, PA,
June 19,
1980.
17. Telephone communication between P. J. Murin, Radian Corporation,
Durham, NC, and J. W. Pressler, U. S. Department of the Interior,
Bureau of Mines, Washington, DC, November 6, 1979.
5/83 Mineral Products Industry 8.14-7
-------
8.19 CONSTRUCTION AGGREGATE PROCESSING
General*
The processing of construction aggregate (crushed stone, sand and gravel,
etc.) usually involves a series of distinct yet interdependent operations.
These include quarrying or mining operations (drilling, blasting, loading and
hauling) and plant process operations (crushing, grinding, conveying and other
material handling and transfer operations). Many kinds of construction aggre-
gate require additional processing (washing, drying, etc.) depending on rock
type and consumer requirements. Some of the individual operations take place
with high moisture, such as wet crushing and grinding, washing, screening
and dredging. These wet processes do not generate appreciable particulate
emissions. Although such operations may be a severe nuisance problem, with
local violations of ambient particulate standards, their generally large
particles can usually be controlled quite readily and satisfactorily to
prevent such problems.
The construction aggregate industry can be broken into various categories,
depending on source, mineral type or form, physical characteristics, wet versus
dry, washed or unwashed, and end uses, to name but a few. The industry is
categorized here into Section 8.19.1, Sand and Gravel Processing, and Section
8.19.2, Crushed Stone Processing. Sand and gravel generally are mined wet and
consist of discrete particles or stones, while crushed stone normally origin-
ates from solid strata which are broken by blasting and which will require
substantial crushing to be a useful consumer product. Further Sections will be
published when data on other processes become available.
Reference for Section 8.19
1. Mr Pollution Control Techniques for Nonmetallic Minerals Industry,
EPA-450/3-82-014, U. S. Environmental Protection Agency, Research Triangle
Park, NC, August 1982.
Notice: Work is being done on emission factors for 8.19.2,
Crushed Stone Processing, and these factors will
be presented in a future Supplement to AP-42.
This new work will replace the present 8.20, Stone
Quarrying and Processing.
5/83 Mineral Products Industry 8.19-1
-------
8.19.1 SAND AND GRAVEL PROCESSING
1-2
8.19.1.1 Process Description
Deposits of sand and gravel, the consolidated granular materials re-
sulting from the natural disintegration of rock or stone, are generally
found in banks and pits and in subterranean and subaqueous beds. Sand and
gravel are products of the weathering of rocks and are mostly silica.
Often, varied amounts of iron oxides, mica, feldspar and other minerals are
present. Deposits are common throughout the country.
Depending upon the location of the deposit, the materials are exca-
vated with power shovels, draglines, cableways, suction dredge pumps or
other apparatus. Lightcharge blasting may occasionally be necessary to
loosen the deposit. The materials are transported to the processing plant
by suction pump, earth mover, barge, truck or other means. The processing
of sand and gravel for a specific market involves the use of different com-
binations of washers, screens and classifiers to segregate particle sizes;
crushers to reduce oversize material; and storage and loading facilities.
8.19.1.2 Emissions and Controls
Dust emissions occur during conveying, screening, crushing and storing
operations. Generally, these materials are wet or moist when handled, and
process emissions are often negligible. (If processing is dry, expected
emissions could be similar to those shown in Section 8.19.2, Crushed
Stone.) Considerable emissions may occur from vehicles hauling materials
to and from a site. Open dust source emission factors for such sand and
gravel processing operations have been determined through source testing at
various sand and gravel plants and, in some instances, through additional
extrapolations, and are presented in Table 8.19.1-1.
As an alternative to the single valued emission factors given in Table
8.19.1-1, empirically derived emission factor equations are presented in
Chapter 11 of this document. Each equation was developed for a single
source operation or dust generating mechanism which crosses industry lines,
such as vehicular traffic on unpaved roads. The predictive equation ex-
plains much of the observed variance in measured emission factors by relat-
ing emissions to different source parameters. These parameters may be
grouped as 1) measures of source activity or expended energy (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 suspendable fines in
the surface material on an unpaved road); and 3) climate (e.g., number of
precipitation free days per year, when emissions tend to a maximum).
Because predictive equations allow for emission factor adjustment to
specific conditions, they should be used instead of the factors given in
Table 8.19.1-1 whenever emission estimates are needed for sources in a spe-
cific sand and gravel processing facility. However, the generally higher
quality ratings assigned to the equations are applicable only if 1) reli-
able values of correction parameters have been determined for the specific
5/83 Mineral Products Industry 8.19.1-1
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8.19.1-2
EMISSION FACTORS
5/83
-------
sources of interest and 2) the correction parameter values lie within the
ranges tested in developing the equations. Chapter 11 lists measured prop-
erties of aggregate materials used in industries relating to the sand and
gravel industry, which can be used to approximate correction parameter val-
ues for the predictive emission factor equations, in the event that site
specific values ane not available. Use of mean correction parameter values
from Chapter 11 reduces the quality ratings of the emission factor equa-
tions by at least one level.
Since emissions from sand and gravel operations are usually in the
form of fugitive dust, control techniques applicable to fugitive dust
sources are appropriate. Control techniques most successfully used1 for
haul roads are application of dust suppressants, paving, route modifica-
tions, soil stabilization, etc.; for conveyors, covering and wet dust sup-
pression; for storage piles, wet dust suppression, windbreaks, enclosure
and soil stabilizers; and for conveyor and batch transfer points (loading,
unloading, etc.), wet suppression and various methods to reduce freefall
distances (e.g., telescopic chutes, stone ladders and hinged boom stacker
conveyors).
Wet suppression techniques include application of water, chemicals or
foam, usually at conveyor feed and discharge points. Such spray systems at
transfer points and on material handling operations are estimated to reduce
emissions 70 to 95 percent.5 Spray systems can also reduce loading and
wind erosion emissions from storage piles of various materials 80 to 90
percent.6 Control efficiencies depend upon local climatic conditions,
source properties and duration of control effectiveness. Table 11.2.1-2
contains estimates of control efficiency for various emission suppressant
methods for haul roads.
References for Section 8.19.1
1. Air Pollution Control Techniques for Nonmetallic Minerals Industry,
U. S. Environmental Protection Agency, Research Triangle Park, NC,
August 1982.
2. S. Walker, "Production of Sand and Gravel", Circular Number 57, Na-
tional Sand and Gravel Association, Washington, DC, 1954.
3. Fugitive Dust Assessment at Rock and Sand Facilities in the South
Coast Air Basin, Southern California Rock Products Association and
Southern California Ready Mix Concrete Association, Santa Monica, CA,
November 1979.
4. C. Cowherd, Jr., et al., Development of Emission Factors for Fugitive
Dust Sources, EPA-450/3-74-037, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1974.
5. R. Bohn, et al. , Fugitive Emissions from Integrated Iron and Steel
Plants, EPA-600/2-78-050, U. S. Environmental Protection Agency,
Washington, DC, March 1978.
5/03 Mineral Products Industry 8.19.1-3
-------
6. G. A. Jutze, and K. Axetell, Investigation of Fugitive Dust, Volume I:
Sources, Emissions and Control, EPA-450/3-74-036a, U. S. Environmental
Protection Agency, Research Triangle Park, NC, June 1974.
8.19.1-4 EMISSION FACTORS 5/83
-------
8.22 TACONITE ORE PROCESSING
8.22.1 General1"2
More than two thirds of the iron ore produced in the United States for
making iron consists of taconite concentrate pellets. Taconite is a low
grade iron ore, largely from deposits in Minnesota and Michigan, but from
other areas as well. Processing of taconite consists of crushing and
grinding the ore to liberate ironbearing particles, concentrating the ore
by separating the particles from the waste material (gangue), and pelletiz-
ing the iron ore concentrate. A simplified flow diagram of these process-
ing steps is shown in Figure 8.22-1.
Liberation - The first step in processing crude taconite ore is crushing
and grinding. The ore must be ground to a particle size sufficiently close
to the grain size of the ironbearing mineral, to allow for a high degree of
mineral liberation. Most of the taconite used today requires very fine
grinding. The grinding is normally performed in three or four stages of
dry crushing, followed by wet grinding in rod mills and ball mills. Gy-
ratory crushers are generally used for primary crushing, and cone crushers
are used for secondary and tertiary fine crushing. Intermediate vibrating
screens remove undersize material from the feed to the next crusher and al-
low for closed circuit operation of the fine crushers. The rod and ball
mills are also in closed circuit with classification systems such as cy-
clones. An alternative is to feed some coarse ores directly to wet or dry
semiautogenous or autogenous grinding mills, then to pebble or ball mills.
Ideally, the liberated particles of iron minerals and barren gangue should
be removed from the grinding circuits as soon as they are formed, with
larger particles returned for further grinding.
Concentration - As the iron ore minerals are liberated by the crushing
steps, the ironbearing particles must be concentrated. Since only about 33
percent of the crude taconite becomes a shippable product for iron making,
a large amount of gangue is generated. Magnetic separation and flotation
are most commonly used for concentration of the taconite ore.
Crude ores in which most of the recoverable iron is magnetite (or, in
rare cases, maghemite) are normally concentrated by magnetic separation.
The crude ore may contain 30 to 35 percent total iron by assay, but theo-
retically only about 75 percent of this is recoverable magnetite. The re-
maining iron becomes part of the gangue.
Nonmagnetic taconite ores are concentrated by froth flotation or by a
combination of selective flocculation and flotation. The method is deter-
mined by the differences in surface activity between the iron and gangue
particles. Sharp separation is often difficult.
Various combinations of magnetic separation and flotation may be used
to concentrate ores containing various iron minerals (magnetite and hema-
tite, or maghemite) or wide ranges of mineral grain sizes. Flotation is
also often used as a final polishing operation on magnetic concentrates.
5/83 Mineral Products Industry 8.22-1
-------
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8.22-2
EMISSION FACTORS
5/83
-------
Pelletization - 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 additive, usually powdered bentonite, may be
added to the concentrate to improve ball formation and the physical quali-
ties of the "green" balls. The bentonite is lightly mixed with the care-
fully moistened feed at 4.5 to 9 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 [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 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 tempera-
tures. The grate/kiln apparatus consists of a continuous traveling grate
followed by a rotary kiln. Pellets indurated by the straight grate appara-
tus 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 countercurrent airflow.
1-3
8.22.2 Emissions and Controls
Emission sources in taconite ore processing plants are indicated in
Figure 8.22-1. Particulate emissions also arise from ore mining opera-
tions. Uncontrolled emission factors for the major processing sources are
presented in Table 8.22-1, and control efficiencies in Table 8.22-2.
The taconite ore is handled dry through the crushing stages. All
crushers, size classification screens and conveyor transfer points are ma-
jor points of particulate emissions. Crushed ore is normally ground in wet
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, so par-
ticulate 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
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,
5/83 Mineral Products Industry 8.22-3
-------
TABLE 8.22-1. UNCONTROLLED PARTICULATE EMISSION
FACTORS FOR TACONITE ORE
PROCESSING3
EMISSION FACTOR RATING: D
Source Emissions
kg/Mg Ib/ton
Fine crushing
Waste gas
Pellet handling
Grate discharge
Grate feed
Bentonite blending
Coarse crushing
Ore transfer
Bentonite transfer
39.9
14.6
1.7
0.66
0.32
0.11
0.10
0.05
0.02
79.8
29.2
3.4
1.32
0.64
0.22
0.20
0.10
0.04
Q
, Reference 1 . Median
values .
£ I 1 _ 4_ _
Expressed as units per unit weight of pellets
produced.
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 sul-
fur dioxide emissions. For a natural gas fired furnace, these emissions
are about 0.03 kilograms of S02 per megagram of pellets produced (0.06 lb/
ton). Higher S02 emissions (about 0.6 to 0.7 kg/Mg, or 0.12 to 0.14 lb/
ton) would result from an oil or coal fired furnace.
Particulate emissions from taconite ore processing plants are con-
trolled by a variety of devices, including cyclones, multiclones, roto-
clones, scrubbers, baghouses and electrostatic precipitators. Water sprays
are also used to suppress dusting. Annular coolers are generally left un-
controlled, because their mass loadings of particulates are small, typi-
cally less than 0.11 grams per cubic meter (0.05 g/scf).
The largest source of particulate emissions in taconite ore mines is
traffic on unpaved haul roads.3 Table 8.22-3 presents size specific emis-
sion factors for this source determined through source testing at one taco-
nite mine. Other significant particulate emission sources at taconite
mines are wind erosion and blasting.3
As an alternative to the single valued emission factors for open dust
sources given in Tables 8.22-1 and 8.22-3, empirically derived emission
8.22-4 Mineral Products Industry 5/83
-------
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Mineral Products Industry
8.22-5
-------
TABLE 8.22-3. UNCONTROLLED PARTICIPATE EMISSION FACTORS FOR
HEAVY DUTY VEHICLE TRAFFIC ON HAUL ROADS AT
TACONITE MINES3
Surface
material
Crushed rock
and gla-
cial till
Crushed
taconite
and waste
Emission factor
< 30 jam
3.1
11.0
2.6
9.3
< 15 urn
2.2
7.9
1.9
6.6
by aerodynamic diameter
< 10 |jm
1.7
6.2
1.5
5.2
< 5 pm
1.1
3.9
0.90
3.2
< 2.5 |Jm
0.62
2.2
0.54
1.9
Units
kg/VKT
Ib/VMT
kg/VKT
Ib/VMT
Emission
Factor
Rating
C
C
D
D
Reference 3. Predictive emission factor equations, which generally pro-
vide more accurate estimates of emissions, are presented in Chapter 11.
VKT = Vehicle kilometers traveled. VMT = Vehicle miles traveled.
factor equations are presented in Chapter 11 of this document. Each equa-
tion 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 ob-
served variance in measured emission factors by relating emissions to pa-
rameters 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
suspendable fines in the surface material on an unpaved road), 3) climatic
parameters (e.g., number of precipitation free days per year, when emis-
sions tend to a maximum).
Because the predictive equations allow for emission factor adjustment
to specific source conditions, the equations should be used in place of
the single valued factors for open dust sources, in Tables 8.22-1 and
8.22-3, if emission estimates for sources in a specific taconite ore mine
or processing facility are needed. However, the generally higher quality
ratings assigned to the equations are applicable only if 1) reliable values
of correction 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. Chapter 11 lists measured properties
of aggregate process materials and road surface materials found in taconite
mining and processing facilities, 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 param-
eter values from Chapter 11 reduces the quality ratings of the emission
factor equations by one level.
8.22-6
EMISSION FACTORS
5/83
-------
References for Section 8.22
1. J. P. Pilney and G. V. Jorgensen, Emissions from Iron Ore Mining, Ben-
ficiation and Pelletization, Volume 1, EPA Contract No. 68-02-2113,
Midwest Research Institute, Minnetonka, MN, June 1978.
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. T. A. Cuscino, et al. , Taconite Mining Fugitive Emissions Study,
Minnesota Pollution Control Agency, Roseville, MN, June 1979.
5/83 Mineral Products Industry 8.22-7
-------
8.24 WESTERN SURFACE COAL MINING
8.24.1 General1
There are 12 major coal fields in the western states (excluding the
Pacific Coast and Alaskan fields), as shown in Figure 8.24-1. Together,
they account for more than 64 percent of the surface minable coal reserves
COAL TYPE
LIGNITE
SUBBITUMINOUSCD
BITUMINOUS
9
10
11
12
Coal field
Fort Union
Powder River
North Central
Bighorn Basin
Wind River
Hams Fork.
Uinta
Southwestern Utah
San Juan River
Raton Mesa
Denver
Green River
Strippable reserves
(106 tons)
23,529
56,727
All underground
All underground
3
1,000
308
224
2,318
All underground
All underground
2,120
5/83
Figure 8.24-1. Coal fields of the western U.S.3
Mineral Products Industry
8.24-1
-------
in the United States.2 The 12 coal fields have varying characteristics
which may influence fugitive dust emission rates from mining operations,
including overburden and coal seam thicknesses and structure, mining equip-
ment, operating procedures, terrain, vegetation, precipitation and surface
moisture, wind speeds and temperatures. The operations at a typical west-
ern surface mine are shown in Figure 8.24-2. All operations that involve
movement of soil, coal, or equipment, or exposure of erodible surfaces,
generate some amount of fugitive dust.
The initial operation is removal of topsoil and subsoil with large
scrapers. The topsoil is carried by the scrapers to cover a previously
mined and regraded area as part of the reclamation process or is placed in
temporary stockpiles. The exposed overburden, the earth which is between
the topsoil and the coal seam, is leveled, drilled and blasted. Then the
overburden material is removed down to the coal seam, usually by a dragline
or a shovel and truck operation. It is placed in the adjacent mined cut,
forming a spoils pile. The uncovered coal seam is then drilled and
blasted. A shovel or front end loader loads the broken coal into haul
trucks, and it is taken out of the pit along graded haul roads to the tip-
ple, or truck dump. Raw coal sometimes may be dumped onto a temporary
storage pile and later rehandled by a front end loader or bulldozer.
At the tipple, the coal is dumped into a hopper that feeds the primary
crusher, then is conveyed through additional coal preparation equipment
such as secondary crushers and screens to the storage area. If the mine
has open storage piles, the crushed coal passes through a coal stacker onto
the pile. The piles, usually worked by bulldozers, are subject to wind
erosion. From the storage area, the coal is conveyed to a train loading
facility and is put into rail cars. At a captive mine, coal will go from
the storage pile to the power plant.
During mine reclamation, which proceeds continuously throughout the
life of the mine, overburden spoils piles are smoothed and contoured by
bulldozers. Topsoil is placed on the graded spoils, and the land is pre-
pared for revegetation by furrowing, mulching, etc. From the time an area
is disturbed until the new vegetation emerges, all disturbed areas are sub-
ject to wind erosion.
8.24.2 Emissions
Predictive emission factor equations for open dust sources at western
surface coal mines are presented in Tables 8.24-1 and 8.24-2. Each equa-
tion is for a single dust generating activity, such as vehicle traffic on
unpaved roads. The predictive equation explains much of the observed vari-
ance in emission factors by relating emissions to three sets of source pa-
rameters: 1) measures of source activity or energy expended (e.g., speed
and weight of a vehicle traveling on an unpaved road); 2) properties of the
material being disturbed (e.g., suspendable fines in the surface material
of an unpaved road); and 3) climate (in this case, mean wind speed).
The equations may be used to estimate particulate emissions generated
per unit of source extent (e.g., vehicle distance traveled or mass of mate-
rial transferred).
8.24-2 EMISSION FACTORS 5/83
-------
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8.24-4
EMISSION FACTORS
5/83
-------
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5/83
Mineral Products Industry
8.24-5
-------
The equations were developed through field sampling 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 equa-
tions, given in Table 8.24-3. However, the equations are derated one let-
ter 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
Source
Blasting
Coal loading
Bulldozers
Coal
Overburden
Dragline
Scraper
Grader
Light/medium
duty vehicles
Haul truck
Correction Number
factor of test
samples
Moisture
Depth
Area
Moisture
Moisture
Silt
Moisture
Silt
Drop distance
Moisture
Silt
Weight
Speed
Moisture
Wheels
Silt loading
5
18
18
7
3
3
8
8
19
7
10
15
7
7
29
26
Range
7.2
6
20
90
1,000
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
- 41
- 135
- 9,000
- 100,000
- 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
- 2,270
Geometric
mean Units
17.2
7.9
25.9
1,800
19,000
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
%
m
ft
m2
ft2
%
%
%
%
%
m
ft
%
%
Mg
tons
kph
mph
%
number
g/m2
Ib/acre
Reference 1.
In using the equations to estimate emissions from sources in a spe-
cific western surface coal mine, it is necessary that reliable values for
correction parameters be determined for the specific sources of interest,
if the assigned quality ratings of the equations are to apply. For exam-
ple, actual silt content of coal or overburden measured at a facility
8.24-6
EMISSION FACTORS
5/83
-------
should be used instead of estimated values. In the event that site spe-
cific values for correction parameters cannot be obtained, the appropriate
geometric mean values from Table 8.24-3 may be used, but the assigned qual-
ity rating of each emission factor equation is reduced by one level (e.g.,
A to B).
Emission factors for open dust sources not covered in Table 8.24-3 are
in Table 8.24-4. These factors were determined through source testing at
various western coal mines.
The factors in Table 8.24-4 for mine locations I through V were devel-
oped for specific geographical areas. Tables 8.24-5 and 8.24-6 present
characteristics of each of these mines (areas). A "mine specific" emission
factor should be used only if the characteristics of the mine for which an
emissions estimate is needed are very similar to those of the mine for
which the emission factor was developed. The other (nonspecific) emission
factors were developed at a variety of mine types and thus are applicable
to any western surface coal mine.
As an alternative to the single valued emission factors given in Table
8.24-4 for train or truck loading and for truck or scraper unloading, two
empirically derived emission factor equations are presented in Section
11.2.3 of this document. Each equation was developed for a source opera-
tion (i.e., batch drop and continuous drop, respectively), comprising a
single dust generating mechanism which crosses industry lines.
Because the predictive equations allow emission factor adjustment to
specific source conditions, the equations should be used in place of the
factors in Table 8.24-4 for the sources identified above, if emission esti-
mates for a specific western surface coal mine are needed. However, the
generally higher quality ratings assigned to the equations are applicable
only if 1) reliable values of correction 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. Table 8.24-3
lists measured properties of aggregate materials which can be used to esti-
mate correction parameter values for the predictive emission factor equa-
tions in Chapter 11, in the event that site specific values are not avail-
able. Use of mean correction parameter values from Table 8.24-3 reduces
the quality ratings of the emission factor equations in Chapter 11 by one
level.
5/S3 Mineral Products Industry 8.24-7
-------
TABLE 8.24-4. UNCONTROLLED PARTICULATE EMISSION FACTORS FOR
OPEN DUST SOURCES AT WESTERN SURFACE COAL MINES
Source
Drilling
Topsoil removal by
scraper
Overburden
replacement
Truck loading by
power shovel
(batch drop)
Train loading (batch
or continuous drop)
Bottom dump truck
unloading
(batch drop)
End dump truck
unloading
(batch drop)c
Scraper unloading
(batch drop)
Wind erosion of
exposed areas
Material Mine
location
Overburden Any
Coal V
Topsoil Any
IV
Overburden Any
Overburden V
Coal Any
III
Overburden V
Coal IV
III
II
I
Any
Coal V
Topsoil IV
Seeded land , Any
stripped over-
burden, graded
overburden
TSP
emission
factor
1.3
0.59
0.22
0.10
0.058
0.029
0.44
0.22
0.012
0.0060
0.037
0.018
0.028
0.014
0.0002
0.0001
0.002
0.001
0.027
0.014
0.005
0.002
0.020
0.010
0.014
0.0070
0.066
0.033
0.007
0.004
0.04
0.02
0.38
0.85
Emission
Units Factor
Rating
Ib/hole
kg/hole
Ib/hole
kg/hole
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/T
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
Ib/T
kg/Mg
T
(acreKyr)
Mcr
HK
(hectare) (yr)
B
B
E
E
E
E
D
D
C
C
C
C
D
D
D
D
£
E
E
E
E
E
E
E
D
D
D
D
E
E
C
C
C
C
Roman numerals I through V refer to specific mine locations for which the
corresponding emission factors were developed (Reference 4). Tables 8.24-4
and 8.24-5 present characteristics of each of these mines. See text for
correct use of these "mine specific" emission factors. The other factors
(from Reference 5 except for overburden drilling from Reference 1) can be
applied to any western surface coal mine.
Total suspended particulate (TSF) denotes what is measured by a standard high
volume sampler (see Section 11.2).
Predictive emission factor equations, which generally provide more accurate
estimates of emissions, are presented in Chapter 11.
8.24-8
EMISSION FACTORS
5/83
-------
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Mineral Products Industry
8.24-9
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8.24-10
EMISSION FACTORS
5/83
-------
References for Section 8.24
1. K. Axetell and C. Cowherd, Improved Emission Factors for Fugitive Dust
from Western Surface Coal Mining Sources, 2 Volumes, EPA Contract No.
68-03-2924, U. S. Environmental Protection Agency, Cincinnati, OH,
July 1981.
2. Reserve Base of U. S. Coals by Sulfur Content: Part 2, The Western
States, IC8693, Bureau of Mines, U. S. Department of the Interior,
Washington, DC, 1975.
3. Bituminous Coal and Lignite Production and Mine Operations - 1978,
DOE/EIA-0118(78), U. S. Department of Energy, Washington, DC, June
1980.
4. K. Axetell, Survey of Fugitive Dust from Coal Mines, EPA-908/1-78-003,
U. S. Environmental Protection Agency, Denver, CO, February 1978.
5. J. L. Shearer, et al., Coal Mining Emission Factor Development and
Modeling Study, Amax Coal Company, Carter Mining Company, Sunoco
Energy Development Company, Mobil Oil Corporation, and Atlantic
Richfield Company, Denver, CO, July 1981.
5/83 Mineral Products Industry 8.24-11
-------
11.2 FUGITIVE DUST SOURCES
Significant atmospheric dust arises from the mechanical disturbance of
granular material exposed to the air. Dust generated from these open
sources is termed "fugitive" because it is not discharged to the atmosphere
in a confined flow stream. Common sources of fugitive dust include unpaved
roads, agricultural tilling operations, aggregate storage piles, and heavy
construction operations.
For the above categories of fugitive dust sources, the dust generation
process is caused by two basic physical-phenomena:
1. Pulverization and abrasion of surface materials by application of
mechanical force through implements (wheels, blades, etc.).
2. Entrainment of dust particles by the action of turbulent air cur-
rents, such as wind erosion of an exposed surface by wind speeds over 19
kilometers per hour (12 miles/hr).
The air pollution impact of a fugitive dust source depends on the
quantity and drift potential of the dust particles injected into the atmo-
sphere. In addition to large dust particles that settle out near the
source (often creating a local nuisance problem), considerable amounts of
fine particles are also emitted and dispersed over much greater distances
from the source.
The potential drift distance of particles is governed by the initial
injection height of the particle, the particle's terminal settling veloc-
ity, and the degree of atmospheric turbulence. Theoretical drift dis-
tances, as a function of particle diameter and mean wind speed, have been
computed for fugitive dust emissions.1 These results indicate that, for a
typical mean wind speed of 16 kilometers per hour (10 miles/hr), particles
larger than about 100 micrometers are likely to settle out within 6 to 9
meters (20 to 30 ft) from the edge of the road. Particles that are 30 to
100 micrometers in diameter are likely to undergo impeded settling. These
particles, depending upon the extent of atmospheric turbulence, are likely
to settle within a few hundred feet from the road. Smaller particles, par-
ticularly those less than 10 to 15 micrometers in diameter, have much
slower gravitational settling velocities and are much more likely to have
their settling rate retarded by atmospheric turbulence. Thus, based on the
presently available data, it appears appropriate to report only those par-
ticles smaller than 30 micrometers. Future updates to this document are
expected to define appropriate factors for other particle sizes.
Several of the emission factors presented in this Section are ex-
pressed in terms of total suspended particulate (TSP). TSP denotes what
is measured by a standard high volume sampler. Recent wind tunnel studies
have shown that the particle mass capture efficiency curve for the high
volume sampler is very broad, extending from 100 percent capture of parti-
cles smaller than 10 micrometers to a few percent capture of particles as
large as 100 micrometers. Also, the capture efficiency curve varies with
5/83 Miscellaneous Sources 11.2-1
-------
wind speed and wind direction, relative to roof ridge orientation. Thus,
high volume samplers do not provide definitive particle size information
for emission factors. However, an effective cutpoint of 30 micrometers
aerodynamic diameter is frequently assigned to the standard high volume
sampler.
Control techniques for fugitive dust sources generally involve water-
ing, chemical stabilization, or reduction of surface wind speed with wind-
breaks or source enclosures. Watering, the most common and generally least
expensive method, provides only temporary dust control. The use of chemi-
cals to treat exposed surfaces provides longer dust suppression but may be
costly, have adverse effects on plant and animal life, or contaminate the
treated material. Windbreaks and source enclosures are often impractical
because of the size of fugitive dust sources.
11.2-2 EMISSION FACTORS 5/83
-------
11.2.1 UNPAVED ROADS
11.2.1.1 General
Dust plumes trailing behind vehicles traveling on unpaved roads are a
familiar sight in rural areas of the United States. When a vehicle travels
an unpaved road, the force of the wheels on the road surface causes pul-
verization of surface material. Particles are lifted and dropped from the
rolling wheels, and the road surface is exposed to strong air currents in
turbulent shear with the surface. The turbulent wake behind the vehicle
continues to act on the road surface after the vehicle has passed.
11.2.1.2 Emissions and Correction Parameters
The quantity of dust emissions from a given segment of unpaved road
varies linearly with the volume of traffic. Also, field investigations
have shown that emissions depend on correction parameters (average vehicle
speed, average vehicle weight, average number of wheels per vehicle, road
surface texture and road surface moisture) that characterize the condition
of a particular road and the associated vehicle traffic.1"4
Dust emissions from unpaved roads have been found to vary in direct
proportion to the fraction of silt (particles smaller than 75 micrometers
in diameter) in the road surface material.1 The silt fraction is deter-
mined by measuring the proportion of loose dry surface dust that passes a
200 mesh screen, using the ASTM-C-136 method. Table 11.2.1-1 summarizes
measured silt values for industrial and rural unpaved roads.
TABLE 11.2.1-1.
TYPICAL SILT CONTENT VALUES OF SURFACE MATERIALS ON
INDUSTRIAL AND RURAL UNPAVED ROADS3
Industry
Road use or
surface material
No. of test
samples
Silt (%)
Range Mean
Iron and steel
production
Taconite mining and
Plant road
References 1-9
5/83
13
Miscellaneous Sources
4.3 - 13
7.3
processing
Western surface coal
mining
Rural roads
Haul road
Service road
Access road
Haul road
Scraper road
Haul road
(freshly graded)
Gravel
Dirt
12
8
2
21
10
5
2
1
3.7
2.4
4.9
2.8
7.2
18
12
- 9.7
- 7.1
- 5.3
- 18
- 25
- 29
- 13
5.8
4.3
5.1
8.4
17
24
12
68
11.2.1-1
-------
The silt content of a rural dirt road will vary with location, and it
should be measured. As a conservative approximation, the silt content of
the parent soil in the area can be used. However, tests show that road
silt content is normally lower than the surrounding parent soil, because
the fines are continually removed by the vehicle traffic, leaving a higher
percentage of coarse particles.
Unpaved roads have a hard nonporous surface that usually dries quickly
after a rainfall. The temporary reduction in emissions because of precipi-
tation may be accounted for by neglecting emissions on "wet" days [more
than 0.254 mm (0.01 in.) of precipitation].
11.2.1.3 Predictive Emission Factor Equations
The following empirical expression may be used to estimate the quan-
tity of size specific particulate emissions from an unpaved road, per ve-
hicle unit of travel, with a rating of A:
/ c\ / Q\ / w \ /w\ /^fi^-rA
E = k(1.7) (jf (•£) yU (|\ (^f-) (kg/VKT) (1)
\1// \HO/ \2..l! \i*I \ Job / °
(ll) (
where: E = emission factor
k = particle size multiplier (dimensionless)
s = silt content of road surface material (%)
S = mean vehicle speed, km/hr (mph)
W = mean vehicle weight, Mg (tons)
w = mean number of wheels
p = number of days with at least 0.254 mm (0.01 in.) of pre-
cipitation per year
The particle size multiplier (k) in Equation 1 varies with aerodynamic par
ticle size range as follows:
Aerodynamic Particle Size Multipler
for Equation 1
< 30 (Jm
0.80
< 15 pm
0.57
< 10 (Jm
0.45
< 5 (Jm
0.28
< 2.5 |Jm
0.16
The number of wet days per year (p) for the geographical area of in-
terest should be determined from local climatic data. Figure 11.2.1-1
gives the geographical distribution of the mean annual number of wet days
per year in the United States.
Equation 1 retains the assigned quality rating if applied within the
ranges of source conditions that were tested in developing the equation, as
follows :
11.2.1-2 EMISSION FACTORS 5/83
-------
cd
.u
to
-d
0)
s
g
w
8.
«
I
1
i
c
o
•H
4J
tfl
M U
J ^
= ^
Z -H
CJ
S-i
p,
U_l
s
» 9 m
" * M
*~ 5
O
(1)
M
i
u
o
•
o
CO
>.
cfl
n
0)
n
to
OJ
(N
(U
S-l
Ml
•H
5/83
Miscellaneous Sources
11.2.1-3
-------
Range of Source Conditions for Equation 1
Road
surface
silt Mean vehicle
content weight
(%) Mg tons
4.3 - 20 2.7 - 142 3 - 157
Mean vehicle Mean
speed No. of
km/hr mph wheels
21-64 13-40 4 - 13
Also, to retain the quality rating of Equation 1 applied to a specific un-
paved road, it is necessary that reliable correction parameter values for
the specific road in question be determined. The field and laboratory pro-
cedures for determining road surface silt content are given in Reference 4.
In the event that site specific values for correction parameters cannot be
obtained, the appropriate mean values from Table 11.2.1-1 may be used, but
the quality rating of the equation is reduced to B.
Equation 1 was developed for calculation of annual average emissions,
and thus, is to be multiplied by annual source extent in vehicle distance
traveled (VDT). Annual average values for each of the correction param-
eters are to be substituted into the equation. Worst case emissions, cor-
responding to dry road conditions, may be calculated by setting p = 0 in
Equation 1 (which is equivalent to dropping the last term from the equa-
tion) . A separate set of nonclimatic correction parameters and a higher
than normal VDT value may also be justified for the worst case averaging
period (usually 24 hours). Similarly, to calculate emissions for a 91 day
season of the year using Equation 1, replace the term (365-p)/365 with the
term (91-p)/91, and set p equal to the number of wet days in the 91 day pe-
riod. Also, use appropriate seasonal values for the nonclimatic correction
parameters and for VDT.
11.2.1.4 Control Methods
Common control techniques for unpaved roads are paving, surface treat-
ing with penetration chemicals, working soil stabilization chemicals into
the roadbed, watering, and traffic control regulations. Paving, as a con-
trol technique, is often not economically practical. Surface chemical
treatment and watering can be accomplished with moderate to low costs, but
frequent retreatments are required. Traffic controls such as speed limits
and traffic volume restrictions provide moderate emission reductions but
may be difficult to enforce. Table 11.2.1-3 shows approximate control ef-
ficiencies achievable for each method. Watering, because of the frequency
of treatments required, is generally not feasible for public roads and is
effectively used only where water and watering equipment are available and
where roads are confined to a single site, such as a construction location.
11.2.1-4 EMISSION FACTORS 5/83
-------
TABLE 11.2.1-3. CONTROL METHODS FOR UNPAVED ROADS11
Approximate
control
Control method efficiency
Paving 85
Treating surface with penetrating
chemicals 50
Working soil stabilizing chemicals
into roadbed 50
Speed control
48 kph (30 mph) 25
32 kph (20 mph) 50
24 kph (15 mph) 63
Based on the assumption that "uncontrolled" speed is
typically 64 kph (40 mph). Between 21 and 64 kph
(13 and 40 mph), emissions are linearly proportional
to vehicle speed (see Equation 1).
References for Section 11.2.1
1. C. Cowherd, et a1., Development of Emission Factors for Fugitive Dust
Sources, EPA-450/3-74-037, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1974.
2. R. J. Dyck and J. J. Stukel, "Fugitive Dust Emissions from Trucks on
Unpaved Roads", Environmental Science and Technology, 10(10):1046-
1048, October 1976.
3. R. 0. McCaldin and K. J. Heidel, "Particulate Emissions from Vehicle
Travel over Unpaved Roads", Presented at the 71st Annual Meeting of
the Air Pollution Control Association, Houston, TX, June 1978.
4. C. Cowherd, Jr., et al., Iron and Steel Plant Open Dust Source Fugi-
tive Emission Evaluation, EPA-600/2-79-103, U. S. Environmental Pro-
tection Agency, Research Triangle Park, NC, May 1979.
5. 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.
6. R. Bohn, Evaluation of Open Dust Sources in the Vicinity of Buffalo,
New York, U. S. Environmental Protection Agency, New York, NY, March
1979.
5/83 Miscellaneous Sources 11.2.1-5
-------
7. C. Cowherd, Jr., and T. Cuscino, Jr., Fugitive Emissions Evaluation,
Equitable Environmental Health, Inc., Elmhurst, IL, February 1977.
8. T. Cuscino, et al. , Taconite Mining Fugitive Emissions Study,
Minnesota Pollution Control Agency, Roseville, MN, June 1979.
9. K. Axetell and C. Cowherd, Jr., Improved Emission Factors for Fugitive
Dust from Western Surface Coal Mining Sources, 2 Volumes, EPA Contract
No^ 68-03-2924, PEDCo Environmental", Inc. , Kansas City, MO,
July 1981.
10. Climatic Atlas of the United States, U. S. Department of Commerce,
Washington, DC, June 1968.
11. G. A. Jutze, et al., Investigation of Fugitive Dust Sources Emissions
and Control, EPA-450/3-74-036a, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1974.
11.2.1-6 EMISSION FACTORS 5/83
-------
11.2.2 AGRICULTURAL TILLING
11.2.2.1 General
The two universal objectives of agricultural tilling are the creation
of the desired soil structure to be used as the crop seedbed and the eradi-
cation of weeds. Plowing, the most common method of tillage, consists of
some form of cutting loose, granulating and inverting the soil, and turning
under the organic litter. Implements that loosen the soil and cut off the
weeds but leave the surface trash in place have recently become more popu-
lar for tilling in dryland farming areas.
During a tilling operation, dust particles from the loosening and pul-
verization of the soil are injected into the atmosphere as the soil is
dropped to the surface. Dust emissions are greatest during periods of dry
soil and during final seedbed preparation.
11.2.2.2 Emissions and Correction Parameters
The quantity of dust from agricultural tilling is proportional to the
area of land tilled. Also, emissions depend on surface soil texture and
surface soil moisture content, conditions of a particular field being
tilled.
Dust emissions from agricultural tilling have been found to vary di-
rectly with the silt content (defined as particles < 75 micrometers in di-
ameter) of the surface soil depth (0 to 10 cm [0 to 4 in.]). The soil silt
content is determined by measuring the proportion of dry soil that passes a
200 mesh screen, using ASTM-C-136 method. Note that this definition of
silt differs from that customarily used by soil scientists, for whom silt
is particles from 2 to 50 micrometers in diameter.
Field measurements2 indicate that dust emissions from agricultural
tilling are not significantly related to surface soil moisture, although
limited earlier data had suggested such a dependence.1 This is now be-
lieved to reflect the fact that most tilling is performed under dry soil
conditions, as were the majority of the field tests.1"2
Available test data indicate no substantial dependence of emissions on
the type of tillage implement, if operating at a typical speed (for exam-
ple, 8 to 10 km/hr [5 to 6 mph]).1"2
11.2.2.3 Predictive Emission Factor Equation
The quantity of dust emissions from agricultural tilling, per acre of
land tilled, may be estimated with a rating of A or B (see below) using the
following empirical expression2:
E = k(604)(s)°-6 (kg/hectare) (1)
E = k(538)(s)°-6 (Ib/acre)
5/83 Miscellaneous Sources 11.2.2-1
-------
where: E = emission factor
k = particle size multipler (dimensionless)
s = silt content of surface soil (%)
The particle size multiplier (k) in the equation varies with aerodynamic
particle size range as follows:
Aerodynamic Particle Size Multiplier for Equation 1
Total
particulate
1.0
< 30 |Jm
0.33
< 15 Mm
0.25
< 10 (Jm
0.21
< 5 (Jm
0.15
< 2.5 |Jm
0.10
Equation 1 is rated A if used to estimate total particulate emissions,
and B if used for a specific particle size range. The equation retains its
assigned quality rating if applied within the range of surface soil silt
content (1.7 to 88 percent) that was tested in developing the equation.
Also, to retain the quality rating of Equation 1 applied to a specific ag-
ricultural field, it is necessary to obtain a reliable silt value(s) for
that field. The sampling and analysis procedures for determining agricul-
tural silt content are given in Reference 2. In the event that a site spe-
cific value for silt content cannot be obtained, the mean value of 18 per-
cent may be used, but the quality rating of the equation is reduced by one
level.
11.2.2.4 Control Methods3
In general, control methods are not applied to reduce emissions from
agricultural tilling. Irrigation of fields before plowing will reduce
emissions, but in many cases, this practice would make the soil unworkable
and would adversely affect the plowed soil's characteristics. Control
methods for agricultural activities are aimed primarily at reduction of
emissions from wind erosion through such practices as continuous cropping,
stubble mulching, strip cropping, applying limited irrigation to fallow
fields, building windbreaks, and using chemical stabilizers. No data are
available to indicate the effects of these or other control methods on
agricultural tilling, but as a practical matter, it may be assumed that
emission reductions are not significant.
References for Section 11.2.2
1. C. Cowherd, Jr., et al., Development of Emission Factors for Fugitive
Dust Sources, EPA-450/3-74-037, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1974.
2. T. A. Cuscino, Jr., et al. , The Role of Agricultural Practices in
Fugitive Dust Emissions, California Air Resources Board, Sacramento,
CA, June 1981.
3. G. A Jutze, et al., Investigation of Fugitive Dust - Sources Emissions
And Control, EPA-450/3-74-036a, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1974.
11.2.2-2 EMISSION FACTORS 5/83
-------
11.2.3 AGGREGATE HANDLING AND STORAGE PILES
11.2.3.1 General
Inherent in operations that use minerals in aggregate form is the
maintenance of outdoor storage piles. Storage piles are usually left un-
covered, partially because of the need for frequent material transfer into
or out of storage.
Dust emissions occur at several points in the storage cycle, during
material loading onto the pile, during disturbances by strong wind cur-
rents, and during loadout from the pile. The movement of trucks and load-
ing equipment in the storage pile area is also a substantial source of
dust.
11.2.3.2 Emissions and Correction Parameters
The quantity of dust emissions from aggregate storage operations var-
ies with the volume of aggregate passing through the storage cycle. Also,
emissions depend on three correction parameters that characterize the con-
dition of a particular storage pile: age of the pile, moisture content and
proportion of aggregate fines.
When freshly processed aggregate is loaded onto a storage pile, its
potential for dust emissions is at a maximum. Fines are easily disaggre-
gated and released to the atmosphere upon exposure to air currents from ag-
gregate transfer itself or high winds. As the aggregate weathers, how-
ever, potential for dust emissions is greatly reduced. Moisture causes ag-
gregation and cementation of fines to the surfaces of larger particles.
Any significant rainfall soaks the interior of the pile, and the drying
process is very slow.
Field investigations have shown that emissions from aggregate storage
operations vary in direct proportion to the percentage of silt (particles
< 75 |Jm in diameter) in the aggregate material.1 3 The silt content is de-
termined by measuring the proportion of dry aggregate material that passes
through a 200 mesh screen, using ASTM-C-136 method. Table 11.2.3-1 summa-
rizes measured silt and moisture values for industrial aggregate materials.
11.2.3.3 Predictive Emission Factor Equations
Total dust emissions from aggregate storage piles are contributions of
several distinct source activities within the storage cycle:
1. Loading of aggregate onto storage piles (batch or continuous drop
operations).
2. Equipment traffic in storage area.
3. Wind erosion of pile surfaces and ground areas around piles.
4. Loadout of aggregate for shipment or for return to the process
stream (batch or continuous drop operations).
5/33 Miscellaneous Sources 11.2.3-1
-------
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Adding aggregate material to a storage pile or removing it usually in-
volves dropping the material onto a receiving surface. Truck dumping on
the pile or loading out from the pile to a truck with a front end loader
are examples of batch drop operations. Adding material to the pile by a
conveyor stacker is an example of a continuous drop operation.
The quantity of particulate emissions generated by a batch drop opera-
tion, per ton of material transferred, may be estimated, with a rating of
C, using the following empirical expression2:
E = k(0.00090)
E = k(0.0018)
0.33
(5) (2.2) (l.s)
/M\2 MM
V27 U.6/
(I) (g) (I)
(if (I)
(kg/Mg)
(1)
0.33
(Ib/ton)
where:
E = emission factor
k = particle size multipler (dimensionless)
s = material silt content (%)
U = mean wind speed, m/s (mph)
H = drop height, m (ft)
M = material moisture content (%)
Y = dumping device capacity, m3 (yd3)
The particle size multipler (k) for Equation 1 varies with aerodynamic par-
ticle size, shown in Table 11.2.3-2.
TABLE 11.2.3-2.
AERODYNAMIC PARTICLE SIZE
MULTIPLIER (k) FOR
EQUATIONS 1 AND 2
Equation < 30 < 15 < 10 < 5 < 2.5
|jm (Jm |jm (Jm (Jm
Batch drop 0.73 0.48 0.36 0.23 0.13
Continuous
drop 0.77 0.49 0.37 0.21 0.11
The quantity of particulate emissions generated by a continuous drop
operation, per ton of material transferred, may be estimated, with a rating
of C, using the following empirical expression3:
5/83
Miscellaneous Sources
11.2.3-3
-------
E = k(0.00090)
E = k(0.0018)
2.2
(JL\
\3.0/
(I)
(kg/Mg)
(2)
(Ib/ton)
where: E = emission factor
k = particle size multiplier (dimensionless)
s = material silt content (%)
U = mean wind speed, m/s (mph)
H = drop height, ra (ft)
M = material moisture content (%)
The particle size multiplier (k) for Equation 2 varies with aerodynamic
particle size, as shown in Table 11.2.3-2.
Equations 1 and 2 retain the assigned quality rating if applied within
the ranges of source conditions that were tested in developing the equa-
tions, as given in Table 11.2.3-3. Also, to retain the quality ratings of
Equations 1 or 2 applied to a specific facility, it is necessary that reli-
able correction parameters be determined for the specific sources of inter-
est. The field and laboratory procedures for aggregate sampling are given
in Reference 3. In the event that site specific values for correction pa-
rameters cannot be obtained, the appropriate mean values from Table
11.2.3-1 may be used, but in that case, the quality ratings of the equa-
tions are reduced by one level.
TABLE 11.2.3-3.
RANGES OF SOURCE CONDITIONS FOR
EQUATIONS 1 AND 2a
Silt Moisture
Equation content content
(%) (%)
Dumping capacity
ma yda
Drop height
m ft
Batch drop 1.3-7.3 0.25-0.70 2.10-7.6 2.75-10
NA
NA
Continuous
drop 1.4-19 0.64-4.8 NA
NA 1.5-12 4.8-39
NA = not applicable.
For emissions from equipment traffic (trucks, front end loaders, doz-
ers, etc.) traveling between or on piles, it is recommended that the equa-
tions for vehicle traffic on unpaved surfaces be used (see Section 11.2.1).
For vehicle travel between storage piles, the silt value(s) for the areas
11.2.3-4
EMISSION FACTORS
5/83
-------
among the piles (which may differ from the silt values for the stored mate-
rials) should be used.
For emissions from wind erosion of active storage piles, the following
total suspended particulate (TSP) emission factor equation is recommended:
E = 1.9 • (kg/day/hectare) (3)
E = l'7 fe) (H?) (if) (^/day/acre)
where: E = total suspended particulate emission factor
s = silt content of aggregate (%)
p = number of days with ^ 0.25 mm (0.01 in.) of precipitation
per year
f = percentage of time that the unobstructed wind speed ex-
ceeds 5.4 m/s (12 mph) at the mean pile height
The coefficient in Equation 3 is taken from Reference 1, based on sam-
pling of emissions from a sand and gravel storage pile area during periods
when transfer and maintenance equipment was not operating. The factor from
Test Report 1, expressed in mass per unit area per day, is more reliable
than the factor expressed in mass per unit mass of material placed in stor-
age, for reasons stated in that report. Note that the coefficient has been
halved to adjust for the estimate taat the wind speed through the emission
layer at the test site was one half of the value measured above the top of
the piles. The other terms in this equation were added to correct for
silt, precipitation and frequency of high winds, as discussed in Refer-
ence 2. Equation 3 is rated C for application in the sand and gravel in-
dustry and D for other industries.
Worst case emissions from storage pile areas occur under dry windy
conditions. Worst case emissions from materials handling (batch and con-
tinuous drop) operations may be calculated by substituting into Equations 1
and 2 appropriate values for aggregate material moisture content and for
anticipated wind speeds during the worst case averaging period, usually
24 hours. The treatment of dry conditions for vehicle traffic (Section
11.2.1) and for wind erosion (Equation 3), centering around parameter p,
follows the methodology described in Section 11.2.1. Also, a separate set
of nonclimatic correction parameters and source extent values corresponding
to higher than normal storage pile activity may be justified for the worst
case averaging period.
11.2.3.4 Control Methods
Watering and chemical wetting agents are the principal means for con-
trol of aggregate storage pile emissions. Enclosure or covering of in-
active piles to reduce wind erosion can also reduce emissions. Watering is
useful mainly to reduce emissions from vehicle traffic in the storage pile
area. Watering of the storage piles themselves typically has only a very
temporary slight effect on total emissions. A much more effective tech-
nique is to apply chemical wetting agents for better wetting of fines and
5/83 Miscellaneous Sources 11.2.3-5
-------
longer retention of the moisture film. Continuous chemical treatment of
material loaded onto piles, coupled with watering or treatment of roadways,
can reduce total particulate emissions from aggregate storage operations by
up to 90 percent.8
References for Section 11.2.3
1. C. Cowherd, Jr., et al., Development of Emission Factors for Fugitive
Dust Sources, EPA-450/3-74-037, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1974.
2. 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.
3. C. Cowherd, Jr., et al. , Iron and Steel Plant Open Dust Source Fugi-
tive Emission Evaluation, EPA-600/2-79-103, U. S. Environmental Pro-
tection Agency, Research Triangle Park, NC, May 1979.
4. R. Bohn, Evaluation of Open Dust Sources in the Vicinity of Buffalo,
New York, U. S. Environmental Protection Agency, New York, NY, March
1979.
5. C. Cowherd, Jr., and T. Cuscino, Jr., Fugitive Emissions Evaluation,
Equitable Environmental Health, Inc., Elmhurst, IL, February 1977.
6. T. Cuscino, et al. , Taconite Mining Fugitive Emissions Study,
Minnesota Pollution Control Agency, Roseville, MN, June 1979.
7. K. Axetell and C. Cowherd, Jr., Improved Emission Factors for Fugitive
Dust from Western Surface Coal Mining Sources, 2 Volumes, EPA Contract
No. 68-03-2924, PEDCo Environmental, Inc., Kansas City, MO, July 1981.
8. G. A. Jutze, et al., Investigation of Fugitive Dust Sources Emissions
and Control, EPA-450/3-74-036a, U. S. Environmental Protection Agency,
Research Triangle Park, NC, June 1974.
11.2.3-6 EMISSION FACTORS 5/83
-------
11.2.6 INDUSTRIAL PAVED ROADS
11.2.6.1 General
Various field studies have indicated that dust emissions from indus-
trial 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 un-
paved 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 var-
ies 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 par-
ticular road and associated vehicle traffic.1"2
Dust emissions from industrial paved roads have been found to vary in
direct proportion to the fraction of silt (particles < 75 Hm in diameter)
in the road surface material.1"2 The silt fraction is determined by mea-
suring the proportion of loose dry surface dust that passes a 200 mesh
screen, using the ASTM-C-136 method. In addition, it has also been found
that emissions vary in direct proportion to the surface dust loading.1"2
The road surface dust loading is that loose material which can be collected
by vacuuming and broom sweeping the traveled portion of the paved road.
Table 11.2.6-1 summarizes measured silt and loading values for industrial
paved roads.
TABLE 11.2.6-1. TYPICAL SILT CONTENT AND LOADING VALUES FOR
PAVED ROADS AT IRON AND STEEL PLANTS3
Silt (%) Loading
Travel Range Mean
Industry lanes Range Mean kg/km Ib/mi kg/km Ib/mi
Iron and
steel
production 2 1.1-13 5.9 18 - 4,800 65 - 17,000 760 2,700
References 1-3. Based on nine test samples.
5/33 Miscellaneous Sources 11.2.6-1
-------
11.2.6.3 Predictive Emission Factor Equation
The quantity of particulate emissions generated by vehicle traffic on
dry industrial paved roads, per vehicle mile traveled, may be estimated,
with a rating of B or D (see below), using the following empirical expres-
sion:
E = k(0.025)1 (£) (^) (^) (A) ' (kg/VKT) (1)
E = k(0.090)1 (Ib/VMT)
where: E = emission factor
k = particle size multiplier (dimensionless) (see below)
I = industrial augmentation factor (dimensionless) (see below)
n = number of traffic lanes
s = surface material silt content (%)
L = surface dust loading, kg/km (Ib/mile) (see below)
W = average vehicle weight, Mg (tons)
The particle size multipler (k) above varies with aerodynamic size range as
follows:
Aerodynamic Particle Size Multiplier (k)
for Equation 1
< 30 pm < 15 |jm < 10 |jm < 5 pm < 2.5 Mm
0.86 0.64 0.51 0.32 0.17
To determine particulate emissions for a specific particle size range, use
the appropriate value of k shown above.
The industrial road augmentation factor (I) in the equation 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. I = 1.0 for cases in
which traffic does not travel unpaved areas. A value of I between 1.0 and
7.0 should be used in the equation which best represents conditions for
paved roads at a certain industrial facility.
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:
11.2.6-2 EMISSION FACTORS 5/83
-------
Silt
content Surface loading No. of Vehicle weight
(%) kg/km Ib/mile lanes Mg tons
5.1 - 92 42.0 - 2,000 149 - 7,100 2-4 2.7-12 3-13
If I > 1.0, the rating of the equation drops to D because of the arbitrari-
ness in the guidelines for estimating I.
Also, to retain the quality ratings of Equation 1 applied to a spe-
cific industrial paved road, it is necessary that reliable correction pa-
rameter values for the specific road in question be determined. The field
and laboratory procedures for determining surface material silt content and
surface dust loading are given in Reference 2. In the event that site spe-
cific values for correction parameters cannot be obtained, the appropriate
mean values from Table 11.2.6-1 may be used, but the quality ratings of the
equation are reduced by one level.
References for Section 11.2.6
1. 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.
2. C. Cowherd, Jr., et al. , Iron and Steel Plant Open Dust Source Fugi-
tive Emission Evaluation, EPA-600/2-79-103, U. S. Environmental Pro-
tection Agency, Research Triangle Park, NC, May 1979.
3. R. Bohn, Evaluation of Open Dust Sources in the Vicinity of Buffalo,
New York, U. S. Environmental Protection Agency, New York, NY, March
1979~.
5/83 Miscellaneous Sources 11.2.6-3
-------
SOME USEFUL WEIGHTS AND MEASURES
grain
gram
ounce
kilogram
pound
0.002
0.04
28.35
2.21
0.45
ounces
ounces
grams
pounds
kilograms
pound (troy)
ton (short)
ton (long)
ton (metric)
ton (shipping)
12 ounces
2000 pounds
2240 pounds
2200 pounds
40 feet3
centimeter
inch
foot
meter
yard
mile
0.39 inches
2.54 centimeters
30.48 centimeters
1.09 yards
0.91 meters
1.61 kilometers
centimeter2 0.16 inches2
inch2
foot2^
meter2
yard2
mile2
6.45 centimeters2
0.09 meters2
1.2 yards2
0.84 meters2
2.59 kilometers2
centimeter^
inch3
foot3
foot3
meter3
yard3
0.061 inches3
16.39 centimeters3
centimeters3
inches3
yards3
283.17
1728
1.31
0.77
meters
cord
cord
peck
bushel (dry)
128 feet3
4 meters;
8 quarts
4 pecks
bushel 2150.4 inches3
gallon (U.S.)
barrel
hogshead
township
hectare
231 inches3
31.5 gallons
2 barrels
36 miles2
2.5 acres
MISCELLANEOUS DATA
One cubic foot of anthracite coal weighs about 53 pounds.
One cubic foot of bituminous coal weighs from 47 to 50 pounds.
One ton of coal is equivalent to two cords of wood for steam purposes.
A gallon of water (U.S. Standard) weighs 8.33 Ibs. and contains 231
cubic inches.
There are 9 square feet of heating surface to each square foot of grate
surface.
A cubic foot of water contains 7.5 gallons and 1728 cubic inches, and
weighs 62.5 Ibs.
Each nominal horsepower of a boiler requires 30 to 35 Ibs. of water per
hour.
A horsepower is equivalent to raising 33,000 pounds one foot per minute,
or 550 pounds one foot per second.
To find the pressure in pounds per square inch of column of water,
multiply the height of the column in feet by 0.434.
2/80
Appendix
A-9
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A-10
Appendix
5/83
-------
DENSITIES OF SELECTED SUBSTANCES
Substance
Fuels
Crude Oil
Residual Oil
Distillate Oil
Gasoline
Natural Gas
Butane
Propane
Wood (Air dried)
Elm
Fir, Douglas
Fir, Balsam
Hemlock
Hickory
Maple , Sugar
Maple, White
Oak, Red
Oak, White
Pine, Southern
Agricultural Products
Corn
Milo
Oats
Barley
Wheat
Cotton
Mineral Products
Brick
Cement
Cement
Concrete
Glass , Common
Gravel , Dry Packed
Gravel, Wet
Gypsum, Calcined
Lime, Pebble
Sand, Gravel (Dry, loose)
Density
874 kg/m3
944 kg/m3
845 kg/m3
739 kg/m3
673 kg/m3
579 kg/m3
507 kg/m3
561 kg/m3
513 kg/m3
400 kg/m3
465 kg/m3
769 kg/m3
689 kg/m3
529 kg/m3
673 kg/m3
769 kg/m3
641 kg/m3
25.4 kg/bu
25.4 kg/bu
14.5 kg/bu
21.8 kg/bu
27.2 kg/bu
226 kg/ bale
2.95 kg/brick
170 kg/bbl
1483 kg/m3
2373 kg/m3
2595 kg/m3
1600-1920 kg/m3
2020 kg/m3
880-960 kg/m3
850-1025 kg/m3
1440-1680 kg/m3
7.3 Ib/gal
7.88 Ib/gal
7.05 Ib/gal
6.17 Ib/gal
1 lb/23.8
4.84 Ib/gal
4.24 Ib/gal
35 lb/ft3
32 lb/ft3
25 lb/ft3
29 lb/ft3
48 lb/ft3
43 lb/ft3
33 lb/ft3
42 lb/ft3
48 lb/ft3
40 lb/ft3
56 Ib/bu
56 Ib/bu
32 Ib/bu
48 Ib/bu
60 Ib/bu
500 Ib/bale
ft3
(liquid)
(liquid)
6.5 Ib/brick
375 Ib/bbl
2500 lb/yd3
4000 lb/yd3
162 lb/ft3
100-120 lb/ft3
126 lb/ft3
55-60 lb/ft3
53-64 lb/ft3
90-105 lb/ft3
5/83
Appendix
A-ll
-------
CONVERSION FACTORS FOR COMMON AIR POLLUTION MEASUREMENTS
AIRBORNE PARTICIPATE MATTER
To convert from
Mllllgrams/cu m
Grams/cu ft
Grams/ cu m
Mlcrograms/cu m
Mlcrograms/cu ft
Pounds/1000 cu ft
To
Grams/cu ft
Grams/cu m
Micrograms/cu m
Micrograms/cu ft
Pounds/1000 cu ft
Milllgrams/cu m
Grams/cu m
Micrograms/cu m
Micrograms/cu ft
Pounds/1000 cu ft
Milligrams/cu m
Grams/cu ft
Micrograms/cu m
Micrograms/cu ft
Pounds/1000 cu ft
Milligrams/cu m
Grams/cu ft
Grams/cu m
Micrograms/cu ft
Pounds/1000 cu ft
Milligrams/cu m
Grams/cu ft
Grams/cu m
Micrograms/cu m
Pounds/1000 cu ft
Milligrams/cu m
Grams/cu ft
Micrograms/cu tn
Grams/cu m
Micrograms/cu ft
Multiply by
283.2 x ID"6
0.001
1000.0
28.32
62.43 x 10-6
35.3145 x 103
35.314
35.314 x 106
1.0 x 106
2.2046
1000.0
0.02832
1.0 x 106
28.317 x 103
0.06243
0.001
28.317 x 10-9
1.0 x 10-6
0.02832
62.43 x 10-9
35.314 x 10-3
1.0 x 10-6
35.314 x 10-6
35.314
2.2046 x 10-6
16.018 x 103
0.35314
16.018 x 106
16.018
353.14 x 103
SAMPLING PRESSURE
To convert from
To
Multiply by
Millimeters of mercury
(0°C)
Inches of mercury
(0°C)
Inches of water (60°F)
Inches of water (60°F)
Inches of water (60°F)
Millimeters of mercury
(0°C)
Inches of mercury (0°C)
0.5358
13.609
1.8663
73.48 x 10-3
A-12
Appendix
5/83
-------
CONVERSION FACTORS FOR COMMON AIR POLLUTION MEASUREMENTS
ATMOSPHERIC GASES
To convert from
To
Multiply by
Milligrams/cu m
Micrograms/cu m
Micrograms/liter
Ppm by volume (20°C)
Ppm by weight
Pounds/cu ft
Micrograms/cu m
Micrograms/li ter
Ppm by volume (20°C)
Ppm by weight
Pounds/cu ft
Milllgrams/cu m
Micrograms/liter
Ppm by volume (20°C)
Ppm by weight
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
Ppm by volume (20°C)
Ppm by weight
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
Micrograms/li ter
Ppm by weight
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
Micrograms/liter
Ppm by volume (20°C)
Pounds/cu ft
Milligrams/cu m
Micrograms/cu m
Micrograms/liter
Ppm by volume (20°C)
Ppm by weight
1000.0
1.0
24.04
M
0.8347
62.43 x 10~9
0.001
0.001
0.02404
M
834.7 x 10-6
62.43 x 10~12
1.0
1000.0
24 .04
M
0.8347
62.43 x 10~9
M
24.04
M
0.02404
M
24.04
M
28.8
M
385.1 x 10b
1.198
1.198 x 10-3
1.198
28.8
M
7.48 x 10-6
16.018 x 106
16.018 x 109
16.018 x 106
385.1 x 1Q6
M
133.7 x 103
M = Molecular weight of gas.
5/83
Appendix
A-13
-------
CONVERSION FACTORS FOR COMMON AIR POLLUTION MEASUREMENTS
VELOCITY
To convert from
Meters/sec
Kiloraeters/hr
Feet/ sec
Miles/hr
To
Kiloraeters/hr
Feet/ sec
Miles/hr
Meters/sec
Feet/sec
Miles/hr
Meters/sec
Kilometers/hr
Miles/hr
Meters/sec
Kilometers/hr
Feet/sec
Multiply by
3.6
3.281
2.237
0.2778
0.9113
0.6214
0.3048
1.09728
0.6818
0.4470
1.6093
1.4667
ATMOSPHERIC PRESSURE
To convert from
Atmospheres
Millimeters of mercury
Inches of mercury
Millibars
To
Millimeters of mercury
Inches of mercury
Millibars
Atmospheres
Inches of mercury
Millibars
Atmospheres
Millimeters of mercury
Millibars
Atmospheres
Millimeters of mercury
Inches of mercury
Multiply by
760.0
29.92
1013.2
1.316 x ID"3
39.37 x 10~3
1.333
0.03333
25.4005
33.35
0.00987
0.75
0.30
VOLUME EMISSIONS
To convert from
Cubic m/min
Cubic ft/min
To
Cubic ft/min
Cubic m/min
Multiply by
35.314
0.0283
A-14
Appendix
5/83
-------
BOILER CONVERSION FACTORS
1 Megawatt = 10.5 x 106 BTU/hr
(8 to 14 x 106 BTU/hr)
1 Megawatt - 8 x 103 Ib steara/hr
(6 to 11 x 103 Ib steam/hr)
1 BHP
34.5 Ib steam/hr
1 BHP = 45 x 103 BTU/hr
(40 to 50 x 103 BTU/hr)
1 Ib steam/hr - 1.4 x 103 BTU/hr
(1.2 to 1.7 x 103 BTU/hr)
NOTES: In the relationships,
Megawatt Is the net electric power production of a steam
electric power plant.
BHP is boiler horsepower.
Lb steam/hr is the steam production rate of the boiler.
BTU/hr is the heat Input rate to the boiler (based on the
gross or high heating value of the fuel burned).
For less efficient (generally older and/or smaller) boiler operations,
use the higher values expressed. For more efficient operations
(generally newer and/or larger), use the lower vlaues.
VOLUME
Cubic Inches
Mllllliters
Liters
Ounces (U. S. fl.)
Gallons (U. S.)*..
Barrels (U. S.)...
Cubic feet
cu. in.
0.061024
61.024
1 .80469
231
7276.5
1728
ml.
16.3868
1000
29.5729
3785.3
1.1924x105
2.8316x10*
liters
.0163868
0.001
0.029573
3.7853
119.2369
28.316
ounces
(U. S. fl.)
0.5541
0.03381
33.8147
128
4032.0
957.568
gallons
(U. S.)
4.3290xlO~3
2.6418x10-*
0.26418
7. 8125xlO-3
31.5
7.481
barrels
(U. S.)
1.37429x10-*
8.387xlO-6
8. 387xlO-3
2 .48x10-*
0.031746
0.23743
cu. ft.
5.78704x10-*
3.5316x10-5
0.035316
1.0443xlO"3
0.13368
4.2109
S. gallon of water at 16.7°C (62°F) weighs 3.780 kg. or 8.337 pounds (avoir.)
MASS
Grams
Kilograms
Ounces (avoir.)...
Pounds (avoir.)*..
Grains
Tons (U. S.)
Milligrams
grams
1000
28.350
453.59
0.06480
9.072xl05
0.001
kilograms
0.001
0.028350
0.45359
6.480x10-5
907.19
lxlO~6
ounces
( a vo 1 r . )
3.527x10-2
35.274
16.0
2.286X10'3
3 .200x10*
3.527x10-5
pounds
(avoir.)
2.205xlQ-3
2.2046
0.0625
1.429x10-*
2000
2.205x10-6
grains
15.432
15432
437.5
7000
1.4xl07
0.015432
tons
(U. S.)
1.102x10-6
1. 102xlO-3
3.125x10-5
5.0x10-*
7.142xlO-8
1.102x10-9
milligrams
1000
IxlO6
2.8350x10*
4.5359xl05
64.799
9.0718xl08
*Mass of 27.692 cubic inches water weighed In air at 4.0°C, 760 mm mercury pressure.
5/83
Appendix
A-15
-------
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Kilowatt Hours
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A-16
Appendix
5/83
-------
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u
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u
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-------
TECHNICAL REPORT DATA
ff 'least' read Instructions on the reverse before completing}
1. REPORT NO.
AP-42, Supplement 14
4. TITLE AND SUBTITLE
3. RECIPIENT'S ACCESSION NO.
Supplement 14 for Compilation of Air Pollutant
Emission Factors, AP-42
6. PERFORMING ORGANIZATION CODE
; REPORT DATE
1983
7. AUTHOR(S)
Monitoring and Data Analysis Division
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U. S. Environmental Protection Agency
Office of Air, Noise and Radiation
Office of Air Quality Planning and Standards
Research Triangle, North Carolina 27711
10. PROGRAM ELEMENT NO.
11. CON'lrtACT/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 for AP-42, new or revised emissions data are presented for
Anthracite Coal Combustion; Wood Waste Combustion In Boilers; Residential Fireplaces;
Wood Stoves; Open Burning; Large Appliance Surface Coating; Metal Furniture Surface
Coating; Adipic Acid; Synthetic Ammonia; Carbon Black; Charcoal; Explosives; Paint
and Varnish; Phthalic Anhydride; Printing Ink; Soap and Detergents; Terephthalic
Acid; Maleic Anhydride; Primary Aluminum Production; Iron and Steel Production;
Gypsum Manufacturing; Construction Aggregate Processing; Sand and Gravel Processing;
Taconite Ore Processing; Western Surface Coal Mining; Fugitive Dust Sources; Unpaved
Roads; Agricultural Tilling; Aggregate Handling and Storage Piles; and Industrial
Paved Roads.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
Fuel Combustion
Emissions
Emission Factors
Stationary Sources
b IDENTIFIERS/OPEN ENDED TERMS
18 DISTRIBUTION. STATEMENT
c. COSATI Held/Group
21 MO OF PAGES
i __ _ 190
!22. PRICE
-„ T • C N iS OBSOUETL
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