MEMORANDUM

DATE: August 29, 2014

SUBJECT: Mercury Control Options and Impacts for the Ferroalloys Production Industry

FROM: Bradley Nelson, EC/R, Inc.

TO: Phil Mulrine, EPA OAQPS/SPPD/MICG

1.0 PURPOSE

The purpose of this memorandum is to present the results of the maximum achievable control 

technology (MACT) analysis for mercury from ferroalloy furnace smelting operations and the 

control options and impacts for these sources based on the MACT analysis. The impacts include 

the capital and annual control costs, emission reductions, and cost effectiveness for each of these 

control options. 

This analysis supplements the original MACT analysis 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). The existing MACT standards, which are also known as NESHAP, 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. Mercury 

emission limits were not established in the original MACT, and this analysis supports 

development of proposed limits. 

 

2.0 BACKGROUND

The raw materials used to produce ferroalloys contain trace amounts of mercury, which is 

emitted during the smelting process. These mercury emissions are derived primarily from the 

manganese ore, although there may be trace amounts in the coke or coal used in the smelting 

process. The mercury emissions can exist in three forms: elemental, oxidized, and as a 

particulate. While some of the mercury in particulate and oxidized forms is captured by the 

particulate control devices, the elemental mercury is largely emitted to the atmosphere. 
2

Control technologies used to reduce mercury emissions from combustion sources have been used 

with success on other sources. The most advanced technology, activated carbon injection (ACI) 

has been used on facilities that burn municipal solid waste, cement plants and electric generating 

units for the past decade. This technology uses particles of activated carbon to capture the 

mercury in the exhaust gas stream. This is achieved by injecting the activated carbon into the 

exit gas flow, downstream from the combustion source. Brominated ACI is especially effective 

at capturing mercury emissions. The mercury adsorbs to the activated carbon particles and is 

removed from the gas stream (along with the activated carbon particles) in a downstream 

particulate control device. This control technology may achieve 90 percent or greater removal of 

mercury from the exhaust stream (depending on the uncontrolled concentration and other 

factors), and it was selected as the control technology that would be used to reduce mercury 

emissions from the furnace smelting process at ferroalloy production facilities under two of the 

three options described in the following pages. 

In addition to mercury control, ACI would also be expected to achieve emission reductions of 

polycyclic aromatic hydrocarbons (PAH) from the furnace outlet. The PAH compounds are 

captured using the same adsorption mechanism as is used for oxidized mercury control by ACI. 

In adsorption, the PAH compounds adhere to the surface of a solid carbon particles. Based on 

information from carbon vendors, an activated carbon system that is designed to achieve up to 90 

percent reduction in mercury emissions, should also achieve significant reductions in PAH with 

no additional costs. Albemarle, a company that provides mercury control equipment to 

industries, noted in a presentation1that 9 out of 10 conventional boilers equipped with ACI 

reported PAH analytical results below the detection limit. The other boiler reported PAH results

that were only 10 percent above the detection limit. Another study2found that ACI can achieve 

74-91 percent reduction in PAH emissions depending on the concentration of activated carbon in 

the flue gas. 

3.0 FERROALLOY FACILITY SUMMARY

The following section describes the primary mercury emission sources for the Eramet Marietta, 

Inc. and Felman Production, Inc. ferroalloy production facilities, which are the two existing 

facilities in the source category. 

 

1

Presentation by Dr.Ronald R. Landreth, Albemarle, Alternative Method of Hg and THC Control Using Existing 

Cement Kiln Particulate Control Equipment, February 9, 2010.

2 Hong-Cang Zhou, Zhao-Ping Zhong, Bao-Sheng Jin, Ya-Ji Huang, and Rui Xiao, Experimental study on the 

removal of PAHs using in-duct activated carbon injection, Chemosphere, November 17, 2004.
3

Eramet Marietta Inc.

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

silicomanganese (SiMn) 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. Furnace 12 is a submerged arc 

furnace rated at 22 MW and is equipped with two wet venturi scrubbers to control primary and 

secondary emissions from melting and tapping. The scrubbers operate simultaneously and 

exhaust through a single stack. The facility has a third furnace, Furnace 18, which is permitted, 

but is considered to be inoperable until extensive repair can be made to the furnace. Therefore, 

Furnace 18 was not considered an emission source and was not included in this analysis. 

Felman Production Inc. 

The Felman facility is located in New Haven, West Virginia, and it 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 limit emissions of PM and metal HAP from the 

furnace. 

4.0 MACT FLOOR ANALYSIS

Mercury emissions data for each of the furnaces were obtained from the facilities from 

Information Collection Requests (ICR) in 2010 and 2012 and from stack test submittals by the 

facilities. More information on the test data collected in the ICR can be found in the test data 

review summaries3,4located in the docket. The individual test reports submitted by the facilities 

can also be found in the docket. The mercury test data from the 2010 ICR were collected using 

EPA Method 29, and the mercury test data from the 2012 ICR and other submitted test reports 

were collected using EPA Method 30B. The mercury test results from the two test methods were 

considered to be comparable and were used in the MACT Floor analysis. All of the test reports 

provided analytical results for mercury that were above the detection limit. The following 

sections outline the steps taken in determining the revised mercury MACT floors for the 

Ferroalloys Production source category using the upper prediction limit (UPL).

 

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

Report Review, May 28, 2013.

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

Report Review, July 29, 2013.
4

For mercury test datasets (for the development of a specific emissions limit) that consisted of at 

least 3 test runs but fewer than 7 test runs, an approach developed for limited datasets was used 

to calulate the UPL.5

4.1 Upper Predictive Limit (UPL) Methodology

The UPLs for mercury in the supplemental proposal were calculated using guidelines provided in 

the EPA UPL memorandum.

6

This document explains EPA’s use of the UPL, which is the 

statistical methodology EPA uses as the primary tool to account for emissions variability when 

setting emissions standards under Sections 112 and 129, and explains how the UPL is used to 

calculate the average emissions limitation achieved over time by the best performing source or 

sources.

4.2 Subcategorization of Mercury Emissions

The mercury test results for FeMn production were significantly different in comparison to the 

mercury test results during SiMn production. This difference is a direct result of the amount of 

raw materials and procedures used to produce the different products. The FeMn product consists 

of approximately 78 percent Mn content with a carbon content ranging from 7.5 to 0.5 percent 

carbon, and is produced using Mn ore and high carbon coke. The formula used to produce FeMn 

requires a much greater amount of Mn ore in comparison to the SiMn production, and the high 

carbon coke is needed to reduce the manganese oxide (MnO2) in the ore to produce the high Mn 

content in the FeMn product. The SiMn product is approximately 65 percent manganese, and 

includes approximately 16 percent silicon and 2 percent carbon. A different formulation of raw 

materials is used to produce the SiMn product. As stated previously, the primary source of 

mercury emissions from the furnace smelting process is the Mn ore used to produce the products. 

Because of the difference in the amount of Mn ore that is needed for FeMn production, the 

mercury emissions from FeMn production are significantly higher than the mercury emissions 

from SiMn production. Therefore, the ferroalloy products (FeMn and SiMn) were 

subcategorized for determining mercury emissions limits. 

4.2 Existing Furnace - Mercury

A total of eleven mercury tests from the outlet of the control device from the furnace smelting 

process were submitted to EPA from the Ferroalloy facilities. Two of the tests were measured 

using EPA Method 29 and the other nine were measured using EPA Method 30B. For the 

 

5 Memorandum from Barrett Parker and Brian Shrager, EPA OAQPS to Docket ID No. EPA-HQ-OAR-2010-0895, 

Approach for Applying the Upper Prediction Limit to Limited Datasets, September 3, 2014. (This memo is also 

referred to as the Limited Dataset Memo). 

6 Memorandum from Phil Mulrine, EPA OAQPS to Docket ID No. EPA-HQ-OAR-2010-0895, Use of the Upper 

Prediction Limit for Calculating MACT Floors, July 30, 2014.
5

purposes of determining a MACT floor, the mercury tests that were based on less than 3 runs

were removed from the data set, because they do not reflect a three run compliance test. The 

EPA Method 30B quality assurance criteria requires the paired samples to have a relative 

deviation of less than or equal to 10 percent for samples with a mercury concentration of greater 

than 1 microgram per dry standard cubic meter (μg/dscm). Five of the nine tests did not meet 

this criterion and were not used to determine the test average and are not included in the data set. 

A statistical analysis was performed on each of the data sets that were based on 3-run test data 

and a summary of the results is provided in Table 4-1. The skewness and kurtosis tests 

performed on each of the data sets showed that both the FeMn Production and the SiMn 

Production data sets were normally distributed based on the results of the skewness and kurtosis 

tests. The UPL for normally distributed data (Equation 1) was used to calculate the UPL for 

each of the two data sets. As the results show, the FeMn Production UPL result of 170 μg/dscm

(rounded up to the nearest whole integer using 2 significant figures) provides a limit that is 

higher than any of the test data results (to account for variability in the data set) and provides a 

limit that can be achieved using the current control technology. 

The mercury data set for SiMn production was also determined to normally distributed and the 

UPL for the data set was calculated to be 12 μg/dscm (rounded up to the nearest whole integer). 

The UPL, as described above, accounts for variability in the test data set and was determined to 

be achievable using the current control technology.

4.3 New Furnace - Mercury

The MACT floor for new sources was calculated by first determining the “best performing 

source” for each of the FeMn and SiMn production data sets. This was done by ranking the 

sources by the 99 percent UPL of the test data for each furnace. The source with the lowest UPL 

by furnace product (FeMn or SiMn) would be established as the “best performing source”, and 

the 99 percent UPL would be the MACT floor limit for new sources. A summary of the test data 

and the UPL rankings are provided in Appendix A. The test data for FeMn production only 

included data from Furnace 12 and therefore this furnace was selected as the “best performing 

source” and the 99 percent UPL was calculated to be 170 μg/dscm (same as the MACT floor for 

existing FeMn production furnaces).
6

Table 4-1. Results of Statistical Analysis of the Ferroalloys Mercury Test Concentration 

Data (μg/dscm) from the Furnace

Statistic FeMn 

Production

SiMn 

Production

Total Facility Count 1 2

Total Furnace Count 2 5

Average - All Runs 66.41 3.65

Sample Size (n) 6 12

Skewness (S) 0.35 1.04

Skewness Test Normal Normal

Kurtosis (K) -2.45 -0.46

Kurtosis Test Normal Normal

Normal Distribution UPL (99% Confidence Level) 162.16 11.04

Note: the calculated average, minimum, maximum, and UPL values shown in the table are in 

units of μg/dscm.

The MACT floor dataset for mercury from new furnaces producing SiMn includes 3 test runs 

from a single furnace (Felman Furnace 7) that was identified as the best performing unit based 

on average emissions. After determining that the dataset is best represented by a normal 

distribution and ensuring that the correct equation for the distribution was used, the variance of 

this unit was evaluated (Felman Furnace 7). The analysis showed that this unit, identified as the 

best unit based on average emissions, also had the lowest variance, indicating consistent 

performance. Therefore, it was determined that the emission limit reasonably accounts for 

variability and that no changes to the standard floor calculation procedure were warranted for 

this pollutant and subcategory, and it was proposed that the MACT floor is 4.0 μg/dscm for Hg

from new furnaces producing SiMn. More discussion on the development of MACT limits based 

on the use of limited datasets can be found in the FR Notice for this supplemental proposal and 

in the Limited Dataset Memo.

 

4.4 Beyond-The-Floor 

The beyond-the-floor control technology that was selected to reduce mercury from the 

production furnaces was ACI using brominated carbon sorbents. The bromine in the activated 

carbon can oxidize elemental mercury (Hg0) to oxidized mercury (Hg+2). The oxidized mercury 

is then suitable to be adsorbed by the activated carbon sorbent, which is then removed from the 
7

exhaust gas stream using a particulate control device. All of the furnaces at Felman (Furnaces 2, 

5, and 7) and one of the two furnaces at Eramet (Furnace 1) are equipped with a fabric filter 

system to reduce particulate matter. 

The other furnace at Eramet (Furnace 12) controls PM using a wet venturi scrubber. Limited 

data are available for the mercury reduction of ACI with a venturi scrubber system, but we 

identified one study conducted by the Minnesota Taconite Mercury Control Advisory Committee 

that evaluated mercury reductions from particulate scrubber systems and ACI.7In 2011, a field 

trial was conducted at Hibbing Taconite to demonstrate the effectiveness of brominated ACI in 

controlling mercury emissions from a taconite facility. The trial of the brominated ACI system 

was conducted in September and October 2011, and it was determined that 75 percent Hg 

removal could be achieved with a brominated ACI rate of about 3 lb/MMacf (126 lb/hr). This 75 

percent mercury reduction was demonstrated during a two-week continuous injection run. The 

project also noted that better mercury removal results could be achieved with improved sorbent 

distribution. Therefore, it is expected that the retrofit of ACI on the furnaces controlled by a 

scrubber would achieve at least 50 percent additional mercury reduction beyond the level of 

control that the scrubber is currently achieving. Because of the lower potential mercury 

reductions expected for brominated carbon ACI and a venturi scrubber (compared to the 

reductions that would be achieved with use of ACI with fabric filters), we decided that a 

reduction percentage of 50 percent should be used in establishing the beyond-the-floor mercury 

emissions limit to ensure that the limit could be achieved with brominated ACI on the furnace

equipped with a wet venturi scrubber at all times during FeMn production. 

For new and reconstructed production furnaces, it was concluded that these sources would be 

equipped with fabric filters and the installation of brominated carbon ACI would achieve 90 

removal of mercury from the furnace production exhaust gas stream. Therefore, it is 

recommended that the beyond-the-floor limit for new and reconstructed production furnaces be 

based on 90 percent mercury reduction.

5.0 MERCURY CONTROL OPTIONS

Three mercury control options were developed for new, reconstructed, and existing furnace 

melting operations based on the analysis of the test data. The mercury control options for exiting 

sources developed for consideration by EPA for the Supplemental proposal are as follows:

 

7 Michael E Berndt, Minnesota Department of Natural Resources, Division of Lands and Minerals, Minnesota 

Taconite Mercury Control Advisory Committee:

Summary of Phase One Research Results (2010-2012), November 29, 2012. 

http://files.dnr.state.mn.us/lands_minerals/reclamation/berndt_2012_final.pdf. 
8

 Option 1 

o Propose mercury limits based on the calculated UPL (i.e., MACT Floor) for each 

of the product types (SiMn, FeMn) for existing production furnaces; 

o Propose beyond-the-floor mercury limit (based on the installation of ACI and 

fabric filter) for new and reconstructed FeMn production furnaces; and

o Propose the best performing UPL mercury limit for new and reconstructed SiMn 

production furnaces (i.e., MACT Floor level for new sources). 

 Option 2 

o Propose beyond-the-floor mercury limit (based on the installation of ACI) for 

existing FeMn production furnaces;

o Propose the calculated UPL (i.e., MACT floor) for existing SiMn production 

furnaces;

o Propose beyond-the-floor mercury limit (based on the installation of ACI and 

fabric filter) for new and reconstructed FeMn production furnaces; and

o Propose the best performing UPL mercury limit for new and reconstructed SiMn 

production furnaces.

 Option 3 

o Propose beyond-the-floor mercury limit (based on the installation of ACI) for 

existing FeMn and SiMn production furnaces; and

o Propose beyond-the-floor mercury limit (based on the installation of ACI and 

fabric filter) for new and reconstructed FeMn and SiMn production furnaces.

Option 1 would base the mercury limits on the calculated UPL for existing FeMn and SiMn 

production furnaces from the mercury test data submitted by the facilities. For new sources, 

Option 1 would require 90 percent reduction of mercury for new and reconstructed production 

furnaces producing FeMn, and new and reconstructed SiMn production furnace mercury limit 

would be based on the UPL of the best performing source. 

The mercury limits for Option 2 would be based on the beyond-the-floor mercury reduction of 

50 percent from the existing FeMn furnaces and MACT Floor level of control for SiMn 

production furnaces. The mercury limits for Options 3 would be based on the beyond-the-floor 

mercury reduction of 50 percent from the existing FeMn and SiMn production furnaces 

calculated UPL values. A summary of the mercury limits for the proposed options are shown in 

Table 5-1. For new sources, Option 2 would require 90 percent reduction of mercury for new and 

reconstructed production furnaces producing FeMn, and new and reconstructed SiMn production 

furnace mercury limit would be based on the UPL of the best performing source. A summary of 

each of the mercury control option limits are provided in Table 5-1.
9

6.0 MERCURY CONTROL OPTION IMPACTS

The impacts of reducing mercury emissions from the furnace smelting process at ferroalloys 

production facilities are based on the costs and emission reductions achieved through the retrofit 

of ACI. This section summarizes the methodology and estimates the capital cost, annual cost, 

and expected mercury emission reduction of retrofitting ACI on the furnaces at Eramet and 

Felman. 

Table 5-1. Summary of Mercury Control Option Limits (μg/dscm) for Ferroalloy 

Production Furnaces

Mercury Control 

Option

FeMn 

Production

(Existing 

Sources)

FeMn 

Production

(New and 

Reconstructed 

Sources)

SiMn 

Production

(Existing 

Sources)

SiMn 

Production

(New and 

Reconstructed 

Sources)

Option 1 170 17 12 4

Option 2 85 17 12 4

Option 3 85 17 6 2

6.1 Capital and Annual Costs

The capital and annual costs of retrofitting ACI on ferroalloy furnaces were estimated using ACI 

cost algorithms8developed for the Mercury and Air Toxics Standards (MATS). The total capital 

investment (TCI) equation uses exhaust gas flow rate and carbon injection rate as variables to 

scale the cost of retrofitting ACI to the exhaust duct. The equation used for estimating TCI for 

the retrofit of ACI in 2012 dollars is presented below:

 

 

where;

Q = Volumetric flow rate of the exhaust gas in actual standard cubic feet per minute (acfm), 

 

8

Sargent & Lundy, IPM Model – Revisions to Cost and Performance for APC Technologies, Mercury Control Cost 

Development, Final, March 2013.
10

ACI Injection Rate = Estimated carbon injection rate (lb/MMacf), assumed 2.0 for furnaces 

equipped with a fabric filter and 5.0 for furnaces equipped with a venturi scrubber,

1,600,000 = Cost constant for installing an ACI system,

1.2 = Retrofit factor,

The TCI for the ACI algorithm include the costs for all of the equipment, installation, buildings, 

foundations, electrical, and retrofit factor to address difficulty of installation. This cost equation 

was used to estimate TCI for retrofitting ACI on each of the ferroalloy furnaces. It was assumed 

that the retrofit would take place upstream from the existing control device for Furnaces 2, 5, and 

7 at Felman and Furnace 12 at Eramet. For Furnace 1 at Eramet, it was assumed that a polishing 

baghouse would be installed and the ACI would be installed after the existing baghouse and prior 

to the newly installed polishing baghouse. The equation used to estimate the TCI for adding a 

polishing baghouse with an air-to-cloth ratio of 6.0 in 2012 dollars is presented below:

 

 

where;

Q = Volumetric flow rate of the exhaust gas in actual standard cubic feet per minute (acfm), 

530 = Cost constant for installing a fabric filter system with an air-to-cloth ratio of 6.0,

1.2 = Retrofit factor

To estimate the capital, engineering, and construction costs (CECC), expenses for engineering 

and construction management (10% of TCI), labor adjustments (5% of TCI), and contractor 

profit and fees (5% of TCI) were added to the calculated TCI equations above. The total project 

cost (TPC) was calculated by adding in the owner’s costs of engineering, construction, and 

procurement activities (5% of CECC) and allowance for funds used during construction (6% of 

CECC) to the total CECC.

Annual costs for operation of the ACI were broken into direct annual costs and indirect annual 

costs. Direct annual costs included operating labor, administrative and supervisory labor, 

maintenance and materials, amount of activated carbon injected, and the cost for disposal of the 

captured carbon. Indirect annual costs consisted of overhead, property taxes, insurance, 

administration, and capital recovery. Table 5-1 lists the assumptions used to calculate each of 

these direct and indirect costs.

The capital recovery factor was calculated assuming a 20-year equipment life and 7 percent 

interest. Additional cost data used for this estimate were obtained from a mercury control cost 
11

document developed for coal-fired utility boilers.9 This document provided the ACI injection 

rate (2 lb/MMacf for fabric filter applications, 5 lb/MMacf for non-fabric filter applications), 

non-hazardous waste disposal costs ($30/Ton), and cost for the ACI ($0.85/lb). A summary of 

the ACI costs is provided in Appendix B. In addition to these costs, the cost estimate also 

provides the cost of replacement of baghouse dust with manganese ore for the furnaces at 

Felman based on estimates provided by the facility. Felman currently recycles the baghouse dust 

back in the process and are unable to install polishing fabric filters on the existing positivepressure fabric filters.

Table 6-1. Activated Carbon Injection Model Annual Costs

Parameter Equation/Assumptions

Direct Annual Cost ($/yr)

1

Additional 

Operating Labor1 = $0

2 Supervisory Labor = 0.03 * (Operating Labor + 40% of Maintenance Costs)

3 Maintenance = 0.005 * TCI for ACI/Retrofit Factor 

4 Activated Carbon = (ACI Injection rate, lb/MMacf)*(Exhaust Flow Rate, acf/min) 

*(MMacf/106acf)*(60 min/hr)*(8760 hr/yr)*($0.75/lb)

5 Dust Disposal

= (ACI Injection rate, lb/MMacf)*(Exhaust Flow Rate, acf/min) 

*(MMacf/106acf)*0.99*(60 min/hr)*(8760 hr/yr)*(Ton/2000 lb) 

*($40/Ton)

Indirect Annual Cost ($/yr)

1 Overhead = 0.6 * (Labor + Maintenance)

2

Property taxes, 

insurance, and 

administration

= 0.04 * TCI

3 Capital Recovery = CRF * TCI

1

It was assumed that no additional operating labor is needed to operate the ACI.

 

9

Sargent & Lundy, IPM Model - Revisions to Cost and Performance for APC Technologies, Mercury Control Cost 

Development Methodology Final, March 2013.
12

6.2 Enhanced Capture Mercury Emissions

The enhanced capture emissions were used to estimate the emission reductions and cost 

effectiveness of applying ACI to control mercury from the furnace exhaust. The enhanced 

capture emissions for the furnaces include the following assumptions from baseline:

 Increase of Eramet Furnace 1 baghouse outlet emissions due to the addition of tapping and 

casting fugitive emissions to the furnace control device (e.g., increase of the volumetric flow rate 

to the furnace fabric filter),

 Decrease of Eramet Furnace 12 outlet emissions due to the subtraction of tapping fugitive 

emissions from the furnace control device (e.g., decrease of the volumetric flow rate to the 

furnace venturi scrubber),

 Increase of Felman furnace baghouse outlet emissions (applicable to Furnace 2, 5, and 7) 

due to the increased capture of tapping and casting fugitive emissions (e.g., increase of the 

volumetric flow rate to the furnace fabric filter).

The total baseline mercury emissions from the facilities were estimated to be 377.2 pounds per 

year (lb/yr), with 342 lb/yr generated by Eramet and 35.2 lb/yr generated by Felman. The total 

enhanced capture emissions from the facilities were estimated to be 363 lb/yr (328 lb/yr from 

Eramet and 35 lb/yr from Felman) and include the mercury reductions by the existing control 

devices (assumed to be 15% for baghouse and scrubbers). A summary of the baseline and 

enhanced capture mercury emissions are provided in Appendix A.

The mercury emissions for Option 2 were calculated using the enhanced capture modeling 

mercury emissions from Furnaces 1 and 12 at Eramet. This option does not apply to Felman, 

because they produce only SiMn in each of their three furnaces. The enhanced capture modeling 

emissions assumes 50 percent production of FeMn and 50 percent production of SiMn during the 

year. To estimate the mercury emissions during FeMn production, the hourly mercury test data 

for each of the furnaces were used to calculate the percentage of mercury emissions that occur 

during FeMn production. A summary of the mercury emissions test data and the enhanced 

capture modeling emissions are provided in Appendix A.

For each of the furnaces at Eramet, the average mercury emissions rate in pounds per hour (lb/hr) 

from the test data for each product was multiplied by 4,380 hours per year (i.e., 50% annual 

production of FeMn and SiMn). The percentage of mercury during FeMn production was then 

calculated by dividing the FeMn mercury emissions by the total mercury emissions for each 

furnace. The percentages of mercury emissions during FeMn production were calculated to be 

81.0 percent for Furnace 1 and 96.9 percent for Furnace 12. These percentages were applied to 

the total enhanced capture mercury emissions to calculate the enhanced capture emissions during 

FeMn production.
13

For Option 3, the mercury emissions for Eramet and Felman were calculated using the enhanced 

capture modeling emissions for mercury from each of the furnace outlets. For Eramet, the 

enhanced capture emissions assume equal annual production of FeMn and SiMn (e.g., 50% 

annual production of FeMn and 50% production of SiMn) in each of the furnaces. The Felman 

enhanced capture emissions assume 100 percent production of SiMn.

Impacts

A summary of the impacts for each of the proposed Mercury Control Options are presented in 

Table 6-2. The impacts for Control Option 1 were calculated to be zero. These impacts are 

based on the assumption that the facilities would be able to meet the mercury limits with their 

current furnace controls. The impacts for Control Option 2 are based on the installation of ACI 

on Furnace 1 and 12 at Eramet with operation only during the production of FeMn, and a 

polishing baghouse on Furnace 1. The emissions and annual cost for this option are based on the 

assumption that both furnaces produce FeMn 50 percent annually (or 4,380 hours per year). The 

mercury reduction is assumed to be 90 percent for the installation of ACI and the polishing 

baghouse on Furnace 1 at Eramet, and 50 percent for installation of ACI and the existing 

scrubber on Furnace 12 at Eramet.

The impacts for Control Option 3 were calculated assuming that all of the furnaces at Eramet and 

Felman would install and operate ACI during FeMn and SiMn production. Again, the 

assumption that ACI would be installed downstream from the Furnace 1 baghouse and a second 

polishing baghouse would be added. The emissions and annual cost for this option are based on 

the assumption that both furnaces at Eramet produce 50 percent annually (or 4,380 hours per 

year) of FeMn and 50 percent annually of SiMn. The furnaces at Felman are assumed to produce 

SiMn only. The mercury reduction is assumed to be 90 percent for the installation of ACI and 

the polishing baghouse on Furnace 1, and 50 percent for installation of ACI and the existing 

scrubber on Furnace 12 at Eramet. The mercury reduction for ACI installed with the existing 

baghouses at Felman is assumed to be 90 percent.

A breakdown of the individual furnace emission reductions and the capital and annual costs are 

provided in Tables 6-3 and 6-4. The spreadsheet calculation sheet with the control cost 

algorithms are provided in Appendix B for Options 2 and 3.
14

Table 6-2. Summary of the Estimated Emissions Reductions and Cost Impacts for the 

Mercury Control Options Considered for Existing Furnaces

Mercury Control 

Option

Hg Emission 

Reductions 

(lb/yr)

Total Capital 

Cost ($2012)

Total Annual 

Cost ($/year)

Cost 

Effectiveness 

($/lb)

Option 1 – MACT 

Floor for FeMn and 

SiMn Production

0 $0 $0 -----

Option 2 – Beyondthe-floor for FeMn 

Production and MACT 

Floor for SiMn 

Production

191 $30,195,970 $3,357,000 $17,579

Option 3 – Beyondthe-floor for FeMn and 

SiMn Production

251 $41,681,908 $6,868,423 $27,324
15

Table 6-3. Summary of Mercury Cost Effectiveness for Control Option 2

(Beyond-the-floor Mercury Control for Furnaces Producing FeMn Only)

Cost Parameter

Eramet EAF 1 

Cost ($2012)

Eramet EAF 12 

Cost ($2012)

Total Eramet 

Cost ($2012)1

Existing FF w/ 

ACI & New 

Polishing FF

ACI w/ Existing 

Venturi Scrubber

Polishing Baghouse Capital Cost2$14,659,265 $0 $14,659,265

Activated Carbon Injection Capital Cost2$3,184,766 $3,625,211 $6,809,977

Other Installation Capital Cost3$7,974,497 $752,231 $8,726,729

Total Capital Cost $25,818,528 $4,377,442 $30,195,970

Direct Annual Cost ($/yr)4$212,575 $318,449 $531,023

Indirect Annual Cost ($/yr)5$2,334,447 $491,529 $2,825,976

Total Annual Cost ($/yr) $2,547,022 $809,977 $3,357,000

Enhanced Capture Mercury Emission Rate (lb/yr)6127.5 152.4 279.9

Mercury Emission Reduction w/ ACI (lb/yr)7114.8 76.2 191.0

Mercury Cost Effectiveness ($/lb) $22,195 $10,628 $17,579

1 Mercury Control Option 1 includes: Eramet EAF 1 - adding ACI and polishing fabric filter (FF) to existing EAF #1 

w/ FF, Eramet EAF 12 - adding ACI to existing EAF #12 with a Venturi Scrubber (VS).

2

ACI and baghouse (BH) costs developed using capital and annual cost algorithms from the IPM Model -

Revisions to Cost and Performance for APC Technologies, Mercury Control Cost Development Methodology, 

March 2011.

3

Other installation capital costs include: engineering and construction management, construction labor 

adjustment, and contractor profit & fees.

4

Direct annual costs include: operating labor, administrative and supervisory labor, maintenance labor and 

materials, activated carbon, and non-hazardous dust disposal for Eramet.

5

Indirect annual costs include: overhead, property tax, insurance, administration, and capital recovery (20 

years @ 7% interest).

6 Mercury enhanced capture emissions during FeMn Production were assumed to be 81% for Furnace 1 and 

96.9% for Furnace 12 of the total enhanced capture mercury emissions from the respective furnace.

7

Assumes 90% mercury reduction for FF and 50% mercury reduction with a VS.
Table 6-4. Summary of Mercury Cost Effectiveness for Control Option 3

(Beyond-the-floor Mercury Control for Furnaces Producing FeMn and SiMn)

Felman Furnace 2 

Cost ($2012)

Felman Furnace 5 

Cost ($2012)

Felman Furnace 7 

Cost ($2012)

Eramet EAF 1 Cost 

($2012)

Eramet EAF 12 

Cost ($2012)

ACI w/ Existing 

Fabric Filter

ACI w/ Existing 

Fabric Filter

ACI w/ Existing 

Fabric Filter

Existing FF w/ ACI 

& New Polishing FF

ACI w/ Existing 

Venturi Scrubber

Polishing Baghouse Capital Cost2 $ 0 $ 0 $ 0 $ 0 $14,659,265 $ 0 $14,659,265

Activated Carbon Injection Capital Cost2 $3,320,988 $3,069,015 $3,122,161 $9,512,164 $3,184,766 $3,625,211 $6,809,977

Other Installation Capital Cost3 $689,105 $636,821 $647,848 $1,973,774 $7,974,497 $752,231 $8,726,729

Total Capital Cost $4,010,093 $3,705,836 $3,770,009 $11,485,937 $25,818,528 $4,377,442 $30,195,970

Direct Annual Cost ($/yr)4 $653,379 $513,562 $737,893 $1,904,834 $309,190 $534,886 $844,076

Indirect Annual Cost ($/yr)5 $451,132 $417,674 $424,731 $1,293,537 $2,334,447 $491,529 $2,825,976

Total Annual Cost ($/yr) $1,104,511 $931,236 $1,162,624 $3,198,371 $2,643,638 $1,026,415 $3,670,052

Enhanced Capture Emission Rate (lb/yr)6 21.0 4.47 9.05 34.5 157.4 157.3 314.7

Mercury Emission Reduction w/ ACI (lb/yr)7 18.9 4.02 8.15 31.0 141.7 78.6 220.3

Mercury Cost Effectiveness ($/lb) $58,516 $231,461 $142,732 $103,026 $18,660 $13,051 $16,658

7

 Assumes 90% mercury reduction for FF and 50% mercury reduction with a VS.

5

 Indirect annual costs include: overhead, property tax, insurance, administration, and capital recovery (20 years @ 7% interest).

Total Eramet Cost 

($2012)1

6

 Eramet mercury enhanced capture emissions based on 50/50 production of FeMn and SiMn. Felman mercury enhanced capture emissions based on 100% production of SiMn.

Total Felman Cost 

($2012)1

1

 Mercury Control Option 1 includes: Eramet EAF 1 - adding ACI and polishing FF to existing EAF #1 w/ FF, Eramet EAF 12 - adding ACI to existing EAF #12 w/ VS.

Cost Parameter

2

 ACI and BH costs developed using capital and annual cost algorithms from the IPM Model - Revisions to Cost and Performance for APC Technologies, Mercury Control Cost Development 

Methodology, March 2011.

3

 Other installation capital costs include: engineering and construction management, construction labor adjustment, and contractor profit & fees.

4

 Direct annual costs include: operating labor, administrative and supervisory labor, maintenance labor and materials, activated carbon, and non-hazardous dust disposal.
Appendix A

Ferroalloys Enhanced Capture Modeling Emissions
Furnace Exhaust Metals Data - Mercury

Facility Sample Date Sample Location Test Method

Furnace 

Product

Run 1 

Concentration 

(ug/dscm)

Run 2 

Concentration 

(ug/dscm)

Run 3 

Concentration 

(ug/dscm)

Average 

Concentration 

(ug/dscm)

Furnace 

Average Conc 

(μg/dscm)

Number of 

Test Runs in 

Furnace 

Average

Furnace 99% 

UPL

Eramet 8/16/2010 Furnace 12 Scrubber Outlet Method 29 FeMn 30.91690882 29.04580776 34.71330978 31.55867545

Eramet 7/25/2012 Furnace 12 Scrubber Outlet Method 30B FeMn 79.18319179 117.865174 106.7332978 101.2605545 66.41 6 162.2

Eramet 7/24/2012 Furnace 1 Baghouse Outlet Method 30B SiMn 8.82639694 11.8671484 9.616869043 10.10347146 10.10 3 19.1

Felman 7/9/2010 Furnace 2 Baghouse Outlet Method 29 SiMn 0.58892451 4.78456279 4.118866388 3.164117896

Felman 3/20/2013 Furnace 2 Baghouse Outlet Method 30B SiMn 0.377592727 0.468697016 0.527722169 0.458003971 1.81 6 6.7

Felman 8/7/2012 Furnace 7 BaghouseOutlet Method 30B SiMn 0.346541306 0.68328608 1.53470698 0.854844789 0.85 3 4.3
Enhanced Capture Modeling Emissions for Mercury

Emission Description Baseline Mercury 

TPY

Enhanced Capture 

Mercury TPY

Eramet Marietta

Furnace #1 Baghouse Outlet 0.0780 0.0787

Furnace #1 Fugitives 0.00172 0.00172

Furnace #1 Casting Baghouse 0.0000526 0.000121

Furnace #1 Tapping Fugitives 0.000820 0.0000512

Furnace #12 Scrubber Outlet 0.0855 0.0786

Furnace #12 Fugitives 0.00189 0.00189

Furnace #12 Tapping Fugitives 0.000690 0.0000493

MOR Process Baghouse Outlet 0.00212 0.00232

MOR Process Fugitives 0.000176 0.0000147

Furnace #1 Casting 0.000150 0.00000749

Furnace #12 Casting 0.000144 0.00000720

MOR casting 0.000176 0.0000147

Furnace #12 Tap/Cast Baghouse ----- 0.000661

MOR Secondary Baghouse ----- 0.0000749

Eramet Marietta Total 0.171 0.164

Felman Production

Furnace No. 2 Baghouse Outlet 0.0103 0.0105

Furnace No. 2 Fugitives 0.000228 0.0000285

Furnace No. 2 Tapping Fugitives 0.0000909 0.0000152

Furnace No. 5 Baghouse Outlet 0.00219 0.00224

Furnace No. 5 Fugitives 0.0000484 0.00000605

Furnace No. 5 Tapping Fugitives 0.0000450 0.00000750

Furnace No. 7 Baghouse Outlet 0.00446 0.00453

Furnace No. 7 Fugitives 0.0000985 0.0000123

Furnace No. 7 Tapping Fugitives 0.0000450 0.00000750

Furnace No. 2 Casting 0.0000266 0.00000221

Furnace No. 5 Casting 0.0000132 0.00000110

Furnace No. 7 Casting 0.0000132 0.00000110

Secondary Furnace Baghouse ----- 0.000208

Felman Production Total 0.0176 0.0175

Note that these enhanced emissions estimates in this table do not include any reductions due to 

the installation of ACI and only include the reductions from the existing control technology.
Appendix B

ACI Control Cost Spreadsheet Calculation Sheets for the Mercury Control Options
Activated Carbon Injection Model Costs1

 - Option 2

Ferroalloys Furnace Eramet EAF 1 Eramet EAF 12

Control Device

Existing FF w/ ACI & 

New Polishing FF

ACI w/ Existing 

Venturi Scrubber

Annual Operating Hours, hr/yr (H) 4380 4380

Exhaust Gas Flow Rate, acfm (Qa) 243,217 230,724 Scrubber outlet flow rates for EAF 12 corrected to 375 F to estimate inlet flow rate

Exhaust Gas Flow Rate, dscfm (Q) 187,152 146,142

Operating Labor Rate, $/hr (LR) $60.00 $60.00 Labor rates listed in Eramet Comments

Activated Carbon Cost, $/lb (ACC) $0.85 $0.85 Cost for from IPM ($1700/Ton, 2012 dollars)

Dust Disposal Cost, $/Ton (DDC, Non-Hazardous) $30.00 $30.00 Cost based on email from Chuck French 11/05/2013, FW: Question regarding costs of diposing ACI mercury control wastes

Dust Disposal Cost, $/Ton (DDC, Hazardous) N/A N/A Dust is assumed not to be hazardous waste

Capital Recovery Factor (CRF) 0.094392926 0.094392926 CRF calculated assuming 20-year equipment life and 7% interest

ACI Adjustment Factor (AF) 0.9 0.5 Estimated Hg control efficiency

ACI Injection Rate (lb/MMacf) 2.0 5.0

ACI Injection Rate, lb/hr (M) 29.2 69.2 Calculated using acfm*60*ACI Injection Rate (lb/MMACF)/1000000

Retrofit Factor 1.2 1.2

Outlet PM Emission Rate (Tons/yr) 3.3 15.7 PM emission rate during FeMn production

ACI Total Capital Investment, $ (TCI) $3,184,766 $3,625,211 Calculated using algorithm1 1,600,000*Retrofit Factor*ACI Injection Rate (lb/hr) (2012 dollars)

BH Total Capital Investmant, $ (TCI) $14,659,265 $ 0 Calculated using algorithm1 530*Retrofit Factor*(acfm^0.81) for 6.0 cloth-to-air ratio (2012 dollars)

Engineering & Construction Management $1,784,403 $181,261 10% of total TCI w/ baghouse, 5% of TCI w/o baghouse

Labor Adjustment (shift, per diem, etc.) $1,784,403 $181,261 10% if baghouse addition, else 5% of total TCI

Contractor Profit and Fees $1,784,403 $181,261 10% if baghouse addition, else 5% of total TCI

Capital, Engineering, and Construction Cost, $ (CECC) $23,197,240 $4,168,993

Owners costs $1,159,862 $208,450 5% of CECC (Owners engineering, management, and procurement activities)

Engineering and construction cycle $1,461,426 $ 0 6% of CECC + Owners cost for additional baghouse (2-year engineering and construction cycle), 0% for ACI only (1-year engineering and construction cycle)

Total Project Cost, $ (TPC) $25,818,528 $4,377,442

Direct Annual Cost, $/yr (DAC)

Operating Labor $16,425 $16,425 Calculated using (0.25 hr/8-hr shift) x 3 shifts/day x 365 days/yr x LR

Administration & Supervisory Labor $1,385 $855 Calculated using 3% of the sum of the Operating Labor and 40% of the Maintainance

Maintenance & Materials $74,350 $30,210 Fixed O&M additional maintenance material and labor costs (0.01 for ACI only, 0.005 BH and ACI)

Activated Carbon $108,660 $257,695

Dust Disposal (Non-Hazardous) $11,755 $13,263 Calculated using ACI injection rate, 99% capture efficiency, and non-hazardous disposal cost

Indirect Annual Cost, $/yr (IAC)

Overhead $55,296 $28,494 OAQPS Control Cost Manual - calculated using 0.6 x (Labor + Maintenance)

Property Tax, Insurance, & Admin $594,801 $120,840 OAQPS Control Cost Manual - calculated using 0.04 x TCI

Capital Recovery $1,684,350.28 $342,194 Calculated using CRF x TCI

Total Annual Cost $2,547,022 $809,977 Sum of DAC + IAC

1

 Sargent & Lundy, IPM Model - Revisions to Cost and Performance for APC Technologies, Mercury Control Cost Development Methodology Final, March 2013
22

Activated Carbon Injection Model Costs1 - Option 3

Ferroalloys Furnace Felman EAF 2 Felman EAF 5 Felman EAF 7 Eramet EAF 1 Eramet EAF 12

Control Device

ACI w/ Existing 

Fabric Filter

ACI w/ Existing 

Fabric Filter

ACI w/ Existing 

Fabric Filter

Existing FF w/ ACI & 

New Polishing FF

ACI w/ Existing 

Venturi Scrubber

Annual Operating Hours, hr/yr (H) 8760 8760 8760 8760 8760

Exhaust Gas Flow Rate, acfm (Qa) 321,558 190,022 213,065 243,217 230,724 Scrubber outlet flow rates for EAF 12 corrected to 375 F to estimate inlet flow rate

Exhaust Gas Flow Rate, dscfm (Q) 195,393 123,696 142,661 187,152 146,142

Operating Labor Rate, $/hr (LR) $60.00 $60.00 $60.00 $60.00 $60.00 Labor rates listed in Eramet Comments

Activated Carbon Cost, $/lb (ACC) $0.75 $0.75 $0.75 $0.75 $0.75 Cost for from IPM ($1500/Ton, 2009 dollars)

Dust Disposal Cost, $/Ton (DDC, Non-Hazardous) $30.00 $30.00 $30.00 $30.00 $30.00 Cost based on email from Chuck French 11/05/2013, FW: Question regarding costs of diposing ACI mercury control wastes

Dust Disposal Cost, $/Ton (DDC, Hazardous) N/A N/A N/A N/A N/A Dust is assumed not to be hazardous waste

Capital Recovery Factor (CRF) 0.094392926 0.094392926 0.094392926 0.094392926 0.094392926 CRF calculated assuming 20-year equipment life and 7% interest

ACI Adjustment Factor (AF) 0.9 0.9 0.9 0.9 0.5 Estimated Hg control efficiency

ACI Injection Rate (lb/MMacf) 2.0 2.0 2.0 2.0 5.0

ACI Injection Rate, lb/hr (M) 38.6 22.8 25.6 29.2 69.2 Calculated using acfm*60*ACI Injection Rate (lb/MMacf)/1000000

Retrofit Factor 1.2 1.2 1.2 1.2 1.2

Outlet PM Emission Rate (Tons/yr) 14.5 13.2 21.7 7.2 42.1

ACI Total Capital Investment, $ (TCI) $3,320,988 $3,069,015 $3,122,161 $3,184,766 $3,625,211 Calculated using algorithm1 1,600,000*Retrofit Factor*ACI Injection Rate (lb/hr) (2012 dollars)

BH Total Capital Investmant, $ (TCI) $ 0 $ 0 $ 0 $14,659,265 $ 0 Calculated using algorithm1 530*Retrofit Factor*(acfm^0.81) for 6.0 cloth-to-air ratio (2012 dollars)

Engineering & Construction Management $166,049 $153,451 $156,108 $1,784,403 $181,261 10% of total TCI w/ baghouse, 5% of TCI w/o baghouse

Labor Adjustment (shift, per diem, etc.) $166,049 $153,451 $156,108 $1,784,403 $181,261 10% if baghouse addition, else 5% of total TCI

Contractor Profit and Fees $166,049 $153,451 $156,108 $1,784,403 $181,261 10% if baghouse addition, else 5% of total TCI

Capital, Engineering, and Construction Cost, $ (CECC) $3,819,136 $3,529,367 $3,590,485 $23,197,240 $4,168,993

Owners costs $190,957 $176,468 $179,524 $1,159,862 $208,450 5% of CECC (Owners engineering, management, and procurement activities)

Engineering and construction cycle $ 0 $ 0 $ 0 $1,461,426 $ 0 6% of CECC + Owners cost for additional baghouse (2-year engineering and construction cycle), 0% for ACI only (1-year engineering and construction cycle)

Total Project Cost, $ (TPC) $4,010,093 $3,705,836 $3,770,009 $25,818,528 $4,377,442

Direct Annual Cost, $/yr (DAC)

Operating Labor $16,425 $16,425 $16,425 $16,425 $16,425 Calculated using (0.25 hr/8-hr shift) x 3 shifts/day x 365 days/yr x LR

Administration & Supervisory Labor $825 $800 $805 $1,385 $855 Calculated using 3% of the sum of the Operating Labor and 40% of the Maintainance

Maintenance & Materials $27,675 $25,575 $26,018 $74,350 $30,210 Fixed O&M additional maintenance material and labor costs (0.01 for ACI only, 0.005 BH and ACI)

Activated Carbon $253,516 $149,813 $167,980 $191,752 $454,757

Dust Disposal (Non-Hazardous) $132,762 $119,050 $194,378 $25,278 $32,639 Calculated using ACI injection rate, 99% capture efficiency, and non-hazardous disposal cost

Additional ore for loss of BH dust $222,176 $201,899 $332,287 $ 0 $ 0 $756,361

Indirect Annual Cost, $/yr (IAC)

Overhead $26,955 $25,680 $25,949 $55,296 $28,494 OAQPS Control Cost Manual - calculated using 0.6 x (Labor + Maintenance)

Property Tax, Insurance, & Admin $110,700 $102,300 $104,072 $594,801 $120,840 OAQPS Control Cost Manual - calculated using 0.04 x TCI

Capital Recovery $313,478 $289,693 $294,710 $1,684,350 $342,194.27 Calculated using CRF x TCI

Total Annual Cost $882,336 $729,337 $830,337 $2,643,638 $1,026,415 Sum of DAC + IAC

1

 Sargent & Lundy, IPM Model - Revisions to Cost and Performance for APC Technologies, Mercury Control Cost Development Methodology Final, March 2013