MIDWEST RESEARCH INSTITUTE
MRI
REPORT
OPEN DUST SOURCES AROUND
IRON AND STEEL PLANTS
DRAFT
SPECIAL REPORT
ADDENDUM
Prepared for:
Industrial Environmental Research Laboratory
Environmental Protection Agency
Research Triangle Park
North Carolina 27711
Under Contract No. 68-02-2120
MRI Project No. 4123-L
Special Report
Date Prepared: January 11, 1977
by
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
MIDWEST RESEARCH INSTITUTE 425 VOLKER BOULEVARD, KANSAS CITY, MISSOURI 64110 • 816753-7600
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MRI-NORTH STAR DIVISION 3100 38th Avenue South, Minneapolis, Minnesota 55406* 612 721-6373
MRI WASHINGTON, D.C. 20005-1522 K STREET, N.W. • 202 293-3800
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OPEN DUST SOURCES AROUND
IRON AND STEEL PLANTS
DRAFT
SPECIAL REPORT
ADDENDUM
Prepared for:
Industrial Environmental Research Laboratory
Environmental Protection Agency
Research Triangle Park
North Carolina 27711
Under Contract No. 68-02-2120
MRI Project No. 4123-L
Special Report
Date Prepared: January 11, 1977
by
Midwest Research Institute
425 Volker Boulevard
Kansas City, Missouri 64110
MIDWEST RESEARCH INSTITUTE 425 VOLKER BOULEVARD, KANSAS CITY, MISSOURI 64110 • 816753-7600
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PREFACE
This report addendum was prepared for the Environmental Protection Agency
(Mr. Robert V. Hendriks, Project Officer) to present the results of a sur-
vey of open dust sources around an iron and steel plant. The work was per-
formed in the Environmental and Materials Sciences Division of Midwest Re-
search Institute under EPA Contract No. 68-02-2120. This report was written
by Dr. Chatten Cowherd and Mr. Russell Bohn.
Approved:
MIDWEST RESEARCH INSTITUTE
L. J.(Shannon, Director
Environmental and Materials
Sciences Division
January 11, 1977
ii
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TABLE OF CONTENTS
Page
1.0 Introduction 1
2.0 Unpaved and Paved Roads 1
2.1 Source Extent • 1
2.2 Correction Parameters 4
2.3 Aggregate Storage Piles 5
2.4 Wind Erosion of Exposed Areas 9
2.5 Summary of Dust Emissions 10
References 14
List of Tables
No. Title Page
1 Experimentally Determined Fugitive Dust Emission Factors . 2
2 Plant C: Road Emissions ....... 3
3 Plant C: Storage Pile Emissions 6
4 Plant C: Open Area Emissions 11
5 Plant C: Summary of Open Dust Source Emissions. ..... 12
6 Plant C: Unit Emissions 13
iii
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1.0 Introduction
Significant quantities of fugitive dust may be emitted from storage
piles, vehicular traffic, and wind erosion of exposed areas around
iron and steel plants. Reliable estimates of these emissions require
the use of (a) data on source extent and/or activity levels and (b)
emission factors which have been appropriately corrected for local
climatic conditions and silt (fines) content of the emitting surface.
Table 1 lists the measures of source extent, the basic emission fac-
tor formulae, and the correction parameters associated with each per-
tinent source category. The mathematical expressions for each emis-
sion factor were derived from field measurements described in reports
1-3/
prepared by Midwest Research Institute (MRI) .—- Supporting informa-
tion for several of these factors is presented in EPA's Emission Fac-
tor Handbook.—' The factors presented in Table 1 describe emissions
of particles smaller than 30 u in diameter, the approximate effective
cutoff diameter of a standard high volume particulate sampler (based
on particle density of 2 to 2.5 g/cm^).!'
This report presents the results of a survey of open dust sources at
a representative iron and steel plant, designated as Plant "C." Sur-
vey results and procedures are given below for each source category,
following the format used in the report for Plants A and B, dated
November 2, 1976.
2.0 Unpaved and Paved Roads
Table 2 lists source extent and activity factors, emission factor cor-
rection parameters, and calculated emission rates for specific unpaved
and paved roads lying within the property boundaries of Plant C.
The experimentally determined emission factors for paved and unpaved
roads given in Table 1, with an additional correction for vehicle
weight, were used to calculate fugitive dust emissions. The appropri-
ate measure of source extent is vehicle-miles traveled.
2.1 Source Extent
The following steps were used to develop the inventory of roads, ve-
hicle types and mileage traveled:
1. Road segments with specific surface and traffic characteristics
were identified and the length of each segment was determined by
plant personnel.
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Table 1. EXPERIMENTALLY DETERMINED FUGITIVE DUST EMISSION FACTORS
Source category
Aggregate storage
(sand and gravel;
crushed stone)
Unpaved roads
Paved roads
Measure of extent
Tons of aggregate put
through storage cycle
Vehicle-miles traveled
(light duty)
Vehicle-miles traveled
(light duty)
Emission factor—
(Ib/unit of
source extent)
0.33
(PE/100)
0.49 (su)
9 x 10"5 L sr
Correction parameters
PE = Thornthwaites precipitation
evaporation index
u
road surface silt content (%)
S = average vehicle speed (mph)
d = dry days per year
L = surface loading (Ib/mile)
s = fractional silt content of
road surface material
Wind erosion
Acre-years of exposed
land
18
esf
(PE/50)'
e = soil erodibility (tons/acre-yr)
s = silt content of surface soil (7o)
f = fraction of time wind exceeds
12 mph
PE = Thornthwaites precipitation-
evaporation index
a/ Annual average emissions of dust particles smaller than 30 micrometers in diameter based on particle
density of 2.5 g/cm^.
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Table 2. PLANT C: ROAD EMfSSIONS
U>
Velilcle classk/
Light Duty A
Medium Duty B
Roada Heavy Duty C
Unpaved B
C
Total
Dusty paved B
C
Other paved B
C
Total
Source extent
Road length-'
(miles)
3.6
1.6
5.2
3.2
1.4
12.0
5.2
21.8
Correction factors
Velilcle miles-
traveled
(miles/day)
517
222
739
253
101
927
404
1,685
Vehicle weight
correction
(baaed on
observation)
3.5
8.0
3.5
8.0
3.5
8.0
Vehicle spoedt/
(mph)
25
25
25
25
25
25
Road surface
silt content*!/
tt)
10
10
10
10
10
10
/"""}
Surface loadln\£lS Emission
(Ib material factor
per mile) (Ib/VMT)
11.6
26.4
15,000 0.5
15,000 1.1
5,000 0.2
5,000 0.4
Emissions-/
Dally
emissions
(tons/day)
3.0
2.9
5.9
0.06
0.06
0.09
0.08
0.29
Yearly
emissions
(tons/year)
1,095
1.059
2,154
22
22
33
29
106
a_/ All emissions are based on particulates less than 30 u In diameter.
b/ Obtained from plant personnel.
Data calculated as an average of the dally VKT at Plants A and B.
An a
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2. The types and sizes of vehicles traveling on each road segment
were specified by plant personnel.
3. Figures on the daily mileages traveled by each vehicle type were
not furnished by plant personnel. MRI derived the daily mileages
traveled by averaging mileage data from previously surveyed Plants
A and B.
4. Information provided by plant personnel was used to apportion the
mileage traveled by each vehicle type over the various road seg-
ments.
Approximately 7670 of Plant C's 21.8 miles of roads are paved and on
the whole have relatively low particulate surface loadings and resul-
tant emission rates. There are 4.6 miles of "dusty-paved" roads within
Plant C, as indicated by plant personnel. These roads have consider-
ably higher surface particulate loadings with resultant higher emis-
sion factors than the other paved roads within the plant.
Vehicular traffic at Plant C was comprised of three basic vehicle
types:
1. Type A - Light duty (automobiles and pick-up trucks--determined
to be negligible).
2. Type B - Medium duty (flatbeds and other medium sized trucks).
3. Type C - Heavy duty (larger trucks with load capacity of 25 to 50
tons).
Data pertaining to the road length traveled by heavy vehicles within
the plant (8.1 miles) was obtained from plant personnel. It was indi-
cated that this mileage was evenly distributed over the various road
types at the plant. The remaining road length was assigned to medium
duty vehicles.
2.2 Correction Parameters
Because of adverse weather conditions during the time of the survey,
it was not possible to obtain representative samples of road surface
dust from which to determine silt content. Therefore, a silt content
of 10% for the particulate loading on Plant C's roadways was assumed.
Average vehicle speed for each segment of unpaved or paved road was
estimated by plant personnel and the number of dry days per year for
the plant locale was determined from the Climatic At las. L'
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Because the experimentally determined emission factors for paved and
unpaved roads were developed for light duty vehicles, it was neces-
sary to apply vehicle weight correction multipliers to account for
increased emissions from medium duty and heavy duty vehicles. It was
assumedthat emissions increase in proportion to vehicle weight. Ra-
tios of average empty truck weights to average light-duty vehicle
weight (4 tons) were used as correction multipliers, because trucks
travel at higher speeds during the unloaded portions of travel cycles.
2.3 Aggregate Storage Piles
An inherent part of the operation of integrated iron and steel plants
is the maintenance of outdoor storage piles of mineral aggregates used
as raw materials and of process wastes. Storage piles are usually left
uncovered, partially because of the necessity for frequent transport
of material into or out of storage.
Dust emissions occur at several points in the storage cycle—during
loading of material onto the pile, whenever the pile is acted on by
strong wind currents, and during load-out of material from the pile.
Truck and loading equipment traffic in the storage pile areas are also
a substantial source of dust emissions.
Table 3 gives data on the extent of open storage operations involving
primary aggregate materials at Plant C. This information was developed
from (a) discussions with plant personnel, (b) plant statistics on
quantities of materials consumed, and (c) field estimations during the
plant survey.
The emission factor for aggregate storage piles given in Table 1 was
derived from field measurements of dust emissions from active and in-
active storage piles of sand, gravel, and crushed stone. The major op-
erational contributions to storage pile emissions were found to be:
1. Loading onto piles from dump trucks,
2. Vehicular traffic around piles during 90-day storage,
3. Wind erosion during 90-day stroage, and
4. Load-out from piles to dump trucks utilizing high loaders.
As expected, the quantity of emissions is directly proportional to
the amount of material put through the storage cycle.
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Table 3. P1ANT C: STORAGE PILE EMISSIONS
Source extent
Amount In
Material In storage Annual throughput
storage (tons)— (million tons)—
Coal
Lou volatility 31,795 0.05
High volatility 15,150 0.08
Iron ore screened
Bed No. I 2,032 0.04
Bed No. 26E 18,996 0.03
Blended ore 34,763 1.11
(sinter Input)
Flue dust - 0.03
Limestone
Monarch 152,173 0.22
Dolomite 4.277 0.07
Total 259,186 1.63
Correction factors
Duration of Load-In
Silt content storage (Ib/ton Vehicular traffic
(7.) (days)-/ stored) (Ib/ton stored)
5.5-' 90 0.11 1.7
2-' 66 0.04 0.60
18.8^' 18 0.38 £/
18.8^' 45 0.38 g/
14.7-^ 11 0.39 g/
14. 0*' 90 0.37 8.4
1.5^' 90 0.03 0.9
1.5-S/ 90 0.03 0.9
Emission factorsS./
Load-out Total storage
Wind erosion (Ib/ton cycle (Ib/ton
(Ib/ton stored) stored) stored)
2.8 0.13 4.74
0.74 0.46 1.84
1.9 3.3 5.5
3.2 3.3 6.9
0.91 2.5 3.8
7.1 3.2 19.1
0.76 0.35 2.04
0.76 0.35 2.04
Yearly
emissions
(tons/year)
119
74
no
104
2,109
286
224
71
3,097
a_/ All emissions are based on participates leas than 30 |i In diameter.
b/ Obtained from plant personnel.
c_/ Derived from given plant data.
d/ Determined by means of dry sieving.
e/ Assumed silt content based on previous sieving of similar materials.
i_l An assumed silt content.
g/ Determined negligible.
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Because aggregate storage operations in the iron and steel industry
are similar to operations described above, the experimentally deter-
mined emission factor and operational contributions were used as a
basis for the development of estimated emission factors for each ma-
terial/operation combination. In each case, the factor was adjusted
to the content of silt (fines) in the given aggregate and to the de-
gree of material-handling equipment activity in comparison with the
operations used in the sand and gravel and crushed stone industries.
Table 3 presents the emission factors for the storage of primary ag-
gregate materials used in Plant C. The rationale for the derivation
of the emission factor expression for each operation is given below.
2.3.1 Loading onto Piles
The method of loading onto storage piles at Plant C consisted of uti-
lizing front-end loader (for flue dust) and movable stacker/reclaim-
ers (for all other materials) coupled with a sizable conveyor network.
The stacker method of loading onto piles was judged to emit less dust
than the emission-tested load-in process, so an activity factor of
0.75 was incorporated into the load-in emission factor equation. Based
on these assumptions, the load-in emission factor equation becomes:
EFi = 0.04 — K
1.5
where EF, = emission factor (pounds per ton of material trans-
ferred)
i
0.04 = experimentally determined emission factor for load-
ing of sand and gravel
S = silt content of the aggregate material (percent)
K = activity factor related to method of loading onto
the piles (1.0 for flue dust, 0.75 for all other
materials)
2.3.2 Vehicular Traffic
Vehicular traffic around emission-tested aggregate (sand and gravel)
storage piles, consisting of truck and high loader movements associ-
ated with the load-in and load-out, was generally more intense than
traffic around storage piles at the iron and steel plant. The follow-
ing stored aggregate materials were assigned a traffic-related emis-
sion factor of zero:
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1. Iron ore, screened, and
2. Blended ore (sinter plant charge).
At Plant C there is vehicular traffic around the low and high vola-
tility coal piles and the limestone-dolomite piles, as represented by
an activity factor of 0.5. The flue dust pile was assigned an activ-
ity factor of 1 for vehicular traffic.
Based on these considerations, the emission factors for traffic around
storage piles were calculated according to the following equation:
EF
2
0.13 (S/1.5) K
(PE/100)2
where EF2 = emission factor (pounds per ton of material stored)
PE = Thornthwaites precipitation-evaporation index (38)
S = silt content of the storage material (percent)
K = activity factor =0.5 for coal and stone piles and
for ore bedding, and 1 for flue dust
The value 0.13 lb/ ton was the factor experimentally determined for
piles with a silt content of 1.570 stored in a locality with a PE value
of 100.
(
2.3.3 Wind Erosion
The correction factors deemed to be appropriate for dust emissions
generated by wind erosion were silt content, PE index, and length of
time material is in storage. The silt content and PE index were ra-
tioed in the same manner as for the traffic related factor. Because
the relationship of emissions to duration in storage was assumed to
be linear, the correction multiplier is simply a direct ratio between
the duration of given material in storage and the 90-day estimate of
duration for the emission-tested aggregate materials. These assump-
tions are incorporated into the following equation.
EF = 0.11 (S/1.5) OD)_
(100/PE)2 90
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where EF3 = emission factor (pounds per ton of material stored)
PE = Thornthwaites precipitation-evaporation index (38)
S = silt content of given stored material (percent)
D = duration of material in storage (days)
The value 0.11 Ib/ton was the factor experimentally determined for
wind erosion from sand and gravel piles with a silt content of 1.5%
stored for 90 days in a locality having a PE index of 100.
2.3.4 Load-Out
Methods of loading out materials from the storage piles at Plant C
included (a) stacker/reclaimers which "rake" the materials onto a con-
veyor and (b) front-end loaders which transfer the material to a con-
veyor bin, a process similar in nature to the load-out of emission-
tested aggregate. Because the stacker/reclaimer method is less likely
to produce dust emissions than the front-end loader method, an activ-
ity factor of 0.75 was assigned to the former method, and an activity
factor of 1 to the latter. Based on these considerations, emission
factors for aggregate load-out were calculated by the following equa-
tion:
0.05
(100/PE)2
where EF^ = emission factor (pounds per ton of material trans-
ferred)
PE = Thornthwaites precipitation-evaporation index (38)
S = silt content of the storage material (percent)
K = activity factor = 0.75 for Utah and blended ore, and
1.0 for coal, flue dust and stone
The value 0.05 Ib/ton was the factor experimentally determined for
load-out of sand and gravel and crushed stone storage piles with a
silt content of 1.5% in a locality having a PE index of 100.
2.4 Wind Erosion of Exposed Areas
Unsheltered areas of bare ground around plant facilities are subject
to atmospheric dust generated by wind erosion, whenever the wind exceeds
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the threshold velocity of about 12 mph. The bare ground area within
the boundaries of Plant B was estimated to be 26.4 acres, based on
plant map areas outlined by plant personnel. This is an extremely low
value for bare area within an integrated iron and steel plant facil-
ity, reflecting the fact that the vast majority of active open areas
within Plant C have been paved.
As indicated in Table 1, the parameters which influence the amount
of dust generated by wind erosion are soil erodibility, silt content
of surface soil, precipitation-evaporation index, and fraction of the
time the wind speed exceeds 12 mph. Soil erodibility and silt content
were derived from the soil type in the vicinity of Plant C. The cal-
culated emissions from wind erosion are presented in Table 4.
2.5 Summary of Dust Emissions
A breakdown of calculated emissions from open dust sources at Plant
C is presented in Table 5. Unpaved roads (40%) is the largest con-
tributing dust source, followed by the blended ore pile (39%). The
other sources of open dust at Plant C, as seen in Table 6, are rela-
tively small in comparison.
Table 6 gives Plant C's emissions from open dust sources expressed in
pounds of particulate per short ton of steel produced.
10
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Table 4. PLANT C: OPEN AREA EMISSIONS
Source
Total
plant
area
^acre s )
extent
Total
open
area
(acres)
Correction factors
Soil
credibility^/
(tons/acre year)
Surface silt
soil content
(%)
Wind
speed—
PE
index£/
Emission
factor
Lib/acre year)
Emissions
Daily
emissions
(tons/day)
Yearly
emissions
(tons/year)
63(£/
26.
'.d/
156-
e/
0.27
38
5,932
0.21
78
£/ Tons of material eroded per acre year.
b/ Fraction of the time the wind speed is greater than 12 mph.
£/ Thornthwaites precipitation-evaporation index.
d_/ Obtained from plant personnel.
e/ Assumed value.
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Table 5. PLANT C: SUMMARY OF OPEN DUST SOURCE EMISSIONS
Percentage
Source Tons of particulate/year of total
1. Unpaved roads 2,154 40
2. Paved roads
Dusty paved 44 1
Other paved 62 1
3. Total wind erosion - 78 1
open areas
4. Storage piles
Low volatility coal 119 2
High volatility coal 74 1
Iron ore screened
Bed No. 1 110 2
Bed No. 26E 104 2
Blended ore (sinter input) 2,109 39
Flue dust 286 5
Limestone
Monarch 224 5
Dolomite 71. 1
Total all open sources 5,435 100
12
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Table 6. PLANT C: UNIT EMISSIONS
Source
Unpaved roads
Paved roads
Wind erosion - open areas
Storage piles
Total
Pounds particulates^' per short ton
of steel produced
2.7
0.1
0.1
3.9
6.8
af Particulates less than 30 u in diameter.
13
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REFERENCES
1. Cowherd, C., Jr., K. Axetell, Jr., C. M. Guenther, and G. A. Jutze,
Development of Emission Factors for Fugitive Dust Sources, EPA
Publication No. EPA-450/3-74-037, June 1974.
2. Cowherd, C., Jr., C. M. Guenther, D. Nelson, and N. Stich, Quantifica-
tion of Dust Entrainment From Paved Roadways, Final Report Draft,
EPA Contract No. 68-02-1403 (Task 7), March 31, 1976.
3. Cowherd, C., Jr., C. M. Guenther, D. Nelson, and K. Walker, Develop-
ment of a Methodology and Emission Inventory For Fugitive Dust For
the Regional Air Pollution Study, EPA Publication No. EPA-450/3-
76-003, January 1976.
4. Compilation of Air Pollution Emission Factors, U.S. Environmental
Protection Agency, Publication AP-42, October 1975.
5. Climatic Atlas of the United States, U.S. Department of Commerce,
Environmental Science Services Administration, Environmental Data
Service, U.S. Government Printing Office, Washington, D.C., June
1968.
14
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