United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S7-86/036 Feb. 1987
Project Summary
Iron and Steel Industry
Particulate Emissions: Source
Category Report
John Jeffery and Joseph Vay
The objective of this study was to de-
velop particulate emission factors
based on cutoff size for inhalable parti-
cles for the iron and steel industry.
After reviewing available information
characterizing particulate emissions
from iron and steel plants, the data
were summarized and rated in terms of
reliability. Size specific emission factors
were developed from these data for the
major processes used in the manufac-
ture of iron and steel. A detailed proc-
ess description was presented with em-
phasis on those factors affecting the
generation of emissions. A replacement
for Section 7.5 (Iron and Steel Produc-
tion) of EPA report AP-42, A Compila-
tion of Air Pollutant Emissions Factors,
was prepared, containing the size
specific emission factors developed
during this program.
This Project Summary was devel-
oped by EPA's Air and Energy Engineer-
ing Research Laboratory, Research Tri-
angle Park, NC, to announce key
findings of the research project that is
fully documented in a separate report
of the same title (see Project Report or-
dering information at back).
Introduction
The purpose of this program was to
summarize the best available informa-
tion on emissions of inhalable particu-
late matter in the iron and steel indus-
try. The main objective of the program
was to develop reliable size-specific
emission factors for the various proc-
esses used in the production of iron and
steel. Both uncontrolled and controlled
emission factors are presented in the re-
port. The uncontrolled factors represent
emissions which would result if the par-
ticulate control device (baghouse,
scrubber, etc.) were bypassed, and the
controlled factors represent emissions
emanating from a particular type of con-
trol system. The size-specific emission
factors are generally based on the re-
sults of simultaneous sampling con-
ducted at the inlet and outlet of the con-
trol device(s), utilizing a variety of
particle sizing techniques. Other objec-
tives of this program were to present
current information on the iron and
steel industry as well as prepare a re-
placement for Section 7.5 of EPA report
AP-42, "A Compilation of Air Pollutant
Emissions Factors."
The above objectives were met by a
thorough literature search which in-
cluded the following sources:
Data from inhalable particulate
characterization program,
Fine Particle Emissions Inventory
System (FPEIS),
AP-42 background file at EPA's Of-
fice of Air Quality Planning and
Standards (OAQPS),
GCA files, and
Various industry sources (e.g.,
American Iron and Steel Institute).
The emission data contained in 45 ref-
erence documents were reviewed, ana-
lyzed, summarized, and ranked accord-
ing to the criteria established by OAQPS
as published in the report, "Technical
Procedures for Developing AP-42 Emis-
sion Factors and Preparing AP-42 Sec-
tions," April 1980. After ranking the
data, emission factors were calculated
using the highest quality data available.
The quality of the data used to develop
-------
each emission factor is indicated by the
emission factor rating.
Process control system operating
data as well as general industry infor-
mation were also obtained and summa-
rized as general background informa-
tion. It was not part of this program to
provide detailed engineering analyses,
product specifications, or detailed eval-
uation of trends in the industry.
Summary of Results
Participate emissions are generated
from several iron and steel facility activ-
ities, including sintering, iron and steel
production, semifinished product
preparation, and open dust sources.
The most significant source of emis-
sions from sintering operations is the
windbox exhaust. Windbox emissions
may be controlled by cyclones, electro-
static precipitators (ESPs), scrubbers, or
fabric filters. Most plants use cyclones
as pretreatment to remove large partic-
ulate from the gas stream to reduce fan
wear. Most plants use ESPs or scrub-
bers for windbox emission controls.
The casthouse is the major source of
particulate emissions associated with
blast furnace operations. A variety of
techniques for capturing emissions
from new casthouses and for retrofit-
ting other casthouses have been ap-
plied. Several shops have experimented
with and installed total casthouse evac-
uation, partial casthouse evacuation,
local hoods, runner evacuation, or pas-
sive emission suppression systems.
Fabric filters are used to clean collected
gas for all collection techniques.
Emissions from basic oxygen fur-
naces (BOFs) are divided into two cate-
gories, primary and secondary. Primary
emissions refer to any emissions gener-
ated while the furnace is in an upright
position. Secondary emissions refer to
any emission generated while the fur-
nace is tilted; i.e., charging, turndowns,
tapping, and slagging. Primary emis-
sions are captured by open or closed
hoods. ESPs are the predominant gas
cleaner used in conjunction with open
hood systems, and venturi scrubbers
are used with closed hood systems.
Secondary emissions are captured by
one or more of the following tech-
niques: complete furnace enclosures
with or without charge- and tap-side in-
terior hoods, partial furnace enclosures,
local hoods, deflector mechanisms to
direct fumes toward the primary hood
in open hood systems, and careful oper-
ating and maintenance procedures
using the existing primary hood.
Emissions from electric arc furnaces
(EAFs) occur during charging, melting,
oxygen-blowing, and tapping opera-
tions. Fugitive dust emissions are gen-
erated by scrap and raw material un-
loading, storage, and transfer activities.
A variety of systems have been devel-
oped to capture emissions from EAFs
including direct shell evacuation
through a fourth hole in the furnace
cover, total building evacuation, canopy
hoods, and local hoods. Almost all EAFs
use fabric filters to clean furnace emis-
sions.
External desulfurization is becoming
increasingly popular. The injection and
subsequent reaction of desulfurization
reagents with the hot metal (iron) create
significant amounts of fume. Emissions
are captured by collection hoods lo-
cated above or alongside the mouth of
the furnace. The most common gas
cleaning devices used for controlling
desulfurization fumes are fabric filters.
The total mass controlled and uncon-
trolled emission factors for iron and
steel production are presented in
Table 1. The size-specific controlled and
uncontrolled emission factors are pre-
sented in Table 2. Uncontrolled particu-
late emission factors for open dust
sources in an iron and steel plant are
presented in Table 3.
Table 1. Particulate Emission Factors for Iron and Steel Mills
Source
Units
Emission Factor
Emission
Factor
Rating
Particle
Size
Data
Sintering
Windbox
Uncontrolled
Leaving grate
After coarse particulate removal
Controlled by dry ESP
Controlled by wet ESP
Controlled by venturi scrubber
Controlled by cyclone
Sinter discharge (breaker and hot
screens)
Uncontrolled
Controlled by baghouse
Controlled by venturi scrubber
Windbox and discharge
Controlled by baghouse
Blast furnace
Slip
Uncontrolled casthouse
Roof monitor9
kg/Mg (Ib/ton) finished
sinter
5.56
4.35
0.8
0.085
0.235
0.5
(n.1)
(8.7)
(1.6)
(0.17)
(0.47)
(1.0)
kg/Mg (Ib/ton) finished
sinter
kg/Mg (Ib/ton) finished
sinter
kg/Mg (Ib/ton) slip
kg/Mg (Ib/ton) hot metal
3.4 (6.8)
0.05 (0.1)
0.295 (0.59)
0.15 (0.3)
39.5 (87.0)
0.3 (0.6)
B
A
B
B
B
B
B
B
A
Yes
Yes
Yes
Yes
Yes
D
B
Yes
-------
'able 1. (Continued)
Source
Furnace with local evacuation13
Taphole and trough only (not
runners)
Hot metal desulfurization
Uncontrolled0
Controlled by baghouse
Basic oxygen furnace (BOF)
Top blown furnace melting and
refining
Uncontrolled
Controlled by open hood
vented to:
ESP
Scrubber
Controlled by closed hood
vented to:
Scrubber
BOF Charging
At source
At building monitor
Controlled by baghouse
BOF Tapping
At source
At building monitor
Controlled by baghouse
Hot metal transfer
At source
At building
Units Emission
0.65
0.75
kg/Mg (Ib/ton) hot metal 0.55
0.0045
kg/Mg fib/ton) steel
14.25
0.065
0.045
0.0034
kg/Mg {Ib/ton) hot metal
0.3
0.071
0.0003
kg/Mg (Ib/ton) steel
0.46
0.145
0.0013
kg/Mg (Ib/ton) hot metal
0.095
0.028
Factor
(1.3)
(0.3)
(1.09)
(0.009)
(28.5)
(0.13)
(0.09)
(0.0068)
(0.6)
(0. 142)
(0.0006)
(0.92)
(0.29)
(0.0026)
10.19)
(0.056)
Emission
Factor
Rating
B
B
D
D
B
A
B
A
D
B
B
D
B
B
A
B
Particle
Size
Data
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
BOF monitor (all sources)
Q-BOF melting and refining
Controlled by scrubber
Electric arc furnace
Melting and refining
Uncontrolled carbon steel
Charging, tapping, and slagging
Uncontrolled emissions escap-
ing monitor
Melting, refining, charging, tap-
ping, and slagging
Uncontrolled
Alloy steel
Carbon steel
Controlled by."
Building evacuation to bag-
house for alloy steel
Direct shell evacuation (plus
charging hood) vented to
common baghouse for car-
bon steel
Open hearth furnace
Melting and refining
Uncontrolled
Controlled by ESP
Roof monitor
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) steel
0.25 (0.5)
0.028 (0.056)
19.0 (38.0)
0.7 (1.4)
5.65 (11.3)
25.0 (50.0)
0.15 (0.3)
0.0215 (0.043)
10.55 (21.1)
0.14 (0.28)
0.084 (0.168)
B
B
C
C
A
C
A
E
D
D
C
Yes
Yes
Yes
Yes
Yes
-------
Table 1.
(Continued)
Source
Units
Emission Factor
Emission
Factor
Rating
Particle
Size
Data
Teeming
Leaded steel
Uncontrolled (measured at
source)
Controlled by side draft hood
vented to baghouse
Unleaded steel
Uncontrolled (measured at
source)
Controlled by side draft hood
vented to baghouse
Machine scarfing
Uncontrolled
Controlled by ESP
Miscellaneous combustion sources*
Boiler, soaking pit, and slab re-
heat
Blast furnace gas'
Coke oven gas'
kg/Mg (Ib/ton) steel
kg/Mg (Ib/ton) metal
through scarfer
kg/109 J (lb/10e Btu)
0.405 (0.81)
0.0019 (0.0038)
0.035 (0.07)
0.0008 (0.0016)
0.05 (0.1)
0.0115 (0.023)
0.015 (0.035)
0.0052 (0.012)
A
A
A
A
B
A
D
D
"Typical of older furnaces with no controls, or for canopy hoods or total casthouse evacuation.
''Typical of large, new furnaces with local hoods and covered evacuated runners. Emissions are higher than without capture systems be-
cause they are not diluted by outside environment.
cEmission factor of 0.55 kg/Mg (1.09 Ib/ton) represents one torpedo car, 1.26 kg/Mg (2.53 Ib/ton) for two torpedo cars, and 1.37 kg/Mg (2.74
Ib/ton) for three torpedo cars.
aBuilding evacuation collects all process emissions, and direct shell evacuation collects only melting and refining emissions.
"For various fuels, use the emission factors in Chapter 1 ofAP-42. The emission factor rating for these fuels in boilers is A, and is soaking
pits and slab reheat furnace is D.
'Based on methane content and cleaned paniculate loading.
Table 2. Size Specific Emission Factors
Source
Emission
Factor
Rating
Particle
Size, \i.ma
Cumulative
Mass % <
Stated Size
Cumulative Mass
Emission Factor
kg/Mg (Ib/ton)
Sintering
Windbox emissions
Uncontrolled
leaving grate
Controlled by wet
ESP
Controlled by
venturi scrub-
ber
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
4b
4
5
9
15
2O=
100
18*
25
33
48
59"
69
100
55
75
0.22
0.22
0.28
0.50
0.83
1.11
5.56
0.015
0.021
0.028
0.041
0.050
0.059
0.085
0.129
0.176
(0.44)
(0.44)
(0.56)
(1.00)
(1.67)
(2.22)
(11.1)
(0.03)
(0.04)
(0.06)
(0.08)
(0.10)
(0.12)
(0.17)
(0.26)
(0.35)
-------
Table 2. (Continued)
Source
Emission
Factor
Rating
Particle
Size, \y.ma
Cumulative
Mass % s
Sfafed Size
Cumulative Mass
Emission Factor
kg/Mg (Ib/ton)
2.5
5.0
70
75
d
89
93
96
98
WO
0.209
0.219
0.226
0.230
0.235
(0.42)
(0.44)
(0.45)
(0.46)
(0.47)
Controlled by cy-
clone6
0.5
1.0
2.5
5.0
10
15
d
25C
37"
52
64
74
80
100
0.13
0.19
0.26
0.32
0.37
0.40
0.5
(0.25)
(0.37)
(0.52)
(0.64)
(0.74)
(0.80)
(1.0)
Controlled by
baghouse
0.5
1.0
2.5
5.0
10.0
15.0
d
3.0
9.0
27.0
47.0
69.0
79.0
100.0
0.005
0.014
0.041
0.071
0.104
0.779
0.75
(0.009)
(0.027)
(0.081)
(0.141)
(0.207)
(0.237)
(0.3)
Sinter discharge
(breaker and hot
screens) con-
trolled by bag-
house
0.5
1.0
2.5
5.0
10
15
d
2b
4
11
20
32*
42b
100
0.001
0.002
0.006
0.010
0.016
0.021
0.05
(0.002)
(0.004)
(0.011)
(0.020)
(0.032)
(0.042)
(0.1)
Blast furnace
Uncontrolled cast-
house emissions
Roof monitor'
Furnace with local
evacuation9
Hot metal
desulfurizationh
Uncontrolled
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
4
15
23
35
51
61
100
9
15
20
24
26
100
i
2=
11
19
19
21
100
0.01
0.05
0.07
0.11
0.15
0.18
0.3
0.04
0.06
0.10
0.13
0.16
0.17
0.65
0.01
0,06
0.10
0.10
0.12
0.55
(0.02)
(0.09)
(0.14)
(0.21)
(0.31)
(0.37)
(0.6)
(0.09)
(0.12)
(0.20)
(0.26)
(0.31)
(0.34)
(1.3)
(0.02)
(0.12)
(0.22)
(0.22)
(0.23)
(1.09)
-------
Table 2. (Continued)
Source
Emission
Factor
Rating
Particle
Size, |ima
Cumulative
Mass % =
Stated S/>e
Cumulative Mass
Emission Factor
kg/Mg lib/ton)
Controlled bag-
house
Basic oxygen furnace
Top blown furnace
melting and refin-
ing controlled by
closed hood and
vented to scrub-
ber
BOF Charging
At source11
Controlled by bag-
house
BOF Tapping
At source*
BOF Tapping
Controlled by bag-
house
D
Q-BOP melting and
refining controlled
by scrubber
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
W
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
8
18
42
62
74
78
100
34
55
65
66
67
7?
100
8°
12
22
35
46
56
100
3
10
22
31
45
60
WO
l
11
37
43
45
50
100
4
7
16
22
30
40
100
45
52
0.0004
0.0009
0.0019
0.0028
0.0033
0.0035
0.0045
(0.0007)
(0.0016)
(0.0038)
(0.0056)
(0.0067)
(0.0070)
(0.009)
0.0012
0.0019
0.0022
0.0022
0.0023
0.0024
0.0034
0.02
0.04
0.07
0.10
0.14
0.17
0.3
9.0 x JO'6
3.0 x JO'5
6.6 x 70-5
9.3 x JO-5
0.0007
0.0002
0.0003
i
0.05
0.17
0.20
0.21
0.23
0.46
5.2 x JO-5
0.0001
0.0002
0.0003
0.0004
0.0005
0.0013
0.013
0.015
(0.0023)
(0.0037)
(0.0044)
(0.0045)
(0.0046)
(0.0049)
(0.0068)
(0.05)
(0.07)
(0.13)
(0.21)
(0.28)
(0.34)
(0.6)
1.8 x J0~5
6.0 x JO"5
(0.0001)
(0.0002)
(0.0003)
(0.0004)
(0.0006)
i
(0.10)
(0.34)
(0.40)
(0.41)
(0.46)
(0.92)
(0.0001)
(0.0002)
(0.0004)
(0.0006)
(0.0008)
(0.0010)
(0.0026)
(0.025)
(0.029)
-------
Table 2. (Continued)
Source
Emission Cumulative
Factor Particle Mass % s
Rating Size, (j.ma Stated Size
Cumulative Mass
Emission Factor
kg/Mg (Ib/ton)
2.5
5.0
10
15
d
56
58
68
85°
WO
0.016
0.016
0.019
0.024
0.028
(0.031)
(0.032)
(0.038)
(0.048)
(0.056)
Electric arc furnace
Melting and refining
carbon steel un-
controlled"1
D
Melting, refining,
charging, tapping,
slagging
Controlled by
direct shell evacu-
ation (plus charg-
ing hood) vented
to common bag-
house for carbon
steel"
Open hearth furnace
Melting and refining
Uncontrolled
Controlled by
0.5
1.0
2.5
5.0
10
15
8
23
43
53
58
61
100
0.5
1.0
2.5
5.0
10
15
d
0.5
1.0
2.5
5.0
10
15
d
74"
74
74
74
76
80
100
21
60
79
83
85C
100
1.52
4.37
8.17
10.07
11.02
11.59
19.0
0.0159
0.0159
0.0159
0.0159
0.0163
0.0172
0.0215
0.11
2.22
6.33
8.33
8.76
8.97
10.55
(3.04)
(8.74)
(16.34)
(20.14)
(22.04)
(23.18)
(38.0)
(0.0318)
(0.0318)
(0.0318)
(0.0318)
(0.0327)
(0.0344)
(0.043)
(0.21)
(4.43)
(12.66)
(16.67)
(17.51)
(17.94)
(21.1)
ESP" E 0.5
1.0
2.5
5.0
10
15
d
10"
21
39
47
53"
56"
100
0.01
0.03
0.05
0.07
0.07
0.08
0.14
(0.02)
(0.06)
(0.10)
(0.13)
(0. 15)
(0.16)
(0.28)
"Particle aerodynamic diameter micrometers (\i.m) as define by Task Group on Lung Dy-
namics. (Particle density = 1 g/cm3).
Interpolated data used to develop size distribution.
cExtrapolated, using engineering estimates.
dTotal particulate based on Method 5 total catch. See Table 1.
e'Average of various cyclone efficiencies.
'Total casf/ioose evacuation control system.
^Evacuation runner covers and local hood over taphole, typical of new state of the art blast
furnace technology.
-------
Table 2. (Continued)
''Torpedo ladle desulfurization with CaC2 and CaCO3.
iUnable to extrapolate because of insufficient data and/or curve exceeding limits.
^Doghouse type furnace enclosure using front and back sliding doors, totally enclosing the
furnace, with emissions vented to hoods.
""Full cycle emissions captured by canopy and side draft hoods.
"Information on control system not available.
fMay not be representative. Test outlet size distribution was larger than inlet may indicate
reentrainment problem.
Table 3. Uncontrolled Paniculate Emission Factors for Open Dust Sources at Iron and Steel Mills3
Emissions by Particle Size Range
(aerodynamic diameter)
Operation
Continuous drop
Conveyor transfer station sin-
ter
Pile formation stacker pellet ore
Lump ore
Coal
Batch drop
Front end loader/truck
High silt slag
Low silt slag
Vehicle travel on unpaved
roads
Light duty vehicle
Medium duty vehicle
Heavy duty vehicle
Vehicle travel on paved roads
Light/heavy vehicle mix
<30|xm
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
^15v.m
9.0
0.018
0.75
0.0015
0.095
0.00019
0.034
0.000068
8.5
0.017
2.9
0.0058
0.37
1.3
1.5
5.2
2.7
9.7
0.16
0.58
s10ğm
6.5
0.013
0.55
0.0011
0.075
0.00015
0.026
0.000052
6.5
0.013
2.2
0.0043
0.28
1.0
1.2
4.1
2.1
7.6
0.12
0.44
-Sum
4.2
0.0084
0.32
0.00064
0.040
0.000081
0.014
0.000028
4.0
0.0080
1.4
0.0028
0.18
0.64
0.70
2.5
1.4
4.8
0.079
0.28
S2.5 M-T7
2.3
0.0046
0.17
0.00034
0.022
0.000043
0.0075
0.000015
2.3
0.0046
0.80
0.0016
0.10
0.36
0.42
1.5
0.76
2.7
0.042
0.15
Units'3
g/Mg
Ib/ton
g/Mg
Ib/ton
g/Mg
Ib/ton
g/Mg
Ib/ton
g/Mg
Ib/ton
g/Mg
Ib/ton
kg/VKT
Ib/VKT
kg/VKT
Ib/VKT
kg/VKT
Ib/VKT
kg/VKT
IbA/KT
Emission
Factor
Rating
D
D
B
B
C
C
E
E
C
C
C
C
C
C
C
C
B
B
C
C
aPredictive emission factor equations are generally preferred over these single value emission factors. Predictive emission factor estimates
are presented in Chapter 11, Section 11.2 of AP-42. VKT = Vehicle kilometer traveled. VMT = Vehicle mile traveled.
bUnits/unit of material transferred or units/unit of distance traveled.
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J. Jeffery and J. Vay are with GCA/Technology Division, Bedford, MA 01730.
Dale L. Harmon is the EPA Project Officer (see below).
The complete report, entitled "Iron and Steel Industry Paniculate Emissions:
Source Category Report,"(Order No. PB 87-119 889/AS; Cost: $13.95. subject
to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
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