MEMORANDUM

DATE: August 26, 2014

SUBJECT: Revised Development of the Risk and Technology Review (RTR) Emissions 

Dataset for the Ferroalloys Production Source Category for the 2014 

Supplemental Proposal

FROM: Bradley Nelson, EC/R, Inc.

TO: Phil Mulrine, EPA OAQPS/SPPD/MMG

1.0 PURPOSE

The purpose of this memorandum is to document the methodologies used to estimate pollutant 

emissions from processes at two ferroalloy facilities; Eramet Marietta Inc. (Eramet) and Felman 

Production (Felman). The emission estimates developed in this task were used to create a 

database that will be used as input to the risk assessment modeling to estimate the risks due to 

emissions from these facilities as part of the “risk and technology” (RTR) review for the 

Ferroalloy Production source category. This analysis supplements the original RTR analysis1

that supported proposed amendments to the national emission standards for hazardous air 

pollutants (NESHAP) for the ferroalloys production source category published in the Federal 

Register on November 23, 2011 (76 FR 72508). 

 

2.0 BACKGROUND

Under the "technology review" provision of CAA Section 112, EPA is required to review 

maximum achievable control technology (MACT) standards and to revise them "as necessary 

(taking into account developments in practices, processes and control technologies)" no less 

frequently than every 8 years. Under the "residual risk" provision of the CAA section 112, 

within 8 years after promulgation of the MACT standards, EPA must evaluate the remaining 

risks due to emissions of air toxics from the source category and promulgate amendments to the 

standards if required to provide an ample margin of safety to protect public health or prevent an 

adverse environmental effect. EPA has combined the two review activities into the RTR review 

for the Ferroalloys Production source category. 

 

1 Memorandum from Bradley Nelson, EC/R, Inc. to Conrad Chin, EPA OAQPS/SPPD/MMG, Draft Development of 

the RTR Emissions Dataset for the Ferroalloys Production Source Category, October 14, 2011. EPA-HQ-OAR2010-0895-0040
DRAFT FOR INTERNAL REVIEW

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The MACT standards, for Ferromanganese and Silicomanganese Production apply to new and

existing ferroalloy production facilities that manufacture ferromanganese and/or silicomanganese 

and are major sources of hazardous air pollutant (HAP) emissions or are co-located at major 

sources of HAP emissions. 

These ferroalloy products are produced using submerged electric arc furnaces, which are 

furnaces in which the electrodes are submerged into the charge. The submerged arc process is a 

reduction smelting operation. The reactants consist of metallic ores (ferrous oxides, silicon 

oxides, manganese oxides, etc.) and a carbon-source reducing agent, usually in the form of coke, 

charcoal, high- and low-volatility coal, or wood chips. Raw materials are crushed and sized, and 

then conveyed to a mix house for weighing and blending. Conveyors, buckets, skip hoists, or 

cars transport the processed material to hoppers above the furnace. The mix is gravity-fed 

through a feed chute either continuously or intermittently, as needed. At high temperatures in 

the reaction zone, the carbon source reacts with metal oxides to form carbon monoxide and to 

reduce the ores to base metal.2The molten material (product and slag) is tapped from the 

furnace, sometimes subject to post-furnace refining, and poured into casting beds on the furnace 

room floor. Once the material hardens, it is transported to product crushing and sizing systems 

and packaged for transport to the customer.

The NESHAP established emissions standards for the following HAP emission sources at a

ferroalloy production facility:

 Submerged arc furnaces

 Metal oxygen refining (MOR) process

 Crushing and screening operations

 Fugitive dust sources.

The current rule contains emission standards that limit particulate matter (PM) emissions from 

existing and new or reconstructed emission sources. The limits for the submerged arc furnaces 

depend on the product produced and furnace design. The rule also includes limits for the air

pollution control devices associated with the MOR process and crushing and screening 

operations. The current rule sets emission standards for fugitive dust sources by limiting the 

amount of visible emissions that can be observed from the furnace buildings. 

To estimate the facility HAP emissions, an Information Collection Request (ICR) under Section 

114 of the Clean Air Act (CAA) was sent to both ferroalloy production facilities on April 28,

2010 and December 21, 2012 to gather source emission testing data from the furnaces (which 

 

2 EPA, AP 42, Fifth Edition Compilation of Air Pollutant Emission Factors, Volume 1: Stationary Point and Area 

Sources, Chapter 12.4. Ferroalloy Production. 10/86.
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include emissions that occur during charging, smelting, and tapping), MOR process and the 

product crushing process. The HAP source test data that were collected from the control device 

outlet for each furnace include: metal HAP (arsenic, cadmium, chromium (total and Cr+6), lead, 

manganese, mercury, and nickel)

3

, hydrochloric acid, hydrofluoric acid, hexavalent chromium, 

formaldehyde, polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), and

chlorodibenzodioxins and chlorodibenzofurans (CDD/CDF). In addition, non-HAP emissions 

were measured from the furnace control device outlet for: particulate matter and carbon 

monoxide. The source test data collected for the crushing and sizing operations include: 

particulate matter, metal HAP (arsenic, total chromium, lead, manganese, mercury, and nickel).

4

 

The source test data collected from the MOR baghouse outlet include: particulate matter, metal 

HAP (arsenic, total chromium, lead, manganese, mercury, and nickel).5

3.0 FERROALLOY FACILITY SUMMARY

The following section describes the HAP emission sources for the Eramet and Felman ferroalloy 

production facilities, which are the two existing facilities in the source category. Figure 3-1 

provides a schematic of the smelting, tapping, and casting emission points for a typical 

ferroalloys production operation.

Eramet Marietta Inc.

The Eramet facility is located in Marietta, Ohio, and ferromanganese (FeMn) and 

silicomanganese (SiMn) are produced using two furnaces identified as Furnace 1 and Furnace 

12. 

Furnace 1 is a submerged arc furnace rated at 30 megawatts (MW) and is equipped with a 

negative pressure fabric filter to control particulate emissions and metal HAP. The fabric filter 

controls emissions from the furnace smelting operation and was installed in 2011 to replace a 

wet scrubber system. A separate fabric filter system identified as Furnace 1 Tapping Baghouse 

is used to control captured fugitive emissions from the tapping process from this furnace. The 

casting process associated with this furnace is uncontrolled.

 

3Total phosphorus was measured for the ICR using EPA Method 29; however this method does not distinguish 

between white phosphorus (which is a non-HAP) and red phosphorus (which is a HAP). Due to the uncertainty of 

the percentage of red phosphorus in the total phosphorus test results, it was concluded that phosphorus would not be 

incorporated in the emissions used for modeling.

4 Total phosphorus was measured using Method 29 and therefore not included in the emissions used for modeling.

5 Again, total phosphorus was measured using Method 29 and therefore not included in the emissions used for 

modeling.
Figure 3-1. Diagram of the Ferroalloys Process and Emission Points

Submerged Electric 

Arc Furnace

Tapping Fugitive

Emissions to Atmosphere

Fabric Filter

Exhaust 

to Atmosphere

Casting

Casting Bed

Furnace Smelting and 

Tapping Process Casting Process

Casting Primary 

Capture Hood

Casting Fugitive

Emissions to Atmosphere

Furnace Fugitive

Emissions to Atmosphere

Tapping Primary 

Capture Hood

Tapping
Furnace 12 is a submerged arc furnace rated at 22 MW and is equipped with two wet scrubbers 

to control emissions from the furnace smelting operation and captured fugitive emissions from 

the tapping process. The scrubbers operate simultaneously and exhaust through a single stack. 

The casting process associated with this furnace is uncontrolled.

The facility has a third furnace, Furnace 18, which is permitted, but is considered to be 

inoperable until extensive repair is made to the furnace. Therefore, Furnace 18 was not 

considered an emission source and was not included in the emission inventory for Eramet for 

actual emissions. However, an estimate of Furnace 18 emissions was included for the calculation 

of MACT “allowable” emissions. Other HAP emission sources include the MOR process 

controlled by a positive-pressure baghouse which also controls fugitive emissions captured from 

casting of the product from MOR and a crushing and sizing system (C2P) that is controlled by 

three negative pressure baghouses. There are also fugitive emissions that are emitted from each 

of these emission sources, in addition to the fugitive emissions from the casting operations for 

Furnace 1, Furnace 12, and the MOR process.

The emission sources used for modeling emissions from the Eramet facility were developed 

based on the plant configuration discussed above and data and information collected through the 

ICRs. For the furnaces, emission points were developed for the control device outlet emissions 

and for fugitive emissions from the furnace smelting and furnace tapping. For the MOR process, 

emission points were developed for the MOR baghouse outlet and for fugitive emissions from 

the MOR process. For the crushing system, emission points were developed for each of the three 

baghouse outlets and one emission point for fugitive emissions from the crushing operation. 

Emission points were also developed for fugitive emissions from casting operations associated 

with each of the two furnaces and for the MOR process.

Felman Production Inc.

The Felman facility is located in New Haven, West Virginia and produces SiMn using three 

furnaces identified as Furnace 2, Furnace 5, and Furnace 7. Furnaces 2, 5, and 7 are open 

submerged arc furnaces rated at 32, 20, and 20 MW respectively. Each of these furnaces is

equipped with a positive-pressure baghouse to control emissions of PM and metal HAP from the 

furnace. The baghouse from each furnace also controls the captured fugitive emissions from the 

associated furnace tapping and casting processes.

The facility has a crushing and sizing system controlled using a negative pressure baghouse. 

There are also fugitive emissions that are emitted from each of these emissions sources, in 

addition to the fugitive emissions from the casting operations for Furnace 2, Furnace 5, and 

Furnace 7.
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The Felman facility emission points used for modeling emissions were developed from the plant 

configuration discussed above and data and information collected through the ICR. Emission 

points were developed for the control device outlets for each of the three furnaces, as well as 

fugitive emission points for smelting and tapping at each of the three furnaces. For the crushing 

systems, emission points were developed for the crusher baghouse outlet and fugitive emissions 

from the crushing units. Emission points were also developed for casting fugitive emissions 

from each of the three furnaces.

4.0 POINT SOURCE POLLUTANT EMISSION DATA

The following section describes the test data that were collected from emission point sources at 

each of the ferroalloy facilities. This section will describe the test methods that were used to 

measure emissions for each pollutant from the processes that were tested. A summary of the 

type of pollutant data collected in the ICRs is presented in Table 4-1. More information on the 

test data collected in the ICR can be found in the test data review summaries6,7located in the 

docket. 

These test report reviews provide a description of how the test data were analyzed and compiled, 

and provides a comparison of the reported test results with the calculated results used to estimate 

the modeling emissions. The individual test reports submitted by the facilities can also be found 

in the docket. 

Some of the analytical results for the HAP pollutants were reported below the detection limit. 

For these test results, one half of the detection limit was used to estimate the emission rate of the 

HAP pollutant. The use of one half of the detection limit for calculating emission rates from 

analytical data results reported below the detection limit is based on EPA’s revised procedures8

for developing emission factors.

 

6 Memorandum from Bradley Nelson, EC/R to Conrad Chin, EPA/OAQPS/SPPD/MMG, Ferroalloys 2012 Test 

Report Review, May 28, 2013.

7 Memorandum from Bradley Nelson, EC/R to Conrad Chin, EPA/OAQPS/SPPD/MMG, Ferroalloys 2013 Test 

Report Review, July 29, 2013.

8 Recommended Procedures for Development of Emissions Factors and Use of the WebFIRE Emissions Factor 

Database, Revised Draft Report, December 17, 2010. 

http://www.epa.gov/ttn/chief/efpac/procedures/procedures_draft122010.pdf
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Table 4-1. Summary of HAP Emissions Data Collected in the ICRs

Facility Process

Particulate Matter Metal HAP Mercury Cr+6 HCl/ HF Formaldehyde PAH, PCB, CDD/CDF

Method 

5Da Method 5 Method 29 Method 29/30B

SW Method 

0061 Method 26A Method 316 Method 23/0010

CARB 

428/429

Felman

Furnace       

Crusher   

Eramet

Furnace        

MOR   

Crusher   

a

The furnaces at Felman are each equipped with positive pressure baghouse and therefore Method 5D was used to measure PM 

emissions from these emission sources. All other emission sources are equipped with either a negative pressure baghouse or venturi 

scrubber and were measured using Method 5.
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Particulate Matter

Test data for PM were received from both ferroalloy facilities for each furnace and for one product 

crushing operation. Eramet provided PM results from the Furnace 12 scrubber outlet, the Furnace 1 

baghouse outlet, the Furnace 1 tapping baghouse outlet, the MOR process baghouse outlet, and 

from the crushing and sizing operation baghouses (C2P Crushing/Sizing Baghouse #1) using EPA 

Method 5. Felman provided PM test results from the Furnace 2 baghouse outlet, the Furnace 5 

baghouse outlet, the Furnace 7 baghouse outlet using EPA Method 5D, and the baghouse outlet 

from the crushing and sizing operation using EPA Method 5. 

Metal HAP

Test data for metal HAP (arsenic, cadmium, chromium, lead, manganese, mercury, and nickel) were 

collected from the Furnace 12 scrubber outlet, the Furnace 1 baghouse outlet, the Furnace 1 tapping 

baghouse outlet, and from Baghouse #1 from the product crushing operation at Eramet. The metal 

HAP data for Felman were obtained from the Furnace 2 baghouse outlet, the Furnace 5 baghouse 

outlet, and the baghouse controlling emissions from the crushing and sizing operation. The furnace 

and product crushing test data from both facilities were collected using EPA Method 29 for arsenic 

(As), cadmium (Cd), total chromium (Cr), lead (Pb), manganese (Mn), total mercury (Hg), and 

nickel (Ni). Additional mercury test data were collected for both facilities using EPA Method 30B. 

The EPA Method 29 analytical results were corrected using the reported field blank9results from 

the analytical test report. 

Hexavalent Chromium

Hexavalent chromium (Cr+6) test data were collected from Furnace 2 and Furnace 12 for the Felman 

and Eramet facilities respectively, using EPA SW Method 0061. No hexavalent chromium data 

were requested for the product crushing operations. Hexavalent chromium emissions were 

estimated for the furnaces that were not tested and the product crushing operations by using the 

hexavalent chromium/PM ratio from the tested sources. A discussion of this calculation is provided 

in Section 5.0.

Hydrochloric Acid/Hydrofluoric Acid

Test data for hydrochloric acid (HCl) and hydrofluoric acid (HF) were collected from the Furnace 

12 scrubber outlet, and the Furnace 1 baghouse outlet at Eramet. Test data for HCl was also 

collected for the Furnace 1 tapping baghouse at Eramet. Test data for HCl and HF were collected 

 

9 The primary purpose of field blanks is to trace sources of artificially introduced contamination. The field blank results 

include total ambient conditions during sampling and laboratory sources of contamination.
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for the Furnace 2 baghouse outlet at Felman. In addition, HCl data was collected for the Furnace 5 

and Furnace 7 baghouse outlets at Felman. The HCl and HF data for both facilities were collected 

using EPA Method 26A. The product crushing processes at both facilities were not tested for HCl 

or HF, because it believed that these are non-combustion processes and thus do not emit these HAP 

pollutants.

The test data for HCl is a mixture of detected and non-detected analytical results. There were a 

total of 29 runs that reported non-detect analytical results out of the total of 45 test runs for HCl. 

For the analytical results that were reported as non-detect, one half of the detection limit was used 

to estimate the HCl concentration for the test runs. For HF, all of the test results were reported as 

non-detect, and again, one half of the detection limit was used to estimate the HF concentration for 

the test runs. While we calculated numerical estimates for HF based on the assumption that nondetects were equal to 1⁄2 detection limit and included these estimates in the inputs to our risk model, 

we have no evidence that HF is emitted from these sources. Therefore, for purposes of our estimates 

of emissions and associated risks, we are assuming that HF is not emitted from these sources.

Formaldehyde

Testing for formaldehyde was performed on the Furnace 12 scrubber outlet, the Furnace 1 baghouse 

outlet, and the Furnace 1 tapping baghouse outlet at Eramet, and the Furnace 2 baghouse outlet, 

Furnace 5 baghouse outlet, and Furnace 7 baghouse outlet at Felman. All of the formaldehyde test 

data was collected using EPA Method 316. Formaldehyde testing was not performed on any of the 

product crushing processes, because it believed that these are non-combustion processes and thus 

do not emit these HAP pollutants. 

The test data for formaldehyde reported 6 runs below the detection limit out of a total of 18 test 

runs. The emissions rates for the detected formaldehyde runs ranged from 0.01 to 0.26 pounds per 

hour with an average and median of 0.07 and 0.05 pounds per hour, respectively. For the analytical 

results that were reported as non-detect, one half of the detection limit was used to estimate the 

formaldehyde concentration for the test runs. 

PAH/PCB/CDD/CDF

Test data for polychlorinated biphenyls (PCB), chlorinated dibenzo-p-dioxins (CDD), and 

chlorinated dibenzo-p-furans (CDF) were collected at the Furnace 12 scrubber outlet, Furnace 1 

baghouse outlet, and the Furnace 1 tapping baghouse outlet at Eramet. The test methods used to 

collect the samples were EPA Method 23, Method 0010, California Air Resources Board (CARB) 

Method 428 and CARB 429. Test data were collected for PAH, PCB, and CDD/CDF data for the 

Furnace 2 baghouse outlet and the Furnace 5 baghouse outlet at Felman using CARB methods 428 

and 429. Test data for PAH were collected at the Furnace 7 baghouse outlet at Felman using 

CARB method 429. No PAH, PCB, or CDD/CDF emissions data were collected for the product 
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crushing units, because these are non-combustion processes and thus do not emit these HAP 

pollutants.

The analytical results for CDD/CDF reported 230 of the individual compounds were below the 

detection limit out of a total of 306 reported individual compounds. For the individual CDD/CDF 

compounds that were detected, the emissions ranged from 1.8 x 10-10 to 7.3 x 10-8pounds per hour 

with an average and median of 6.5 x 10-8and 3.5 x 10-9pounds per hour, respectively. For PCBs, 

107 out of 207 reported individual compounds were reported below the detection limit. The 

emissions from these detected individual PCB compounds ranged from 7.0 x 10-10 to 7.5 x 10-6

pounds per hour with an average and median of 5.8 x 10-7and 4.6 x 10-8pounds per hour, 

respectively. For PAHs, 18 out of 513 individual compounds analytical results were reported below 

the detection limit. For the individual PAH compounds that were detected, the emission values 

ranged from 1.9 x 10-6to 1.9 x 10-1pounds per hour with an average and median of 7.6 x 10-3and 

1.5 x 10-3pounds per hour, respectively. For the test results that were reported below the detection 

limit, one half of the detection limit was used to calculate the concentration and emission rate for 

the purposes of estimating emissions for the risk assessment modeling.

Other Data

In addition to the pollutant data described above, analyses of the coal/coke and furnace exhaust 

concentrations of oxygen (O2), carbon dioxide (CO2), and carbon monoxide (CO) were measured. 

The O2 and CO2 concentrations were measured using EPA Method 3A, and the CO concentration 

was measured using EPA Method 10. For coal/coke, the samples were analyzed using ASTM 

D3177-02 for sulfur, D3172-07 for proximate analysis, and D3176-09 for ultimate analysis. Visible 

emission data from the furnace building using EPA Method 9 were also provided in the test reports. 

These visible emission reports provide opacity readings from the furnace buildings for furnace 

smelting and tapping operations during the furnace control device outlet tests.

5.0 METHODOLOGY FOR DEVELOPING EMISSION ESTIMATES

The test data provided in the ICR responses were used to develop a modeling emissions database 

for estimating the risks associated with the HAP emissions from the ferroalloy production facilities. 

The analytical results provided in the ICR responses were used to calculate emissions for each of 

the pollutants. This section describes the methodology used to estimate annual emissions from all 

of the sources at each of the ferroalloy facilities. A summary of the estimated annual HAP 

emissions is provided at the end of this section. 

Some of the pollutant emissions were based on one or more analytical results that were reported 

below the detection limit. For these analytical results, one half of the detection limit was used to 

estimate the pollutant concentration. For some HAP (e.g., dioxins, furans, PCBs), the majority of 
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the test results were below detection limit. For HF, all the results were below detection. 

Nevertheless, to be conservative (i.e., overestimating rather than underestimating emissions and 

risks), we developed estimated emissions for these HAP using the method described above. 

5.1 Furnace Smelting Emissions

The furnace annual emissions for all pollutants were estimated using the information provided in 

the facility’s ICR test reports. The annual emissions for the tested furnace units were calculated 

using stack gas parameters and analytical results provided in the submitted test reports and 

converted to annual emissions assuming the furnaces operate 24 hours per day for 365 days per year 

(i.e., 8,760 hours of operation per year). We have PM test results for all stack emissions points. For

some of the other pollutants, we only have data for a subset of emissions points. For those

pollutants that were not tested for a specific emissions point, the annual emissions were estimated 

by multiplying the PM emissions rate by the pollutant-to-PM ratio from a comparable emission 

source. A more detailed description for each facility is provided in the paragraphs below. 

Eramet

The Eramet facility provided ICR test data for all pollutants for the Furnace 12 scrubber outlet and 

the Furnace 1 baghouse outlet with the exception of Cr+6, which was not tested at the Furnace 1 

baghouse outlet. Eramet also provided test data from the Furnace 1 and 12 smelting baghouse 

outlets and the Furnace 1 tapping baghouse outlet during production of FeMn and SiMn. 

The main source of manganese (Mn) and mercury (Hg) emissions from the furnace smelting

process is the manganese ore used by Eramet to produce the ferroalloys product, which may contain 

Hg as an impurity. The amount of Mn ore used to produce a ton of FeMn is greater than the 

amount of Mn ore used to produce a ton of SiMn. Therefore, Mn and Hg emissions are higher

during the production of FeMn than during the production of SiMn. The other HAP pollutant 

emissions were assumed to be equivalent during the production of either FeMn or SiMn. 

To estimate the annual Mn and Hg emissions for these emission sources, it was assumed that FeMn 

and SiMn were produced equally during the year by each furnace (e.g., 4,380 hours per year 

producing SiMn and 4,380 hours per year producing FeMn). This assumption was based on 

conversations with Eramet on the historical production of the FeMn and SiMn products at their 

facility. The annual emissions were calculated by averaging the emissions during the production of 

each product and multiplying that average value by the number of production hours. The FeMn and 

SiMn totals were then added to calculate the annual emissions. The equation for estimating the 

furnace smelting baghouse outlet and the furnace tapping baghouse Mn emissions is provided 

below.
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where;

MnAnnual = Annual Mn emissions from furnace smelting baghouse outlet or the tapping baghouse 

outlet when producing FeMn and SiMn,

MnSiMn = Average Mn test results when producing SiMn in pounds per hour,

MnFeMn = Average Mn test results when producing FeMn in pounds per hour,

4,380 hours per year.

The same equation is used to estimate the annual Hg emissions using the average Hg test results for 

FeMn and SiMn production. The formula is as follows;

 

where;

HgAnnual = Annual Hg emissions from furnace smelting baghouse outlet or the tapping baghouse 

outlet when producing FeMn and SiMn,

HgSiMn = Average Hg test results when producing SiMn in pounds per hour,

HgFeMn = Average Hg test results when producing FeMn in pounds per hour,

4,380 hours per year.

To estimate the Cr+6 emissions from the Furnace 1 baghouse outlet, the Furnace 1 baghouse outlet 

PM emission rate was multiplied by the Furnace 12 scrubber outlet Cr+6-to-PM ratio. The equation 

for the Cr+6 emissions estimation for the Furnace 1 baghouse outlet are shown below:

 

 (

 

 

 )

where;

Cr+6

Furnace 1 = Estimated Cr

+6 emissions from EAF 1 in tons per year,

PMFurnace 1 = PM test results for the Furnace 1 baghouse outlet in tons per year,

Cr+6

Furnace 12 = Cr+6 test results from the Furnace 12 scrubber outlet in tons per year, and

PMFurnace 12 = PM test results from the Furnace 12 scrubber outlet in tons per year.

Felman
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The Felman facility submitted several test reports for Furnaces 2, 5, and 7 that provided pollutant 

test data. The test reports for Furnace 2 provided test data for PM, metal HAP, Cr+6, HCl, HF, 

formaldehyde, PAH, CDD/CDF, and PCB. The test reports for Furnace 5 provided test data for 

PM, metal HAP, HCl, formaldehyde, PAH, CDD/CDF, and PCB. The test reports for Furnace 7 

provided test data for PM, metal HAP, HCl, formaldehyde, and PAH. The Cr+6 and HF emissions 

for Furnaces 5 and 7 were estimated using the pollutant-to-PM ratio from Furnace 2 using the same 

estimation approach used for Eramet, as described above. The CDD/CDF and PCB emissions from 

Furnace 7 were assumed to be the same as the reported emissions from Furnace 5. This assumption 

is based on the fact that both Furnace 5 and Furnace 7 are the same size and produce the same 

product.

5.2 Furnace Smelting Fugitive Emissions

At the top of the furnaces there is hooding that captures the vast majority of the emissions coming 

out of the top of the furnace smelting operation and these emissions are vented to a control device 

(either a baghouse or scrubber). Therefore, we have developed estimates of the fugitive emissions 

from the top of these furnaces. As shown in table 5-2, we estimate that about 98% of these 

emissions are captured and directed to a control device. This estimate is based on observations of 

the furnace smelting process and hood system. However, it is not a closed system and we believe 

there are some fugitive emissions coming from this source.

We have not identified any emissions factors based on the direct measurement of fugitive emissions 

from ferroalloys production furnaces to estimate these emissions. Therefore, we used a mass 

balance approach to estimate these emissions. The specific method is described in the following 

paragraphs. 

The furnace smelting fugitive emissions were estimated by calculating the uncontrolled PM 

emissions from the furnace and estimating the percentage of the uncontrolled PM emissions that are

captured from the furnace. The difference between the uncontrolled pollutant emissions and the 

estimated captured pollutant emissions were assumed to be the furnace fugitive emissions. The 

uncontrolled PM pollutant emissions were calculated using the furnace annual emissions for PM 

and the estimated control efficiency. A summary of the assumed fabric filter and scrubber control 

efficiencies for the pollutants is presented in Table 5-1. These control efficiencies are based on 

expected control efficiencies found on the EPA Clean Air Technology Center website.

10

 A 

summary of the assumed process fugitive capture efficiencies is provided in Table 5-2. These 

capture efficiencies are based on visual observations of the fugitive capture during process 

operations. It was also assumed that 92 percent of the furnace control device emissions are 

generated from the furnace and 8 percent of the furnace control device emissions are generated

 

10 EPA Technology Transfer Network, Clean Air Technology Center, General Information on CATC Products, 

http://www.epa.gov/ttncatc1/products.html
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Table 5-1. Assumed Control Device Efficiencies used to Estimate Furnace Fugitive Emissions

Pollutant(s) Scrubber Control 

Efficiency (%)

Fabric Filter 

Control 

Efficiency (%)

Particulate Matter 90 98

Metal HAP 90 98

Hexavalent Chromium 90 98

Mercury 15 15

Hydrochloric Acid/Hydrofluoric Acid 90 0

Formaldehyde 90 0

PAH, PCB, CDD/CDF 50 50

Table 5-2. Assumed Baseline Capture Efficiencies used to 

Estimate Process Fugitive Emissions

Pollutant(s)

Assumed Fugitive 

Capture 

Efficiency (%)

Eramet

Furnace 1 and 12 Smelting 98

Furnace 1 Tapping 20

Furnace 12 Tapping 30

MOR Process 40

Furnace 1 and 12 Casting 0

MOR Casting 40

Crushing and Sizing 95

Felman

Furnace 2, 5, & 7 Smelting 98

Furnace 2, 5, & 7 Tapping 70

Furnace 2, 5, & 7 Casting 40

Crushing and Sizing 85
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during tapping of the furnace. These assumptions are based on engineering judgment of the furnace 

operations and the tapping fugitive capture systems. The equation used to estimate fugitive PM 

emissions from the furnace smelting process is shown below;

 [( ) (

 

 ) (

 

 

)] [( ) (

 

 ) ]

where;

PMsmelt = Estimated fugitive PM emissions from the furnace in tons per year,

PMout = Control device outlet PM emissions in tons per year,

CE = Control efficiency of the furnace control device,

0.92 = Percentage of uncontrolled emissions generated from the furnace, and

Captsmelt = Estimated capture efficiency of the furnace smelting operations.

Other furnace smelting fugitive HAP pollutants from the furnace smelting operation were 

calculated by multiplying the calculated PM furnace smelting fugitive emissions value by the HAP 

pollutant-to-PM ratio for the associated furnace. The HAP pollutants that were estimated from the 

furnace smelting process include; metal HAP (e.g., Mn, As, Cd, Cr, Ni, Pb), Cr+6, HCl, HF, 

formaldehyde, PAH, CDD/CDF, and PCB. The equation for estimating these fugitive HAP 

pollutants from the furnace smelting process is shown below;

 (

 

 

)

where;

HAPsmelt = Estimated fugitive HAP emissions from furnace smelting in tons per year,

PMsmelt = Estimated fugitive PM emissions from furnace smelting in tons per year,

HAPout = Reported outlet HAP emissions from the associated furnace in tons per year, and

PMout = Reported outlet PM emissions from the associated furnace in tons per year.

This approach was used to calculate metal HAP (e.g., Mn, As, Cd, Cr, Ni, Pb), Cr+6, HCl, HF, 

formaldehyde, PAH, CDD/CDF, and PCB fugitive emissions from the furnace smelting operation 

for each of the furnaces at Eramet and Felman. 

The fugitive emissions for mercury were calculated using a different methodology because of the 

large difference in control efficiency between PM and mercury. As shown in Table 5-1, the control 

efficiency for PM using a fabric filter is 98 percent (90 percent with a scrubber), whereas the 

control efficiency for mercury using either the fabric filter or scrubber is 15 percent. The lower 

control efficiency for mercury is based on the assumption that 80 percent of the total mercury 

emissions from the furnace smelting process are gaseous elemental mercury and 20 percent are 
DRAFT FOR INTERNAL REVIEW

16

gaseous mercuric chloride.11 The furnace control devices can effectively control particulate 

mercury (e.g., mercuric chloride) from the exhaust stream, but little or no control of gaseous 

elemental mercury emissions or gaseous mercuric chloride. 

Therefore, to account for the difference in control efficiency, an equation using the different control 

efficiencies for PM and mercury were substituted into the equation for calculating HAP fugitive 

emissions from smelting process above. The equation used to estimate fugitive mercury emissions 

from the furnace smelting process is provided below;

 

( )

( )

 (

 

 

)

where;

CEPM = Control efficiency of PM for the control device (98%),

CEHg = Control efficiency of mercury for the control device (15%),

Hgsmelt = Estimated fugitive mercury emissions from furnace smelting in tons per year,

PMsmelt = Estimated fugitive PM emissions from furnace smelting in tons per year,

Hgout = Reported outlet HAP emissions from the associated furnace in tons per year, and

PMout = Reported outlet PM emissions from the associated furnace in tons per year.

5.3 Furnace Tapping Fugitive Emissions

The furnaces at these facilities are typically tapped several times per day from the lower section of 

the furnace. This process results in significant fugitive emissions. The percent capture of tapping 

fugitive emissions varies significantly across furnaces. As shown in table 5-2, we estimate that the 

range is about 20% to 70% capture. This variability relates to the design of the tapping system 

(e.g., use of cascading tapping ladles vs. single ladles), tapping hood design and capacity of the air 

handling system. 

We evaluated available emissions factors (EFs) that could be used to estimate these emissions. We 

did not identify reliable factors that were specific to this industry. However, we found EFs from the 

steel industry, from a similar process, that we believe are appropriate to use to estimate emissions 

for tapping from Ferroalloys furnaces. After searching for, and reviewing, available emissions 

factors, we determined that AP-42 EF for Basic Oxygen Furnace (BOF) tapping were the best 

available EFs to use. Therefore, the furnace tapping fugitive PM emissions for the Eramet and 

Felman facilities were estimated using an AP-42 emission factor (EF) for Basic Oxygen Furnace 

(BOF) tapping12. The AP-42 documentation for BOF tapping fugitives lists two types of EFs 

 

11 EPA, Technology Transfer Network Clearinghouse for Inventories & Emissions Factors Speciate Version 4.3, 

September 2011.

12 AP-42, Compilation of Air Pollutant Emission Factors, Chapter 12.5 Iron and Steel Production, October 1986. 

http://www.epa.gov/ttn/chief/ap42/ch12/final/c12s05.pdf (see Table 12.5-1)
DRAFT FOR INTERNAL REVIEW

17

available to estimate these emissions; one measured at the source (which is 0.92 pound PM per ton 

of product) and one measured at the building monitor (which is 0.29 pound PM per ton of product). 

After reviewing these EFs, we determined that the BOF tapping building monitor EF was not based 

on measurements at the building monitor, but on measurements taken in the primary hood using an 

in-stack filter. The EF incorporates a capture efficiency of 93 percent which was assumed to 

estimate the building monitor EF. The BOF tapping at source EF was conducted in the hood duct 

leading to the wet scrubber. Based on this information, the BOF tapping at source EF was 

determined to be more appropriate and was chosen to estimate the fugitive emissions from tapping 

from the ferroalloy furnaces.

As mentioned above, the EF for BOF tapping at source is listed as 0.92 pound of PM per ton of 

product produced (lb/Ton). However, after reviewing the source of the EF, it was determined that 

the test data used to determine the EF was based on an estimated capture of 70% of the total 

emissions (with 30 percent escaping to the building). Therefore, to estimate the total PM emissions 

from BOF tapping, the EF of 0.92 lb/Ton was divided by 70 percent to obtain the total PM EF of 

1.3 lb/Ton. This EF and the following equation were used to estimate fugitive PM emissions from 

tapping of the furnaces at Eramet and Felman.

 ( ) ( ) 

where;

PMtap = Estimated fugitive PM emissions from tapping in tons per year,

1.3 = PM fugitive EF for BOF tapping in pounds per ton of steel produced,

P = Reported production of product for the associated furnace in tons per hour, and

Capttap = Estimated capture efficiency of the furnace tapping operations (see Table 5-2),

8760 = Hours of operation per year,

2000 = Pounds per ton.

The emissions of metal HAP (e.g., Mn, As, Cd, Cr, Ni, and Pb), Cr+6, HCl, and HF from the furnace 

tapping process were estimated using the HAP-to-PM ratio from the respective furnace outlet 

emissions. The equation for estimating these fugitive HAP emissions is provided below;

 (

 

 

)

where;

HAPtap = Estimated fugitive HAP (e.g., Mn, Ni, Pb, As) emissions from tapping in tons per year,

PMtap = Estimated fugitive PM emissions from tapping in tons per year,
DRAFT FOR INTERNAL REVIEW

18

HAPout = Reported outlet HAP (e.g., Mn, Ni, Pb, As) emissions from the associated furnace in tons 

per year, and

PMout = Reported outlet PM emissions from the associated furnace in tons per year.

The majority of Hg, PCB, PAH, CDD/CDF and formaldehyde emissions are assumed to come from 

the furnace smelting operation, due to the volatility of these HAP and the heat generated in the 

smelting process. The emissions test results from the Furnace 1 tapping baghouse compared to the 

test results from the primary furnace 1 stack confirms that this is the case. For example, the 

measured mercury emissions were about 15,000 times higher from the furnace 1 primary baghouse 

compared to the tapping baghouse. This shows that the vast majority of mercury emissions are 

emitted through the stacks and not as fugitives. However, emissions of these HAP were measured 

in the Furnace 1 tapping baghouse at Eramet (emissions were not zero), and therefore are assumed 

to be emitted to some degree as fugitives during the furnace tapping process. To estimate these 

fugitive emissions, an EF was developed using the available test data from the Furnace 1 tapping 

baghouse for each of these pollutants. For mercury, the EF was developed using the PM and Hg 

emission result from the Furnace 1 tapping baghouse at Eramet and the tapping PM EF used to 

calculate the fugitive PM emissions from tapping. The equation for calculating the Hg EF is as 

follows;

 ( ) (

 

 )

where;

FeMn EFHg tap = Hg fugitive EF from furnace tapping in pounds per ton of FeMn produced,

1.3 = PM fugitive EF for BOF tapping in pounds per ton of steel produced,

0.0000526 = Reported outlet Hg emissions from the Furnace 1 tapping baghouse in tons per year, 

and

2.34 = Reported outlet PM emissions from the Furnace 1 tapping baghouse in tons per year.

This calculation provides an Hg tapping fugitive EF of 2.91 x 10-5pounds per ton of FeMn

produced. The Hg emission rate was calculated using 2013 test data from the Furnace 1 tapping 

baghouse and the PM emissions rate was calculated using 2011, 201213 and 201314 test data from 

the Furnace 1 tapping baghouse. The reported test results are based on the production of FeMn, 

which produces higher Hg emissions rates in comparison to SiMn production. Because there was 

no Hg test data from the Furnace 1 tapping baghouse during SiMn production, an Hg EF was 

developed for SiMn production using the calculated FeMn Hg emissions factor and applying a ratio 

 

13 Memorandum from Bradley Nelson, EC/R to Conrad Chin, EPA/OAQPS/SPPD/MMG, Ferroalloys 2012 Test Report 

Review, May 28, 2013.

14 Memorandum from Bradley Nelson, EC/R to Conrad Chin, EPA/OAQPS/SPPD/MMG, Ferroalloys 2013 Test Report 

Review, July 29, 2013.
DRAFT FOR INTERNAL REVIEW

19

of the Furnace 1 baghouse outlet Hg emissions for SiMn and FeMn production. The equation for 

calculating the Hg EF for SiMn production is as follows;

 ( ) (

 

 )

where;

SiMn EFHg tap = Hg fugitive EF from furnace tapping in pounds per ton of SiMn produced,

2.91 x 10-5= Hg fugitive EF from furnace tapping in pounds per ton of FeMn produced,

0.00678 = Reported outlet Hg emissions from the Furnace 1 baghouse outlet during SiMn 

production in pounds per year, and

0.0288 = Reported outlet Hg emissions from the Furnace 1 baghouse outlet during FeMn 

production in pounds per year.

This calculation provides an Hg tapping fugitive EF of 6.85 x 10-6pounds per ton of SiMn 

produced. The SiMn Hg EF was used to estimate Hg fugitive emissions from the tapping process 

for Furnaces 2, 5, and 7 at Felman, which produce only SiMn. This factor may overestimate the 

mercury emissions from Felman, because Felman uses a lower mercury content manganese ore in 

comparison to the manganese ore used by Eramet. However, since there is no specific test data 

from the tapping process at Felman, it is believed that this SiMn Hg emissions factor will provide a 

conservative estimate of fugitive Hg emissions from tapping. For Eramet, an average of the FeMn 

and the SiMn Hg EFs (1.80 x 10-5pounds per ton of FeMn/SiMn produced) was used to estimate 

Hg fugitive emissions from the tapping process. An average was used because of the assumption 

(as described in Section 5.1) of 50 percent annual SiMn production and 50 percent annual FeMn 

production for both Furnaces 1 and 12 at Eramet. These EFs and the following equation were used 

to estimate fugitive Hg emissions from tapping of the furnaces at Eramet and Felman.

 ( ) ( ) 

where;

Hgtap = Estimated fugitive Hg emissions from tapping in tons per year,

EFHg tap = Hg fugitive EF for tapping in pounds per ton of product (SiMn or SiMn/FeMn),

P = Reported production of product for the associated furnace in tons per hour, and

Capttap = Estimated capture efficiency of the furnace tapping operations,

8760 = Hours of operation per year,

2000 = Pounds per ton. 

The estimated capture efficiency of the tapping operations for each of the furnaces are provided in 

Table 5-2.
DRAFT FOR INTERNAL REVIEW

20

The PCB, PAH, CDD/CDF and formaldehyde fugitive emissions from the tapping process were 

calculated using the same methodology used to estimate fugitive Hg emissions. An EF was 

developed for each of the organic HAP compounds using the test data from the Furnace 1 tapping 

baghouse. It was assumed for this analysis that there is no variation of fugitive organic HAP 

fugitive emissions based on product (e.g., SiMn or FeMn production). As an example, the equation 

for calculating the naphthalene EF is as follows;

 ( ) (

 

 )

where;

EFNaphthalene tap = Naphthalene fugitive EF from furnace tapping in pounds per ton of FeMn or SiMn 

produced,

1.3 = PM fugitive EF for BOF tapping in pounds per ton of steel produced,

1.34 x 10-2= Reported outlet naphthalene emissions from the Furnace 1 tapping baghouse in tons 

per year, and

2.34 = Reported outlet PM emissions from the Furnace 1 tapping baghouse in tons per year.

This calculation provides a naphthalene tapping fugitive EF of 7.42 x 10-3pounds per ton of FeMn 

or SiMn produced. This methodology was used to estimate the fugitive organic HAP emissions 

factor for each of the organic HAP compounds. A table of the organic HAP fugitive EFs for the 

tapping process is provided in Table 5-3. These EFs and the following equation were used to 

estimate fugitive organic HAP emissions from tapping of the furnaces at Eramet and Felman. An 

example of the naphthalene fugitive emission calculation is provided below;

 ( ) ( ) 

where;

Naphthalenetap = Estimated fugitive naphthalene emissions from tapping in tons per year,

EFNaphthalene tap = Naphthalene fugitive EF for tapping in pounds per ton of product (SiMn or 

SiMn/FeMn),

P = Reported production of product for the associated furnace in tons per hour, and

Capttap = Estimated capture efficiency of the furnace tapping operations,

8760 = Hours of operation per year,

2000 = Pounds per ton.

The estimated capture efficiencies of the tapping operations for each furnace are provided in Table 

5-2.
DRAFT FOR INTERNAL REVIEW

21

5.4 Casting/MOR Fugitive Emissions

We also evaluated available emissions factors that could be used to estimate casting and MOR 

fugitive emissions. We identified one EF for casting specific to this industry from Ohio EPA of 2.4 

lb/ton. However, we could not find any documentation to support this emissions factor, so we 

determined it was not appropriate to use it. We did not find any other EFs specific to this industry. 

However, we did identify EFs from the Steel industry from AP-42 for a similar source known as hot 

metal transfer.

15

 Similar to the tapping EFs, we identified two EFs (one “at the monitor” and one 

“at the source”). The “hot metal transfer at monitor” EF is 0.056 lb/ton and the EF for the “hot 

metal transfer at source” is 0.19 lb/ton. However, we evaluated these EFs further and concluded 

there was no actual test at the “monitor”. Furthermore the 0.056 lb/ton test assumed 100% capture 

(the test was conducted using an in-stack filter). Therefore, we determined it was not appropriate to 

use the “at monitor” EF. The only remaining available EF that seemed valid was the 0.19 lb/ton 

EF. Thus, after searching for, and reviewing available emissions factors, we concluded the best 

available EF to use to estimate these emissions was the 0.19 lb/ton EF.

The MOR process involves the top lance injection of oxygen to reduce the carbon content and 

increase the manganese content of the molten FeMn product. The majority of the fugitive 

emissions from this process occur during the transfer of the molten metal from the tapping vessel to 

the MOR vessel, and during the waiting period for the MOR vessel to become free. Other fugitive 

emissions from this source occur during the injection of oxygen. However this process is well 

controlled and is not expected to be a significant source of fugitive emissions. Since the majority of 

fugitive emissions from MOR occur during pouring and waiting, it was assumed that the ‘hot metal 

transfer at source” EF of 0.19 lb/ton would be appropriate for estimating fugitive emission from the 

MOR.

Therefore, particulate matter emissions from casting and the MOR process were estimated using an 

AP-42 PM EF for hot metal transfer (at source) of 0.19 pounds of fugitive PM emissions per ton of 

hot metal. This EF was used to estimate the fugitive PM emissions from casting and MOR 

operations. This EF and the following equation were used to estimate fugitive PM emissions from 

product casting at Eramet and Felman and the MOR process at Eramet.

 ( ) ( ) 

where;

PMcast = Estimated fugitive PM emissions from casting in tons per year,

0.19 = PM EF for hot metal transfer in pounds per ton of steel produced,

P = Reported production of product for the associated furnace in tons per hour, and

 

15 AP-42, Compilation of Air Pollutant Emission Factors, Chapter 12.5 Iron and Steel Production, October 1986. 

http://www.epa.gov/ttn/chief/ap42/ch12/final/c12s05.pdf (see Table 12.5-1)
DRAFT FOR INTERNAL REVIEW

22

Captcast = Estimated capture efficiency of the casting/MOR operations,

8760 = Hours of operation per year,

2000 = Pounds per ton.

The casting/MOR fugitive emissions for metal HAP (e.g., Mn, As, Cd, Cr, Ni, Pb), Cr+6, HCl, and 

HF were estimated using the HAP-to-PM profile based on furnace emissions of each of the 

pollutants and multiplying that profile by the estimated casting fugitive PM emission rate. The 

equation used to estimate these HAP emissions is shown below; 

 (

 

 

)

where;

HAPcast = Estimated HAP emissions from casting/MOR in tons per year,

PMcast = Estimated PM emissions from casting/MOR in tons per year,

HAPout = HAP emissions from the associated EAF in tons per year, and

PMout = PM emissions from the associated EAF in tons per year.

Fugitive emissions of mercury from the casting process were calculated using the Hg tapping EFs 

and a ratio of the tapping and casting fugitive PM EFs. The equation for calculating the Hg EF for 

SiMn production and FeMn/SiMn production is as follows;

 ( ) (

 

 

)

where;

SiMn EFHg cast = Hg fugitive EF from casting in pounds per ton of SiMn produced,

6.85 x 10-6= Hg fugitive EF for tapping in pounds per ton of SiMn produced,

0.19 = PM EF for hot metal transfer in pounds per ton of steel produced,

1.3 = PM fugitive EF for BOF tapping in pounds per ton of steel produced.
DRAFT FOR INTERNAL REVIEW

23

Table 5-3. Summary of Organic HAP Fugitive Emission Factors for Tapping and Casting at 

Ferroalloys Production Facilities

Organic HAP Pollutant

Furnace 1 Tapping 

Baghouse Emissions 

(Tons/yr) Tapping EF (lb/Ton) Casting EF (lb/Ton)

Naphthalene 1.34E-02 7.42E-03 1.08E-03

2-Methylnaphthalene 8.11E-03 4.50E-03 6.57E-04

Acenaphthylene 6.55E-03 3.63E-03 5.31E-04

Acenaphthene 3.18E-03 1.76E-03 2.58E-04

Fluorene 3.66E-03 2.03E-03 2.96E-04

Phenanthrene 1.24E-02 6.88E-03 1.01E-03

Anthracene 2.44E-03 1.36E-03 1.98E-04

Fluoranthene 2.42E-03 1.34E-03 1.96E-04

Pyrene 1.87E-03 1.03E-03 1.51E-04

Benzo(a)anthracene 2.01E-04 1.12E-04 1.63E-05

Chrysene 3.42E-04 1.89E-04 2.77E-05

Benzo(b)fluoranthene 1.66E-04 9.23E-05 1.35E-05

Benzo(k)fluoranthene 8.32E-05 4.61E-05 6.74E-06

Benzo(e)pyrene 2.19E-04 1.21E-04 1.77E-05

Benzo(a)pyrene 6.13E-05 3.40E-05 4.97E-06

Perylene 8.76E-06 4.86E-06 7.10E-07

Indeno(1,2,3-cd)pyrene 3.94E-05 2.19E-05 3.19E-06

Dibenz(a,h)anthracene 1.31E-05 7.29E-06 1.06E-06

Benzo(g,h,i)perylene 9.20E-05 5.10E-05 7.45E-06

Formaldehyde 3.81E-02 2.11E-02 3.09E-03

2,3,7,8-Tetrachlorodibenzo-p-dioxin 6.18E-10 3.42E-10 Not measured

1,2,3,7,8-Pentachlorodibenzo-dioxin 8.45E-10 4.69E-10 Not measured

1,2,3,4,7,8-Hexachlorodibenzo-p-dioxin 5.74E-10 3.18E-10 Not measured

1,2,3,6,7,8-Hexachlorodibenzo-p-dioxin 5.56E-10 3.08E-10 Not measured

1,2,3,7,8,9-Hexachlorodibenzo-p-dioxin 5.65E-10 3.13E-10 Not measured

1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin 1.05E-09 5.83E-10 Not measured

1,2,3,4,6,7,8,9-Octochlorodibenzo-p-dioxin 8.72E-09 4.83E-09 Not measured

2,3,7,8-Tetrachlorodibenzofuran 9.02E-10 5.00E-10 Not measured

1,2,3,7,8-Pentachlorodibenzofuran 6.79E-10 3.76E-10 Not measured

2,3,4,7,8-Pentachlorodibenzofuran 1.07E-09 5.95E-10 Not measured

1,2,3,4,7,8-Hexachlorodibenzofuran 6.75E-10 3.74E-10 Not measured

1,2,3,6,7,8-Hexachlorodibenzofuran 5.21E-10 2.89E-10 Not measured

2,3,4,6,7,8-Hexachlorodibenzofuran 7.84E-10 4.35E-10 Not measured

1,2,3,7,8,9-Hexachlorodibenzofuran 6.18E-10 3.42E-10 Not measured

1,2,3,4,6,7,8-Heptachlorodibenzofuran 1.53E-09 8.50E-10 Not measured

1,2,3,4,7,8,9-Heptachlorodibenzofuran 5.74E-10 3.18E-10 Not measured

1,2,3,4,6,7,8,9-Octochlorodibenzofuran 1.54E-09 8.52E-10 Not measured

Polychlorinated biphenyls 2.14E-07 1.19E-07 Not measured

Particulate Matter 2.345 ---- ----
DRAFT FOR INTERNAL REVIEW

24

The result of this calculation gives an Hg casting fugitive EF of 1.00 x 10-6pounds per ton of SiMn 

produced. The same methodology and equation were used with the average FeMn/SiMn Hg EF

derived in Section 5.3 to calculate the FeMn/SiMn Hg EF which results in an Hg casting fugitive 

EF of 2.63 x 10-6pounds per ton of FeMn/SiMn produced. These EFs were then used to estimate 

fugitive Hg emissions from casting from the furnaces at Eramet and Felman using the equation 

below;

 ( ) ( ) 

where;

Hgcast = Estimated fugitive Hg emissions from casting in tons per year,

EFHg cast = Hg fugitive EF for casting in pounds per ton of product (SiMn or SiMn/FeMn),

P = Reported production of product for the associated furnace in tons per hour, and

Captcast = Estimated capture efficiency of the furnace casting operations (see table 5-2),

8760 = Hours of operation per year,

2000 = Pounds per ton. 

The estimated capture efficiency of the casting operations for each of the furnaces are provided in 

Table 5-2.

For casting, it was assumed that the fugitive emissions of PCB and CDD/CDF occur during the 

tapping process, but do not occur during the casting process because these HAPs are products of 

incomplete combustion and no combustion occurs outside of the furnace. Therefore, only fugitive 

emissions of PAH and formaldehyde were estimated for casting. The PAH and formaldehyde 

fugitive emissions from casting were calculated using the same methodology used to estimate 

fugitive Hg emissions. An EF was developed for each of the organic HAP compounds using the 

tapping EF and the ratio of the tapping and casting fugitive PM EFs. Again, no distinction was 

made between SiMn or FeMn production. As an example, the equation for calculating the 

naphthalene EF is as follows;

 ( ) (

 

 

)

where;

EFNaphthalene cast = Naphthalene fugitive EF from furnace casting in pounds per ton produced,

7.42 x 10-3= Naphthalene fugitive EF for BOF tapping in pounds per ton of steel produced,

0.19 = PM EF for hot metal transfer in pounds per ton of steel produced,

1.3 = PM fugitive EF for BOF tapping in pounds per ton of steel produced.
DRAFT FOR INTERNAL REVIEW

25

This calculation provides a naphthalene casting fugitive EF of 1.08 x 10-3pounds per ton of FeMn 

or SiMn produced. This methodology was used to estimate the fugitive PAH and formaldehyde

emissions factor for each of the compounds. Table 5-3 lists the organic HAP fugitive EFs for the 

tapping process. These EFs and the following equation were used to estimate fugitive PAH and 

formaldehyde emissions from tapping of the furnaces at Eramet and Felman. An example of the 

naphthalene fugitive emission calculation is provided below;

 ( ) ( ) 

where;

Naphthalenecast = Estimated fugitive naphthalene emissions from casting in tons per year,

EFNaphthalene cast = Naphthalene fugitive EF for casting in pounds per ton of product (SiMn or 

SiMn/FeMn),

P = Reported production of product for the associated furnace in tons per hour, and

Captcast = Estimated capture efficiency of the furnace casting operations (see table 5-2),

8760 = Hours of operation per year,

2000 = Pounds per ton.

The estimated capture efficiencies of the casting operations for each of the furnaces are provided in 

Table 5-2.

5.5 Product Crushing Operations Emissions

The product crushing emissions were calculated using the test data provided in the test reports 

submitted by the facilities. The product crushing and sizing operation at Eramet is controlled by 

three baghouses. The facility provided test data for one of the baghouses, and the other two 

baghouses were assumed to have the same emissions. Felman listed two product crushing and 

sizing units in their ICR, but noted that only one of the systems is operated. 

The hourly emissions reported in the test report were multiplied by the annual hours of operation to 

estimate the annual emission from the product crusher. In the case of Eramet, the product crushing 

and sizing system is limited to 5840 hours per year by permit. Therefore, 5840 hours per year was 

used to calculate annual emissions from the Eramet crushing and sizing system. For Felman, the 

crushing and sizing system was estimated to operate 6240 hours per year. These hours of operation 

were provided by the facilities in their estimates of baseline emissions.16,17

 

16 QSEM Solutions, Inc., Eramet Marietta Inc. Technical Comments to Alternative Approach to NESHAP Subpart 

XXX Compliance - November 23, 2011 Proposed Rule, June 29, 2012.

17 Email from Amy M Lincoln, Beveridge & Diamond, P.C. to Conrad Chin, EPA, RE: Felman Fugitive Emissions 

Control and Test Protocols, 8/06/2012.
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26

5.6 Product Crushing Operations Fugitive Emissions

The annual fugitive emissions from the product crushing operations were estimated by using the 

AP-42 EFs for Metallic Minerals Processing.18 The facilities provided information on the number 

of emission sources of fugitive emissions from the product and sizing process. These emission 

sources were classified into the following EF groups; primary crushing, secondary crushing and 

material handling and transfer. The filterable PM-10 EFs were used from each of the classifications 

because these are the respirable portion of PM emissions from the crushing and sizing operation. 

The EFs for primary crushing, secondary crushing, and material handling and transfer are 0.05, 

0.12, and 0.06 pounds per ton processed respectively. The PM-10 EF for secondary crushing was 

listed as non-detect, however the PM-10 EF was estimated by reducing the PM EF for secondary 

crushing by a factor of 10. This is the same factor of reduction that is shown for primary crushing. 

The fugitive emissions were calculated by totaling the number of each crushing and sizing 

operation and multiplying that by the emissions factor, capture efficiency, and the crushing and 

sizing production rate as shown in the equation below:

 [∑ ( ) ( )] 

where;

EFCSPM = Estimated fugitive emissions from crushing and sizing in tons per year,

ƩCS = Number of crushing, screening, conveyor, or material handling emission points,

EFCS = Crushing, screening, conveyor, or material handling EF in pounds per ton,

PEAF = Crushing and sizing production rate in tons per hour,

CAPCS = Assumed capture efficiency for the crushing and sizing operations (95%),

H = number of hours of operation during the year, and

2000 pounds per ton.

The sum of the emissions from the PM fugitive crushing, screening, conveyor, and material 

handling emission points provides the crushing and sizing fugitive emissions. Metal HAP fugitive 

emissions were calculated using the metal HAP-to-PM ratios from the crushing baghouse emissions 

data and multiplying that ratio by the calculated fugitive PM emissions for the crushing and sizing 

fugitives as shown in the equation below. The number of operating hours per year is based on the 

normal annual operating hours or is limited to the number of hours by permit. 

 

 [( ) (

 

 

)]

where;

 

18 AP-42, Compilation of Air Pollutant Emission Factors, Chapter 11.24 Metallic Mineral Processing, August 1982. 

http://www.epa.gov/ttn/chief/ap42/ch11/final/c11s24.pdf (see Table 11.24-2)
DRAFT FOR INTERNAL REVIEW

27

HAPCS = Estimated fugitive HAP emissions from crushing and sizing in tons per year,

PMCS = Estimated fugitive PM emissions from crushing and sizing in tons per year,

HAPCSout = Calculated HAP emissions from crushing and sizing baghouse outlet, and

PMCSout = Calculated PM emissions from crushing and sizing baghouse outlet.

5.7 Baseline Annual HAP Emissions for the Ferroalloy Production Facilities

The baseline annual HAP emissions were calculated for each of the previously described emission 

points and are summarized in Table 5-4. The test data from Eramet Furnace 1 and 12 smelting

baghouse outlets and the Furnace 1 tapping baghouse outlet provided HAP emission results for both 

production of FeMn and SiMn. To estimate the annual HAP emissions for these emission sources, 

it was assumed that both Furnaces 1 and 12 produce FeMn 4,380 hours of the year and SiMn is 

produced 4,380 hours of the year (see section 5.1). The furnaces at Felman Production produce only 

SiMn, and thus no such adjustments to the annual emissions were necessary. As shown in Table 5-

4, fugitive emissions were estimated to be 82 percent of the total HAP emissions from Eramet and 

73 percent of the total HAP emissions from Felman.

5.8 Enhanced Capture Annual HAP Emissions for the Ferroalloy Production Facilities

For purposes of the supplemental analysis, we developed an enhanced capture control option to 

evaluate residual risk. The enhanced capture annual HAP emissions were calculated assuming 95 

percent of fugitive HAP emissions would be captured by the enhanced capture system. Some of the 

fugitive emission sources were assumed to only use primary capture to achieve 95 percent capture. 

Other fugitive emission sources were assumed to use both primary and secondary capture to 

achieve a total of 95 percent capture of fugitive emissions. Captured fugitive HAP emissions from 

the enhanced primary capture system were routed to the assumed source control device and reduced 

using the control efficiencies listed in Table 5-1. Secondary fugitive HAP emissions were assumed 

to be routed to a new control device and reduced by the control efficiency values listed in Table 5-1. 

A summary of the assumptions and calculations are provided for each of the facilities below. A 

schematic of the enhanced capture system is provided in Figure 5-1.
DRAFT FOR INTERNAL REVIEW

28

Table 5-4. Summary of the Baseline Facility Process Annual HAP Emissions (Tons/year) for the 

Ferroalloy Production Industry

Unit Description

Arsenic Cadmium

Chromium 

(III)

Chromium 

(VI) Lead Manganese Mercury Nickel

Hydrogen 

Chloride Total PAH

FormaldehydeTotal 

CDD/CDF Total PCBs Total HAP

Eramet Marietta

Furnace #1 Baghouse Outlet 0.000399 0.00231 0.000714 0.000206 0.0222 1.33 0.0780 0.00316 0.661 2.75 0.338 3.35E-08 5.20E-07 5.18

Furnace #1 Fugitives 0.000374 0.00217 0.000670 0.000194 0.0208 1.25 0.0017 0.00296 0.620 2.58 0.317 3.14E-08 4.88E-07 4.79

Furnace #1 Tapping Baghouse 0.000105 0.0000482 0.000866 0.0000668 0.0108 0.325 0.0000526 0.00125 0.180 0.0553 0.0381 2.18E-08 2.14E-07 0.611

Furnace #1 Tapping Fugitives 0.00326 0.0189 0.00584 0.00169 0.181 24.3 0.0008 0.0259 5.41 1.4 0.96 5.51E-07 5.40E-06 32.3

Furnace #12 Scrubber Outlet 0.00353 0.0283 0.00158 0.00120 0.106 6.88 0.085 0.00234 0.545 0.560 0.145 8.48E-08 3.63E-07 8.35

Furnace #12 Fugitives 0.000662 0.00531 0.000297 0.000225 0.0198 1.29 0.00189 0.000439 0.102 0.105 0.0272 1.59E-08 6.81E-08 1.55

Furnace #12 Tapping Fugitives 0.00417 0.0335 0.00187 0.00142 0.125 20.4 0.0007 0.00277 0.645 1.221 0.842 4.82E-07 4.73E-06 23.3

MOR Process Baghouse Outlet 0.00110 0.00193 0.00426 0.0000821 0.000933 0.982 0.00212 0.00147 0.0373 0.0383 0.00990 NM NM 1.08

MOR Process Fugitives 0.00486 0.00856 0.0188 0.000363 0.00413 5.22 0.000176 0.00649 0.165 0.300 0.2070 NM NM 5.94

Furnace #1 Casting 0.000596 0.00346 0.00107 0.000308 0.0331 4.44 0.00015 0.00472 0.988 0.25 0.176 NM NM 5.90

Furnace #12 Casting 0.000871 0.00699 0.000391 0.000297 0.0261 4.27 0.00014 0.000577 0.135 0.245 0.1691 NM NM 4.85

MOR casting 0.00486 0.00856 0.0188 0.000363 0.00413 5.22 0.000176 0.00649 0.165 0.300 0.2070 NM NM 5.94

C2P Crushing/Sizing Baghouse #1 0.000133 NM 0.00130 0.000103 0.000141 1.49 NM 0.00151 NM NM NM NM NM 1.49

C2P Crushing/Sizing Baghouse #2 0.000133 NM 0.00130 0.000103 0.000141 1.49 NM 0.00151 NM NM NM NM NM 1.49

C2P Crushing/Sizing Baghouse #3 0.000133 NM 0.00130 0.000103 0.000141 1.49 NM 0.00151 NM NM NM NM NM 1.49

C2P crushing and sizing fugitives 0.000567 NM 0.00555 0.000442 0.000603 6.35 NM 0.00646 NM NM NM NM NM 6.37

Fugitive Emissions Total 0.0202 0.0875 0.0534 0.00530 0.415 72.7 0.00576 0.0568 8.23 6.40 2.91 1.08E-06 1.07E-05 90.9

Eramet Marietta Total 0.0258 0.120 0.0647 0.00717 0.555 86.7 0.171 0.0695 9.65 9.81 3.44 1.22E-06 1.18E-05 111

Felman Production

Furnace No. 2 Baghouse Outlet 0.00277 0.000311 0.00564 0.00155 0.180 1.25 0.01035 0.0793 3.48 0.342 0.331 4.12E-07 3.53E-05 5.69

Furnace No. 2 Fugitives 0.00260 0.000292 0.00530 0.00146 0.169 1.17 0.000228 0.0745 3.27 0.321 0.311 3.87E-07 3.31E-05 5.33

Furnace No. 2 Tapping Fugitives 0.00329 0.000369 0.00670 0.00184 0.214 3.97 0.000091 0.0942 4.14 0.407 0.281 1.61E-07 1.57E-06 9.11

Furnace No. 5 Baghouse Outlet 0.000710 0.000175 0.0089 0.00141 0.0173 0.761 0.00219 0.00461 0.351 0.321 0.309 6.41E-07 4.85E-05 1.78

Furnace No. 5 Fugitives 0.000666 0.000164 0.00833 0.00132 0.0163 0.714 0.0000484 0.00433 0.330 0.302 0.290 6.02E-07 4.55E-05 1.67

Furnace No. 5 Tapping Fugitives 0.000459 0.000113 0.00574 0.000913 0.0112 1.96 0.0000450 0.00298 0.227 0.201 0.139 7.95E-08 7.79E-07 2.55

Furnace No. 7 Baghouse Outlet 0.00117 0.000288 0.0146 0.00232 0.0285 2.44 0.00446 0.00759 0.857 0.269 0.611 6.41E-07 4.85E-05 4.24

Furnace No. 7 Fugitives 0.00110 0.000271 0.0137 0.00218 0.0268 2.29 0.000098 0.00713 0.804 0.253 0.573 6.02E-07 4.55E-05 3.97

Furnace No. 7 Tapping Fugitives 0.000459 0.000113 0.00574 0.000913 0.0112 1.96 0.0000450 0.00298 0.337 0.201 0.139 7.95E-08 7.79E-07 2.66

Furnace No. 2 Casting 0.000961 0.0001080 0.00196 0.000539 0.0625 1.160 0.0000266 0.0275 1.21 0.1188 0.0820 NM NM 2.66

Furnace No. 5 Casting 0.000134 0.0000331 0.00168 0.000267 0.00328 0.574 0.0000132 0.000872 0.0664 0.0588 0.0406 NM NM 0.746

Furnace No. 7 Casting 0.000134 0.0000331 0.00168 0.000267 0.00328 0.574 0.0000132 0.000872 0.0985 0.0588 0.0406 NM NM 0.778

Crushing/Screening System #1 0 NM 0 0 0 0 NM 0 NM NM NM NM NM 0.00

Crushing/Screening System #2 0 NM 0.000161 0.0000444 0.000463 0.210 NM 0 NM NM NM NM NM 0.211

Crushing/Screening #1 Fugitives 0 NM 0 0 0 0 NM 0 NM NM NM NM NM 0.00

Crushing/Screening #2 Fugitives 0 NM 0.00359 0.000988 0.0103 3.25 NM 0 NM NM NM NM NM 3.27

Fugitive Emissions Total 0.00980 0.00150 0.0544 0.0107 0.528 17.6 0.000609 0.215 10.5 1.92 1.90 1.91E-06 1.27E-04 32.8

Felman Production Total 0.0144 0.00227 0.0837 0.0160 0.754 22.3 0.0176 0.307 15.2 2.85 3.15 3.61E-06 2.60E-04 44.7
DRAFT FOR INTERNAL REVIEW

29

Eramet Marietta

The methodology for calculating the enhanced capture emissions from Eramet were based on the 

proposed fugitive emissions capture plan19 submitted by the facility. The submitted capture plan 

proposed increasing the primary capture of fugitive tapping emissions from the furnaces to 95 

percent, adding 95 percent primary capture to the casting beds for Furnaces 1 and 12, and adding 

primary and secondary capture to the MOR building to achieve a total capture of 95 percent from 

the MOR process and MOR casting. A mass balance approach was taken to calculate the enhanced 

capture emissions from many of the emission sources that are equipped with control devices. Even 

though, the baghouse or scrubber is a constant outlet device (e.g., the particulate matter 

concentration in the stack gas is constant), the volumetric flow rate to the control device will 

increase due to the addition of the enhanced capture fugitive streams, hence increasing the emission 

rate from the control device outlet. A description of the assumptions used to calculate the enhanced 

capture emissions from each of the emission sources is provided in the following sections. 

Furnace 1 and Associated Emission Sources

The enhanced capture emissions from the Furnace 1 tapping process were calculated assuming an 

increase of the primary capture of the fugitive emissions from the estimated 20 percent at baseline 

to 95 percent at the enhanced capture level. The captured emissions from tapping were assumed to 

be routed to the Furnace 1 baghouse, instead of the dedicated Furnace 1 tapping baghouse. The 

Furnace 1 baghouse was noted in the control plan to have extra capacity to control fugitive emission 

streams from both Furnace 1 tapping and casting. An example of the enhanced capture PM 

emissions calculation for Furnace 1 tapping fugitives is shown below:

 

 

( )

 ( )

where;

3.70 = Enhanced capture fugitive PM emissions from Furnace 1 tapping in tons per year,

59.2 = Baseline fugitive PM emissions from Furnace 1 tapping in tons per year,

20% = Baseline capture percent of Furnace 1 tapping emissions, and

95% = Enhance capture percent of Furnace 1 tapping emissions.

 

19 QSEM Solutions, Inc., Eramet Marietta Inc. Technical Comments to Alternative Approach to NESHAP Subpart 

XXX Compliance - November 23, 2011 Proposed Rule, June 29, 2012.
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30

Submerged Electric 

Arc Furnace

Tapping Fugitive

Emissions to Atmosphere

Fabric Filter

Exhaust 

to Atmosphere

Casting

Casting Bed

Furnace Smelting and 

Tapping Process Casting Process

Casting Primary 

Capture Hood

Casting Fugitive

Emissions to Atmosphere

Furnace Fugitive

Emissions to Atmosphere

Tapping Primary 

Capture Hood

Tapping
DRAFT FOR INTERNAL REVIEW

31

The enhanced capture casting fugitive emissions from Furnace 1 were also calculated using the 

same methodology above. The only exception is that there is currently no capture of fugitive 

emissions from Furnace 1 casting. The control plan submitted by Eramet proposed adding primary 

capture of 95 percent to the Furnace 1 casting area and routing the captured emissions to the 

Furnace 1 tapping baghouse, which in the proposed plan will only be used to control captured 

fugitive emissions for Furnace 1 casting. An example of the enhanced capture PM emissions 

calculation for Furnace 1 casting fugitive is shown below:

 ( )

where;

0.541 = Enhanced capture fugitive PM emissions from Furnace 1 casting in tons per year,

10.8 = Baseline fugitive PM emissions from Furnace 1 casting in tons per year, and

95% = Enhanced capture percent of Furnace 1 casting emissions.

No changes to the capture system for the Furnace 1 smelting operation were proposed in Eramet’s 

capture plan. The current system was assumed to achieve 98 percent capture of fugitive emission 

from the furnace operations, therefore the calculated fugitive emissions at the enhanced capture 

level are the same as the calculated fugitive emissions from baseline. There is an increase in the 

Furnace 1 baghouse outlet emissions in the enhanced capture scenario because the emissions from 

Furnace 1 tapping, and the Furnace 1 tapping baghouse are now routed to the Furnace 1 baghouse. 

The Furnace 1 tapping baghouse was assumed to control captured fugitive emissions from Furnace 

12 tapping and Furnace 12 casting in the enhanced capture scenario. The enhanced capture 

emission rate from the Furnace 1 baghouse outlet was calculated by adding the baseline emissions 

from the Furnace 1 baghouse and the Furnace 1 tapping baghouse with the difference of fugitive 

emissions from Furnace 1 tapping. An example of the PM emissions calculation is shown below:

 (59.2-3.70)*(1-98%)

where;

10.7 = Enhanced capture PM emissions from the Furnace 1 baghouse outlet in tons per year,

7.23 = Baseline PM emissions from the Furnace 1 baghouse outlet in tons per year,

2.34 = Baseline PM emissions from the Furnace 1 tapping baghouse in tons per year, 

59.2 = Baseline fugitive PM emissions from Furnace 1 tapping in tons per year,

3.7 = Enhanced capture fugitive PM emissions from Furnace 1 tapping in tons per year, and

98% = Assumed PM control efficiency of the Furnace 1 baghouse.
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32

Note that the control efficiency is only applied to the fugitive casting emissions. The PM emissions 

from the Furnace 1 baghouse and Furnace 1 tapping baghouse are already provided as controlled 

emissions. 

As noted in the calculation above, the outlet emissions from the Furnace 1 tapping baghouse were 

moved to the Furnace 1 baghouse in the enhanced capture scenario. This baghouse now controls 

captured fugitive emissions from Furnace 1 casting in the enhanced capture scenario. The enhanced 

capture emission rate from this baghouse was calculated by adding the difference of fugitive 

emissions from Furnace 1 casting. Again, a mass balance approach was taken by subtracting the 

difference in Furnace 1 casting emissions from baseline to enhanced capture. An example of the 

PM emissions calculation for the Furnace 1 tapping baghouse is shown below:

 (10.8-0.541)(1-98%)

where;

0.206 = Enhanced capture PM emissions from the Furnace 1 tapping baghouse outlet in tons per 

year,

10.8 = Baseline fugitive PM emissions from Furnace 1 casting in tons per year,

3.7 = Enhanced capture fugitive PM emissions from Furnace 1 casting in tons per year, and

98% = Assumed PM control efficiency of the Furnace 1 tapping baghouse.

Furnace 12 and Associated Emission Sources

The enhanced capture emissions from the Furnace 12 tapping process were calculated assuming an 

increase of the primary capture of the fugitive emissions from the estimated 30 percent at baseline 

to 95 percent at the enhanced capture level. The captured emissions from tapping were assumed to 

be routed to a new Furnace 12 tapping/casting baghouse, instead of the Furnace 12 scrubber. The 

control noted that the Furnace 12 scrubber did not have the capacity to control the enhanced capture 

fugitive emission stream from both Furnace 12 tapping. An example of the enhanced capture PM 

emissions calculation for Furnace 12 tapping fugitives is shown below:

 

 

( )

 ( )

where;

3.56 = Enhanced capture fugitive PM emissions from Furnace 12 tapping in tons per year,

59.2 = Baseline fugitive PM emissions from Furnace 12 tapping in tons per year,

30% = Baseline capture percent of Furnace 12 tapping emissions, and

95% = Enhance capture percent of Furnace 12 tapping emissions.
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33

The enhanced capture casting fugitive emissions from Furnace 12 were also calculated using the 

same methodology above. The only exception is that there is currently no capture of fugitive 

emissions from Furnace 12 casting. The control plan submitted by Eramet proposed adding 

primary capture of 95 percent to the Furnace 12 casting area and routing the captured emissions to a 

new Furnace 12 tapping/casting baghouse. An example of the enhanced capture PM emissions 

calculation for Furnace 12 casting fugitive is shown below:

 ( )

where;

0.520 = Enhanced capture fugitive PM emissions from Furnace 12 casting in tons per year,

10.4 = Baseline fugitive PM emissions from Furnace 12 casting in tons per year, and

95% = Enhanced capture percent of Furnace 12 casting emissions.

No changes to the capture system for the Furnace 12 smelting operation were proposed in Eramet’s 

capture plan. The current system was assumed to achieve 98 percent capture of fugitive emission 

from the furnace operations, therefore the calculated fugitive emissions at the enhanced capture 

level are the same as the calculated fugitive emissions from baseline. There is a decrease in the 

Furnace 12 scrubber outlet emissions in the enhanced capture scenario because the captured 

emissions from Furnace 12 tapping are now being routed to a dedicated Furnace 12 tapping/casting 

baghouse. The enhanced capture emission rate from the Furnace 12 scrubber was calculated by 

assuming that captured tapping emissions are 8 percent of the total emissions from the furnace 

control device outlet. Therefore, the enhanced capture Furnace 12 scrubber outlet emissions were 

assumed to be 92 percent of the baseline Furnace 12 scrubber outlet emissions. An example of the 

PM emissions calculation is shown below:

 

where;

38.7 = Enhanced capture PM emissions from the Furnace 12 scrubber outlet in tons per year,

42.1 = Baseline PM emissions from the Furnace 12 scrubber outlet in tons per year, and

0.92 = Assumed fraction of emissions from the furnace smelting process.

As noted above, the captured emissions from Furnace 12 tapping and casting are routed to a new 

Furnace 12 tapping/casting baghouse in the enhanced capture scenario. The enhanced capture 

emission rate from this baghouse was calculated by adding the difference of fugitive emissions 

from both tapping and casting from Furnace 12. An example of the PM emissions calculation for 

the Furnace 12 tapping/casting baghouse is shown below:
DRAFT FOR INTERNAL REVIEW

34

 [( ) ( ) ( )] ( )

where;

1.19 = Enhanced capture PM emissions from the Furnace 12 tapping/casting baghouse outlet in tons 

per year,

10.4 = Baseline fugitive PM emissions from Furnace 12 casting in tons per year,

0.520 = Enhanced capture fugitive PM emissions from Furnace 12 casting in tons per year, 

49.8 = Baseline fugitive PM emissions from Furnace 12 tapping in tons per year,

3.56 = Enhanced capture fugitive PM emissions from Furnace 12 tapping in tons per year, 

42.1 = Baseline PM emissions from the Furnace 12 scrubber outlet in tons per year,

3.56 = Enhanced capture PM emissions from the Furnace 12 scrubber outlet in tons per year, and

98% = Assumed PM control efficiency of the Furnace 12 tapping/casting baghouse.

MOR and Associated Emission Sources

The enhanced capture fugitive emissions for the MOR process were calculated based on the control 

plan submitted by Eramet. The control plan proposed increasing the primary capture of the MOR 

process and adding secondary capture to the building for an overall capture of 95 percent of fugitive 

emissions generated by the MOR process. To calculate this scenario, it was assumed that the 

primary capture would be increased from 40 percent at baseline to 80 percent at the enhanced 

capture level. An additional capture of 75 percent was used to estimate the secondary capture effect 

to the MOR process fugitive emissions. An example of the calculation is shown below:

 

 

( )

 ( ) ( )

where;

1.06 = Enhanced capture PM emissions from the MOR process in tons per year,

12.7 = Baseline fugitive PM emissions from MOR process in tons per year,

40% = Baseline capture percentage of fugitive emissions from the MOR process, 

80% = Primary capture percentage of MOR process fugitives for enhanced capture, and

75% = Secondary capture percentage of MOR process fugitives for enhanced capture.

The enhanced capture MOR casting fugitive emissions were calculated using the same assumptions 

as above for primary and secondary capture at the enhanced capture level. An example of the 

enhanced capture PM fugitive emissions from MOR casting is shown below.

 

 

( )

 ( ) ( )

where;
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35

1.06 = Enhanced capture PM emissions from the MOR casting in tons per year,

12.7 = Baseline fugitive PM emissions from MOR casting in tons per year,

40% = Baseline capture percentage of fugitive emissions from the MOR casting, 

80% = Primary capture percentage of MOR casting fugitives for enhanced capture, and

75% = Secondary capture percentage of MOR casting fugitives for enhanced capture. 

The enhanced capture emissions from the MOR baghouse were calculated to include the primary 

captured fugitive emissions from the MOR process and MOR casting. An example of the enhanced 

capture PM emissions from the MOR baghouse is shown below. The equation calculates the MOR 

fugitive emissions that are only captured by the primary capture system.

 [ 

 

( )

 ( ) 

 

( )

 ( )]*(1-98%)

where;

3.22 = Enhanced capture PM emissions from the MOR baghouse outlet in tons per year,

12.7 = Baseline fugitive PM emissions from the MOR process in tons per year,

40% = Baseline capture percentage of fugitive emissions from the MOR process, 

80% = Primary capture percentage of MOR process fugitives for enhanced capture,

12.7 = Baseline fugitive PM emissions from the MOR casting in tons per year,

40% = Baseline capture percentage of fugitive emissions from MOR casting, 

80% = Primary capture percentage of MOR casting fugitives for enhanced capture, and

98% = Assumed PM control efficiency of the MOR process baghouse.

The fugitive emissions captured by the secondary capture system in the MOR building were 

assumed to be sent to a new MOR secondary baghouse. An estimate of the PM emissions from this 

baghouse is provided in the calculation below. The equation calculates the fugitive MOR emissions 

that are only captured by the secondary capture system.

 [

 

( )

 ( ) 

 

( )

 ( ) ]*(1-98%)

where;

0.127 = Enhanced capture PM emissions from the MOR secondary baghouse outlet in tons per year,

12.7 = Baseline fugitive PM emissions from the MOR process in tons per year,

40% = Baseline capture percentage of fugitive emissions from the MOR process, 

80% = Primary capture percentage of MOR process fugitives for enhanced capture,

1.06 = Enhanced capture PM emissions from the MOR process in tons per year,

12.7 = Baseline fugitive PM emissions from the MOR casting in tons per year,

40% = Baseline capture percentage of fugitive emissions from MOR casting, 

80% = Primary capture percentage of MOR casting fugitives for enhanced capture,
DRAFT FOR INTERNAL REVIEW

36

1.06 = Enhanced capture PM emissions from the MOR casting in tons per year, and

98% = Assumed PM control efficiency of the MOR secondary baghouse.

Crushing & Screening Operations

The control plan submitted by Eramet did not include any capture enhancements to the crushing 

and sizing system. Therefore, the enhanced capture crushing and screening baghouse and fugitive 

emissions are the same as the calculated baseline emissions for these sources.

Felman Production

The methodology for calculating the enhanced capture emissions from Felman were based on the 

proposed fugitive emissions capture plan20 submitted by the facility. The submitted capture plan 

proposed increasing the primary capture of fugitive and adding secondary capture to the furnace 

building to achieve an overall capture efficiency of 95 percent. To achieve the overall 95 percent 

capture, it was assumed that the primary capture would be increased to 80 percent and the 

secondary capture would capture 75 percent of the remaining fugitive emissions in the building. A 

mass balance approach was taken to calculate the enhanced capture emissions from many of the 

emission sources that are equipped with control devices. A description of the assumptions used to 

calculate the enhanced capture emissions from each of the emission sources is provided in the 

following sections. 

Furnace and Associated Emission Sources

Because the furnace smelting, tapping, and casting operation for Furnace 2, 5, and 7 occur in the 

same building, the same calculation methodology was used for each of these operations. The 

emissions estimate for fugitive tapping emissions for the enhanced capture scenario were calculated 

by applying both the primary capture efficiency and the secondary capture efficiency to the tapping 

operation for Furnaces 2, 5, and 7. An example of the enhanced capture PM tapping fugitive 

emissions estimate for Furnace 2 is shown in the equation below.

 

 

( )

 ( ) ( )

Where;

2.88 = Enhanced capture PM fugitive emissions from Furnace 2 tapping in tons per year,

17.3 = Baseline fugitive PM emissions from Furnace 2 tapping in tons per year,

70% = Baseline capture percentage of fugitive emissions from the Furnace 2 tapping, 

80% = Primary capture percentage of furnace tapping fugitives for enhanced capture, and

 

20 Chu and Gassman, Design Narrative, July 9, 2012.
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37

75% = Secondary capture percentage of furnace tapping fugitives for enhanced capture. 

The casting fugitive emissions are calculated using the same methodology above for tapping 

fugitive emissions. The emissions estimate for fugitive casting emissions for the enhanced capture 

scenario were calculated by applying both the primary capture efficiency and the secondary capture 

efficiency to the casting operation for Furnaces 2, 5, and 7. An example of the enhanced capture 

PM casting fugitive emissions estimate for Furnace 2 is shown in the equation below.

 

 

( )

 ( ) ( )

Where;

0.420 = Enhanced capture PM fugitive emissions from Furnace 2 casting in tons per year,

5.04 = Baseline fugitive PM emissions from Furnace 2 casting in tons per year,

40% = Baseline capture percentage of fugitive emissions from the Furnace 2 casting, 

80% = Primary capture percentage of furnace casting fugitives for enhanced capture, and

75% = Secondary capture percentage of furnace casting fugitives for enhanced capture. 

The proposed control plan submitted by Felman also included changes to the capture of the furnace 

smelting emissions for Furnace 2, 5, and 7. These changes are expected to increase the fugitive 

capture from the furnace smelting operations from 98 to 99 percent. Therefore, there is a reduction 

in the enhanced capture furnace fugitive emissions from Furnaces 2, 5, and 7. An example of the 

furnace smelting fugitive emission calculation for Furnace 2 is shown below:

 

 

( )

 ( ) ( )

where;

1.70 = Enhanced capture PM fugitive emissions from Furnace 2 smelting in tons per year,

13.6 = Baseline fugitive PM emissions from Furnace 2 smelting in tons per year,

98% = Baseline capture percentage of fugitive emissions from the Furnace 2 smelting, 

99% = Primary capture percentage of furnace smelting fugitives for enhanced capture, and

75% = Secondary capture percentage of furnace smelting fugitives for enhanced capture. 

The furnace baghouse outlet emissions from each of the furnaces increase due to the addition of 

primary enhanced capture emissions from smelting, tapping, and casting. An example of the PM 

baghouse outlet emissions from Furnace 2 is shown in the equation below:

 [ 

 

( )

 ( ) 

 

( )

 ( )

 

 

( )

 ( )] ( )
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38

where;

14.8 = Enhanced capture PM emissions from the Furnace 2 baghouse outlet in tons per year,

14.5 = Baseline fugitive PM emissions from the Furnace 2 baghouse outlet in tons per year,

13.6 = Baseline fugitive PM emissions from Furnace 2 smelting in tons per year,

98% = Baseline capture percentage of fugitive emissions from the Furnace 2 smelting, 

99% = Primary capture percentage of furnace smelting fugitives for enhanced capture,

17.3 = Baseline fugitive PM emissions from Furnace 2 tapping in tons per year,

70% = Baseline capture percentage of fugitive emissions from the Furnace 2 tapping, 

80% = Primary capture percentage of furnace tapping fugitives for enhanced capture,

5.04 = Baseline fugitive PM emissions from Furnace 2 casting in tons per year,

40% = Baseline capture percentage of fugitive emissions from the Furnace 2 casting, 

80% = Primary capture percentage of furnace casting fugitives for enhanced capture, and 

98% = Assumed PM control efficiency of the Furnace 2 baghouse.

The Felman control plan proposed that captured secondary fugitive emissions from the furnace 

smelting, tapping, and casting processes would be controlled by a new secondary furnace baghouse. 

An example of the calculated PM emissions from this baghouse is shown below:

 

 

( )

 ( ) ( )

where;

0.742 = Enhanced capture PM emissions from the secondary furnace baghouse in tons per year,

12.4 = Sum of the enhanced capture fugitive PM emissions from smelting, tapping, and casting for 

Furnaces 2, 5, and 7 in tons per year,

75% = Secondary capture percentage of the furnace building fugitives for enhanced capture, and 

98% = Assumed PM control efficiency of the secondary furnace baghouse.
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Crushing & Screening Operations

The control plan submitted by Felman did not include any primary capture enhancements to the 

crushing and sizing system, but does include secondary capture of fugitive emissions from this 

process. The secondary fugitive capture system for the crushing and screening operation is 

expected to achieve 75 percent capture. An example of the PM fugitive emissions calculation for 

the crushing and screening operation is shown below:

 ( )

where;

2.19 = Enhanced capture fugitive PM emissions from crushing and screening in tons per year,

8.74 = Baseline fugitive PM emissions from crushing and screening in tons per year, and

75% = Secondary capture percentage for crushing and screening.

The Felman control plan proposed that captured secondary fugitive emissions from the crushing 

and screening process would be controlled by a new secondary crushing baghouse. An example of 

the calculated PM emissions from this baghouse is shown below:

 

 

( )

 ( ) ( )

where;

0.0656 = Enhanced capture PM emissions from the secondary crushing baghouse in tons per year,

2.19 = Enhanced capture fugitive PM emissions from crushing and screening in tons per year,

75% = Secondary capture percentage of crushing fugitives for enhanced capture, and 

98% = Assumed PM control efficiency of the secondary crushing baghouse.

A summary of the primary and secondary capture assumptions for fugitive emissions from Eramet 

and Felman is provided in Table 5-5. A summary of the enhanced capture emissions for Eramet 

and Felman isprovided in Table 5-6.
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Table 5-5. Summary of Fugitive Capture Assumptions Used to Estimate the 

Enhanced Capture Emissions

Fugitive Emission Source Enhanced Capture HAP Emission Calculation Assumption

Eramet Marietta

Furnace 1 and 12 Furnace 

Fugitives

No change from baseline. Source is assumed to achieve 98% capture.

Furnace 1 Tapping Fugitives The tapping capture is assumed to increase from 20% at baseline to 95%. 

Captured emissions routed to Furnace 1 baghouse.

Furnace 12 Tapping Fugitives The tapping capture is assumed to increase from 30% at baseline to 95%. 

Captured emissions routed to Furnace 12 tapping/casting baghouse 

(currently Furnace 1 tapping baghouse).

Furnace 1 Casting Fugitives The casting capture is assumed to increase from 0% at baseline to 95%. 

Captured emissions routed to Furnace 1 baghouse.

Furnace 12 Casting Fugitives The casting capture is assumed to increase from 0% at baseline to 95%. 

Captured emissions routed to Furnace 12 tapping/casting baghouse 

(currently Furnace 1 tapping baghouse).

MOR Process and Casting 

Fugitives

The MOR process and MOR casting primary capture is assumed to 

increase from 40% at baseline to 80%, and installation of secondary 

capture of 75% for a total overall capture of 95%. Captured primary 

emissions routed to MOR baghouse and captured secondary emissions 

routed to a new MOR secondary baghouse.

Crushing and Sizing Fugitives No change from baseline. Source is assumed to achieve 95% capture.

Felman Production

Furnace 2, 5, 7 Furnace 

Fugitives

The furnace primary capture is assumed to increase from 98% at baseline 

to 99%, and installation of secondary capture of 75% for a total capture of 

99.75%. Captured primary emissions routed to their respective furnace 

baghouse and captured secondary emissions routed to a new secondary 

baghouse.

Furnace 2, 5, 7 Tapping 

Fugitives

The tapping primary capture is assumed to increase from 70% at baseline 

to 80%, and installation of secondary capture of 75% for a total capture of 

95%. Captured primary emissions routed to their respective furnace 

baghouse and captured secondary emissions routed to a new secondary 

baghouse.

Furnace 2, 5, 7 Casting 

Fugitives

The casting primary capture is assumed to increase from 40% at baseline 

to 80%, and installation of secondary capture of 75% for a total capture of 

95%. Captured primary emissions routed to their respective furnace 

baghouse and captured secondary emissions routed to a new secondary 

baghouse.

Crushing and Sizing Fugitives The crushing and sizing primary capture is to be 85%, and installation of 

secondary capture of 75% for a total capture of 96%. Captured primary 

emissions routed to the crushing and sizing baghouse and captured 

secondary emissions routed to a new secondary baghouse.
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Table 5-6. Summary of the Enhanced Capture Ferroalloys Production Facility Annual HAP Emissions (Tons/year) 

Unit Description

Arsenic Cadmium

Chromium 

(III)

Chromium 

(VI) Lead Manganese Mercury Nickel

Hydrogen 

Chloride Total PAH

FormaldehydeTotal 

CDD/CDF Total PCBs Total HAP

Eramet Marietta

Furnace #1 Baghouse Outlet 0.000565 0.00272 0.00169 0.000305 0.0364 2.11 0.00926 0.00490 5.91 3.46 1.28 3.14E-07 3.27E-06 12.8

Furnace #1 Fugitives 0.000374 0.00217 0.000670 0.000194 0.0208 1.25 0.00172 0.00296 0.620 2.58 0.317 3.14E-08 4.88E-07 4.79

Furnace #1 Casting Baghouse 0.0000113 0.0000657 0.0000203 0.00000586 0.000630 0.0843 0.000121 0.0000897 0.939 0.121 0.167 0.00E+00 0.00E+00 1.31

Furnace #1 Tapping Fugitives 0.000204 0.00118 0.000365 0.000105 0.0113 1.52 0.0000512 0.00162 0.338 0.0872 0.0602 3.44E-08 3.38E-07 2.02

Furnace #12 Scrubber Outlet 0.00324 0.0260 0.00145 0.00110 0.0973 6.33 0.0278 0.00215 0.501 0.515 0.133 7.80E-08 3.34E-07 7.63

Furnace #12 Fugitives 0.000662 0.00531 0.000297 0.000225 0.0198 1.29 0.00189 0.000439 0.102 0.105 0.0272 1.59E-08 6.81E-08 1.55

Furnace #12 Tapping Fugitives 0.000298 0.00239 0.000134 0.000101 0.00894 1.46 0.0000493 0.000198 0.0461 0.0872 0.0602 3.44E-08 3.38E-07 1.66

MOR Process Baghouse Outlet 0.00123 0.00216 0.00476 0.0000917 0.00104 1.12 0.00232 0.00164 0.257 0.238 0.286 NM NM 1.92

MOR Process Fugitives 0.000405 0.000713 0.00157 0.0000302 0.000344 0.435 0.0000147 0.000541 0.0137 0.0250 0.0173 NM NM 0.495

Furnace #1 Casting 0.0000298 0.000173 0.0000534 0.0000154 0.00166 0.222 0.00000749 0.000236 0.0494 0.0127 0.00879 NM NM 0.295

Furnace #12 Casting 0.0000436 0.000349 0.0000195 0.0000148 0.00131 0.213 0.00000720 0.0000289 0.00673 0.0123 0.00846 NM NM 0.242

MOR casting 0.000405 0.000713 0.00157 0.0000302 0.000344 0.435 0.0000147 0.000541 0.0137 0.0250 0.0173 NM NM 0.495

C2P Crushing/Sizing Baghouse #1 0.000133 NM 0.00130 0.000103 0.000141 1.49 NM 0.00151 NM NM NM NM NM 1.49

C2P Crushing/Sizing Baghouse #2 0.000133 NM 0.00130 0.000103 0.000141 1.49 NM 0.00151 NM NM NM NM NM 1.49

C2P Crushing/Sizing Baghouse #3 0.000133 NM 0.00130 0.000103 0.000141 1.49 NM 0.00151 NM NM NM NM NM 1.49

C2P crushing and sizing fugitives 0.000567 NM 0.00555 0.000442 0.000603 6.35 NM 0.00646 NM NM NM NM NM 6.37

Furnace #12 Tap/Cast Baghouse 0.0000940 0.000755 0.0000422 0.0000320 0.00282 0.460 0.049729 0.0000623 0.727 0.683 0.943 2.24E-07 2.19E-06 2.87

MOR Secondary Baghouse 0.0000486 0.0000856 0.000188 0.00000363 0.0000413 0.0522 0.0000749 0.0000649 0.0824 0.0750 0.104 NM NM 0.314

Fugitive Emissions Total 0.00299 0.0130 0.0102 0.00116 0.0652 13.2 0.00375 0.0130 1.19 2.94 0.516 1.16E-07 1.23E-06 17.9

Eramet Marietta Total 0.00858 0.0448 0.0223 0.00301 0.204 27.8 0.0930 0.0265 9.61 8.03 3.43 7.32E-07 7.02E-06 49.2

Felman Production

Furnace No. 2 Baghouse Outlet 0.00283 0.000318 0.00576 0.00159 0.184 1.30 0.0105 0.0811 7.31 0.529 0.634 5.35E-07 4.38E-05 10.1

Furnace No. 2 Fugitives 0.000325 0.0000365 0.000662 0.000182 0.0211 0.146 0.0000285 0.00931 0.409 0.0401 0.0388 4.83E-08 4.14E-06 0.666

Furnace No. 2 Tapping Fugitives 0.000548 0.0000616 0.00112 0.000307 0.0357 0.661 0.0000152 0.0157 0.690 0.0678 0.0468 2.68E-08 2.62E-07 1.52

Furnace No. 5 Baghouse Outlet 0.000721 0.000178 0.00902 0.00143 0.0176 0.789 0.00224 0.00469 0.636 0.450 0.528 8.05E-07 6.00E-05 2.44

Furnace No. 5 Fugitives 0.0000833 0.0000206 0.00104 0.000166 0.00203 0.0893 0.00000605 0.000541 0.0412 0.0377 0.0363 7.53E-08 5.69E-06 0.208

Furnace No. 5 Tapping Fugitives 0.0000765 0.0000189 0.000957 0.000152 0.00187 0.327 0.00000750 0.000497 0.0379 0.0335 0.0231 1.32E-08 1.30E-07 0.426

Furnace No. 7 Baghouse Outlet 0.00118 0.000292 0.0148 0.00235 0.0289 2.48 0.00453 0.00769 1.44 0.385 0.971 8.05E-07 6.00E-05 5.34

Furnace No. 7 Fugitives 0.000137 0.0000338 0.00171 0.000273 0.00335 0.286 0.0000123 0.000891 0.101 0.0316 0.0717 7.53E-08 5.69E-06 0.497

Furnace No. 7 Tapping Fugitives 0.0000765 0.0000189 0.000957 0.000152 0.00187 0.327 0.00000750 0.000497 0.0561 0.0335 0.0231 1.32E-08 1.30E-07 0.444

Furnace No. 2 Casting 0.0000801 0.00000900 0.000163 0.0000449 0.00521 0.0967 0.00000221 0.00229 0.101 0.00990 0.00683 NM NM 0.222

Furnace No. 5 Casting 0.0000112 0.00000276 0.000140 0.0000222 0.000273 0.0479 0.00000110 0.0000727 0.00554 0.00490 0.00338 NM NM 0.0622

Furnace No. 7 Casting 0.0000112 0.00000276 0.000140 0.0000222 0.000273 0.0479 0.00000110 0.0000727 0.00821 0.00490 0.00338 NM NM 0.0649

Crushing/Screening System #1 0 NM 0 0 0 0 NM 0 NM NM NM NM NM 0.00

Crushing/Screening System #2 0 NM 0.000161 0.0000444 0.000463 0.210 NM 0 NM NM NM NM NM 0.211

Crushing/Screening #1 Fugitives 0 NM 0 0 0 0 NM 0 NM NM NM NM NM 0.00

Crushing/Screening #2 Fugitives 0 NM 0.000897 0.000247 0.00258 0.813 NM 0 NM NM NM NM NM 0.817

Secondary Crushing Baghouse 0 NM 0.0000538 0.0000148 0.000155 0.0488 NM 0 NM NM NM NM NM 0.0490

Secondary Furnace Baghouse 0.0000809 0.0000123 0.000414 0.0000793 0.00430 0.122 0.000208 0.00179 4.35 0.396 0.760 3.78E-07 2.41E-05 5.63

Fugitive Emissions Total 0.00135 0.000205 0.00779 0.00157 0.0742 2.84 0.0000815 0.0299 1.45 0.264 0.253 2.52E-07 1.60E-05 4.93

Felman Production Total 0.00616 0.00101 0.0380 0.00708 0.310 7.80 0.0175 0.125 15.2 2.02 3.15 2.78E-06 2.04E-04 28.7
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In addition to the changes to the fugitive capture efficiencies for enhanced capture, Eramet was also 

assumed to control mercury emissions from both Furnaces 1 and 12. The mercury emissions are 

generated during the smelting process from the manganese ore used to produce FeMn and SiMn in 

both of the furnaces, although there may be trace amounts in the coke or coal used in the smelting 

process. The production of FeMn generates considerably more mercury emissions than SiMn 

production, and is considered to be a significant source of mercury emissions. Since FeMn is 

produced in each of the furnaces at Eramet, activated carbon injection (ACI) was assumed to be 

retrofit prior to the control device. The ACI control technology was assumed to achieve 70 percent 

mercury reduction on Furnace 12 (currently equipped with a venturi scrubber) and 90 percent 

reduction on Furnace 1 (currently equipped with a fabric filter). Felman produces only SiMn in 

each of their three furnaces and was not found to be a significant source of mercury emissions based

on the test data results. Therefore, no mercury controls were assumed to be retrofit on the furnace 

outlets.

6.0 MODELING DATABASE 

Section 112(f)(2) of the Clean Air Act (CAA) directs EPA to assess the risk remaining (residual 

risk) after the application of maximum achievable control technology (MACT) standards under 

section 112(d). EPA is to promulgate more stringent standards for a category or subcategory of 

sources subject to MACT standards under section 112(d) if promulgation of such standards is 

necessary to protect public health with an ample margin of safety or to prevent (taking into 

consideration various factors) adverse environmental effects.

In an effort to streamline the process of making residual risk decisions, EPA plans to address 

residual risk and perform a technology review simultaneously for multiple source categories. For 

this source category, the first part of this approach is to compile and review facility-specific data 

collected by EPA, and to conduct preliminary risk assessments. The risk assessment will include 

both chronic and acute inhalation risks. The chronic risks are based on long-term, annual average 

emissions, while the acute risks are based on short-term hourly emissions and account for the 

maximum potential short term emission rates for the industry.

6.1 Chronic Modeling Database

The chronic modeling database was assembled using the annual pollutant emissions calculated for 

processes that were tested (e.g., furnace control device outlet, MOR baghouse outlet, crushing and 

sizing baghouse outlet), and from AP-42 EFs for fugitive sources that were not tested (e.g., furnace 

tapping, MOR pouring, crushing and sizing) at each of the ferroalloy facilities. The HAP emissions 

and the source IDs were then assembled into a database that included other facility descriptors and 

emission location parameters (i.e., latitude, longitude, emission release height, emission velocity, 

emission temperature, release length and width). Negative pressure baghouse and scrubber 
DRAFT FOR INTERNAL REVIEW

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emission outlets were set up as point sources in the database. Fugitive and positive pressure 

baghouse outlets were set up as area sources.

6.2 Acute Modeling Factors

Rather than developing a separate acute modeling database, acute multipliers were developed for 

the process emission points. Processes that operate continually, like the furnace control device 

outlets, furnace fugitive emissions, and secondary fugitive capture devices, are considered as 

steady-state operations. Estimated yearly emissions from steady-state emissions points are divided 

by 8760 to calculate estimated hourly emissions. Therefore these processes were given an acute 

multiplier of 1. 

Other emission sources such as, tapping fugitives, MOR fugitives, and casting fugitives are the 

operations that might conceivably result in an emissions spike. These emission points are assumed 

to operate 25 percent of the time (30 minutes out of each two hour period.) This is a conservative 

estimate, because it is very unlikely that all furnaces would ever be tapped simultaneously, and it is 

impossible for tapping and casting from a given furnace to occur simultaneously since casting of 

the molten metal must occur after it is tapped. This methodology is also likely to overestimate the 

operating frequency of product sizing operations. Following this reasoning, estimated yearly 

emissions from intermittent emissions points are divided by 2190 to calculate estimated hourly 

emissions. Therefore these processes were given an acute multiplier of 4. A table of the acute 

multiplier for each of the emissions sources is provided in Table 6-1.

6.3 MACT Allowables

The modeling emissions calculated from the ICR test data represent an estimate of the mass 

emissions actually emitted during the specified annual time period. These “actual” emission levels 

are often lower than the emission levels that a facility might be allowed to emit and still comply 

with the MACT standards. The emissions level allowed to be emitted by the MACT standards is 

referred to as the “MACT-allowable” emissions level. This represents the highest emissions level 

that could be emitted by the facility without violating the MACT standards. The assessment of 

these risks at the MACT-allowable level reflects the maximum level sources could emit and still 

comply with national emission standards. For process sources, the NESHAP specifies numerical 

emissions limits for particulate matter (as a surrogate for non-mercury (or particulate) metal HAP) 

from the electric (submerged) arc furnaces (including smelting and tapping emissions), with the 

specific limits depending on furnace type, size, and product being made. The NESHAP also 

specifies a numerical concentration limit for PM (as a surrogate for non-mercury (or particulate) 

metal HAP) for the crushing and screening process.
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Table 6-1. Listing of Acute Multipliers for Ferroalloy Emission Points

Facility Process Description FacilityID SourceID Acute Multiplier

Eramet Furnace #1 casting 39167NEI11660 M_CA0001 4

Eramet Furnace #12 casting 39167NEI11660 M_CA0002 4

Eramet MOR casting 39167NEI11660 M_CA0003 4

Eramet Electric Arc Furnace #1 Fugitives 39167NEI11660 M_OE0004 1

Eramet Electric Arc Furnace #12 Fugitives 39167NEI11660 M_OE0005 1

Eramet Electric Arc Furnace #1 Tapping Fugitives 39167NEI11660 M_OE0006 4

Eramet Electric Arc Furnace #12 Tapping Fugitives 39167NEI11660 M_OE0007 4

Eramet C2P crushing and sizing fugitives 39167NEI11660 M_PC0007 4

Eramet MOR Process Fugitives 39167NEI11660 M_SE0006 4

Eramet MOR Process Secondary Baghouse 39167NEI11660 M_BV0001 1

Eramet Electric Arc Furnace #1 Building Baghouse 39167NEI11660 M_BV0101 1

Eramet Electric Arc Furnace #12 Building Baghouse 39167NEI11660 M_BV1201 1

Eramet Electric Arc Furnace #1 Baghouse Outlet 39167NEI11660 M_OE0008 1

Eramet Electric Arc Furnace #12 Scrubber Outlet 39167NEI11660 M_OE0009 1

Eramet Electric Arc Furnace #1 Tapping Baghouse 39167NEI11660 M_OE0017 1

Eramet Casting #12 Baghouse 39167NEI11660 M_OE0019 1

Eramet C2P Crushing/Sizing Baghouse #1 39167NEI11660 M_PC0014 4

Eramet C2P Crushing/Sizing Baghouse #2 39167NEI11660 M_PC0015 4

Eramet C2P Crushing/Sizing Baghouse #3 39167NEI11660 M_PC0016 4

Eramet MOR Process Baghouse Outlet 39167NEI11660 M_SE0013 1

Felman ELECTRIC ARC FURNACE NO. 2 CASTING FUGITIVES 54053NEIWV053FELMAN M_CA0001 4

Felman ELECTRIC ARC FURNACE NO. 5 CASTING FUGITIVES 54053NEIWV053FELMAN M_CA0002 4

Felman ELECTRIC ARC FURNACE NO. 7 CASTING FUGITIVES 54053NEIWV053FELMAN M_CA0003 4

Felman ELECTRIC ARC FURNACE NO. 2 54053NEIWV053FELMAN M_OE0008 1

Felman ELECTRIC ARC FURNACE NO. 2 FUGITIVES 54053NEIWV053FELMAN M_OE0011 1

Felman ELECTRIC ARC FURNACE NO. 5 54053NEIWV053FELMAN M_OE0012 1

Felman ELECTRIC ARC FURNACE NO. 5 FUGITIVES 54053NEIWV053FELMAN M_OE0013 1

Felman ELECTRIC ARC FURNACE NO. 7 54053NEIWV053FELMAN M_OE0014 1

Felman ELECTRIC ARC FURNACE NO. 7 FUGITIVES 54053NEIWV053FELMAN M_OE0015 1

Felman ELECTRIC ARC FURNACE NO. 2 TAPPING FUGITIVES 54053NEIWV053FELMAN M_OE0016 4

Felman ELECTRIC ARC FURNACE NO. 5 TAPPING FUGITIVES 54053NEIWV053FELMAN M_OE0017 4

Felman ELECTRIC ARC FURNACE NO. 7 TAPPING FUGITIVES 54053NEIWV053FELMAN M_OE0018 4

Felman CRUSHING AND SCREENING SYSTEM #1 FUGITIVES 54053NEIWV053FELMAN M_PC0007 4

Felman CRUSHING AND SCREENING SYSTEM #2 FUGITIVES 54053NEIWV053FELMAN M_PC0009 4

Felman BUILDING EVACUATION BAGHOUSE 54053NEIWV053FELMAN M_BV0101 1

Felman SECONDARY CRUSHING 1 BAGHOUSE 54053NEIWV053FELMAN M_BV0202 1

Felman SECONDARY CRUSHING 2 BAGHOUSE 54053NEIWV053FELMAN M_BV0303 1

Felman SECONDARY FURNACE BAGHOUSE 54053NEIWV053FELMAN M_BV0404 1

Felman CRUSHING AND SCREENING SYSTEM #1 54053NEIWV053FELMAN M_PC0006 4

Felman CRUSHING AND SCREENING SYSTEM #2 54053NEIWV053FELMAN M_PC0008 4
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To estimate emissions at the MACT-allowable level, a ratio of MACT-allowable to actual 

emissions for each of the process source types that are regulated under the existing NESHAP (i.e., 

furnace control device outlet, MOR baghouse outlet, crushing and screening outlet). This ratio is 

based on the maximum emission limits allowed by the MACT standards compared to the reported 

actual emissions. These ratios for each emission point type at the facilities in this source category

were used to estimate the maximum potential risk estimates that could occur assuming emissions 

are continuously emitted at the maximum allowed emissions level. Mercury is not included with 

metal HAP because the emissions are not currently regulated by the MACT rule and the emissions 

are primarily in gaseous elemental form. A table of the MACT-allowable ratios for metal HAP is 

presented in Table 6-2. An example of the MACT-allowable calculation for the Furnace 1 baghouse 

is shown below:

 

( ) ( )

( ) ( )

where;

0.50 = the assumed fraction of time the facility is producing FeMn or SiMn,

35.9 = the MACT allowable PM emissions rate in pounds per hour when producing SiMn,

29.8 = the MACT allowable PM emission rate in pounds per hour when producing FeMn,

1.79 = the actual average PM emissions rate in pounds per hour based on test data collected during 

the production of SiMn, and

1.52 = the actual average PM emissions rate in pounds per hour based on test data collected during 

the production of FeMn.

As noted in Section 3.0, Eramet has a third furnace (Furnace 18) that is idle because of damage to 

the furnace and is unlikely to be repaired and operated by the facility in the near future. However, 

the furnace is still included in their operating permit; therefore, the emissions will be included in the 

allowable emissions file calculations. This is consistent with RTR policy/procedures, which states 

that if a process unit and/or facility has not been operating for an extended period of time (years), 

and is not currently operating, but the unit or facility could theoretically reopen and start again in 

the future (e.g., still in permit), the emissions should not be included in the calculation of “actual” 

emissions, but should be included in the estimated potential emissions in the “allowables” file.

 

 
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Table 6-2. Summary of MACT-Allowable Ratios for Eramet and Felman

Emission Source Source ID

Actual PM 

Emissons (lb/hr)

MACT-Allowable 

PM Emissions 

(lb/hr)

Actual PM Conc. 

(gr/dscf)

MACT-Allowable 

PM Conc. 

(gr/dscf)

MACT-Allowable/ 

Actual Ratio Comment

Furnace 1 Baghouse Outlet1 M_OE0008 1.79/1.52 35.9/29.8 19.8

63.1652(b)(3)/ 

63.1652(b)(2)

Furnace 12 Scrubber Outlet1 M_OE0009 12.06/7.16 35.9/29.8 3.57

63.1652(b)(3)/ 

63.1652(b)(2)

Furnace 18 Scrubber Outlet2 M_OE0010 7.61 6.9 0.9 63.1652(a)(1)

MOR Baghouse Outlet M_SE0006 0.0004 0.03 81.1 63.1652(d)

C2P BH1 Outlet M_PC0014 0.0033 0.03 9.1 63.1652(e)(2)

C2P BH2 Outlet M_PC0015 0.0033 0.03 9.1 63.1652(e)(2)

C2P BH3 Outlet M_PC0016 0.0033 0.03 9.1 63.1652(e)(2)

Furnace 2 BH Outlet M_OE0008 3.32 27.2 8.2 63.1652(b)(4)

Furnace 5 BH Outlet M_OE0012 3.01 27.2 9.0 63.1652(b)(4)

Furnace 7 BH Outlet M_OE0014 4.96 27.2 5.5 63.1652(b)(4)

Sizing #2 BH M_PC0006 0.0011 0.03 27.7 63.1652(e)(2)

1

 The actual and MACT allowable emissions for Furnace 1 and Furnace 12 are shown as SiMn and FeMn respectively. The MACT/Allowable ratio 

assumes that the furnace produces SiMn, 50% of the time and FeMn, 50% of the time.

2

 Furnace 18 is a 13.5 MW semi-sealed furnace that is assumed to have 50/50 production of SiMn and FeMn. The MACT allowable limit assumes that Furnace 18

would be a new source and would have to meet the new source limit of 0.51 lb/hr/MW (13.5 MW * 0.51 lb/hr/MW = 6.9 lb/hr).

Eramet (Facility ID: 39167NEI11660)

Felman (Facility ID: 54053NEIWV053FELMAN)
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Table 6-3. Summary of Assigned Emission Process Groups for the Ferroalloys SCC

SCC SCC1_DESCRIPTION SCC3_DESCRIPTION SCC6_DESCRIPTION SCC8_DESCRIPTION Emission Process Group

30300601 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace 50% FeSi: Electric Smelting Furnace Open EAF

30300602 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace 75% FeSi: Electric Smelting Furnace Open EAF

30300603 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace 90% FeSi: Electric Smelting Furnace Open EAF

30300604 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Silicon Metal: Electric Smelting Furnace Open EAF

30300605 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Silicomanaganese: Electric Smelting Furnace Open EAF

30300606 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace 80% Ferromanganese Open EAF

30300607 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace 80% Ferrochromium Open EAF

30300608 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Raw Material Unloading Fugitive Dust Sources

30300609 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Raw Material Crushing Raw Material Crushing & Screening Operations

30300610 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Ore Screening Raw Material Crushing & Screening Operations

30300611 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Ore Dryer Raw Material Crushing & Screening Operations

30300613 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Raw Material Storage Fugitive Dust Sources

30300614 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Raw Material Transfer Fugitive Dust Sources

30300615 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Ferromanganese: Blast Furnace Other

30300616 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Ferrosilicon: Blast Furnace Other

30300617 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Cast House Casting

30300618 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Mix House/Weighing Fugitive Dust Sources

30300619 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Raw Material Charging Fugitive Dust Sources

30300620 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Tapping Tapping Operation

30300621 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Casting Casting

30300622 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Cooling Fugitive Dust Sources

30300623 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Product Crushing Product Crushing & Screening Operations

30300624 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Product Storage Fugitive Dust Sources

30300625 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Product Loading Fugitive Dust Sources

30300651 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Sealed Furnace: Ferromanganese: Electric Arc Furnace Other

30300652 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Sealed Furnace: Ferrochromium: Electric Arc Furnace Other

30300653 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Sealed Furnace: Ferrochromium Silica: Electric Arc Furnace Other

30300654 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Sealed Furnace: EAF - Other Alloys: Specify in Comment Other

30300699 Industrial Processes Primary Metal Production Ferroalloy, Open Furnace Other Not Classified Other

30300701 Industrial Processes Primary Metal Production Ferroalloy, Semi-covered Furnace Ferromanganese: Electric Arc Furnace Semi-closed EAF

30300702 Industrial Processes Primary Metal Production Ferroalloy, Semi-covered Furnace Electric Arc Furnace: Other Alloys/Specify Open EAF

30300703 Industrial Processes Primary Metal Production Ferroalloy, Semi-covered Furnace Ferrochromium: Electric Arc Furnace Semi-closed EAF

30300704 Industrial Processes Primary Metal Production Ferroalloy, Semi-covered Furnace Ferrochromium Silicon: Electric Arc Furnace Semi-closed EAF

Note: Highlighted SCCs are included in the Ferroalloys modeling database.
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6.4 Emission Process Groups

The emission sources from the test data were divided into emission process groups using the 

Standard Classification Codes (SCC) supplied by the facility in the ICR. The emission process 

groups provided in the SCC list for the Ferroalloys category were; open EAF, fugitive dust sources, 

raw material crushing and screening operations, casting, and other. Table 6-3 presents a summary 

of the SCC and the assigned emission process group. As shown in Table 6-3, the emission process 

groups assigned in the modeling database for the emission sources were: Open EAF, Raw Material 

Crushing and Screening Operations, Fugitive Dust Sources, and Casting.

6.5 Latitude/Longitude QA/QC

The latitude and longitude coordinates provided by the facilities were reviewed to ensure that the 

coordinates matched the location of the emission points. This was done by plotting each emission 

point on a map of the facility using Google Earth. The plotted emission points were then evaluated 

in comparison to building layout diagrams provided by the facilities to determine if the emission 

point matched the expected location of the emission point. If it was determined that the emission 

point did not match the expected location on the diagrams, the point was moved to the expected 

location and new latitude and longitude coordinates were determined. The map and the emission 

point coordinates were sent to the facilities for confirmation of the locations in the December 21, 

2013 ICR submittal.

6.6 Stack and Fugitive Parameters QA/QC

The stack and fugitive emission parameters provided by the facility in the ICR were verified to 

ensure they were correct. The volumetric flow rates for the point sources were checked by 

calculating the volumetric flow rate using the velocity and duct dimensions. The calculated flow 

rates were compared with the volumetric flow rates provided in the test reports. If the flow rate 

difference exceeded 30 percent, engineering judgments were made to revise the velocity or duct 

dimension data. Fugitive parameters were assigned using the Google Earth map for each of the 

facilities and estimating the length, width, and angle of the fugitive emissions. These parameters 

were sent to the facilities for confirmation of the values that were determined in the December 21, 

2013 ICR submittal.