EPA-600/7-86-039
November 1986
FERROALLOY INDUSTRY PARTICULATE EMISSIONS; SOURCE CATEGORY REPORT
by
Evelyn J. Limberakis
Joseph Vay
Stephen Gronberg
6CA CORPORATION
GCA/TECHNOLOGY DIVISION
Bedford, Massachusetts 01730
EPA Contract No. 68-02-3157
Technical Directive 16
EPA Project Officer
Dale L. Harmon
Air and Energy Engineering Research Laboratory
Research Triangle Park, North Carolina 27711
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Development
Washington, D.C. 20460
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ABSTRACT
A review was made of all available data characterizing particulate
emissions from ferroalloy producing electric arc furnaces. The data was
summarized and rated in texms of reliability. Total and size specific
emission factors were developed for the ferroalloy industry. The ferroalloy
industry and furnace operation was described in detail with emphasis on
factors affecting emissions. A replacement for Section 7.4, Ferroalloy
Production in AP-42 was prepared which includes size specific emission
factors. —
ii
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CONTENTS
Figures ....... iv
Tables vi
1. Introduction . . 1
2. Industry De scri.pt ion 4
General ..... 4
Ferroalloy Production Process ....... .... 6
Furnace Description ......... ..... 10
finission Sources. 16
Emission Controls ...................... 21
3. Ferroalloy Production Emission Factors 23
Total and Size-Specific Emission Factors 23
Data Review 23
Emission Factor Ratings ..... ..... 49
Emission Factor Calculations. ................ 52
4. Chemical Characterization. ........ . 60
5. Proposed AP-42 Section for Ferroalloy Industry .......... 69
References for Sections 1 to 4 96
iii
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i
%
FIGURES
Number Page
1 Ferroalloy production flow diagram 9
2 Open furnace 14
3 Sealed furnace 15
4 Mix sealed 15
5 Ferroalloy production flow diagram showing potential emission
points 17
6 Uncontrolled, 50% FeSi-producing, open furnace particle size
distribution 30
7 Controlled (baghouse), 50% FeSi-producing, open furnace
particle size distribution 31
8 Uncontrolled, 80% FeMn-producing, open furnace particle size
~ distribution 32
9 Controlled (baghouse), 80% FeMn-producing, open furnace
particle size distribution 33
10 Uncontrolled, Si metal producing, open furnace particle size
distribution 34
11 Controlled (baghouse), Si metal producing, open furnace
particle size distribution 35
12 Uncontrolled, FeCr-producing, open furnace particle size
distribution 36
13 Controlled (ESP), FeCr (HC)-producing, open furnace particle
size distribution 37
14 Uncontrolled, SiMn-preducing open furnace, particle size
distribution 38
iv
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FIGURES (continued)
Number Page
15 Controlled (scrubber), SiMn-producing open furnace particle
size distribution «... 39
7.4-1 Typical ferroalloy production process, showing emission points. . 71
7.4-2 Uncontrolled, 50% FeSi producing, open furnace particle size
distribution. ....... . 81
7.4-3 Controlled (baghouse), 50% FeSi, open furnace particle size
distribution 82
7.4-4 Uncontrolled, 80% FeMn producing, open furnace particle size
distribution. 83
7.4-5 Controlled (baghouse), 80% FeMn producing, open furnace size
distribution 84
7.4-6 Uncontrolled, Si metal producing, open furnace particle size
distribution. .... ................ 85
7.4-7 Controlled (baghouse), Si metal producing, open furnace particle
size distribution 86
7.4-8 -Uncontrolled, FeCr producing, open furnace particle size
distribution 87
7.4-9 Controlled (ESP) FeCR(HC) producing, open furnace particle size
distribution 88
7.4-10 Uncontrolled, SiMn producing, open furnace particle size
distribution 89
7.4-11 Controlled (scrubber), SiMn producing, open furnace particle size
distribution. ..... . 90
v
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TABLES
Number Page
1 Ferroalloy Processes and Respective Product Groups 5
2 Producers of Ferroalloys in the United States in 1981 ..... 7
3 Ferroalloy Process Weight Rates Related to Furnace Power
Consumption. 12
4 Particulate Emission Factor Table 24
5 Size Specific Emission Factors ... 26
6 Particulate Emission Tests Reviewed 40
7 Sulfur Dioxide, Carbon Monoxide and Organics Emission Tests
Reviewed 41
8 Sulfur Dioxide, Carbon Monoxide and Organic Emission Factor
Table 42
9 Furnaces in the United States Versus Furnaces Tested and
Included in Emission Factor Table. 50
10 Composition of Ferroalloys 61
11 Chemical Composition of Ores 65
12 Typical Furnace Fume Characteristics ...... 66
13 Typical Properties of Silica Fume from Bag Collector on Silicon
Metal Furance 67
7.4-1 Ferroalloy Processes and Respective Product Groups 72
7.4-2 Furnace Power Requirements for Different Ferroalloys 73
7.4-3 Emission Factors for Particulate from Submerged Arc Ferroalloy
Furnaces 75
7.4-4 Size Specific Emission Factors for Submerged Arc Ferroalloy
Furnaces 77
7.4-5 Emission Factors for Sulfur Dioxide, Carbon Dioxide, Lead and
Volatile Organics from Submerged Arc Ferroalloy Furnaces ... 91
vi
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SECTION 1
INTRODUCTION
The purpose of this program is to provide a summary of the best available
information on inhalable particulate matter emissions in the ferroalloy
industry. The program objective was to develop reliable total and size
specific emission factors for each ferroalloy product group. This will enable
a reasonable estimation of emissions from ferroalloy sources to update
Section 7,4, Ferroalloy Production, in AP-42, "A Compilation of Emission
Factors", which was last revised in February 1972.
Both uncontrolled and controlled emission factors are presented in this
report. The uncontrolled emission factors represent emissions that would
result from a particulate control system if the control device (baghouse,
scrubber, etc.) were bypassed. The controlled emission factors represent
emissions from a particulate control system. Size specific emission factors
are generally—based on the results of cascade impactor sampling conducted
simultaneously with total particulate sampling procedures at the inlet or
outlet to a control device. The second objective of this program is to
present current information on the ferroalloy industry.
The above objectives were met by an intensive, 10 week search for
emissions data. Data were collected from the following sources:
• New England Research Application Center (NERAC) computerized
literature searches;
• State and Federal regulatory and air planning staffs;
• Industry personnel;
• Environmental consultants;
• GCA/Technology Division files;
• AP-42 ferroalloy background file at IPA's Office of Air Quality
Planning and Standards (OAQPS); and
• EPA's Fine Particle Emission Information System (FPEIS),
The particulate emissions data were reviewed, summarized, and ranked
according to the criteria provided in the report "Technical Procedures for
Developing AP-42 Emission Factors and Preparing AP-42 Sections,"! April
1980. As specified in this document, the data are rated as follows:
I
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• A ¦ Tests performed by a sound methodology and reported in enough
detail for adequate validation. These tests are not necessarily EPA
reference method tests, although such reference methods are
certainly to be used as a guide,
• B = Tests that are performed by a generally sound methodology but
lack enough detail for adequate validation.
• C * Tests that are based on an untested or new methodology or that
lack a significant amount of background data.
• D - Tests that are based on a generally unacceptable method but may
provide an order-of-magnitude value for the source.
After ranking the obtained 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. The
following ratings were applied to each emission factor.
• A 88 Excellent—Developed from A-rated test data taken from many
randomly chosen facilities in the industry population. The source
category* is specific enough to minimize variability within the
source category population.
• B = Above Average—Developed only from A-rated test data from a
reasonable number of facilities. Although no specific bias is
evident, it is not clear if the facilities tested represent a random
sample of the industry. As in the A rating, the source category is
specific enough to minimize variability within the source category
— population.
• C = Average—Developed only from A- and B-rated test data from a
reasonable number of facilities. Although no specific bias is
evident, it is not clear if the facilities tested represent a random
sample of the industry. As in the A rating, the source category is
specific enough to minimize variability within the source category
population;
• D = Below Average—The emission factor was developed only from A-
and B-rated test data from a small number of facilities, and there
may be reason to suspect that these facilities do not represent a
random sample of the industry. There also may be evidence of
variability within the source category population. Limitations on
the use of the emission factor are footnoted in the emission factor
table.
*Source category: A category in the emission factor table for which an
emission factor has been calculated; generally a single process.
2
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• E = Poor—The emission factor was developed from C~ and D-rated test
data, and there may be reason to suspect that the facilities tested
do not represent a random sample of the industry. There also may be
evidence of variability within the source category population.
Limitations on the use of these factors are always footnoted.
This report is structured according to the "Outline for Source Category
Reports" which was included in the technical directive to conduct this
program. There is necessary duplication of information between Section 5, the
proposed AP-42 section, and Sections 1 through 4 of the report in order that
the proposed AP-42 section 5 can stand alone once inserted into the AP-42
document .
No environmental measurements were conducted during this program,
therefore, no separate QA section is contained in this report. The quality of
the existing data has been evaluated as described above.
3
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SECTION 2
INDUSTRY DESCRIPTION
GENERAL
A ferroalloy is an alloy of iron and one or more other elements, for
example, silicon. Ferroalloys can contain very little iron, as in 98 percent
silicon metal, or consist of mostly iron with small amounts of other elements.
The iron and steel industry consumes approximately 95 percent of the
ferroalloys produced in the U.S.2 The alloys are used to impart unique
characteristics and properties to steel and cast iron. The remaining
5 percent are consumed in the production of nonferrous metals including cast
aluminum, nickel-cobalt base alloys, titanium alloys, and are also used as raw
materials for production of other ferroalloys.
The-mate*4.als generally considered products of the ferroalloy industry
are listed in Table 1. There are other materials which are not considered
products of the ferroalloy industry even though they are an alloy of iron and
an element or they are produced in the same facilities as ferroalloys. For
example,_ferrophosphorus is considered a byproduct of phosphorus manufacturing.
Calcium carbide, which has a different end-use, is produced at some ferroalloy
facilities} but is not considered a product of the ferroalloy industry.
Three major groups of ferroalloys known as bulk alloys constitute
approximately 85 percent of the ferroalloys produced in the U.S.2 The three
major groups are ferromanganese, ferrosilicon, and ferrochromium. Subgroups
of these bulk alloys include silicomanganese, and silicon metal. The bulk
ferroalloys are manufactured in a variety of grades distinguished by carbon,
silicon, or aluminum content. Further subclassifications exist for each
grade. Fifteen percent of the ferroalloys produced in the U.S. are specialty
alloys^ which are typically produced in small tonnages. Components of
specialty alloys and metals include vanadium, columbium, molybdenum, nickel,
aluminum, boron, and tungsten.
The United States is still the world's largest producer of ferroalloys
even though production has recently declined to 1945 levels. The decline in
production is due to an increase in imports and declining requirements for
ferroalloys by the iron and steel industry. Imported ferroalloys have
increased from approximately 2.4 percent of domestic consumption in 1945 to
over 40 percent in the years since 1975.^
4
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TABLE 1. FERROALLOY PROCESSES AND RESPECTIVE PRODUCT GROUPS
Process
Products
Submerged-arc furnace process3
Exothermic process^
Silicon reduction process
Aluminum reduction process
Mixed aluminothermal-
siTIcothermal process
Electrolytic process^
Vacuum furnace process^
Induction furnace processe
Silvery iron (15-22% Si)
Ferrosilicon (50% Si)
Ferrosilicon (65-75% Si)
Silicon metal
S i1ic on-mang ane s e-z i rc on ium (SMZ)
High-carbon (HC) ferromanganese
S i1ic omangane s e
Charge chrome and HC ferrochrome
F erroc hrome-s i1ic on
FeSi (90% Si)
Low-carbon (LC) ferrochrome
LC ferromanganese
Medium-carbon (MC) ferromanganese
Chromium metal, Ferrotitanium,
Ferrovanadium, Ferrocolumbium
Ferromolybdenum, Ferrotungsten
Chromium metal
Manganese metal
LC ferrochrome
Ferrotitanium
aThe process in which metal is smelted in a refractory lined, cup
shaped, steel shell by three submerged graphite electrodes.
bThe process in which molten charge material is reduced, in an
exothermic reaction, by the addition of silicon, aluminum or a
combination of the two.
cThe process in which simple ions of a metal, usually chromium
or magnesium, in an electrolyte are plated on cathodes by a direct
low-voltage current.
dThe process in which carbon is removed from solid state, high
carbon ferrochrome within vacuum furnaces maintained at a
temperature near the melting point of the alloy.
^he process which converts electrical energy without electrodes
into heat to melt the metal charge in a cup or drum shaped vessel.
5
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A list of foreign and domestically owned ferroalloy producers located in
the U.S. in 1981 is presented in Table 2. Presently, the industry is unstable
in that there are many idle furnaces, plants that are being closed, and older
furnaces being replaced by larger, more efficient furnaces. The industry
appears to have no plans to expand U.S. production of ferroalloys.
It is interesting to note that many ferroalloy producers are changing
ownership. For instance, Airco Alloys, the largest and most diversified
domestic producer of ferroalloys, sold all of its ferroalloy operations to
Autlan Manganese Corp., and SKW Alloys Inc., both of West Germany and to
Macalloy Inc. of the United States in 1979. This change left Union Carbide as
the largest wholly domestically owned producer of ferroalloys in the U.S.
During July 1981, Union Carbide sold most of its operations (except vanadium
and tungsten) in the U.S., Canada and Europe to groups led by Elkem A/S of
Norway. Kewicky Bryelko of the United States sold its silicon metal producing
facility located in Springfield, Oregon to Dow Corning of the United States in
October 1980.
FERROALLOY PRODUCTION PROCESS
The manufacture of ferroalloys is a multistep process. On arrival at the
plant, the raw materials which are specified for the desired products are
unloaded and stored. These materials are withdrawn, pretreated (by crushing
and drying) and then weighed, mixed, and charged to the furnace where smelting
takes place. The molten metal is tapped, cast and allowed to cool and
solidify.- The-ferroalloys are crushed prior to shipment. Figure 1 is a
general flow schematic of a typical ferroalloy production facility.
Raw materials which include quartz or other forms of silicon, metallic
ores, scxap iron, scrap steel, reducing agents such as coal or coke,
limestone, and woodchips, are delivered to ferroalloy facilities by ship,
railroad cars, trucks, or river barges. The raw materials are stored in open
separate storage piles which are sometimes sheltered by block walls, snow
fences, or plastic covers. Raw materials are withdrawn from storage to
satisfy production requirements. Pretreatment may be necessary to ensure
satisfactory furnace operation. Dryers are sometimes used to reduce raw
material moisture, which can be as high as 20 percent.-* Raw materials
charged to calcium carbide and chrome ore/lime melt furnaces must be dried;
however, drying is not a standard procedure for the production of the major
types of ferroalloys. After pretreatment, the materials are conveyed to the
mix house. In the mix house, the specified proportions of each raw material
are weighed into larry cars, conveyors, buckets or skip hoists and transferred
to a hopper above the furnace. The blended raw materials in the hopper are
normally charged to the furnace by gravity flow through one or more feed
chutes. A few open furnaces use manually operated skip loaders to charge the
furnace. Raw materials are charged to the furnace continuously or
intermittently, electric power is applied to the furnace continuously.
Tapping, the withdrawal of molten metal and slag from the furnace vessel
through the taphole, is performed at 1- to 5-hour intervals and lasts from 10
to 15 minutes. Tapholes are pierced by a shot pellet fired from a gun, by
6
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TABLE 2. PRODUCERS OF FERROALLOYS IN THE UNITED STATES IN 19816
Producer Former owner1 Plant location Ferroalloy productab Furnace type
Alabama Alloy Co., Inc.
i
Bessemer, AL
FeSi
Electric
Alunima Co. of Aaerica,
Northwest Alloys, Inc.
i
V
Addy,, HA
| ' ,
Si, FeSi
Electric
Autlan Manganese Corp., HV
r
Airco Alloys, Inc.
Mobile, ALj
SiMn
Electric
AHAX Inc.,
Climax Molybdenum Co. Div.
Langeloth, PA
FeMo
Exothermic
Cabot Corp•
KBI Div.
Penn Rare Metal Div.
Revere, PA
FeCb
Exothermic
Chroaasco Ltd.,
Chromium Mining & Smelting Corp. Div.
Hoodstock, IN
FeCr, FeSi
Electric
Dow Corning
Kewicky Bryelko
Springfield OR
Si
Electric
Elkea Metals Company
Union Carbide0
Alloy, WV
Ashtabula, OH
Marietta, OH
Si, SrSi
FeSi, SrFeSi,
FeB, FeCr, FeMn, FeSi, FeV, Si, SiMn
Electric
Electric
Electric
Engelhard Minerals i Chemicals Corp.,
Minerals and Chemical Div.
Straaburg, VA
FeV
Exothermic
Foote Mineral Co., Ferroalloy* Div.
Caabridga, OH
Crahaa, WV
Keokuk, 1A
FeSi, FeV, silvery pig iron, other1'
Electric
Electric
Electric
Hanna Mining Co., The
Hanna Nickel Smelting Co.
Silicon Div,
Riddle, OR
Henatchee, HA
FeNi, FeSi
Si, FeSi
Electric
Electric
Interlake, Inc.,
Globe Metallurgical Div.
Beverly, OH
Selaa, AL
FeCr, FeCrSi, Si, FeSi, SiMn
Electric
Electric
International Minerals i Cheaical Corp.,
Industry Croup, TAC Alloy* Div.
Bridgeport, AL
Kimbal, IN
FeSi
Electric
Electric
(continued)
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TABLE
2 (continued)
Producer
Foraer owner*
Plant location
Ferroalloy products'*
Furnace type
Macalloy Inc.
Airco Alloya, Inc. 1
Charleston, |,SC
FeCr, FeCrSi
Electric
Metallurg, Inc., Shieldalloy Corp.
Mewfield, HJ
FeAl, Fel, FeCb, FeTi,
FeV, other''
Exotheraic
Ohio Ferro-Alloya Corp.
fl
Montgcnsery, j AL
Philo, OH !
Powhatan Point, OH
FeB, FeMn, FeSi, Si, SiMn
Electric
Penncoil Co., Duval Corp.
Sahuarita, AZ
FeMo
Exotheraic
Pease* Co., The
Newton Falla, OH
Solon, OH
Pulaski, PA
Fort Worth, TX
FeAl, FeS, FeCb, FeMo,
FeV, FeW, other4
FeHi, FeTi,
Electric & exotheraic
Reactive Metals and Alloya Corp.
Heat Pittsburgh, PA
FeTi, other''
Electric
Reading Alloys, Inc.
Kobeaonia, PA
FeCb, FeV
Exotheraic
Satra Corp., Satralloy, Inc. Div.
Foote Mineral Co.
Steubenville, OH
FeCr, FeCrSi
Electric
SEDEMA S.A., Cheaetals Corp.
Kingwood, WV
FeMn
Electrolytic
SKU Alloya, Inc.
Airco Alloys Inc.
Calvert City, KY
Niagara Falla, HY
FeMn, FeSi, SiMn
Electric
Electric
South African Manganese Aacor, Ltd.
Roane Ltd.
tockvood, TO
FeMn, SiMn
Electric
Teledyne, Inc., Teledyne Hah
Chang, Albany Div.
Albany, OE
FeCb
Exotheraic
Union Carbide Corp., Metala Div.
•
Niagara Falla, NT
FeV, FeW
Electric
Union Oil Co. of California,
Waahington, PA
FeB, FeMo, FeW
Electric & exotheraic
Holycorp, Inc.
•it changed within paat 5 years.
^FeAl, ferroaluainuii; FeB, ferroboron; FeCb, ferrocolunbiua; FeCr, ferrochroaiua; FeCrSi, ferrochroaiua-ailicon; FeMn, ferroaanganese; FeMo,
ferroanlybdenua; FeHi, ferronickeli PeP, ferrophoaphorus; FeSi, farroailicon; FeTi, ferrotitaniua; FeV, ferrovanadiua; FeW, ferrotungaten; Si,
ail icon Metal; SiMn, silicoaanganese; SrSi, strontium ailicon.
cChange of ownership froa Union Carbide to Elkea Metals Co^iany occurred during July of 1981.
''includes specialty ailicon alloya, zirconiua alloys, and aiacellaneoua ferroalloys.
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SHIPMENT
/
I
"\ /"
\
CRUSHING
SCREENING
STORAGE
Figure 1. Ferroalloy production flow diagram.
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drilling or by oxygen lancing, and may be enlarged during the tap with wooden
poles or oxygen lances. The pellet fired from a gun is the procedure typically
used to open the taphole. The molten metal flows into a carbon-lined trough
arrangement fixed at or near the furnace shell and is poured into carbon-lined
runners that direct it either to a reaction ladle or directly to a casting bed
or pigging unit. Tapping is terminated by manually inserting a carbon paste
plug into the taphole. In some facilities, the molten metal is poured
directly into pouring ladles which transport and pour it into reaction ladles,
pigging units or cast beds, A reaction ladle is used when additional material
is added to produce a specific product or if other treatment, like vacuum
degassing, is necessary to meet product specifications.
Pigging units are molds used to produce individual ingots that weigh up
to 75 pounds.3 Cast beds or chills are broad, flat, iron or steel pans that
allow heat to dissipate rapidly. While casting in the pigging unit and cast
bed, the floating slag containing impurities is skimmed off to a slag pot or
slag pot. Slag may be disposed of in landfills, or sold for road ballast.
Large ferroalloy castings are broken by drop weights or hammers and then
crushed with large jaw crushers, roll mills, or grinders. The crushed product
is then sized through various mesh screens. The sized product is either
packaged or stockpiled for shipment. Some ferroalloy ingots are not crushed
and sized, but are shipped whole.
FURNACE DESCRIPTION
The following furnace types are used to produce ferroalloys:
• Submerged Electric Arc - Open;
• - Submerged Electric Arc - Covered;
• Vacuum;
• Induction
• Electrolytic and exothermic processes using reaction vessels are
used to produce certain ferroalloys.
Bulk ferroalloys, which comprise 95 percent of all ferroalloys produced
in the U.S., are manufactured in submerged electric arc furnaces.2 These
furnaces, which are normally comprised of a cylindrical steel shell with a
flat bottom, are supported on an open foundation that permits air cooling and
heat dissipation. Two or more layers of carbon blocks lining the bottom
interior of the steel shell comprise the hearth. Refractory or carbon bricks
line the interior walls of the furnace shell. Molten ferroalloy and slag are
removed from the furnace through one or more tapholes located in the lower
half of the furnace, just above the carbon hearth.
10
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Some furnaces are designed to rotate at a very slow speed. Some furnaces
are split and the two halves rotate at different speeds. The upper part,
which rotates more rapidly than the lower part, is a relatively narrow ring
with flat interior surfaces. In one design, the ring rotates at 0.1
revolution per hour (rph) while the furnace rotates at 0.01 rph.22 Furnace
rotation supplements manual stoking to prevent the formation of a crust near
the electrodes which can result in dangerous "blows," the rapid evolution of
trapped gases caused by the collapse of the charge.^3
Usually, three carbon electrodes are arranged in a triangle formation,
extending downward through the charge material to a depth of 3 to 5 ft. These
electrodes, which may be prebaked or of the self-baking, Sodenberg type,
convert electrical energy to heat by arcing high voltage current through the
charge, melting the charge and raising its temperature into the range where
mixing and reactions can occur. Electrode depth is continually varied by
mechanical or hydraulic means as required to maintain a near uniform
electrical load. Individual furnace power consumption rates range from about
7 megawatts to over 50 megawatts, depending on the furnace size and product
being made. The average rating for an individual furnace is 17.2
megawatts.5
Typical process weights and ferroalloy production related to furnace
kilowatt capacity are presented in Table 3. The ferroalloy industry annually
consumes approximately 8,900,000 megawatt-hours of electricity. Six percent
of the electricity is consumed by pollution control devices. Pollution
control devices" account for up to 11 percent of the power used to operate open
and mix-sealed furnaces and approximately 2 percent of the power used in
operating sealed furnaces.^
Submerged electric arc furnaces are categorized by the type of furnace
top cover used. The two basic categories are open and covered and there are
two subtypes for each category. About 86 percent of the submerged electric
arc furnaces in the U.S. are of the open type. Covered furnaces comprise the
remaining 14 percent of submerged electric arc furnaces.4
There are two types of open furnaces; the totally open furnace and the
close hoode'd furnace. Totally open furnaces have an open gap of 1 meter or
more between the furnace top and the fume collecting hood. The gap in the
close hooded furnace is significantly reduced by movable doors or panels that
reduce the amount of air drawn into the hood system.2 a schematic of
totally open furnace is presented in Figure 2.
The covered furnace category is comprised of the mix-sealed furnace and
the sealed furnace. In the mix-sealed furnace, a water cooled cover fits
tightly onto the furnace. Raw materials are fed through annular gaps around
each electrode. The gaps are partially sealed by manual application of raw
materials placed around the electrodes. Sealed furnaces are similar to the
mix-sealed furnaces except that mechanical seals are used around the electrode
and charging occurs through chutes extending through the cover. Schematics of
a totally sealed furnace and a mix-sealed furnace are presented in Figures 3
and 4, respective ly.
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TABLE 3. FERROALLOY PROCESS WEIGHT RATES RELATED TO FURNACE POWER CONSUMPTION3
Charge weight rate,
lb/lb alloy produced
Furnace load, KW-hr/lb
' alloy produced
Charge
weight rate
(lb charged/
MW-hr used)
Product
weight rate
(lb alloy
produced/
MW-hr used)
Product
Range
Approximate »
average
Rakge
Approximate
average
Silvery
iron
1.7-1.9
1.8
1.2-1.4
1.3
1380
770
50% FeSi
2.3-2.5
2.5
2.4-2.5
2.5
1000
400
65-75% FeSi
4.3-4.5
4.5
4.2-4.5
4.4
1020
227
Silicon
metal
4.6-5.0
4.9
6.0-8.0
7.0
700
144
SMZa
4.3-4.5
4.5
4.2-4.5
4.4
1020
227
CaSi
3.8-4.0
3.9
5.7-6.1
5.9
660
170
HC FeMn
2.9-3.3
3.0
1.0-1.2
1.2
2500
834
SiMn
2.7-3.3
3.1
2.0-2.3
2.2
1410
454
FeMnSi
4.2-4.4
4.3
2.4-3.0
2.7
1590
370
Mn ore/lime
melt
3.2-3.6
3.5
0.6-1.0
0.8
4280
1350
Chg Cr
3.7-4.1
4.0
2.0-2.2
2.1
1900
476
HC FeCr
3.7-4.1
4.0
2.0-2,2
2.1
1900
476
(continued)
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TABLE 3 (continued)
Product
Charge weight rate,
lb/lb alloy produced
Range
Approximate
average
Furnace load, KW-hr/lb Product
I, alloy produced Charge weight rate
weight rate (lb alloy
Approximate (lb charged/ produced/
R^nge
average
MW-hr used) MW-hr used)
Cr ore/lime
melt
FeCrSi
Ca carbide
NAd
3.2-3.6
1.5-1.7
1.2
3.4
1.6
0.5-0.7
3.6-3.8
1.3-1.4
aSi - 60 to 65%; Mn - 5 to 7%; Zr - 5 to 71,
^Data not available.
0.6
3.7
1.3
2000
920
1230
1670
270
770
-------
ELECTRODES
TO BAGHOUSE
REACTION
GASES
3
Figure 2. Open furnace.
14
-------
ELECTROOES
MIX FEED
I TYPICAL)
X
electrode seal
COVER
TO AIR POLLUTION
CONTROL DEVICE
AND FLARE
Figure 3. Sealed furnace.
ELECTRODES
MIX CHUTE
(TYPICAL)
TO AIR POLLUTION
CONTROL DEVICE
AND FLARE
Figure 4. Mix sealed."
15
-------
A variety of furnace types, including vacuum, induction, electrolytic,
and exothermic, are utilized to manufacture specialty alloys. The vacuum
furnace is used primarily to produce low carbon (LC) ferrochrome from high
carbon (HC) ferrochrome (produced in a submerged electric arc furnace) by
removing the carbon in a solid state within the furnace at a temperature near
the alloy's melting point. Electric resistance elements supply heat to the
furnace. Induction furnaces produce small tonnages of specialty alloys by
remelting the materials in specified proportions.
The use of blast furnaces to produce ferromanganese was discontinued in
1977. The iron and steel industry produces some high carbon ferromanganese in
blast furnaces, but the process is not considered part of the ferroalloy
industry.
The exothermic process is used to produce low-carbon ferrochrome, low and
medium carbon ferromanganese, chromium metal, ferrotitanium, ferrocolumbium,
and ferrovanadium. Molten alloys (which may first be fused in a furnace) are
blended with reducing agents such as silicon and/or aluminum in a reaction
ladle. The charge material is reduced, generating considerable heat, and the
slag is removed to produce the desired ferroalloy product.
High purity chromium and manganese are produced electrolytically. An
electrolyte solution of the desired metal is prepared and a low voltage direct
current is passed through the solution causing the ions to deposit on the
cathodes.
EMISSION SOURCES
Several types of pollutants are emitted from ferroalloy facilities.
Particulate i-s the major air emission in the industry. Particulate is emitted
in the form of dust and fume. Dust is a result of abrasive processes such as
raw material handling, storage, crushing, screening, drying, weighing, mixing,
and final product handling. Fine particulate that has resulted from
condensation from the gas phase, gas phase reaction, or atomization of a fluid
is emitted in the form of fumes. Fumes result from furnace operations,
furnace tapping, and ladle operations. Potential source of dust and fume
emissions are displayed in Figure 5. In addition to particulate, large
quantities of carbon monoxide (CO) are emitted from the submerged electric arc
furnaces. The weight of carbon monoxide produced sometimes exceeds that of
the metallic product.19
Electric Arc Furnaces
The submerged electric arc furnace emits particulate in the form of a
fume and accounts for an estimated 94 percent of the particulate emissions in
the ferroalloy industry. An uncontrolled electric arc furnace may emit
between 150 and 2,000 lb of particulate per hour, depending upon the type of
alloy produced, type and size of raw materials, operating techniques and
furnace operating conditions.
16
-------
I
11
DUST
OUST
OUST
OUST
// OUST
AND
.// FUMES
smelting TAPPING casting
DUST
i£i=Ci
CRUSHING ' STORAGE
SCREENING
SHIPMENT
3
Figure 5, Ferroalloy production flow diagram showing potential emission points.
-------
Large amounts of carbon monoxide and organic matter are emitted by
submerged electric arc furnaces. Carbon monoxide is formed as a byproduct of
the chemical reaction between the oxygen in the metal oxides of the charge and
the carbon contained in the coke or other reducing agent added to the charge.
The carbon monoxide rises from a region of higher temperature to an area of
lower temperature entraining finer size constituents of the mix and carrying
fume and fume precursors to the top of the furnace. The weight of carbon
monoxide produced sometimes exceeds that of the metallic product.19 An
increase in moisture in the charge materials, reducing agent volatile matter,
thermal decomposition products of raw ore and intermediate products of
reaction cause an increase in primary gas generation. These latter sources
normally account for less than 30 percent of the carbon monoxide production.
Organic emissions from electric arc furnaces have been measured to range
from 71.8 lb/ton of alloy produced in silicon metal producing open furnaces to
1.4 lb of organics per ton of alloy produced in covered ferromanganese
furnaces. Benzo(a)pyrene concentrations in emitted furnace gas were greater
for three of five furnaces tested by EPA than the 0.02 yg/m^ of gas® DMEG
limit. N0X and SO2 concentrations were insignificant (less than 7 lb/hr
or 1 to 17 ppm, respectively from five submerged electric arc furnaces tested
by EPA.20
Ferrosilicon operations producing alloys greater than 75 percent silicon
are known as "hot" operations and are subject to "blows." Blows occur when
the charge material forms a crust or a bridge and does not descend evenly.
When the^crus 6—breaks and falls, extremely hot gases are expelled violently
from the surface. Molten alloy and slag or charged material may be expelled
with the gas.
Manganese operations produce a brown fume consisting of a mixture of
SiC>2 and manganese oxides. The manganese oxides arise from the vaporization
of manganese or production of a volatile intermediate.19 Manganese ores can
contain a significant amount of water and higher manganese oxides which, when
heated to temperatures below 1,000°C, dissociate to lower oxides and oxygen.
This can cause sudden releases of gas causing mix to be ejected from the
furnace.
Tapping also generates fumes. Since tapholes are opened intermittently,
tapping fumes occur only from 10 to 20 percent of the furnace operating time.
Some fumes originate from the taphole carbon lip liner, but most result from
flow induced by heat transfer from molten metal or slag. Significant fume
emissions are intermittently generated after tapping, during conveying,
pouring, and casting as a result of heat-induced flow as the molten metal
contacts the runners, ladles, cast beds, and ambient air. Typically,
extensive hooding around tapping and pouring operations direct fumes to an
emission control system.
A gray fume containing a high percentage of amorphous silicon dioxide
(Si02) is produced from silicon alloys.19 The Si02 results from the
oxidation and disproportionation of SiO, a gaseous intermediate at reaction
temperatures.3 The SiO losses increase correspondingly with the increase in
18
-------
the percentage of silicon in the alloy. Thus, more SiC>2 fumes are produced
by the production of higher silicon alloys than lower silicon alloys at the
same load. Some tars and carbon, also present in the fume, evolve from the
coal, coke or wood chips used in the charge.
Hearth buildup of silicon carbide may also result from high silicon
operations. If this occurs the electrodes must operate in a higher position,
often resulting in more fume. Chromium furnaces produce a light-colored fume,
containing SiC^, MgO, and iron and chromium oxide. Furnaces producing
ferrochrome-silicon emit SiC>2 fumes similar to those produced by
ferrosilicon.
Additional emissions may be generated by furnaces with self-baking
electrodes. Fumes are generated from the electrode paste during heating and
baking. These fumes are usually directly vented to the atmosphere.
Self-baking electrodes may also increase emissions as a result of "fluting" or
grooving of the electrodes in the relatively oxidizing atmosphere. These
grooves provide direct passage for fumes to escape from the high temperature
regions of the furnace to the surrounding atmosphere.
Along with volatile materials in the furnace charge, the presence of fine
or dense material in the feed may cause rough furnace operation. These
materials may cause non-uniform descent of charge causing the gas to channel
or bypass these obstructions. The sudden collapse of a bridge results in a
momentary burst of fume. Less desirable raw materials containing more fumes
and volatile matter may be used as dictated by economics, resulting in rough
furnace operation and pollution.
Differences in operating techniques affect the amount of fume emissions
substantially^ Furnace gas production rate is roughly proportional to
electrical energy input. Thus, an increase in the electrical load applied to
a furnace results in at least a proportional increase in fume emissions.19
In some instances, emissions increase greater than the proportional increase
in electrical load input because of rough operation and inadequate gas
withdrawal.
Fume emission can vary depending upon how well and how often a furnace is
manually worked or stoked. Some operations, especially silicon metal
operations, require stoking to break up crusts, cover areas of gas blows, and
allow the flow of reaction gases. Sealed furnaces cannot be stoked. Alloys
which are particularly prone to blows, such as silicon metal, are not usually
produced in sealed furnaces. Furnace rotation can substitute somewhat for
stoking and extra care in material preparation and furnace operation can help
to minimize bridging. The accumulation of materials under the cover and in
gas take-off ducts, which reduce the gas withdrawal capacity of the exhaust
system, can cause abnormally high emissions from sealed furnaces.
Shutdowns and startups of submerged electric arc furnaces, which are
designed to operate continuously, can adversely affect emission rates. Normal
furnace shutdowns are usually not more than several hours and may average 4 to
10 percent of the operating time. In open furnaces, the control systems
19
-------
usually remain in operation during startup and shutdown; in semi-sealed
furnaces the mix seals are empty. Operating under these conditions results in
heavier-than-normal emissions which may last from a few days up to a month
when starting up a new furnace, a furnace with a cleaned out hearth, or one
with a cold hearth after a long shutdown.
Some ferroalloy products are produced from a non-continuous batch
operated furnace in which the melt is poured by tilting the furnace. Violent
gas eruptions can result following the sudden addition of mix, containing
volatile or reactive constituents (coal volatiles, moisture, aluminum), to a
hot furnace.In manganese ore-lime melt furnaces, the gas flow
immediately following mix addition may be five times greater than the average
flow. Temperature and dust loading increase correspondingly with the increase
in gas flow. The mix used in chromium ore-lime melt operations contains
little or no gas-releasing constituents and does not result in violent initial
gas eruptions.
Reaction Ladle Emissions
The chemical constituents of the heat-induced fumes correspond to the
oxides of the products being produced, carbon from the reducing agent, and
enrichment of Si02, CaO, and MgO, if present in the charge. Particle size
usually ranges from 0.1 ym to greater than 20.0 ym. Larger particles are
sometimes emitted as a result of agglomeration of finer particles or as ejecta
from the charge. Collected particulate in the dry state is very light,
varying "in bulTE density between 4 and 30 lb/ft3.
In addition to heat induced fumes, fumes may be generated as a result of
reactions conducted in the reaction ladle such as chlorination, oxidation,
slag-metal reactions, and stirring of molten metal with gas. The ladle
reactions are intermittent and have not been quantified.
Vacuum, Induction and Other Process Emissions
Emissions from vacuum, induction, electrolytic or exothermic ferroalloy
furnaces are negligible in comparison to submerged electric arc furnaces. No
particulate emissions are generated by the vacuum process; small quantities of
carbon monoxide gas are withdrawn by a steam jet ejector. The induction
process does not produce any emissions. No particulate emissions are
generated by the electrolytic process, but generation of minor amounts of
ammonia or sulfur oxides sometimes occurs. Oxide fumes, whose physical
characteristics are similar to those fumes from submerged electric arc
furnaces, are produced in the reaction ladle or furnace during the exothermic
process. Emission generation correlates with periods of highest temperature
and greatest agitation.
Fugitive Dust Emissions
Fugitive dust emissions are generated by raw material storage, transport,
unloading and transfer activities. Moisture in the raw materials, which may
be as high as 20 percent, can minimize these emissions. Sometimes, raw
20
-------
materials may be dried in rotary or other type dryers prior to charging to
reduce off gas volumes and enhance furnace operation. These dryers may
generate significant particulate emissions.
Ferroalloys are crushed and screened into different product sizes before
marketing. This process creates undersized pieces and airborne
particles.19 xhe quantity of dust emitted as a result of casting, breaking,
and screening operations has not been quantified, but is substantially less
than that of furnace emissions.3
The properties of particulates emitted as dust are similar to the natural
properties of the ores or alloy from which they originate. These dust
particles range in size from 3 to 100 ym.l®
EMISSION CONTROLS
Control devices are always used to control emissions from smelting.
Control of emissions from tapping is frequently integrated with the furnace
control system. Other particulate-generating activities i.e., storage of
materials, crushing, pretreatment of raw materials and crushing and sizing of
finished products, are controlled by about one-half of domestic ferroalloy
facilities.
Furnace Controls
Hooding constructed around the submerged electric arc furnace tapping
area directs fumes to a control system. One primary emission control system
is usually all that is needed to capture emissions from open electric arc
furnaces, since the emissions from all furnace operations can be collected by
the same_fume-Lhood.
Two emission capture systems are needed for covered furnaces. A primary
capture system withdraws gases from beneath the furnace cover. A secondary
system captures fumes released around the electrode seals and during tapping
operation. The two capture systems are not usually connected to the same
control device. Flares are usually used on sealed and semi-sealed furnaces to
combust carbon monoxide at the control system exhaust. Some plants use some
or all of the carbon monoxide as a fuel in such processes as kilns or
sintering machines.
Gas cleaning devices currently used on submerged electric furnaces to
control particulate emissions are the baghouse (fabric filter), high pressure
venturi scrubber and electrostatic precipitator (ESP). Fabric filters are
employed on 85 percent of the open furnaces in the U.S. Scrubbers are
employed on 13 percent and electrostatic precipitators are employed on
2 percent. Scrubbers are used almost exclusively to clean the high
temperature combustible gases withdrawn from covered (closed) furnaces.
Baghouses are effective in removing particulates from gas streams, but not as
effective for capturing organic emissions. Particulate collection
efficiencies in excess of 99 percent have been achieved for fabric filters
with glass fiber or Nomex bags and for some high pressure drop scrubbers with
21
-------
pressure drops of 13.7 to 23.9 KPA (55 to 96 inches of water)A The
air-to-cloth ratios in baghouses are 1:1 to 2:1 and bag life is on the order
of 2 years. Visible emissions from particulate collectors of less than
10 percent opacity have also been achieved.3
The efficiency of a scrubber for controlling organic emissions is in the
range of 16 to 97 percent.^ Electrostatic precipitators (ESPs) are not
usually used as control devices in the ferroalloy industry because of
potential resistivity problems in the temperature ranges encountered. When
used, however, ESPs are typically installed on open furnaces and can be
expected to be about 98 percent efficient in particulate removal.3
Furnaces and scrubbers utilize large quantities of water. Furnaces use
from 3,000 to 10,000 gallons per megawatt-hour of water for noncontact
cooling.3 Scrubber control systems use from 500 to 3,500 gallons per
megawatt-hour depending on the type of scrubber and the product being
made,3 Wastewater treatment facilities clean scrubber water so that it can
be recycled and/or used as a cooling agent. Treatment facilities for scrubber
water differ from facility to facility. Usually, chemical and physical
treatment of waste streams is performed. Scrubber water is usually clarified
to reduce suspended solids concentration to less than 50 mg/1.3
Fugitive Dust Controls
Raw material storage is controlled by storing the materials in separate
storage piles -sheltered by block walls, snow fences, or plastic covers. The
piles are sometimes sprayed with water to help minimize fugitive dust
emissions. Dust collection equipment, usually a baghouse, is used to minimize
emissions from raw material crushing and sizing of the finished product.
Emission_control equipment for pretreatment such as drying of raw materials
include scrubbers, cyclones, or baghouse collectors. The raw material
emission control equipment is sometimes connected to the furnace control
system.
Transferring the dust from the baghouse to trucks that remove it from the
site is sometimes a problem because of leaks in transfer mechanisms. This can
result in dust being resuspended when there is significant wind velocity.
22
-------
SECTION 3
FERROALLOY PRODUCTION EMISSION FACTORS
TOTAL AND SIZE-SPECIFIC EMISSION FACTORS
Emission factors for uncontrolled and controlled total particulate have
been developed in this report for the ferroalloy industry. Size specific
emission factors have also been calculated based on cascade impactor test
results. These emission factors and size distributions are listed in Tables 4
and 5 and illustrated in Figures 6 through 15.
The data used in the calculation of emission factors presented in this
report are from different test reports than the data used in the current AP-42
ferroalloy section (2/72). As shown in Table 6, additional data of improved
quality have been developed in the past 10 years. Test data quantifying
emissions of sulfur dioxide, carbon monoxide and organics are summarized in
Table 7 «id emission factors for those emissions are presented in Table 8.
The procedures used in compiling this information, calculating the emission
factors and rating the emission factors are detailed in the following pages.
DATA REVIEW
All available sources of data were reviewed for the compilation of
emission factors. There were no data available from EPA's FPEIS which were
useful in the calculation of emission factors.
Sources of data that were the results of actual measurements and
observations were considered primary sources. All other sources of data that
referred to summarized emission data performed and reported by a different
organization or author were considered secondary sources. Only primary
sources were considered suitable for calculating emission factors.
The data review process consisted of two steps. The first step consisted
of obtaining sources of emission data, and judging if it should be considered
a primary or secondary source. If judged secondary, an attempt was made to
obtain the primary source(s).
All primary data sources were extensively reviewed and analyzed. The
data were ranked using an A through D grading system based on data quality and
reliability according to the criteria described earlier, and in the manual
"Technical Procedures for Developing AP-42 Emission Factors and Preparing
AP-42 Sections."!
23
-------
TABLE 4. EMISSION FACTORS FOR PARTICULATE FROM SUBMERGED ARC FERROALLOY FURNACES33
Uncontrolled"
particulate
Controlled"
eaiasion
factor*
Eaiaaion
i
emissions
—
Factor
1,
—.—
.......
Emission
Product****
Furnace
kg/Mg
lb/ton
kg/MW-
lb/HW-
. Sating
Sice
Control
H /*i
lb/ton kg/HW-
lb/MW-
Factor Size
type
alloy
alloy
hr
hr
(A-E)
* •
data
Notes
device*®*1
alloy
alloy hr
hr
Rating data
Notes
FeSi
Open
35
70
7.4
16.3
B
Yes
1
a ,'b, c
Baghouae
0.9
1.8 0.2
0.4
B Yes
a,b
(50%)
Covered
46
92
9.3
20.5
E
b
Scrubber—
high energy
0.24
0.48 0.05
0.1
g
d
Scrubber—
low energy
4.5
9-0 0.7?
1.7
E
d,e
FeSi
Open
158
316
16
35
E
f
(752)
Covered
104
206
13
29
E
d.e
Scrubber—
low energy
4.0
8.0 0.5
1.1
E
d,e
FeSi
Open
282
564
24
53
E
f
(90%)
Si Metal
Open
436
872
33
n
B
Yes
Baghouse
16
32 1.2
2.6
B Yes
(982)
FeMn
Open
14
28
4.8
11
B
Yes
i.j
Eaghouse
0.24
0.48 0.078
0.2
B Yes
M
(BOX)
Scrubber—
high energy
0.8
1,6 0.34
0.7
E
e,k
FeMn
Covered
6
12
2.4
5.3
E
m,n
Scrubber-
(11 Si)
Sealed
3?
74
17
37
E
r ,8
high energy
0.25
0.5 0.10
0.2
C
k,p,q
FeCr
(High Carbon)
Open
78
157
15
33
C
Yea
t ,u
ESP
1.2
2.3 0.23
0.5
C Yes
t ,U
SiMn
Open
96
192
20
44
c
Yes
v,w
Scrubber
2.1
4.2 0.44
1.0
C Yes
w,x
Sealed
Scrubber—
high energy
0.15
0.30 0.016
0.04
E
S,p
••Particulate emission factors are listed for main furnace dust collection system before and/or after control device. In cases where other
emissions such as leaks or tapping are included or quantified separately a consent is footnoted. Other sources of particulate enissions which are
not included in this table are; raw material handling, storage and preparation and product cruahing, screening, handling and packaging.
bb(X) refers to percent of main alloying element in product.
ccIn moat source testing, fugitive emissions were not measured or collected. In cases where tapping emissions were controlled by the primary
system, their contribution to total emissions could not be determined, Fugi tive emissions may vary greatly between sources based on furnace and
collection system design and operating practices.
d<*Low energy scrubber refers to those with £P <20 in. High pressure refers to those with &P >20 in.
(continued)
-------
TABLE 4 (continued)
alncludes fuaei captured by a tapping hood (efficiency estimated to be nearly 100Z).
^References No. 7 and 8*
cEmission factor is the average of 3 sources. Fugitive emissions are not included. Fugitive emissions at one of the sources were measured to
contribute an additional 10.5 kg/Mg alloy or 2.7 kg/MW-hr. This was approximately half as much as collected by the primary system.
dBoes not include emissions from tapping or mix seal leaks.
Reference No. 4.
*Reference ho. 32.
S60Z of tapping emissions estimated to be captured by emission control system, escaping fugitive emissions not included in emission factor.
^References No. 8 and 10*
*50% of tapping emissions estimated to be captured by emission control system, escaping fugitive emissions not included in emission factor.
^References No. 8 and 9.
^Includes fume from primary control system only.
"Includes tapping fumes and mix seal leak fugitive emissions. Fugitive emissions measured were 33% of total uncontrolled emissions.
"Reference No. 8.
PBoea not include tapping or fugitive emissions,
fvj ^Emission factor if uncontrolled tapping and fugitive emissions are included * 2.0 kg/Mg alloy.
Ui rAssumed that tapping fumes are not included in emission factor*
"Reference No* 11.
cTapping emissions included. Emission factor developed from two test series performed on the same furnace separated by a 7 year tine frame.
The later test measured emissions 36% less than the initial test.
References No. 12, 13 and 14.
vFactor is average of two test series. The teats at one source included fugitive emissions which amounted to 3.42 of total uncontrolled
emissions. The second test did not provide enough information to determine if fugitive emissions were included in total.
'"References No. IS and 17.
*Factors developed from two scrubber controlled sources, one operated at aAP ¦ 47-57" H20, the other at an unspecified&P. Emission factor
if uncontrolled tapping operations are included * 4.2 kg/Mg alloy.
-------
TABLE 5.
SIZE SPECIFIC
EMISSION FACTORS
Cumulative mass
Emission
particle8j
Emission
Factor
Factor
size
Cumulative mass %
Control
Eating
(micro-
less than
kg/Mg alloy
Product
device
(A-E)
'iietArs) |
stated size
(lb/ton
alloy)
50% FeSib«e
None
B
0.63
45
16
(32)
Open furnace
1.00
50
18
(35)
1.25
53
19
(37)
2.50
57
20
(40)
6.00
61
21
(43)
10.00
63
22
(44)
15.00
66
23
(46)
20.00
69
24
(48)
d
100
35
(70)
50% FeSib»e
Baghouse
B
0.63
31
0.28
(0.56)
Open furnace
1.00
39
0.35
(0.70)
1.25
44
0.40
(0.80)
2.50
54
0.49
(1.0)
6.00
63
0.57
(1.1)
10.00
72
0.65
(1.3)
15.00
80
0.72
(1.4)
20.00
85
0.77
(1.5)
100
0.90
(1.8)
80% FeMnf>8
None
B
0.63
30
4
( 8)
Open furnace
1.00
46
7
(13)
1.25
52
8
(15)
2.50
62
9
(17)
6.00
72
10
(20)
10.00
86
12
(24)
(continued)
-------
Emission
Factor
Control Rating
Product device (A-E)
80% FeMnf»g
Open furnace
(cont.)
80% FeMn^ Baghouse B
Open furnace
Si Metal8»h None B
Open furnace
TABLE 5 (continued)
Particle3
i •size
(micro- '
meters)
Cumulative mass %
less than
stated size
Cumulative mass
Emission Factor
kg/Mg alloy
(lb/ton alloy)
15.00
20.00
d
0.63
1.00
1.25
2.50
6.00
10.00
15.00
20.00
d
96
97
100
20
30
35
49
67
83
92
97
100
13
14
14
0.048
0.070
0.085
0.120
0.160
0.200
0.220
0.235
0.240
(26)
(27)
(28)
(0.10)
(0.14)
(0.17)
(0.24)
(0.32)
(0.40)
(0.44)
(0.47)
(0.48)
0.63
57
249
(497)
1.00
67
292
(584)
1.25
70
305
(610)
2.50
75
327
(654)
6.00
80
349
(698)
10.00
86
375
(750)
15.00
91
397
(794)
20.00
95
414
(828)
d
100
436
(872)
(continued)
-------
TABLE 5 (continued)
Product
Control
device
Emission1 Particle3
Factor size
Rating |, (micro-
(A-E) meters)
Cumulative mass %
less than
stated size
Cumulative mass
Emission Factor
kg/Mg alloy
(lb/ton alloy)
Si Metal
Baghouse
B
1.00
49
7.8
(15.7)
Open furnace
1.25
53
8.5
(17.0)
2.50
64
10.2
(20.5)
6.00
76
12.2
(24.3)
10.00
87
13.9
(28.0)
15.00
96
15.4
(31.0)
20.00
99
15.8
(31.7)
100
16.0
(32.0)
FeCr^»i
None
C
0.5
19
12
(24)
Open furnace
1.0
36
22
(44)
2.0
60
37
(74)
4.0
76.
47
(94)
io.oi
91J
56 J
(112)J
d
100
62
(123)
FeCr (HC)b ESP C 0.5 33 0.30 (0.59)
Open furnace 1.0 47 0 42 (0.85)
2.5 67 0.60 (1.21)
5.0. 80 0.72 (1.44)
10.0J 90J 0.81J (1.62)J
100 0.90 (1.8)
(continued)
-------
TABLE 5 (continued)
Product
Control
device
Emission l Particli3
Factor size
Rating
(A-E)
P
(micro-
meters)
Cumulative mass Z
less than
stated size
Cumulative mass
Emission Factor
kg/Mg alloy
(lb/ton alloy)
SiMnb»k
None C
0.5
28
27
(54)
Open furnace
1.0
44
42
(84)
2.0
60
58
(115)
4.0.
76.
73,
(146)
10.oJ
96J
92 J
(177)J
d
100
96
(192)
SiMnm»k
Scrubber C
0.5
56
1.18
(2.36)
Open furnace
1.0
80
1.68
(3.44)
2.5
96
2.02
(4.13)
5.0
99
2.08
(4.26)
10.0
99.9J
2.10 J
(4.30)J
100
2.1
(4.3)
aParticle aerodynamic diameter based on Task Group on Lung Dynamics definition.
(particle density * 1 gr/cm^).
^Tapping emissions included.
cReferences No. 10 and 21.
^Total particulate based on Method-5 total catch, see Table 4.
eIncludes tapping fume, however, tapping capture efficiency was less than 50%.
^References No. 21 and 12.
^Includes tapping fume, however, tapping capture efficiency was estimated to be 60%.
^References No. 21 and 13.
^References No. 15, 16 and 17.
Jlnterpolated data.
^References No. 18 and 19.
"Primary emission control system only, does not include tapping emissions.
-------
99.990
99.950
99.90
99.80
99.50
99
96
95
l
; 90
80
70
60
50
40
30
' 20
ro
5
2
I
0.5
0.2
0.15
0.1
0.0
10
TOTAL PARTICULATE
EMISSION RATE
35
PARTICULATE
Mg ALLOY
JLhLJmJLXJLLLI
J 1 1 I j I I j
1
I II 111
24
20
16
•o° 101 10*
PARTICLE DIAMETER, micrometers
Figure 6. Uncontrolled, 50% FeSi producing, open furnace particle
size distribution.
30
-------
99.990
99.950
99.90
99.60
99.50
99
98
95
i
i
; 90
i
! 80
; 70
60
; so
' 40
i 30
i 20
*
\ *
i
: 5
i
>
2
I
0.5
0.2
0.15
0.1
0.0
10
total particulate
EMISSION RATE
=0 go PARTICULATE
Mg ALLOY
-I ..1 1—' ' ' « i ' I
J L
I I I I 11
10° ,0'
PARTICLE DIAMETER, micrometers
0.77
0.72
0.65
0.57
0.49
0.40
0.35
0.28
i > i .u
to'
UJ
N
<7>
o
ui
H-
<
|—
w
V
UJ
z>
u
ac
<
Q.
o>
UJ
>
»-
<
-I
z>
2
u
Figure 7. Controlled (baghouse), 50% FeSi, open furnace particle
size distribution.
31
-------
ft.
I
99.990
99.950
99.90
99.80
99.50
99
98
95
¦' 90
i
1 80
s »
60
: 50
j 40
i 30
i 20
!
i
i 5
0.5
0.2
0.15
0.1
0.0
TOTAL PARTICULATE
EMISSION RATE
14
kg PARTICULATE
Mq ALLOY
10
14
13
12
10
9
8
7
..1 l I—l l I
A
j ' I 11»1
j—i—i 1111.
«0° 101
PARTICLE DIAMETER, micrometers
10*
ui
N
to
a
ui
i-
<
tn
V
UJ
3
u
p
ae
<
a.
LU
>
H
<
3
2
3
O
>
O
-J
<
9
2
Figure 8. Uncontrolled, 80% FeMn producing, open furnace particle
size distribution.
32
-------
99.990 r
99.950 ¦
99.90 ¦
99.80 ¦
99.50 ¦
99-
98-
95 ¦
so.
I 80-
70-
I
60-
50-
40-
30-
20-
10-
5 -
2 ¦
I •
0.5 ¦
0.2 ¦
0.15 ¦
0.1 -
0.0
10*
TOTAL PARTICULATE kq PARTICULATE
EMISSION RATE "U.Z40 ——
Mg ALLOY
-u—II i 1111
J—i—i i 111 l1
x..i i ijj
0.235
0.220
0.200
UJ
N
(7)
o
UJ
H
<
W
0.160 y
0.120
0.085
0.070
0.048
3
O
0C
<
Q.
>
o
<
o»
s
o»
JC
yj
>
3
S
3
O
I0U 101 I01
PARTICLE DIAMETER, micrometers
Figure 9. Controlled (baghouse), 80% FeMn producing, open furnace
size distribution.
33
-------
u
N
55
Q
UJ
i*
in
v
z
UJ
o
ec
Ui
a.
UJ
>
5
_i
3
Z
3
O
99.990
99.950
99.90
99.80
99.50
99
98
95
90
80
70-
60
50
40 -
30
20-
-10
5
2
I
0.5
0.2
0.15
0.1
0.0
TOTAL PARTICULATE
EMISSION RATE
.436 k9 PARTICULATE
Mg ALLOY
A II.
xu
1
-I 1—t . I III LI
JUU
414
397
375
349
327
305
292
249
10
10° 101 10"
PARTICLE DIAMETER, micrometers
Figure 10. Uncontrolled, Si metal producing, open furnace
particle size distribution.
34
-------
99.990
99,950
99.90
99.80
99.50
99
98
95
J
4
j 90
3
* 80
! »
60
50
40
30
20
5
2
I
0.5
0.2
0.15
0.1
0.0
10
TOTAL PARTICULATE
EMISSION RATE
16.0
kg PARTICULATE
Mg ALLOY
-J—U—I „ I I I, I, 11
-I 1—I J llll
i
J » i '
10° 101
PARTICLE DIAMETER, micrometers
jjJ
10*
Figure 11. Controlled (baghouse), Si metal producing, open
furnace particle size distribution.
35
-------
UJ
N
en
a
Ll)
£/>
Z
u
o
5
mJ
D
Z
3
O
99.990
99.950
99.90
99.80
99.50
99
98
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
0.1
0.0
total particulate
EMISSION RATE
62 N PARTICULATE
Mg ALLOY
i, l I, l
xA
J I L
JLbJLJL
1
I I I IJ
56
47
37
22
12
10
10° 101 10*
PARTICLE DIAMETER, micrometers
u
N
m
a
LiJ
I-
<
_J
3
2
3
O
>
o
_J
-J
<
Figure 12. Uncontrolled, FeCr producing, open furnace particle
size distribution.
36
-------
39.990
99,950
99.90
99.80
99.50
99
98
95
i
; 90
i
! 80
; 70
60
50
40
30
20
IS
5
TOTAL PARTICULATE kg PARTICULATE
h EMISSION RATE "° 90 — r—rr:
Mg ALLOY
0.5
0.2
0.15
0.1
0.0
10
0.81
0.72
0.60
0.42
0.30
1 I lit! I ll
-I
J 1—1 1 ¦ 1 ' ' 1
J 1 I—L
u
N
cn
£2
yj
H
<
I-
(/}
V
u
I-
<
u
H
CC
<
0.
U
>
h*
<
3
U
I0U 101
PARTICLE DIAMETER, micrometers
10'
Figure 13. Controlled (ESP), FeCr (HC) producing, open furnace
particle size distribution.
37
-------
99.990
TOTAL PARTICULATE
99.950- EMISSION RATE
99.90
99.80
99.50
99
98
95
90
80
70
60 -
50-
40
30 -
2-0 -
10
5
2
I
0.5
0.2
0.15
= 96
kg PARTICULATE
Mg ALLOY
0.1 -
92
73
- 58
0.0
10
* ' «¦¦¦¦¦
J I L
111
1
J—I—* » ¦ ' ¦¦
10° 101 10'
PARTICLE DIAMETER, micrometers
Ui
N
CO
o
UJ
<
h
-
t-
<
_i
3
s
Z>
a
Figure 14. Uncontrolled, SiMn producing, open furnace
particle size distribution.
38
-------
99.990
99.930
99.90
99.80
99.50
99
96
95
i
; 90
80
70
60
50
40
30
20
2.10
yj
2.08
w
2.02 Q
yj
.68
- 1.18
10
5
2
I
0.5
0.2
0.15
0.1
TOTAL PARTICULATE „ . Kg PARTICULATE
EMISSION RATE . Mg ALLOY
0.0
10
-u I I I I I II
J—i i i i in
J L
10° 101
PARTICLE DIAMETER, micrometers
10*
Figure 15. Controlled (scrubber), SIMn producing, open furnace
particle size distribution.
39
-------
TABLE 6. PARTICULATE EMISSION TESTS REVIEWED
Uncontrolled Controlled
Teat
No.
Product
Furnace
type
Control
device
Power
rating
(mi
Source|
Reference
Ho,
11
Eaia.ioi^
factor
(kg/Mg)
alloy,
" 1
is...
HW-hr
Rating
Particle
size data
and
rating
Emission
factor -
(kg/Mg)
alloy
sife
Rating
(A-D)
Particle
size data
and
rating
1
FeSi 501
Open
Baghouse
35
7, 8
IJ
35 ¦
7.4
A
Yea, A
0.9
0*20
A
Yea, A
2
FeSi 501
Open
Scrubber
48
4
49
9.7
C
No
3
PeSi 501
Covered
Scrubber
45
8
32
7.1
C
No
0.25*
0.055
D
No
4
FeSi 50*
Covered
High energy
48
4
46»-b
9.3
D
No
0.23"
0.04?
D
No
rubber
5
FeSi 501
Covered
Low energy
17
4
69a,b
11
D
No
4.5*
0.7?
D
No
scrubber
6
FeSi 752
Covered
Scrubber
17
4
103s
13
B
No
4.0"
0.50
D
No
7
Si Metal 982
Open
Baghouse
17
8, 10
436
33
A
Yes, A
16
1.2
A
Yes, A
8
FeHn 80%
Open
Baghouse
10 ea.
8, 9
14
4.8
A
Yes, A
0.24
0.078
A
Yes, A
9
FeMn 80S
Open
High energy
16
4
49
11
B
No
0.8
0.34
C
No
scrubber
10
FeHn 80%
Covered
Scrubber
8
4
6*
2.4
C
No
0,16*
0.07
5
No
11
FeHn 80S
Covered
Scrubber
11
8
10
4.1
C
No
0.25c
0.10
B
No
12
FeMn BOX
Sealed
7
11
37
17
D
No
13
FeCr (HC)
Open
ESP
37
12, 14
81
14.5
B
No
1.1
0.19
B
No
14
FeCr (HC)
Open
ESP
35
13
75
16
B
Yes, C
1.2
0,27
B
Yes t B
15
FeCr (HC)
Open
10
16
84
10
C
No
16
SiHn
Open
Scrubber
7
15
69
14
B
No
3.2
0.67
B
No
17
SiMn
Open
Scrubber -
27
17
123
25
B
Yes, B
l.ld
0.21
B
Yes, B
18
SiHn
Sealed
High energy
22
11
0.06
0.016
C
No
•crubber
*Pris»ary emission control iya(c« tested only.
^Not used in category EF calculation because secondary emissions not included.
cEsission factor if uncontrolled tapping and fugitive emissions are included ¦ 2,0 kg/Mg. 0.78 kg/MW-hr.
^Emission factor if uncontrolled tapping emissions are included ¦ 4.2 kg/Mg, 0*98 kg/MW-hr.
-------
TABLE 7. SULFUR DIOXIDE, CARBON MONOXIDE AND ORGANICS EMISSION TESTS REVIEWED
Rating (A-D)
rest
4o.
Product
Furnace
type
Control
device
1
Po«er
ratiil^
(MB)
1,
Source
(Reference
No!'
S02
lb/ton
alloy
-
CO
lb/ton
alloy
-
Organics
Uncontrolled Controlled
lb/ton lb/ton
alloy alloy
1
FeSi 501
Open
Baghouse
35
7, 8
6.4s
4.4a
C
2
FeSi 50%
Open
Scrubber
48
4
2.5b
D
3
FeSi 50*
Covered
Scrubber
45
8
2l80b
15.0a
0,61c
C
4
FeSi 50%
Covered
High energy
48
4
D
15.8b
0.52b
D
scrubber
7.3b
1.5b
5
FeSi 50*
Covered
Low energy
17
4
D
scrubber
6
FeSi 75%
Covered
Scrubber
17
4
3230b
D
20.5b
4.8b
D
7
Si Metal 98%
Open
Baghouse
17
8, 10
71.8d
51.6d
C
8
FeMn 80%
Open
Baghouse
10
8, 9
10.6b
3.72b
C
9
FeMn 80%
Open
High energy
16
4
1,64b
1.36b
D
scrubber
0.14b »e
10
FeMn 802
Covered''
Scrubber
8
4
45e
D
0.30b>*
D
U
FeMn 80%
Covered
Scrubber
U
8
0.013^
1.38b
0.80b
C
12
FeMn 80%
Sealed
7
11
D
13
FeCr .i
C
18
SiMn
Sealed
High energy
22
11
0.021d
D
1690b
D
0.09b
D
scrubber
"Includes tapping emissions.
''Primary emission control system tested only, does not include tapping or leak emissions.
Additional emission factor for uncontrolled secondary emissions = 4.26 lb/ton.
''primary hood estimated to capture 60% of tapping emissions.
CMix seal furnace has holes in cover to allow combustion air to enter and bum hot gas.
^High carbon.
8ESP outlet.
''Emissions at outlet of scrubber.
'Additional emission factor for uncontrolled tapping emissions = 0.072 lb/ton.
-------
TABLE 8. SULFUR DIOXIDE, CARBON MONOXIDE AND VOC EMISSION FACTOR TABLE3
vocd voc
Uncontrolled Controlled®
Product
Furnace
type
b
S02
lb/ton
COc
lb/ton
kg/Mg
alloy
(lb/ton)
alloy
Control
device
kg/Mg
alloy
(lb/ton)
alloy
FeSi - 50%
Open
Covered
2180f
2.25f
6.35f
(4.5)£
(12.7)£
Baghouse
Scrubber --
High energy
Scrubber —
Low energy
2.2
0.28
0.75
(4.4)
(0.56)
(1.5)
FeSi - 752
Covered
3230f
10.25£
(20.5)
Scrubber
2.4
(4.8)
Si Metal 98Z
Open
35.90f
(71.8)f
Baghouse
25.9
(51.6)
FeMn - 802
Open
3.05£
(6.1)f
Baghouse
Scrubber —
High energy
1.85
0.70
(3.7)
(1.4)
Covered
Sealed
0.009
0.70*
C1.4)£
Scrubber
0.40
(0.8)
FeCr h
Scrubber
Sealed
0.021£
1690f
Scrubber
High energy
0.05
(0.10)
"All emission factors are rated D.
bS02 emission- will depend on amount of sulfur in the feed materials.
cCO emissions are measured before control by flare. CO emissions from open furnaces are
low. The quantity of emissions from covered furnaces will vary with the volume of air
drawn into the cover. Excess air will reduce CO emissions.
dOrganic emissions may increase if dirty scrap iron or steel is feed to the furnace.
'Controlled emissions are measured before any flare in the control system.
£Does not include seal leaks or tapping emissions; hoods on open furnace may capture
part of tapping emissions.
(Includes tapping emissions.
^Emission factor for tapping emissions.
42
-------
The data review process was conducted on primary data sources describing
17 tests of uncontrolled emissions, and 15 tests of controlled emissions..
The data contained in each test report were used to develop an emission factor
specific to that test site. Of the 17 uncontrolled data sources, three were
rated A, four were rated B, three were rated C and seven were rated D. Of the
15 controlled data sources, three were rated A, five were rated B, two were
rated C, and five were rated D. The data sources were they grouped by
product, furnace type, and control device. Source specific emission factors
were then calculated and rated.
The ratings assigned to the emission factors reflects the ratings of the
data used to develop that emission factor. An A through E scale, as defined
earlier, was used to indicate the reliability of each emission factor. A
brief summary of the relevant details of each test and the basis for the
assigned rating follows.
One souree^O listed in FPEIS was the Chromasco, Woodstock, TN
facility. These data were the result of efficiency testing performed on a two
phase jet scrubber. The original report was obtained on microfiche. The
report lacked information necessary for the calculation and verification of
emission factors. Some data concerning production rates and emissions
appeared to be very different from the range of expected values based on data
from other FeCr producing facilities, therefore none of the data contained in
the report were used in the compilation of emission factors.
Fifty Percent-^eSi: Open Furnaces
Test Number 1 was performed in March 1980 at the Foote Mineral Co.,
Graham, WV facility.® The Number 2 furnace was tested while producing 50
percent EeSi and was observed to operate at 32 MW (design = 35 MW) during the
test period. The emission control system included a tapping hood which was
judged to be almost 100 percent effective, thus the emission factor is
reported to include tapping emissions. The test location at the inlet to the
baghouse was located more than 8 diameters downstream of a flow disturbance.
Five Method 5, and 17 Andersen cascade impactor runs were performed on the
inlet and averaged to determine the reported uncontrolled emission factor.
Three Method 5 and nine Andersen Impactor runs were performed on the baghouse
outlet. The baghouse outlet sampling was single-point and superisokinetic due
to very low flow rates. This is not considered a major problem due to the
small particles present in the baghouse outlet stream. Detailed process data
were obtained during the test and adequately reported. The tests were
conducted according to EPA's inhalable particulate test protocol only during
the range of normal furnace operation. No serious problems were uncovered in
the review of the reports. This test report was given an A rating.
Test Number 2 was performed at the Union Carbide Corp. (now Elkem
Metals), Ashtabula OH plant during April 1979.4 a 52 MW open furnace was
tested. The furnace emission control system did not collect tapping fumes.
The test consisted of one test run of 135-minute duration using the Source
Assessment Sampling System (SASS). This high volume total particulate
sampler, used in Level 1 assessments, was run at the inlet to the control
device. Detailed process documentation was not provided. The SASS test
43
-------
method is a generally accepted emission quantification procedure for research
type programs, however it is of lower accuracy than Method 5. For this reason
the test report was rated C.
Fifty Percent FeSi: Mix-Sealed Covered Furnaces
Test Number 3 was performed at Union Carbide Corp. (now Elkem Metals) ,
Ashtabula, OH plant in-November 1980.8 The emission control system
consisted of a scrubber which collected primary emissions by evacuating the
covered furnace. A secondary hood, ducted to a baghouse, controlled tapping
fumes and fumes escaping the mix seals. The two emission control systems were
tested in order to determine the total emissions generated by the furnace.
However, the scrubber and baghouse were not tested simultaneously. The test
program consisted of three, single point Method 5 runs on the scrubber outlet,
two impactor runs on the baghouse inlet. An analysis of scrubber influent and
effluent solids was made concurrent with the test runs to determine
particulate captured by the scrubber. Six Method 5 runs were performed on the
baghouse inlet and three on the outlet. The test results, were averaged,
summed and reported as total uncontrolled furnace emissions. Samples for the
scrubber solids determination were collected using an automatic composite
sampler. Effluent flow rate was determined from overflow weir calculations.
Developing uncontrolled particulate emission factors from scrubber water
solids determinations is not a reliable method since other species, such as
condensible organic compounds, may be included. Single point testing in a
scrubber—out left-, where cyclonic flow and other effects reduce the reliability
of the data, is also not considered acceptable. However, the combined methods
do provide an order of magnitude estimate. The outlet test results represent
a much smaller mass of particulate than that reported for the scrubber inlet
or secondary emissions captured. The total particulate emission factor thus
determined was rated C. The controlled furnace emission factor was calculated
from the scrubber outlet data only. The secondary control system handles
approximately 10 percent of the uncontrolled emission, however the baghouse
outlet emissions were not incorporated into the controlled emission factor
because of low baghouse efficiency at the time of the test. The results for
controlled primary emissions were also rated C.
Two Andersen impactor runs were made at the inlet to the baghouse. One
was performed during tapping and another during a period when no tapping was
occurring. Very little information was provided describing particle sizing
procedures used in the field or in the subsequent analysis of the data. The
particle sizing data obtained were judged unacceptable for development of
emission factors because only two runs were made at the secondary emission
control system baghouse outlet.
Test Number 4 was performed at the Union Carbide Corp. (now Elkem
Metals), Ashtabula, OH plant in April 1979.^ The 48 MW mix-sealed furnace
was sampled with one SASS (Source Assessment Sampling System, a high-volume .
total particulate sampler used in Level 1 assessments) run. The sample was
taken at the gas main bypass stack which was reported to carry 20 percent of
the primary emissions exhaust flow after control by dual high energy scrubbers.
44
-------
Secondary emissions were not measured. During the SASS run, three samples of
scrubber influent and effluent water were taken in order to perform a mass
balance calculation of particulate collected by the scrubber. Insufficiencies
found while reviewing the test included the lack of information describing the
test and the process operation during testing. For example, no flow
measurements were taken of either the scrubber gas or water discharge rates.
Because of these problems, the test report was rated D.
Test Number 5 was conducted at Union Carbide Corp. (now Elkem Metals),
Sheffield, AL plant during June 1979.^ The furnace primary emissions were
controlled by dual parallel scrubbers and fugitive emissions collected by a
hood and ducted to a baghouse. Testing was performed only on the outlet of
one scrubber. Flow and emissions from the other scrubber were assumed to be
identical for the purpose of calculating total emissions. One SASS run was
performed on the outlet of the scrubber. During the 139-minute test, three
samples of scrubber effluent were taken and composited in order to determine
solids caught in the scrubber by mass balance calculation. The report did not
detail how the scrubber flow rate was determined. Due to this consideration,
along with the fact that only one of the two scrubbers was tested a single
time by the SASS methodology, which is not highly accurate, the test report
was rated D.
Seventy-Five Percent FeSi Covered, Mix Seal Furnace
Test Number 6 was also performed at the Union Carbide Corp. (now Elkem
Metals) S-heffield, AL plant during June 1979.^ The 17 MW furnace tested was
controlled by a system similar to that described in the preceding paragraph
describing test Number 5. The same test methodology was also used and for
similar reasons the test report was also rated D.
Silicon Metal Open Furnace
Test Number 7 was performed at the Interlake Inc. Plant in Selma, AL
during January 1981.8,10 The hood which collected emissions from the open,
17 MW furnace was estimated to also capture 60 percent of the tapping fume.
The test program consisted of six Method 5 runs during which 13 Andersen
impactor runs were made at the inlet to the baghouse. Five Method 5 runs were
made concurrent with nine Andersen Impactor runs on the baghouse outlet. The
outlet runs were hyperisokinetic because of very low velocities in the
baghouse. The reports contained complete descriptions of test procedures and
process data. No significant problems were evident in the review of the test
reports, therefore an A rating was assigned.
FeMn Open Furnace
Test Number 8 was conducted at the Eoane Limited, Rockwood, TN plant in
February 1981.9 The test program consisted of six Method 5 runs at the
baghouse inlet during which 16 Andersen impactor runs were completed.
Concurrently, four Method 5 runs and 16 Andersen impactor runs were performed
on the baghouse outlet. Testing was performed on the emission control system
that was common to both furnaces 3 and 4. The canopy hoods were reported to
45
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collect less than 50 percent of tapping fumes; however, emissions from tapping
were also reported to be light. Testing was performed only during periods
when both 10 MW furnaces were operating simultaneously under normal
conditions. The test reports reviewed presented process data and test
procedures in adequate detail. The only problems apparent from the review of
the reports were that the isokinetics on the Method 5 sampling were low,
averaging 90 percent, and the outlet sampling was hyperisokinetic because of
low velocities in the baghouse. The test report was rated A.
Test Number 9 was conducted at the Union Carbide Corp. (now Elketn
Metals), Marietta, OH plant in April 1979.^ The 16 MW furnace emission
control system did not collect tapping fumes. Uncontrolled emissions were
determined by adding scrubber outlet emissions with scrubber solids catch.
One 117-minute SASS run was performed on the scrubber outlet, during which
three scrubber effluent water samples were taken and composited to determine
solids catch. Very little process data were reported and there was no
description of how the scrubber water feed rate was determined. For these
reasons and because only a single SASS test was performed, the uncontrolled
emissions test results as reported, were rated D. The controlled emissions
data were determined directly from testing and were therefore rated C.
FeMn Covered Furnace, Mix Sealed
Test Number 10 was also performed at the Union Carbide Corp. (now Elkem
Metals), Marietta, OH plant (test 11 was also performed at this plant) , in
April 191-9A -The test consisted of one SASS run lasting 67 minutes on the
scrubber outlet concurrent with effluent water sampling to determine the
particulate caught by the scrubber. The scrubber water flow rate was not
measured, but was estimated by plant personnel. Emissions from tapping and
mix seal_leaks were significant and were not quantified. Process data
describing operating conditions during the test were not carefully documented
and reported. The test results for each controlled and uncontrolled emissions
were rated D.
Test Number 11 was performed at the Marietta, OH plant of Union Carbide
Corp. (now Elkem Metals) in March 1981.® The subject furnace was rated at
8 MW. A scrubber controlled the furnace emissions. Fumes from tapping and
mix seal leaks were captured by a secondary hood and exhausted uncontrolled
from the building through four stacks. The scrubber outlet and the four
secondary hood stacks were tested for a total of five Method 5 runs.
Scrubber effluent was automatically composited during the test and analyzed
for solids content. Scrubber water feed rate was determined by overflow weir
calculations. Each run consisted of a Method 5 run on the scrubber outlet
simultaneous with one of the four secondary stacks. The secondary stacks were
not all tested. Flow rates on two of the three untested stacks were measured
during the test runs. For purposes of total emissions calculations, the
particulate concentration for each of the four stacks was assumed to be the
same. Approximately two-thirds of the total emissions as measured were
captured by the scrubber and one-third were emitted from the four secondary
stacks. Process data were taken during the test and reported in detail; the
furnace was operating within what is considered the normal range of conditions
during the test. The reported test results were rated C. This rating was
46
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chosen because the secondary stacks were not tested simultaneously, and
measuring solids in scrubber liquor is not an accurate method for determining
uncontrolled emissions. The controlled emission factor for the primary
emissions was rated B.
FeMn Sealed Furnace
Test Number 12 was conducted at the Union Carbide Corp. Ltd., Canada
plant in Beauharnois, Quebec during August 1977. H One SASS run was
performed at the control system bypass stack. The test was reported with very
little detail concerning test and process conditions. The test was run for
only 20 minutes and isokinetics were 298 percent. The test was rated D due to
its short duration, poor isokinetics, low accuracy of test method, and poor
documentation.
FeCr Open Furnace
Test Number 13 was performed at the Airco Alloys and Carbide (now
Macalloy Corp.), Charleston, SC plant in June 1978.12,14 six Method 5 runs
were conducted at both the inlet and outlet to the control device. The
capture efficiency of the hood was varied for each run by changing the inlet
opening on the ID fan. The data utilized herein was for the run with the
largest ID fan opening. These data compare well with the data for Test
Number 14. Emissions from tapping were reported to be included in the total
particulate results. The test report lacked data describing the test
procedures and furnace operating parameters at the time of the test.
Supplemental-information necessary to calculate emission factors was obtained
from plant personnel and estimated using Reference 3. The source emission
factor was calculated two ways using information from the above two sources.
The resulting emission factors varied by 22 percent. The average of these two
methods of calculation was reported in Table 4. The emission factors were
assigned a rating of B due to the lack of descriptive process data in the test
report.
Test Number 14 was conducted in September 1971 at the same Airco Alloys
(now Macalloy Corp.) furnace described above as Test Number 13.13 The
testing consisted of three separate Method 5 runs, each consisting of two
trains operated simultaneously at the two inlet ducts. The Method 5 runs were
each 100 minutes long. The sampling location was in an expanding section of a
rectangular duct. The duct was divided into 25 equal areas for sampling.
Controlled emissions were measured at the ESP outlet with three Method 5
tests. Process information was provided indicating that the 35 MW furnace was
operating within the range of normal conditions. The canopy hood was reported
to effectively capture tapping emissions. It was necessary to use information
from Reference 3 relating energy input to alloy production in order to
calculate an emission factor based on process production rate. The total
particulate emission factor thus determined was rated B. Also conducted were
six Brinks impactor runs to measure particle size distribution of the fumes at
the inlet and at the outlet to the control device. Flow and volume were
determined by pressure drop across a calibrated orifice, not by a dry gas
meter. The major problem with the inlet impactor tests was that they were
conducted at an expanding section of duct work, which is not ideal. Because
47
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of inertial effects of the flow irregularity, the particle size data may be
biased. The results thus determined were rated C. The outlet test results
were rated B.
Test Number 15 was conducted at the Foote Mineral Corp., Vancoram
Operations in Steubenville, OH in May 1971.16 Testing was done using two
different sample methods for total particulate, the OAP method, which is
essentially Method 5, and the ASME method which consists of an instack alundum
thimble. Due to process abnormalities during some of the tests, only two of
the four OAP runs and the two ASME runs were averaged in calculating the
emission factor. Only one of two exhaust stacks were tested; emissions from
the untested stack were assumed to equal the tested stack. Process data
necessary for the calculation of emission factors were not contained in the
report and the information needed was assumed using References 3 and 5. The
emission factor thus calculated was rated C due to the lack of firsthand
reporting of some significant process variables. Three Brinks impactor runs
were made during the testing to determine the fume particle size distribution.
The test report did not contain significant amounts of descriptive information
concerning the size distribution testing. The results were rated C. The
calculation of the emission factor is not included in the emission factor
example calculation section because it is quality rated less than two other
tests and was not included in the calculation of the FeCr emission factor.
SiMn Open Furnaces
Test: Number 16 describes the sampling performed at the Chromium Mining
and Smelting Corp., Woodstock, TN plant in February 1972.15 Three Method 5
runs were performed at both the inlet and the outlet to the scrubber. The
process was reported to operate normally during the testing. The report did
not present data on production rate during testing necessary for the
calculation of emission factors. This data was obtained from Reference 3 and
the emission factors thereby calculated were rated B.
Test Number 17 was conducted at the Union Carbide Corp. (now Elkem
Metals), Marietta, OH plant in August 1971.17 Primary fumes from furnace
Number 1 were sampled in the ductwork prior to the scrubber. Tapping fumes
were captured by a separate hood and exhausted directly to the atmosphere
through a stack. Nine Method 5 type runs were conducted on the scrubber
inlet, seven on the outlet. Six runs were conducted on the two tapping
stacks. The report failed to present production data necessary to calculate
the emission factor. Data were therefore obtained from Reference 3. Twelve
Brinks impactor runs were conducted to measure uncontrolled emissions during
the test program, eight on the inlet to the dust collector and four on the
tapping stacks. Eight impactor runs were also performed on the scrubber
outlet. The report did not provide detailed background information concerning
the size distribution tests and analysis. The lack of process and background
information resulted in a B rating for both the total particulate and size
distribution data.
48
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SiMn Sealed Furnace
Test No. 18 was performed on a sealed SiMn (67 percent) furnace at Union
Carbide Corp. in Beauharnais, Quebec.H One SASS run was performed at the
outlet of the scrubber controlling gases evacuated from the furnace. Secondary
emissions were not controlled by the scrubber. Because only one run was
performed and there was a lack of important process data, the test results
were rated C.
EMISSION FACTOR RATINGS
The emission factor chosen to represent each source category has been
ranked according to the following criteria
• A = Excellent—Developed from A-rated test data taken from many
randomly chosen facilities in the industry population. The source
category is specific enough to minimize variability within the
source category population.
• B = Above Average—Developed only from A-rated test data from a
reasonable number of facilities. Although no specific bias is
evident, it is not clear if the facilities tested represent a random
sample of the industries. As in the A rating, the source category
is specific enough to minimize variability within the source
category population.
• C - Average—Developed only from A- and B-rated test data from a
reasonable number of facilities. Although no specific bias is
evident, it is not clear if the facilities tested represent a random
- sample of the industry. As in the A rating, the source category is
specific enough to minimize variability within the source category
population.
• D = Below Average—The emission factor was developed only from A-
and B-rated test data from a small number of facilities, and there
may be reason to suspect that these facilities do not represent a
random sample of the industry. There also may be evidence of
variability within the source category population. Limitations on
the use of the emission factor are footnoted in the emission factor
table.
• E = Poor—The emission factor was developed from C- and D-rated test
data, and there may be reason to suspect that the facilities tested
do not represent a random sample of the industry. There also may be
evidence of variability within the source category population.
Limitations on the use of these factors are always footnoted.
Uncontrolled Emissions
The A through E rating criteria for emissions factors are different than
the A through D ratings for the test data.
49
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The ferroalloy industry was divided into specific categories for the
purpose of developing and presenting emission factors. The total number of
furnaces in the industry is 77 as shown in Table 9. Seven specific source
category emission factors were developed from different test series. Viewed
in this manner, a sample size of 11 out of a population of 77 is reasonable.
The product categories presented previously in Table 4 are specific enough to
minimize variability within the source category population. There is no
apparent reason to suspect that the facilities tested form a biased sample set.
TABLE 9. FURNACES IN THE UNITED STATES VERSUS FURNACES TESTED
AND INCLUDED IN EMISSION FACTOR TABLES
Emission factor
developed from
Furnaces in U.S.15
Size of
Furnace Avg. size Number of furnaces
Product type Number (MW) furnaces (MW)
FeSi
Open
23
25
1
35
Closed
3
26
1
45
Si-^etal—
Open
22
17
1
17
FeMn
Open
7
10
2
10, 10
Closed
6
8
1
8
—
Sealed
—
—
1
7
FeCr.
Open
8
17
2
36
SiMn
Open
_8
15
_2
7, 27
Total/Average
77
21
11
The particulate emission factors for source categories Si metal,
50 percent FeSi, and FeMn open furnaces were rated B (above average) on the
A-E scale because they were each developed from a single A rated test series
consisting of several runs. The FeMn test was performed on two furnaces
operating simultaneously. A single test series was considered a reasonable
sample size considering the source category population.
The emission factor for 50 percent FeSi covered furnaces was developed
from one C and two D rated test series; all of which used measured scrubber
particulate catch in determining uncontrolled emissions. One test included
fugitive emissions, however the emission factor for that test is lower than
the tests which did not include fugitives. The uncontrolled emission factor
is rated E (poor).
50
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The particulate emission factors for FeMn covered furnaces were also
developed from a single test series. These tests were rated C due to the use
of scrubber water data therefore the assigned emission factor was rated E
(poor). The factors for FeCr and SiMn were each developed from two test
series. The data from these test series were rated B so the assigned emission
factor rating is C (average).
The emission factors for 75 percent FeSi covered furnaces and FeMn sealed
furnaces were developed from D quality data since no better data were
available. Accordingly, the emission factors are expected to provide only an
order of magnitude estimate and are rated E (poor).
The particle size distribution data were assigned an emission factor
quality rating using the same criteria as for the particulate data. The size
data for FeSi, FeMn and Si metal were obtained during the same test programs
as the data used to develop the total particulate emission factors for the
same categories. The size distribution and total particulate data were both
quality rated A on the A through D scale. The size specific emission factors
similar to the total particulate emission factors have been assigned a B
(above average) rating on the A through E emission factor scale as only a
reasonable number of facilities were tested, not a large number as required
for an A rating.
The size distribution data for the FeCr and SiMn categories were each
developed from impactor data obtained during one of the two test series used
to develop the associated total particulate emission factor. The size data
for the FeCr category was rated C on the A-D data qualilty scale and the total
particulate emission data were rated B. Size specific emission factors for
FeCr are therefore rated E (poor) on the A-E emission factor rating scale.
The size data and the total particulate data for the SiMn category are both
rated B on the A-D data quality scale. The size specific emission factors
have therefore been assigned a C rating (average) on the A-E emission factor
rating scale. This is the same rating as applied to the total particulate
emission factor.
Controlled Emissions
The total particulate emission factor for the categories FeSi-50 percent,
open furnace, baghouse controlled, Si metal, open furnace, baghouse controlled
and FeMn-80 percent open furnace, baghouse controlled were each developed from
a single A rated test series. The total particulate emission factor was rated
B on the A-E emission factor scale. The size distribution data for these
three categories developed from the same test programs were also rated B on
the A-E scale.
The FeMn-80 percent, covered furnace, scrubber controlled category
emission factor was developed from a single B-rated test series, therefore the
emission factor is rated C on the A-E emission factor scale.
51
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The FeSi-50 percent, covered furnace, high energy scrubber controlled
category emission factor was developed from the average of two tests rated C
and D. The emission factor was therefore rated E (poor) on the A-E rating
scale. The FeSi-50 percent, covered furnace, low energy scrubber controlled,
FeSi-75 percent covered furnace, scrubber controlled, FeMn-80 percent, open
furnace, high energy scrubber controlled and SiMn sealed furnace, scrubber
controlled category emission factors were developed from a single C or D-rated
test series and were therefore also assigned an E (poor) emission factor
ra t ing.
The FeCr, open furnace, 1SF controlled and SiMn open furnace, scrubber
controlled category emission factors were each developed from the average of
two B-rated test series. The size distribution data for each of these
categories was developed from a single B-rated test series. The total
particulate and size specific emission factors for these two categories were
each rated C on the A-E emission factor scale.
EMISSION FACTOR CALCULATIONS
When more than one set of test data were available for a given source
category and the data were of the same quality rating (see Table 6), the
emission factors were averaged to determine the source category emission
factor. In cases where emission factors of different quality ratings were
available, only data of the higher quality rating were used. In most of the
test reports used to compile the source category emission factors, the desired
emission factor, in terms of mass of emission per alloy production unit, was
calculated by the author and presented in the subject test report.
In cases where the provided information was not in the form of the
desired emission factor, it was necessary to calculate it. This involved
combining data from both the report and other sources with appropriate
assumptions. The emission factors for all but two of the nine categories
contained in Table 4 were developed from a single test for which no
assumptions or manipulation of the data were necessary.
The emission factors for two categories, FeCr and SiMn, are both
calculated from results of two tests which had to be manipulated in order to
get them into the required emission factor units. The sources of information,
assumptions and calculations associated with those emission factors are
detailed in the following paragraphs. Similar calculations were also made for
some of the emission factors presented in Table 4; however, not all of these
are documented here. In cases where assumptions were made to calculate an
emission factor in Table 6, and the data were subsequently quality ranked
lower than another data source for the same category, (therefore, not being
incorporated into the Ferroalloy Emission Factor Tables 4 and 5) the
calculations are not described below.
Example Particulate Emission Factor Calculations
Two methods were used to obtain emissions factors presented in the
tables. Method 1 requires that the emission rates in lb/hour and production
rates in tons/hour be known. Method 2 requires that following data: emission
52
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rates in lb/hour, furnace load in MW-hr and the industry average or unit
specific energy consumption, MW-hr per ton of alloy produced for each type
ferroalloy produced. The industry average energy consumption was obtained
from references 3.
Method 1:
lb pollutant emitted/hr _ lb pollutant emitted
Emission actors tons alloy produced/hr tons alloy produced
Method 2:
„ . lb pollutant emitted/hr MW-hr consummed
Emission factor = L —: ___ . x — — ,
energy consumption MW-hr tons alloy produced
Facility and pollutant specific examples are presented below.
Particulate Emission Factor: Ferrochrome production
1. Test No. 13 performed at Airco Alloys, Charleston, SC (now Macalloy Corp.)
in June 1978.12
• data from test report:
average uncontrolled emission rate = 1134 lb/hr
average furnace load = 35.4 MW
average controlled emission rate = 15 lb/hr
• data from Reference 14:
average furnace process rate = 6 ton alloy/hr
• assumption: that during the test period the furnace produced
approximately 6 tons of alloy per hour:
• data from reference 3 for (HC) FeCr production industry average
MW-hr/ton product =4.2
Uncontrolled Emission Factor
Method 1:
,, j _ 1134 lb particulate/hour _ 189 lb particulate
Uncontrolled EF, = 7—r——n 7r z— 11
1 6 ton alloy/hr ton alloy
(EF = emission factor)
Method 2:
1134 lb particulate 4.2 MW-hr _ 135 lb particulate
Uncontrolled EF = , x — — — = c——
2 35.4 MW-hr ton alloy product ton alloy
53
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The average
189 ~ 135 _ 162 lb particulate _ 81 kg particulate
2 ~ ton alloy Mg alloy produced
Controlled Emission Factor
• A similar calculation with the controlled emission rate of 15 lb/hr
yields an EF of 2.1 lb/ton alloy =1.1 kg/Mg alloy.
2. Test Number 14 - test performed in September 1971 at the same Airco (now
Macalloy Corp.) facility as the previous test.13
• data from test report:
average uncontrolled emission rate « 1293 Ib/hr
average furnace load ¦ 36 MW
average controlled emission rate = 21 lb/hr
• data from Reference 3 for (HC) FeCr production industry average
MW-hr/ton product * 4.2
Emission factor calculated by Method 2.
• Uncontrolled emission factor
IT „ ,, , 1293 lb particulate 4.2 MW-hr
Uncontrolled EF , x rr r
36 MW-hr ton alloy produced
Uncontrolled EF - 151 lb P"**'"1*" , 75 "8 particulate
ton alloy Mg alloy
• A similar calculation with the controlled emission rate of 21 lb/hr
yields an Ef of 2.5 lb/ton alloy = 1.3 kg/Mg alloy.
The particulate emission factors for FeCr production was taken as the average
for the above tests:
Uncontrolled EF„ „ = 151 * 162 - 156.5 lb Particulate . 78 k? particulate
FeCr 2 ton alloy Mg alloy
. Controlled EF „ - ^ * 2"3 = 2.3 lb Pa"ici,Ut«
FeCr 2 ton alloy
Controlled EF_ „ - 1.2 Particulate
FeCr Mg alloy
54
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Particulate Emission Factor SiMn Production
3. Test Number 16 - performed at CROMASCO1s Woodstock, TN plant in February
1972.15
• data from test report:
average uncontrolled emission rate = 226 lb particulate/hr
average furnace load = 7.2 MW
average controlled emission rate = 10.6 particulate/hr
• data from Reference 3: for SiMn production
industry average MW-hr/ton product = 4.4
,, , _ 226 lb particulate 4.4 MW-hr
Uncontrolled EF 7.2 MW-hr x ton alloy product
Uncontrolled EF - U8 f P«""uUte , 69 kg particulate
ton alloy Mg alloy
,, , 10.6 lb particulate 4.4 MW-hr
Controlled EF ¦ _ „r ¦" . x 7: 3——
7.2 MW-hr ton alloy product
Controlled EF = 6.5 lb particulate . 3.2
ton alloy Mg alloy
4. Test Number 17 - performed at Union Carbide's (now Elkem Metals) Marietta,
OH plant in August
1971.17
• data average uncontrolled emission rate ¦ 1391 lb particulate/hr
average furnace load = 25 MW
average controlled emission rate = 11.8 lb particulate/hr
• data from Reference 3: for SiMn production industry average
MW-hr/ton alloy product = 4.4
„ _ . __ 1391 lb particulate 4.4 MW-hr
Uncontrolled EF = •_ •», x rr -—-
25 MW-hr ton alloy product
Uncontrolled EF - 245 lb particulate = 123 kg particulate
ton alloy Mg alloy
• Average of uncontrolled emission factors calculated from SiMn tests
16 and 17:
,, , 138 + 245 192 lb particulate
Uncontrolled EFgiMn - j ton alloy
Uncontrolled EF„. = 96 kg particulate
SiMn Mg alloy
55
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„ _ ,, j 11.8 lb part. „ 4.4 MW-hr
• Controlled EF —x-r f x rr -—-
25 MW-hr ton alloy product
,, , 2.1 lb particulate 1.1 kg part.
Controlled —rr = — fr*
ton alloy Mg alloy
• Average of controlled emission factors calculated from SiMn tests 16
and 17:
Controlled EF - 6"S ! 2>1 - 4.3 ^Particulate , ^ particulate
2 ton alloy Mg alloy
• Test Number 18—performed at Union Carbide's, Beauharnais, Quebec
plant in August 1977.11
Data presented in report for scrubber outlet:
controlled particulate emissions ¦ 64 mg/m3
flow rate exhaust ¦ 1.51. m3/sec
furnace load * 22.5 MW-hr
actual energy product ratio ¦ 1.75 kW-hr/lb alloy = 3.5 MW/ton
alloy
Emission Factor Calculating Method 1
Emission rate = 64 rag/m^ x 1.51 ra^/sec x 3600 sec/hr x 1 kg/10^ mg
- 0.35 kg/hr = 0.77 lb/hr
Controlled EF = 0«77 lb/hr 3.5 MW m ^ ^ ib/ton » 2^2§. ^S—
controliea t* 215 m_hj_ x ton all(jy u.iz it>/ton aU(jy
SOp Emission Factor Calculations
1) Test Number 17^7
was performed on an open SiMn furnace at the Union
Carbide Corp. plant in Marietta, Ohio in 1971
Scrubber emissions:
• data from test report:
scrubber flow ¦ 115,070 dscfm
SO2 concentration ¦ 0.35 ppm
furnace power « 25 MW-hr
• From reference 3 for SiMn production industry average MW/ton product
- 4.4
r.n _ « ~>r ,, lb dscf ,„ min , , MW-hr
EF = 0.35 ppm x 64 -rr x 115070 — x 60 r x 4.4
lb-mole Min— hour * ton alloy
386 * 106 I^fle * 25 «"-hr
EF - 0.070 lb S02/ton alloy
56
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4) Test #12 was performed on a sealed furnace producing FeMn at the Union
Carbide plant in Beauharnois, Quebec during August 1977.H
• data from test report
flow rate = 2550 scfm
concentration of SC>2 and reduced sulfur species = 3.1 ppm
furnace load = 17.3 MW-hr
production rate = 8.4 ton/hr.
assume all reduced sulfur is oxidized to SO2 at flare.
The emission factor for uncontrolled emissions is:
scf lb min , _0
2550 min x 64 lb-mole x 60 hr x 3.1 x 10 2
EF = = 0.013 rr—
scf o , ton ton alloy
386 -r-r :— x 8.4 t—
lb-mole hr
5) Test #18 was performed during the production of SiMn in the same furnace
as test #12.
• data from report:
scrubber flow = 3200 scfm
concentration of SO2 and reduced sulfur species = 4.17 ppm
furnace load = 22.5 MW-hr
production rate = 6.25 ton/hr
assume all reduced sulfur is oxidized to SO2 at flare.
The emission factor for scrubber emissions is:
— lb min SQ
r.™ _ 3200 min x 64 lb-mole x 60 hr x 4.17 x 10 2
— _ — U.UZ1
386 fJSV x 6.25 ^ C
-------
i
2) Test #6 was performed on a covered furnace producing 75 percent FeSi at
Union Carbide Corp.'s Sheffield, AL plant in June 1979.^
• data from test report
scrubber flow rate = 5526 dscfm
CO concentration = 28.2%
production rate = 1.9 Mg/hr =2.1 ton/hr.
dscf lb min
_ 5526 min x 28 lb-mole x 60 hr x 0.282 _ lb CO
iftA dscf _ , ton ton alloy
lb-mole * hr
3) Test #10 was performed on a covered furnace producing FeMn. The furnace
cover had holes cut in it to allow almost complete combustion. The
testing occurred at Union Carbide Corp.'s Marietta, OH plant during April
1979.4
• data from test report:
scrubber flow rate = 9010 dscfm
CO = 0.60%
production rate =4.7 Mg/hr=5.2 ton/hr
dscf lb min
EF = 9010 min x 28 lb-mole x 60 hr x 0.006 _ ^ lb CO
toc. dscf c „ ton ton alloy
jOO -ii i X j • Z. .
lb-mole hr
4) Test #18 was performed on a sealed furnace producing SiHn at Union
Carbide Corp's plant in Beauharnois, Quebec in August 1977.H
• data from test report:
scrubber flow rate = 3200 scfm
CO = 76 percent
production rate = 6.25 ton/hr (see SO2 examples)
scf lb min
_ 3200 rain x 28 lb-mole x 60 hr x 0.76 _ , lb CO
Hi - - loyU ——
386 sc£ x 6.25 ton alloy
lb-mole hr
Example Organic Emission Factor Calculations
1) Test #18 was performed on a sealed furnace producing SiMn at Union
Carbide Corp.'s plant in Beauharnois, Quebec during August 1977.
58
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• data from test report:
scrubber flow rate = 3200 scfm = 91
nonmethane organic compound concentration = 47.6 mg/m3
production rate = 6.25 ton/hr = 5.67 Hg/hr (see SO2 example)
the emission factor for scrubber emissions is:
EF = 90 «_ x 60 Hi2 x 47.6 2| x 1 kS = 0.046 kf.—
am hr 3 , n6 Mg alloy
m 10 mg 0 J
^ alloy/hr
= n 09 ¦
u>uy ton alloy
59
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SECTION 4
CHEMICAL CHARACTERIZATION
Ferroalloys are grouped according to their primary elemental
constituents. A composition summary of the many ferroalloy products appears
in Table 10.3 The range of typical chemical composition of ores used in
ferroalloy production is contained in Table 11.3
Emissions generated by ferroalloy submerged arc furnaces include
particulate matter, organic material and carbon monoxide. Particulate
material is generated by two distinct processes. The most significant type of
particulate is fume generated in the reaction zone of the furnace. This fume
is of amorphous structure and is generated mostly in the form of submicron
particles. Particle size has been reported to be generally smaller than 2
microns, ranging from 0.1 to 1.0 ym with a geometric mean of 0.3 to 0.6 pm,
depending on the ferroalloy produced.24 Although the fume is generated as a
submicron particle, agglomeration does occur and the effective particle size
may be much larger.24 The bulk density of ferroalloy fume has been reported
to vary from from 4 to 30 lb/ft3,24 Chemical analysis of the fume
indicates it is composed of oxides of the product ferroalloy with the addition
of carbon, imparted by the reducing agent, and oxides of other metals
contained in the charge.19 Table 12 presents typical chemical analyses of
ferroalloy furnace fume.19 References 3 and 8 also contain chemical
analysis. The chemical and physical analysis of silica fume collected by a
baghouse controlling a silicon metal furnace is presented in Table 13.19
The second source of particulate emitted from submerged arc furnaces is
fine particles of the raw material feedstock entrained in the furnace reaction
gases as they flow up through the mix and escape the furnace. Table 9 can be
referred to for the chemical composition of typical feed ores.
The relative proportions of the two different particulates described
above will depend on several factors; these include furnace design, electrical
operating conditions, conditions of charge, degree and frequency of stoking,
fines content of charge, and work practices of the furnace operator.
The submerged arc process utilizes carbon to reduce the silicon and metal
oxides in the feedstock. This results in the generation of large amounts of
carbon monoxide. In some cases, the carbon monoxide produced exceeds the
weight of the corresponding ferroalloy produced.3 The reactions occurring
60
-------
TABLE 10. COMPOSITION OF FERROALLOYS3>b
Elemental composition,0 X by weight (exclusive of Fe)
Ferroalloy A1 B C Ca Cb Co Cr Fe Mn Mo Nb Ni Si Ta Ti V W Zr
Ferromanganese
Spiegeleisend
Si 1icomanganese
High-carbon (HC)
ferromanganese
Medium-carbon (MC)
ferromanganese
Low carbon (LC)
ferroaanganese
Electrolytic manganese
Manganese-boron
1.25-
1,50
0.10-
0.75
21
78
16-
23
63-
66
78
80-
85
99.9
75
22-
28
1.5
Standard LC ferrochrome
0.020-
6-
0,050
73
Simplex ferrochrome
0.010-
68-
0.020
72
Ferrochrome
64-
67
Charge Cr
52-
55
9S C Cr
9
65-
68
HS Cr 50
5.5-6
65
6
Chromsol FeCr
5.5-6
65
6
Blocking C Reg.
5
60-67
High carbon (HC) FeCr
4.5-
67-
70
751 Cr
75
731 Cr
0.5
73
0.5
1.0
(continued)
-------
TABLE 10 (continued)
Ferroalloy
A1
Elemental composition^ X by weight (exclusive of Fe)
Ca Cb Co Cr Fe Mn Mo Nb Hi Si Ta Ti
Zr
NJ
Ferrocliromium
36/40
40/43
Silicon Metal
Ferrooolybdenun
Vanadium Metal
Chromium Metal
9% C Metal
Chromium-carbon
50% Ferrosilicon
65% Ferrosilicon
high purity
75% Ferrosilicon
0.51 Ca
Low AI
85% Ferrosilicon
0.5 Ca
Low A1
0.5 to 1.51 Ca
36
40
0.35-
1.50
50-
60
9
5-
10
99.8
90-
95
0.40
0.5
0.5
0.5-
1.5
40
43
50
65
75
75
85
85
85
85
90
SHE
Magnesium ferrosilicon
5% Mg
9% Mg
Silvery pigiron
FerrotItanium
30% Ti
4.5% A1
40% Ti
70% Ti
5-7
2
3
4.5
3
4
60-
65
50
50
14-
22
I
4
0.5
5-7
25
30
30
40
70
(continued)
-------
TABLE 10 (continued)
Ferroalloy
A1
Elemental compos it ion,c % by weight (exclusive of Fe}
Ca Cb Co Cr Fe Mn Mo Hb Ni Si Ta Ti
Zr
Ferrocoluabiun
40% Cb
60% Cb
65% Cb
70% Cb
62% Cb
Ferrotungsten
High purity
Low moly
Ferrovanadium
Si 1icomanganese
Calcium Silicon
Aluminum
Ferroaluminum
35% AL
40% A1
45% A1
50% A1
Ferroaluminunr-s il icon
Cobalt metal
100
35
40
45
50
50
55"
60
40
60
65
70
62
30-
33
1.5-
3.0
1
1
1.5
3% C grade
3
65-
12-
68
14.5
2% C grade
2
65-
15-
68
17.5
1.5% C grade
1.5
65-
18-
68
20
Low C
65-
68
High Mn
73
60-
65
3?
77-
83
76-
84
52-
75
100
(continued)
-------
TABLE 10 (continued)
Ferroalloy
A1
Elemental composition,1 t by weight (exclusive of Fe)
Ca Cb Co Cr Fe Mn Mo Nb Ni Si Ta Ti V
Nickel metal
Ferrotantalym
Zirconium-s i1 icon
100
9 1
50
50
"American Society for Testing Materials, STP No. 739, lampman/Peters, Ed., 216 pages.
''American Metal Market, February 3, 1972, reproduced from Reference 3.
cC, carbon; Ca, calcium; Cb, columbium; Co, cobalt, Cr, chromium; Al, aluminum; Fe, iron; Nnf manganese; Mo, molybdenum; Nb, niobium; Ni,
nickel; Si, silicon; Ti, titanium; V, vanadium; U, tungsten; Zr, zirconium; Ta, tantalum; B, boron.
dA European produced ferroalloy containing small amounts of manganese.
40
-------
TABLE 11. CHEMICAL COMPOSITION OF ORES3
Chemical Manganese Silicon Chromium
constituent ore (%) ore (%) ore
Mn 43 to 54
Si02 4.15 98.5 1.2
Cr203 ~ ~ 45 to 53
Fe 1 to 2 - 11
AI2O3 1 to 3 - 9.8
MgO 0.1 to 2 - 16.6
BaO 1 to 3
CaO 1 to 3
P 0.18
«20 5 to 16
65
-------
TABLE 12. TYPICAL FURNACE FUME CHARACTERISTICS19
Furnace product
Parameter
50% FeSi
SMZ»
8iMnb
SiMnb
FeMn
FeCr (HC)
Chrome ore-
liae aelt
Mn ore-
lime melt'1
Furnace type
Open
Open
Covered
Covered
Open
Covered
Open
Open
Fume shape
Spherical,
Spherical,
Spherical
Spherical
Spherical
Spherical
Spherical
Spherical
sometimes
sometiaes
tod
and
in chains
in chains
irregular
irregular
Fuse size.
microns
Maximum
0.75
0.8
0.75
0.75
0.75
1.0
0.50
2.0
Moat particles
0.05 to 0.3
0.05 to 0.3
0.2 to 0.4
0.2 to 0.4
0.05 to 0.4
0.1 to 0.4
0.05 to 0.2
0.2 to 0.5
X-ray diffraction
Primary
All
fumes were
primarily amorphous
Trace constituents
FeSi
Fe3°4
Hn3°4
Quartz
MnjO^
Spinel
Spinel
CaO
PeSi2
Fe2°3
MnO
SiMn
MnO
Quartz
Quartz
Quartz
Spinel
Quartz
SiC
Chemical analysis,
percent
Si02
63 to 88
61.12
15.68
24.60
25.48
20.96
10.86
3.28
FeO
-
14.08
6.75
4.60
5.96
10.92
7.48
1.22
MgO
-
1.08
1.12
3.78
1.03
15.41
7.43
0.96
CaO
-
1.01
-
1.58
2.24
-
15.06
34.24
MnO
-
6.12
31.35
31.92
33.60
2.84
-
12.34
AI2O3
-
2.10
5.55
4.48
8.38
7.12
4,88
1.36
L0lc
-
-
23.25
12.04
-
-
13.86
11.92
Total Cr as CroOi
-
-
-
-
-
29.27d
14.69
-
SiC
-
1.82
-
-
-
-
-
-
ZrOj
-
1.26
-
-
-
»
-
-
PbO
-
-
0.47
-
-
-
-
0.98
Naj
-
-
-
2.12
-
1,70
2.05
BaO
-
-
-
-
-
-
-
1.13
K20
**
""
13.08
aSi - 60 to 651; Mn - 5 to 7%; Zr - 5 to 7*.
''Manganese tune analyse! in particular are subject to wide variations, depending on the ores used.
cLOI is loss on ignition at 1000*C.
''Fume* from open furnace contain less chrome oxide.
-------
TABLE 13. TYPICAL PROPERTIES OF SILICA FUME FROM
BAG COLLECTOR ON SILICON METAL FURNACE 19
Parameter Value
SiO^, % by weight 94.4-96.1
Fe2°3 0.34-0.46
MnO 0.09
A1203 0.21-0.67
CaO 0.35-0.16
MgO 0.23-0.37
K20 0.59
Na20 0.07-0.12
S03 0.35
LOIa 1.68-3.22
Surface area, M^/g 25.9
Particle size range, microns 0.02-0.25
Average particle size, microns 0,12
Bulk density as generated, lb/ft 4-6
Bulk density (packed), lb/ft"* 12-14
Color Gray
pH 6.7
Oil absorption, lb oil/100 lb 85-95
LOIa 105°C, 1 hour 0.46%
LOI 1000°C, 1 hour 1.22%
aLoss on ignition.
67
-------
in the production of 50 percent ferrosilicon are described in a simplified
form by the following equation:3
2 Si02 + Fe203 + 7C 2 FeSi + 7CO
Covered furnaces can emit large quantities of carbon monoxide to the
atmosphere if not properly flared. CO emissions are not a problem with open
furnaces because oxidation to carbon dioxide occurs as the hot gas mixes with
ambient air at the surface of the charge.
The degradation of carbonaceous reducing material; i.e., coal, coke, wood
chips, etc. generates organic emissions. Categories of compounds observed in
¦ferroalloy emissions include aliphatic hydrocarbons, aromatic hydrocarbons,
fused aromatics, heterocyclic nitrogen, heterocyclic sulfur, ketones, esters,
and carboxylic acids. Carcinogens such as benzoapyrene have been found in
submerged arc furnace emissions.20 References 8, 9, 12 and 19 contain
detailed information on organic compound concentrations measured at specific
furnaces. The organic compound emitted can be in the form of gas or it can be
adsorbed onto the surface of particulate material.
68
-------
SECTION 5
PROPOSED AJP-42 SECTION FOR
FERROALLOY INDUSTRY
The proposed revision to Section 7.4 of AP-42
is presented in the following pages as it would
appear in the actual document.
69
-------
7.4 FERROALLY PRODUCTION
7.4.1 General
A ferroalloy Is an alloy of iron and one or more other elements, such as
silicon, manganese or chromium. Ferroalloys are used as additives to impart
unique properties to steel and cast iron. The iron and steel industry consumes
approximately 95 percent of the ferroalloy produced in the United States. The
remaining 5 percent is used in the production of nonferrous alloys, including
cast aluminum, nickel/cobalt base alloys, titanium alloys, and in making other
ferroalloys.
Three major groups, ferrosilicon, ferromanganese, and ferrochrorae, con-
stitute approximately 85 percent of domestic production. Subgroups of these
alloys include siliconmanganese, silicon metal and ferrochromium. The variety
of grades manufactured is distinguished primarily by carbon, silicon or aluminum
content. The remaining 15 percent of ferroalloy production is specialty alloys,
typically produced in small amounts and containing elements such as vanadium,
columblum, molybdenum, nickel, boron, aluminum and tungsten.
Ferroalloy facilities in the United States vary greatly in size. Many
facilities have only one furnace and require less than 25 megawatts. Others
consist of 16 furnaces, produce six different types of ferroalloys, and require
over 75 megawatts of electricity.
A typical ferroalloy plant is illustrated in Figure 7.4-1. A variety of
furnace types produces ferroalloys, including submerged electric arc furnaces,
Induction furnaces, vacuum furnaces, exothermic reaction furnaces and elec-
trolytic cells. Furnace descriptions and their ferroalloy products are given
in Table 7.4-1. Ninety-five percent of all ferroalloys, including all bulk
ferroalloys, are produced in submerged electric arc furnaces, and it Is the
furnace type principally discussed here.
The basic design of submerged electric arc furnaces is generally the same
throughout the ferroalloy industry in the United States. The submerged elec-
tric arc furnace comprises a cylindrical steel shell with a flat bottom or
hearth. The Interior of the shell is lined with two or more layers of carbon
blocks, law materials are charged through feed chutes from above the furnace.
The molten metal and slag are removed through one or more tapholes extending
through the furnace shell at the hearth level. Three carbon electrodes,
arranged in a delta formation, extend downward through the charge material to
a depth of 3 to 5 feet to melt the charge.
Submerged electric arc furnaces are of two basic types, open and covered.
About 80 percent of submerged electric arc furnaces in the United States are of
the open type. Open furnaces have a fume collection hood at least one meter
above the top of the furnace. Moveable panels or screens sometimes are used to
reduce the open area between the furnace and hood to improve emissions capture
Metallurgical Industry
70
7.4-1
-------
a
•o
fsJ
DUST
DUST
DUST
PS
X
1-1
VJ
to
t—t
o
55'
•n
o
H
o
po
c/i
OUST
OUST
- Ja-.5L
unloading
DUST
/
//
/>
/
i
'¦ OUST
> AND
7 FUMES
STORAGE
j® 17 ,r
CRUSHING WEIGH -FEEOING
SMELTING TAPPING CASTING
DUST I
•J
CRUSHING ' STORAGE
SCREENING
shipment
Figure 7.4-1. Typical ferroalloy production process, showing emission points.
-------
TABLE 7.4-1. FERROALLOY PROCESSES AND RESPECTIVE PRODUCT GROUPS
Process
Product
Submerged arc furnace8
Silvery iron (15 - 22% Si)
Ferrosilicon {50% Si)
Ferrosilicon (65 - 75% Si)
Silicon metal
Si11con/manganese/zirconium (SMZ)
High carbon (HC) ferromanganese
Siliconmanganese
HC ferrochrome
Ferrochrome/silicon
FeSi (90% Si")
Exothermic^
Silicon reduction
Aluminum reduction
Low carbon (LC) ferrochrome, LC
ferromanganese, Medium carbon (MC)
ferromanganese
Chromium metal, Ferrotitanium,
Ferrocolumbium, Ferrovanadium
Mixed aluminothermal/
silicothermal
Ferromolybdenum, Ferrotungsten
Ilectrolyticc
Chromium metal, Manganese metal
Vacuum furnace"*
LC ferrochrome
Induction furnacee
Ferrotitanium
aProcess by which metal is smelted
tn a refractory lined cup shaped steel
shell by three submerged graphite electrodes.
^Process by which molten charge material is reduced, in exthermic reaction,
by addition of silicon, aluminum or combination of the two,
cProcess by which simple ions of a metal, usually chromium or manganese
in an electrolyte, are plated on cathodes by direct low voltage current.
^Process by which carbon is removed from solid state high carbon
ferrochrorae within vacuum furnaces maintained at temperature near melting
point of alloy.
®Process which converts electrical energy without electrodes into heat,
without electrodes, to melt metal charge in a cup or drum shaped vessel.
Metallurgical Industry
72
7.4-3
-------
efficiency. Covered furnaces have a water cooled steel cover to seal the top,
with holes through it for the electrodes. The degree of emission containment
provided by the covers is quite variable. Air infiltration sometimes is reduced
by placing charge material around the electrode holes. This type is called a
mix seal or semi enclosed furnace. Another type is a sealed or totally closed
furnace having mechanical seals around the electrodes and a sealing compound
packed around the cover edges.
The submerged arc process is a reduction smelting operation. The reactants
consist of metallic ores and quartz (ferrous oxides, silicon oxides, manganese
oxides, chrome oxides, etc.). Carbon, usually as coke, low volatility coal or
wood chips, is charged to the furnace as a reducing agent. Limestone also may
be added as a flux material. After crushing, sizing, and in some cases, dry-
ing, the raw materials are conveyed to a mix house for weighing and blending,
thence by conveyors, buckets, skip hoists, or cars to hoppers above the furnace.
The mix is then fed by gravity through a feed chute either continuously or
Intermittently, as needed. At high temperatures in the reaction zone the car-
bon sources react chemically with oxygen in the metal oxides to form carbon mon-
oxide and to reduce the ores to base metal. A typical reaction, illustrating 50
percent ferrosilicon production, is;
Fe203 + 2 Si02 + 7C ~ 2 FeSi + 7C0.
Smelting in an electric arc furnace is accomplished by conversion of
electrical energy to heat. An alternating current applied to the electrodes
causes a current flow through the charge between the electrode tips. This
provides a reaction zone of temperatures up to 2000°C (3632°F). The tip of
each electrode changes polarity continuously as the alternating current flows
between the tips. To maintain a uniform electric load, electrode depth is con-
tinuously varied automatically by mechanical or hydraulic means, as required.
Furnace power requirements vary from 7 megawatts to over 50 megawatts, depending
upon the furnace size and the product being made. The average is 17.2 mega-
watts®. Electrical requirements for the most common ferroalloys are given in
Table 7.4-2.
TABLE 7.4-2. FURNACE POWER REQUIREMENTS FOR DIFFERENT FERROALLOYS
Product
Fumi
(kw-hr/lb a]
ice load
loy produced)
Range
Approximate
average
50% FeSi
Silicon metal
High carbon FeMn
High carbon FeCr
SiMn
2.4 - 2.5
6.0 - 8.0
1.0 - 1.2
2.0 - 2.2
2.0 - 2.3
2.5
7.0
1.2
2.1
2.2
7.4-4
EMISSION FACTORS
73
-------
The molten alloy and slag that accumulate on the furnce hearth are removed
at 1 to 5 hour intervals through the taphole. Tapping typically lasts 10 to 15
minutes. Tapholes are opened with a pellet shot from a gun, by drilling or by
oxygen lancing. The molten metal and slag flow from the taphole into a carbon
lined trough, then into a carbon lined runner which directs the metal and slag
into a reaction ladle, ingot molds, or chills. Chills are low flat iron or
steel pans that provide rapid cooling of the molten metal. Tapping is termin-
ated and the furnace resealed by Inserting a carbon paste plug into the taphole.
When chemistry adjustments after furnace smelting are necessary to produce
a specified product, a reaction ladle is used. Ladle treatment reactions are
batch processes and may include chlorination, oxidation, gas mixing, and slag-
metal reactions.
During tapping, and/or in the reaction ladle, slag is skimmed from the
surface of the molten metal. It can be disposed of in landfills, sold as road
ballast, or used as a raw material in a furnace or reaction ladle to produce a
chemically related ferroalloy product.
After cooling and solidifying, the large ferroalloy castings are broken
with drop weights or hammers. The broken ferroalloy pieces are then crushed,
screened (sized) and stored In bins until shipment.
7.4.2 Emissions And Controls
Particulate is generated from several activities at a ferroalloy facility,
including raw material handling, smelting and product handling. The furnaces
are the largest potential sources of particulate emissions. The emission fac-
tors in Tables 7.4-3 and 7.4-4 and the particle size information in Figures
7.4-2 through 7.4-11 reflect controlled and uncontrolled emissions from ferro-
alloy smelting furnaces. Emission factors for sulfur dioxide, carbon monoxide
and organic emissions are presented in Table 7.4-5.
Electric arc furnaces emit particulate in the form of fume, accounting for
an estimated 94 percent of the particulate emissions in the ferroalloy industry.
Large amounts of carbon monoxide and organic materials also are emitted by sub-
merged electric arc furnaces. Carbon monoxide is formed as a byproduct of the
chemical reaction between oxygen in the metal oxides of the charge and carbon
contained in the reducing agent (coke, coal, etc.). Reduction gases containing
organic compounds and carbon monoxide continuously rise from the high temper-
ature reaction zone, entraining fine particles and fume precursors. The mass
weight of carbon monoxide produced sometimes exceeds that of the metallic
product (see Table 7.4-5). The chemical constituents of the heat induced fume
consist of oxides of the products being produced, carbon from the reducing
agent, and enrichment by Si02, CaO and MgO, if present in the charge.20
In an open electric arc furnace, all carbon monoxide burns with induced
air at the furnace top. The remaining fume, captured by hooding about 1 meter
above the furnace, is directed to a gas cleaning device. Baghouses are used to
control emissions from 85 percent of the open furnaces in the United States.
Metallurgical Industry
74
7.4-5
-------
¦£>
I
TABLE 7.4-3. EMISSION FACTORS FOR PARTICULATE FROM SUBMERGED ARC FERROALLOY FURNACES3
m
X
J-i
C/3
CO
>
a
i-3
O
90
in
Product''
Furnace
type
Particulate enlaeton factora
Uncontrol1edc
Site
data
Nstee
Ealtalon
Factor
liting
Control dcvkc^
Particulate ealaaton factora
Control1edc
8S*e
data
Notes
Ealaslon
Factor
Rating
kg/Ng (lb/ton)
alloy
kg (lb)/N#-hr
kg/*fc (Ib/ton)
alloy
kg
0.14 (0.7)
h(a
E
FcHn (It SI)
Covered
6 (12)
2.4 (5.3)
h(t
E
High energy
0*25 (0.5)
0.10 (0.2)
h,atm
C
Sealed
11
1/ (3?)
U.v
E
ttCr (high
carbon)
Open
?» (IS?)
IS (33)
fee
C
ESP
1.2 (2.3)
0.23 (0.5)
fee
i,y
C
StHn
Open
96 (192)
20 (**)
Yea
IaM
c
Scrubber
2.1 (4.2)
0.44 (1.0)
Yea
aa.bb
C
Sealed
<->
<-)
Scrubber
Ittgtt energy
0#I5 (0.10)
0.016 (0.04)
E
-------
TABLE 7.4-3 (Cont.). NOTES
aFactora are for main furnace dust collection system before and after control device. Where other emissions,
such as leaks or tapping, are Included or quantified separately, such Is noted. Particulate sources not
Included; raw material handling, storage, preparation; and product crushing, screening, handling, packaging.
''Percentages are of the main alloying element In product.
cIn most source testing, fugitive emissions not measured or collected. Where tapping emissions are
controlled by primary system, their contribution to total emissions could not be determined. Fugitive
emissions may vary greatly among sources, with furnace and collection system design and operating practices.
Low energy scrubbers are those with A P <20 In. RjO; high energy, with A P >20 In. I^O.
^Includes fumes captured by tapping hood (efficiency estimated near 100Z).
fReferences 4, 10, 21.
SFactor Is average of 3 sources, fugitive emissions not Included. Fugitive emissions at one source
measured an additional 10.5 kg/Mg alloy, or 2.7 kg/Mw hr.
j? ''References 4, 10.
£ J Does not Include emissions from tapping or mix seal leaks.
£ References 25-26.
c "Reference 23.
^ <*3 "Estimated 60X of tapping emissions captured by control system (escaped fugitive emissions not
on n Included In factor).
H PReferences 10, 13.
M 1Estimated 50% of tapping emissions captured by control system (escaped fugitive emissions not
•3 Included In factor).
C rReferences 4, 10, 12.
(J 99
rt "Includes fume only from primary control system.
cIncludes tapping fumes and nix seal leak fugitive emissions. Fugitive emissions measured at 33% of total
uncontrolled emissions.
uAssuaes tapplng fumes not Included In emission factor.
vReference !4. Dash • No data.
"Does not include tapping or fugitive emissions.
"Tapping emissions Included. Factor developed from two test series performed on the same furnace 7
years apart. Measured emissions In latter test were 36Z less than In former.
yReferences 2, 15-17.
'Factor Is average of two test series. Tests at one source Included fugitive emissions (3.4X of total
uncontrolled emissions). Second test Insufficient to determine If fugitive emissions were Included
In total.
"References 2, 18-19.
Factors developed from two scrubber controlled sources, one operated at A P - 47-57" 1^0, the other at
^ unspecified A P. Uncontrolled tapping operations emissions are 2.1 kg/Mg alloy.
•
I
-------
TABLE
7.4-4. SIZE SPECIFIC EMISSION FACTORS FOR SUBMERGED ARC FERROALLOY FURNACES
Product
Control
device
Particle size3
(urn)
Cumulative mass %
< stated size
Cumulative mass
emission factor
kg/Mg (lb/ton)
alloy
Emission Factor
Rating
501 FeSi
Open furnace
None**»c
0.63
45
16 (32)
B
1.00
50
18 (35)
1.25
53
19 (37)
2.50
57
20 (40)
6.00
61
21 (43)
10.00
63
22 (44)
15.00
66
23 (46)
20.00
69
24 (48)
d
100
35 (70)
Baghouse
0.63
31
0.28 (0.56)
1
1.00
39
0.35 (0.70)
1.25
44
0.40 (0.80)
2.50
54
0.49 (1.0)
6.00
63
0.57 (1.1)
!
10.00
72
0.65 (1.3)
15.00
80
0.72 (1.4)
20.00
85
0.77 (1.5)
100
0.90 (1.8)
80% FeMn
Open furnace
Nonee»*
0.63
30
4 (8)
B
1.00
46
7 (13)
1.25
52
8 (15)
2.50
62
9 (17)
6.00
72
10 (20)
10.00
86
12 (24)
15.00
96
13 (26)
20.00
97
14 (27)
d
100
14 (28)
(continued)
-------
n
rt-
o»
c
OQ
H-
oo o
S
c
M
Product
80% FeMn
Open furnace
Si Metal^
Open furnace
Cont rol
device
Baghousee
NoneS
Baghouse
Particle si
(>im)
nJ
I
vO
TABLE 7.4-4 (cont.)
Cumulative massZ
< stated size
Cumulative mass
emission factor
kg/Mg (lb/ton)
alloy
20
0.048 (0.10)
30
0.070 (0.14)
35
0.085 (0.17)
49
0.120 (0.24)
67
0.160 (0.32)
83
0.200 (0.40)
92
0.220 (0.44)
97
0.235 (0.47)
100
0.240 (0.48
57
249 (497)
67
292 (584)
70
305 (610)
75
327 (654)
80
349 (698)
86
375 (750)
91
397 (794)
95
414 (828)
100
436 (872)
49
7.8 (15.7)
53
8.5 (17.0)
64
10.2 (20.5)
76
12.2 (24.3)
87
13.9 (28.0)
96
15.4 (31.0)
99
15.8 (31.7)
100
16.0 (32.0)
Emission Factor
Rating
B
(continued)
-------
TABLE 7.4-4 (cant.)
Cumulative mass
emission factor
Product
Control
Particle slzea
Cumulative massZ
Emission Factor
device
(pm)
stated size
kg/Wg (lb/ton)
Rating
alloy
FeCr (HC)
Open furnace
None^tJ
0.5
19
15
(30)
C
1.0
36
28
(57)
2.0
60
47
(94)
2.5
63k
49
(99)
4.0
76
59
(119)
6.0
88k
67
(138)
10.0
91
71
(143)
d
100
78
(157)
ISP
0.5
33
0.40
(0.76)
C
1.0
47
0.56
(1.08)
2.5
67
0.80
(1.54)
5.0
80
0.96
(1.84)
6.0
86
1.03
(1.98)
10.0
90
1.08
(2.07)
d
100
1.2
(2.3)
SiMn
Open furnace
Noneh »m
0.5
28
27
(54)
C
1.0
44
42
(84)
2.0
60
58
(115)
2.5
65
62
(125)
4.0
76
73
(146)
6.0
85
82
(163)
10.0
96k
92k
(I77)k
d
100
96
(192)
(continued)
-------
TABLE 7.4-4 (cont.)
Product
Cont rol
device
Particle size3
Gim)
Cumulative mass%
< stated size
Cumulative mass
emission factor
kg/Mg (lb/ton)
alloy
Emission Factor
Rating
SiMn
Open furnace
(cont.)
Scrub-
berm»n
0.5
56
1.18 (2.36)
C
1.0
80
1,68 (3.44)
2.5
96
2.02 (4.13)
5.0
99
2.08 (4.26)
6.0
99.5
2.09 (4.28)
10.0
99.9k
2.10k (4.30)k
100
2.1 (4.3)
aAerodynamlc diameter, based on Task Group On Lung Dynamics definition.
Particle density - 1 g/cra^.
kIncludes tapping emissions.
cReferences 4, 10, 21.
^Total particulate, based on Method 5 total catch (see Table 7.4-3).
eIncludes tapping fume (capture efficiency 50%).
^References 4, 10, 12.
Slncludes tapping fume (estimated capture efficiency 60%).
^References 10, 13.
J References 1, 15-17.
^Interpolated data.
"References 2, 18-19.
"Primary emission control system only, without tapping emissions.
-------
99.990
99.950
99.90
99.80
99.50
99
98
95
i
i
; 90
i
i 80
¦ 70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
0.1
0.0
TOTAL PARTICULATE
EMISSION RATE
= 35
*9 PARTICULATE
Mg ALLOY
24
20
16
' ' ' 1
1
10 I0U 101 10'
PARTICLE DIAMETER, micrometers
UJ
y
m
o
u
»-
<
H
W
V
kJ
I"
mi
3
U
o:
<
Op
UJ
>
=>
2
3
O
>
o
mi
mi
<
o>
2
Figure 7,4-2. Uncontrolled, 50% FeSi producing, open furnace particle
size distribution.
7.4-12
EMISSION FACTORS
81
-------
UJ
«
a
ui
i«
w
V
I-
z
UI
o
a;
ui
a.
ui
>
<
3
2
3
O
99.990
99.930
99.90
99.80
99.50
99
98
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
0.1
0.0
TOTAL PARTICULATE
EMISSION RATE
=0.90.
H PARTICULATE
Mg ALLOY
I i.J—' i » ' ¦ 'I
J—J « i i * « i
L
J t_L
•o"' 10° 101
PARTICLE 01AMETER, micrometers
0.7?
0.72
0.65
0.57
0.49
0.40
0.35
0.28
10*
UJ
y
cn
o
111
<
H
tfi
UJ
3
O
f-
o
—1
mi
<
o>
2
>
H
<
-I
z
3
O
Figure 7.4-3 Controlled (baghouse), 50% FeSi, open furnace particle
size distribution
Metallurgical Industry
82
7.4-13
-------
Ui
M
CO
O
Ui
£
tn
v
h"
Z
w
u
a:
ui
a.
Ui
>
P
<
.j
Z3
Z
3
O
99.990
99.950
99.90
99.80
99.50
99
98
95
90
80
70
60
50
40
30
20
10
5
- EMISSION RATE
0.5
0.2
0.15
0.1
0.0
10
TOTAL PARTICULATE kg PARTICULATE
CT illcC l/N fcl O ATP 1 *
Mg ALLOY
1 i I l l. l
,11 ll,
14
13
12
10
9
8
?
J—till
111
10" 10*
PARTICLE DIAMETER, micrometers
10*
Figure 7.4-4. Uncontrolled, 80% FeMn producing, open furnace particle
size distribution
7.4-14
EMISSION FACTORS
83
-------
99.990
99.930
99.90
99.80
99.50
99
98
95
I
1
; 90
' 80
70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
0.1
0.0
10
TOTAL PARTICULATE _ -AO*? PARTICULATE
EMISSION RATE -°-240~ ——
Mq ALLOY
» » ' i » i 11 11
J »—' ' »«»
10° 101
PARTICLE 01AMETER, micrometers
0.235
0.220
0.200
0.160
- 0.120
0.085
0.070
0.048
10*
Figure 7.4-5. Controlled (baghouse), 80% FeMn producing, open furnace
size distribution
Metallurgical Industry
84
7.4-15
-------
I
Ui
N
55
Q
Ui
S
CO
V
H
z
Ui
o
m
Ui
o.
Ui
>
P
<
_i
3
2
3
O
99.990
99.950
99.90
99.60
99.50
99
98
95
90
80
TO
60
50
40
30
20
10
5
0.5
0.2
0.15
0.1
0.0
10
TOTAL PARTICULATE
EMISSION RATE
:436 H PARTICULATE
Mg ALLOY
- 414
397
375
349
327
305
292
249
¦x i i—' ¦ i ¦ ¦ 11
J—« » ¦ "
10" 10' 10'
PARTICLE DIAMETER, micrometers
yj
h4
m
a
H
<
H
m
v
UJ
t—
<
-J
3
U
I-
3
s
U
>•
O
_J
_)
<
o»
Figure 7.4-6. Uncontrolled, Si metal producing, open furnace
particle size distribution
7.4-16
EMISSION FACTORS
85
-------
i.
99.990
99.930 -
99.90
99.80
99.50
99
98
UJ
N
55
a
Ui
S
CS)
V
»-
z
UI
o
cc
UJ
a.
Id
>
<
_i
3
2
3
U
95
90
80
70
60
50
40
30
20
10
5
Z
I
0.5
0.2
0.15
0.1
0.0
10
TOTAL PARTICULATE
EMISSION RATE
= 16 0 N particulate
Mg ALLOY
- 15.8
15.4
13.9
12.2
10.2
8.5
7.8
I i I—i i ill iJ
J l—JL
I I I I I
I * » i
10" 10' 10'
PARTICLE DIAMETER, micrometers
uu
CO
Q
UJ
I-
<
W
V
yj
3
O
H
m
<
CL
>
O
_J
<
9
2
o»
M
UJ
>
H
<
-I
3
z
3
U
Figure 7.4-7. Controlled (baghouse), Si metal producing, open
furnace particle size distribution
Metallurgical Industry
86
7.4-17
-------
99.990
TOTAL PARTICULATE 70 kg PARTICULATE
ruitciAu OA-re =/o rw"'"'uu*lt
99.9501- EMISSION RATE
99.90
99.80
99.50h
99
98
95
! so-
80 -
70
60-
50
40 -
30
20
10 -
5
2
I
0.5
0.2
0.15
0.1
0.0
Mg ALLOY
10
1 1 1 ' ' '
Xi-J 1 1 1 1 1 1 1 11
71
59
47
28
15
10 101 10*
PARTICLE DIAMETER, micrometers
UJ
w
o
UJ
t—
<
H
CO
V
UJ
t-
<
-J
=>
u
H
QC
<
0.
o»
UJ
>
<
O
2
=>
u
>
o
01
Z
Figure 7.4-8. Uncontrolled, FeCr producing, open furnace particle
size distribution
7.4-18
EMISSION FACTORS
87
-------
UI
N
55
a
ui
£
co
UJ
o
(E
UI
£L
UI
>
<
_l
3
Z
3
U
99.990
99.950
99.90
99.80
99.50
99
98
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
0.1
TOTAL PARTICULATE
EMISSION RATE
1 • 20
N PARTICULATE
M« ALLOY
1-08
0.96
0.80
0-56
0-40
• 0 10' 10*
PARTICLE DIAMETER, micrometers
Figure 7.4-9. Controlled (ESP), FeCr
-------
99.990
99.950 -
99.90
99.80 -
99.50
99
98
95
i
; 90
)
! 80
c
; 70
60
: 50
I 40
j 30
i 20
»
f 10
j
>
: 5
3
>
2
I
0.5
0.2
0.15
0.1
0.0
10"
TOTAL PARTICULATE
EMISSION RATE
96
H PARTICULATE
Mg ALLOY
JJI—l I I I I I
1
J—» 1,1 I I „Ll
J 1—i i i i y
92
73
58
42
27
10° 101
PARTICLE DIAMETER, micrometers
10*
Figure 7.4-10. Uncontrolled, SiMn producing, open furnace
particle size distribution
7.4-20
EMISSION FACTORS
89
-------
99.990
99.950
99.90
99.80
99.30
99
98
Ui
N
<7>
a
Ui
£
CO
V
K
z
Ui
o
oc
Ui
a.
Ui
>
K
<
-i
3
Z
3
u
95
90
80
70
60
50
40
30
20
10
5
2
I
0.5
0.2
0.15
0.1
0.0
10
TOTAL PARTICULATE „ . Kg PARTICULATE
EMISSION RATE *dA Mg ALLOY
—I .1 I 11, 11
i,. i.i-i.
2.10
Ui
2.08 £
in
2.02 o
Ui
i-
<
h
W
1.68
1.18
io° 101 10*
PARTICLE DIAMETER, micrometers
yj
H
<
mJ
3
U
t-
ac
<
Q.
UJ
>
<
2
ZS
u
>
O
-J
<
Figure 7.4-11. Controlled (scrubber), SiMn producing, open furnace
particle size distribution
Metallurgical Industry
90
7.4-21
-------
i- TABLE 7.4-5. EMISSION FACTORS FOR SULFUR DIOXIDE, CARBON MONOXIDE, LEAD
k. AND VOLATILE ORGANICS FROM SUBMERGED ARC FERROALLOY FURNACES3
h)
EMISSION FACTOR RATING: D
LEAD:
VO
cn
in
M
o
•z,
>
n
H
O
£
Cdc,d,e
Volatile Organic Compounds
Product
Furnace
SO,"
Lead'
Oncont rol1«dd»•
kg/Mg (lb/ton)
type
(lb/ton)
(lb/ton)
kg/1% (lb/ton)
Cont rol 1 edS
kg/Mg (lb/ton)
Cont rol
device
FeSi - 501
Open
Covered
-
2180
0.15 (0.29)
2.25 (4.5)
6.35 (12.7)
2.2 (4.4)
0.28 (0.56)
0.75 (1.5)
Baghouse
Scrubber
High energy
Low energy
feSi - 751
Open
Covered
-
3230
0.0015 (0.0031)
10.25 (20.5)
2.4 (4.8)
Scrubber
Si Metal - 98%
Open
-
0.0015 (0.0031)
35.90 (71.8)
25.9 (51.6)
Baghouse
FeMn - 801
Open
Covered
Sealed
0.010h
-
0.06 (0.11)
3.05 (6.1)
0.70 (1.4)
1.85 (3.7)
0.70 (1.4)
0.40 (0.8)
Baghouse
High energy scrubber
Scrubber
FeCr (HC)
FeCr-Si
SIMn
Open
Open
Open
Sealed
5.4h,j
0.070®.*
0.021®«k
1690
0.17 (0.34)
0.04 (0.08)
0.0029 (0.0057)
-
0.05 (0.10)
High energy scrubber
"Expressed as weight/unit weight of specified product (alloy). Dash - No data.
^References 14-15, 17, 19, 30. Emissions depend on amount of sulfur in feed Material.
References 4, 14. Measured before control by flare. 00 emissions fro* open furnaces are low. Quantity
fro* covered furnaces will wary with volume of air drawn into cover. Increased air will reduce CO emissions.
^References 4, 10, 12-15, 17, 19, 21. May Increase if furnace feed is dirty scrap iron or steel.
*Does not Include seal leaks or tapping emissions. Open furnace hoods may capture some tapping emissions.
'References 2, 20, 27-29.
^Measured before any flare in the control system.
^Uncontrolled.
J Includes tapping emissions.
''Scrubber outlet.
-------
Scrubbers are used on 13 percent of the furnaces, and electrostatic precipita-
tors on 2 percent. Control efficiences for well designed and operated control
systems [i. e., baghouses with air to cloth ratios of 1:1 to 2:1 ft^/ft^, and
and scrubbers with a pressure drop from 14 to 24 kllopascals (kPa) (55 to 96
inches H20)], have been reported to be in excess of 99 percent. Air to cloth
ratio is the ratio of the volumetric air flow through the filter media to the
media area.
Two emission capture systems, not usually connected to the same gas clean-
ing device, are necessary for covered furnaces. A primary capture system with-
draws gases from beneath the furnace cover. A secondary system captures fume
released around the electrode seals and during tapping. Scrubbers are used
almost exclusively to control exhaust gases from sealed furnaces. The gas from
sealed and mix sealed furnaces is usually flared at the exhaust of the scrub-
ber. The carbon monoxide rich gas has an estimated heating value of 300 Btu
per cubic foot and is sometimes used as a fuel in kilns and sintering machines.
The efficiency of flares for the control of carbon monoxide and the reduction
of organic emission has been estimated to be greater than 98 percent for steam
assisted flares with a velocity of less than 60 feet per second and a gas heat-
ing value of 300 Btu per standard cubic foot^^. For unassisted flares, the
reduction of organic and carbon monoxide emissions is 98 percent efficient with
a velocity of less than 60 feet per second and a gas heating value greater than
200 Btu per standard cubic foot.
Tapping operations also generate fumes. Tapping is intermittent and is
usually conducted during 10 to 20 percent of the furnace operating time. Some
fumes originate from the carbon lip liner, but most are a result of induced
heat transfer from the molten metal or slag as it contacts the runners, ladles,
casting beds and ambient air. Some plants capture these emissions to varying
degrees with a main canopy hood. Other plants employ separate tapping hoods
ducted to either the furnace emission control device or a separate control
device. Emission factors for tapping emissions are unavailable because of a
lack of data.
A reaction ladle may be involved to adjust the metallurgy after furance
tapping by chlorlnatlon, oxidation, gas mixing and slag metal reactions. Ladle
reactions are an Intermittent process, and emissions have not been quantified.
Reaction ladle emissions often are captured by the tapping emissions control
system.
Available data are insufficient to provide emission factors for raw
material handling, pretreatment and product handling. Dust particulate is
emitted from raw material handling, storage and preparation activities (see
Figure 7.4-1), from such specific activities as unloading of raw materials from
delivery vehicles (ship, railcar or truck), storage of raw materials in piles,
loading of raw materials from storage piles into trucks or gondola cars and
crushing and screening of raw materials. Raw materials may be dried before
charging in rotary or other type dryers, and these dryers can generate signif-
icant particulate emissions. Dust may also be generated by heavy vehicles used
for loading, unloading and transferring material. Crushing, screening and
storage of the ferroalloy product emit particulate in the form of dust. The
Metallurgical Industry
92
7.14-23
-------
properties of particulate emitted as dust are similar to the natural properties
of the ores or alloys from which they originated, ranging in size from 3 to 100
micrometers.
Approximately half of ferroalloy facilities have some type of control for
dust emissions. Dust generated from raw material storage may be controlled
in several ways, including sheltering storage piles from the wind with block
walls, snow fences or plastic covers. Occasionally, piles are sprayed with
water to prevent airborne dust. Emissions generated by heavy vehicle traffic
may be reduced by using a wetting agent or paving the plant yard.3 Moisture
in the raw materials, which may be as high as 20 percent, helps to limit dust
emissions from raw material unloading and loading. Dust generated by crushing,
sizing, drying or other pretreatment activities is sometimes controlled by dust
collection equipment such as scrubbers, cyclones or baghouses. Ferroalloy pro-
duct crushing and sizing usually require a baghouse. The raw material emission
collection equipment may be connected to the furnace emission control system.
For fugitive emissions from open sources, see Section 11.2 of this document.
References for Section 7.4
1. F. J. Schottman, "Ferroalloys", 1980 Mineral Facts and Problems, Bureau Of
Mines, U. S. Department Of The Interior, Washington, DC, 1980.
2. J. 0. Dealy, and A. M. Killin, Engineering and Cost Study of the Ferroalloy
Industry, EPA-450/2-74-008, U. S, Environmental Protection Agency, Research
Triangle Park, NC, May 1974.
3. Backgound Information on Standards of Performance: Electric Submerged Arc
Furnaces for Production of Ferroalloys, Volume I: Proposed Standards,
EPA-450/2-74-018a, 0. S. Environmental Protection Agency, Research Triangle
Park, NC, October 1974,
4. C. W. Westbrook, and D. P. Dougherty, Level I Environmental Assessment of
Electric Submerged Arc Furnaces Producing Ferroalloys, EPA-600/2-81-038,
U. S. Environmental Protection Agency, Washington, DC, March 1981.
5. F. J. Schottman, "Ferroalloys", Minerals Yearbook, Volume I; Metals and
Minerals, Bureau Of Mines, Department Of The Interior, Washington, DC,
1980.
6. S. Beaton and H. Klemm, Inhalable Particulate Field Sampling Program for
the Ferroalloy Industry, TR-80-115-G, GCA Corporation, Bedford, MA,
November 1980.
7. G. W. Westbrook and D. P. Dougherty, Environmental! Impact of Ferroalloy
Production Interim Report: Assessment of Current Data, Research Triangle
Institute, Research Triangle Park, NC, November 1978.
8. K. Wark and C. F. Warner, Air Pollution: Its Origin and Control, Harper
and Row Publisher, New York, 1981.
7.4-24
EMISSION FACTORS
93
-------
9. M. Szabo and R. Gerstle, Operations and Maintenance of Particulate Control
Devices on Selected Steel and Ferroalloy Processes, EPA-600/2-78-037, U. S.
Environmental Protection Agency, Washington, DC, March 1978.
10. C, W. Westbrook, Multimedia Environmental Assessment of Electric Submerged
Arc Furnaces Producing Ferroalloys, EPA-600/2-83-092, U. S. Environmental
Protection Agency, Washington, DC, September 1983.
11. S. Gronberg, et al., Inhalable Particulate Source Category Report for the
Ferroalloy Industry, TR-82-25-G, EPA Contract No. 68-02-3157, GCA Corpor-
ation, Bedford, MA, March 1982.
12. T. Epstein, et al., Ferroalloy Furnace Emission Factor Development, Roane
Limited, Rockwood, Tennessee, EPA-600/X-85-325, U. S. Environmental Pro-
tection Agency, Washington, DC, June 1981.
13. S. Beaton, et al., Ferroalloy Furnace Emission Factor Development, Inter-
lake Inc., Alabama Metallurgical Corp., Selma, Alabama, EPA-600/X-85-324,
U. S. Environmental Protection Agency, Washington, DC, May 1981.
14. J. L. Rudolph, et al., Ferroalloy Process Emissions Measurement, EPA-600/
2-79-045, U. S. Environmental Protection Agency, Washington, DC, February
1979.
15. Written communication from Joseph F. Eyrich, Macalloy Corporation, Charles-
ton, SC to GCA Corporation, Bedford, MA, February 10, 1982, citing Airco
Alloys and Carbide test R-07-7774-000-1, Gilbert Commonwealth, Reading,
PA, 1978.
16. Source test, Airco Alloys and Carbide, Charleston, SC, EMB-71-PC-16(FEA),
U. S. Environmental Protection Agency, Research Triangle Park, NC, 1971.
17. Telephone communication between Joseph F. Eyrich, Macalloy Corporation,
Charleston, SC and Evelyn J. Litnberakis, GCA Corporation, Bedford, MA,
February 23, 1982.
18. Source test, Chromium Mining and Smelting Corporation, Memphis, TN, EMB-
72-PC-05 (FEA), U. S. Environmental Protection Agency, Research Triangle
Park, NC, June 1972.
19. Source test, Union Carbide Corporation, Ferroalloys Division, Marietta,
Ohio, EMB-71-PC-12(FEA), U. S. Environmental Protection Agency, Research
Triangle Park, NC, 1971.
20. R. A. Person, "Control of Emissions from Ferroalloy Furnace Processing",
Journal Of Metals, 23(4):17-29, April 1971.
21. S. Gronberg, Ferroalloy Furnace Emission Factor Development Foote Minerals,
Graham, W. Virginia, EPA-600/X-85-327, U. S. Environmental Protection
Agency, Washington, DC, July 1981.
22. R. W. Gerstle, et al., Review of Standards of Performance for New Station-
ary Air Sources - Ferroalloy Production Facility, EPA-450/3-80-041, U. S.
Environmental Protection Agency, Research Triangle Park, NC, December 1980.
Metallurgical Industry
94
7.4-25
-------
23. Air Pollutant Emission Factors, Final Report, APTD-0923, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, April 1970.
24. Telephone communication between Leslie B. Ivans, Office Of Air Quality
Planning And Standards, U. S. Environmental Protection Agency, Research
Triangle Park, NC, and Richard Vacherot, GCA Corporation, Bedford, HA,
October 18, 1984,
25. R. Ferrari, Experiences in Developing an Effective Pollution Control
System for a Submerged Arc Ferroalloy Furnace Operation, J. Metals,
p. 95-104, April 1968.
26. Fredriksen and Nestaas, Pollution Problems by Electric Furnace Ferroalloy
Production, United Nations Economic Commission for Europe, September 1968.
27. A. E. Vandergrlft, et al., Particulate Pollutant System Study - Mass Emis-
sions , PB-203-128, PB-203-522 and P-203-521, National Technical Information
Service, Springfield, ?A, May 1971.
28. Control Techniques for Lead Mr Emissions, EPA-450/2-77-012, U. S. Environ-
mental Protection Agency, Research Triangle Park, NC, December 1977.
29. W. E. Davis, Emissions Study of Industrial Sources of Lead Air Pollutants,
1970, EPA-APTD-1543, W. E. Davis and Associates, Leawood, KS, April 1973.
30. Source test, Foote Mineral Company, Vancoram Operations, Steubenvllle, OH,
EMB-71-PC-08(FEA), U. S. Environmental Protection Agency, Research Triangle
Park, NC, August 1971.
7.4-26
EMISSION FACTORS
95
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1
2
3
4
5
6
7
8
9
10
12
13
REFERENCES (for Sections 1 to 4)
Technical Procedures for Developing AP-42 Emission Factors and Preparing
AP-42 Sections, U.S. Environmental Protection Agency, Air Management
Technology Branch, OAQPS, April 1980.
F. J. Schottman, "Ferroalloys", 1980 Mineral Facts and Problems, Bureau
of Mines, U. S. Department of the Interior, Washington, DC 1980.
J. 0. Dealy, and A. M. Killin, Engineering and Cost Study of the Ferroalloy
Industry, EPA-450/2-74-008, U.S. Environmental Protection Agency, Research
Triangle Park, NC, May 1974.
C. W. Westbrook, and D.P. Dougherty, Level I Environmental Assessment of
Electric Submerged Arc Furnaces Producing Ferroalloys, EPA-600/2-81-038,
U.S. Environmental Protection Agency, Washington, DC, March 1981.
S. Beaton and H. Klemm, Inhalable Particulate Field Sampling Program for
the Ferroalloy Industry, TR-80-115-G, GCA Corporation, Bedford, MA,
November 1980.
F. J. Schottman, "Ferroalloys", Minerals Yearbook. Volume I; Metals and
Minerals, Bureau of Mines, U.S. Department of the Interior, Washington, DC,
1980.
S. Gronberg, Ferroalloy Furnace Emission Factor Development Foote Minerals,
Graham, W. Virginia, EPA-60G/X-85-327, U.S. Environmental Protection
Agency, Washington, DC, July 1981.
C. W. Westbrook, Multimedia Environmental Assessment of Electric Submerged
Arc Furnaces Producing Ferroalloys, EPA-600/2-83-092, U.S. Environmental
Protection Agency, Washington, DC, September 1983.
T. Epstein, et al., Ferroalloy Furnace Emission Factor Development, Roane
Limited, Rockwood, Tennessee, EPA-600/X-85-325, U.S. Environmental Pro-
tection Agency, Washington, DC, June 1981.
S. Beaton, et al., Ferroalloy Furnace Emission Factor Development, Inter-
lake Inc., Alabama Metallurgical Corp., Selma, Alabama, EPA-600/X-85-324,
U.S. Environmental Protection Agency, Washington, DC, May 1981.
J. L. Rudolph, et al., Ferroalloy Process Emissions Measurement, EPA-600/
2-79-045, U.S. Environmental Protection Agency, Washington, DC, February
1979.
Written communication from Joseph F. Eyrich, Macalloy Corporation,
Charleston, SC to Evelyn J. Limberakis, GCA Corporation, Bedford, MA,
February 10, 1982, citing Airco Alloys and Carbide test R-07-7774-000-1,
Gilbert Commonwealth, Reading, PA, 1978.
Source test, AIRCO Alloys and Carbide, Charleston, SC, EMB-71-PC-16 (FEA),
U. S. Environmental Protection Agency, Research Triangle Park, NC, 1971,
96
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14
15
16
17
18
19
20
21
22
23
24
25
26
Telephone communication between Joseph F. Eyrich, Macalloy Corporation,
Charleston, SC and Evelyn J. Limberakis, GCA Corporation, Bedford, MA,
February 23, 1982.
Source test, Chromium Mining and Smelting Corporation, Memphis, TN, EMB-
72-PC-05 (FEA), U.S. Environmental Protection Agency, Research Triangle
Park, NC, June 1972.
Source test, Foote Mineral Company, Yancoram Operations, Steubenville, OH,
EM8-71-PC-08 (FEA), U.S. Environmental Protection Agency, Research
Triangle Park, NC, August 1971.
Source test, Union Carbide Corporation, Ferroalloys Division, Marietta,
Ohio, EM8—71 —PC—12(FEA), U.S. Environmental Protection Agency, Research
Triangle Park, NC 1971.
Same as Reference 4.
R. A. Person, "Control of Emissions from Ferroalloy Furnace Processing",
Journal of Metals, 23(4):17-29, April 1971.
Background Information on Standards of Performance: Electric Submerged
Arc Furnaces for Production of Ferroalloys, Volume I; Proposed Standards,
fc.PA-450/2-74-018a, U.S. Environmental Protection Agency, Research Triangle
Park, NC, October 1974.
Telephone communication between Mr. Tom Jones, United States Bureau of
Mines, Washington, DC, and Evelyn J. Limberakis, GCA Corporation,
Bedford, MA, January 19, 1982.
Telephone communication between Dr. Wayne Westbrook, Research Triangle
Institute, Research Triangle Park, NC and Evelyn J. Limberakis,
GCA Corporation, Bedford, MA, January 19, 1982.
i
Telephone conversation between Mr. Ronald Thomas, Reynolds Metals,
Sheffield, Alabama and Evelyn J. Limberakis, GCA Corporation, Bedford, MA,
February 22, 1982.
Telephone communication between George Stokes, Elkem Metals Company,
Marietta, Ohio, and Evelyn J. Limberakis, GCA Corporation, Bedford, MA,
February 22, 1982.
Telephone communica'tion between Gary Moore, Elkem Metals Company, Alloy,
W. Virginia, and Evelyn J. Limberakis, GCA Corporation, Bedford, MA,
February 22, 1982.
Telephone communication between Bob A1lenbach, Elkem Metals Company,
Niagara Falls, New York, and Evelyn J, Liberakis, GCA Corporation,
Bedford, MA, February 22, 1982.
97
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27. K. Wark and C. F. Warner, Air Pollution; Its Origin and Control.
Harper and Row Publisher, New York, 1981.
28. P. Wechsler, "UC Closing Oregon Unit by Mid-8l," American Metal Market,
Vol. 89, No. 30, February 13, 1981.
29. M. Szabo and R. Gerstle, Operations and Maintenance of Particulate
Control Devices on Selected Steel and Ferroalloy Processes, EPA-600/2-
78-037, U.S. Environmental Protection Agency, Washington, DC, March
1978.
30. J. McCain, Evaluation of Aronetics Two-Phase Jet Scrubber, EPA-650/
2-74-129, U.S. Environmental Protection Agency, Research Triangle
Park, NC, December 1974.
31. R. W. Gerstle, et al., Review of Standards of Performance for New
Stationary Air Sources - Ferroalloy Production Facility, EPA-450/3-80-
041, U.S. Environmental Protection Agency, Research Triangle Park, NC,
December 1980,
32. Ferroalloy Production 7.4, Compilation of Air Pollutant Emission
Factors. AP-42 Part B, Third Edition, U.S. Environmental Protection
Agency, Research Triangle Park, NC, August 1977.
98
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