MEMORANDUM

DATE: August 29

, 201 4

SUBJECT: Mercury Control Options and Impacts for th e Ferroalloys Production Industry

FROM: Bradley Nelson, EC/R, Inc.

TO: Phil Mulrine , EPA OAQPS/SPPD/ M IC G

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 s melting operations and the control options and impacts for these sources based on the MACT analysis. Th e 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 sta ndards, 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 (HA P) 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 mer cury 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 device s , the elemental mercury is largely emitted to the atmosphere.2

C ontrol 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 p articles 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 c ombustion 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 particu late 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, t h e 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 reduction s in PAH with
no additional costs. Albemarle, a company that provides mercury control equipment to industries, noted in a presentation 1 that 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 study 2 found 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 followin g section describes the primary mercury e mission 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 pres sure 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 oper ate 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 emi ssion source and was not included in th is 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 M ACT 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 f ound in the test data
review summaries 3

, 4 located 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 w ere collected using EPA Method 29, and the mercury test dat a from the 2012 ICR and other submitted test reports

w ere 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 analyt ical 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 predicti on limit (UPL)

.

3 Memorandum from Bradley Nelson, EC/R to Conrad Chin, EPA/OAQPS/SPPD/M IC G

, Ferroalloys 2012 Test Report Review

, May 28, 2013

. 4 Memorandum from Bradley Nelson, EC/R to Conrad Chin, EPA/OAQPS/SPPD/M IC G

, Ferroalloys 201 3 Test Report Review , July 29 , 2013

.4

For mercury test data sets (for the development of a specific emissions limit) that consist ed 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 UPL s for mercury in the supplemental proposal w ere 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 S ections 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 Emission s

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 (MnO 2 ) in the ore to produce the high Mn
content in the FeMn product. T he SiMn product is approximately 65 percent manganese , and includes appro ximately 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 (Fe Mn 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

- 089 5, 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 s kewness and kurtosis tests performed on each of the data set s showed that both the FeMn Production and the SiMn
Production data sets were normal ly distributed based on the results of the skewness and kurtosis

test s

. The UPL for normally distributed data (Equation 1) was used to calculate the UPL for
each of the t wo data sets

. As the results show, the FeMn Production UPL result of 1 70 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 prod uct (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 f or FeMn production on ly 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 Stati stical Analysis of the Ferroalloys Mercury Test Concentration

Data ( μg/dscm ) f

rom 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 1 2

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) 1 62.16 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 w as 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 evaluate d ( Felman F urnace 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 propos ed 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 c ontrol 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 (Hg 0 ) to oxidized mercury (Hg +2 ) . The oxidized mercury is then suitable to be adsorbed by the activated carbon sorbent, which is then removed from the7

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. 7 In 2011, a field trial was conducted at Hibbing Taconite to d emonstrate 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 achieve d 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 sorben t
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 es tablishing 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

T hree 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 proposa l 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 Rese arch 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
f abric 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 lim it (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) fo r 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 exi sting 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 f

rom the existing FeMn furnaces and MACT Floor level o f 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 t he 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) Si

Mn
Production (Existing Sources) Si

Mn
Production (New and
Reconstructed Sources)
Option 1 1 70 1 7 12 4

Option 2 8 5 1 7 12 4

Option 3 8 5 1 7 6 2

6 .1 Capital and Annual Costs

The capital and annual cost s of retrofitting ACI on ferroalloy furnaces w ere estimated using ACI

cost algorithms 8 developed 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

– Revisi ons to Cost and Performance for APC Technologies, Mercury Control Cost Development

, Final, March 201 3

.10

ACI Injection Rate = Estimated carbon injection rate (lb/MMacf), assumed 2.0 for furnaces equipped with a fabric filter and 5.0 for f urnaces equipped with a ventur i scrubber, 1, 60 0,000 = 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 retrof it 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 t he retr ofit 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. T he equat ion 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 m inute (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 o wner’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 rec overy. 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 w ere obtained from a mercury control cost11

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 disposa l 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 b ased 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 positive

pressure fabric filters.

Table 6

- 1. Activated Carbon Injection Model Annual Costs

Parameter Equation/Assumptions

Direct Annual Cost ($/yr)

1 Additional Operating Labor 1 = $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/10 6 acf)*(60 min/hr)*(8760 hr/yr)*($0.75/lb)

5 Dust Disposal = (ACI Injection rate, lb/MMacf)*(Exhaust Flow Rate, acf/min) *(MMacf/10 6 acf)*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 merc ury 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 fur nace 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 volume tric 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 me rcury 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 w ere used to calculate the percentage of mercury emissions that occur during FeMn production. A summary o f 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 mercur y 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 pro duction.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 Fe Mn 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 emission s and annual cost for this option are based on the assumption that bo th 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 5 0 percent for installation of ACI and the existin g 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 5 0 percent for installation of ACI and the e xisting
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 i n 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 o f the Estimated Emissions Reductions and Cost Impacts for the

Mercury Control Option s 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

– Beyond

the

- floor for FeMn
Production and MACT
Floor for SiMn
Production 191 $ 30

, 195

, 970 $ 3

, 3 57

, 000 $1 7

, 579

Option 3

– Beyond

the

- floor for FeMn and
SiMn Production 251 $ 41

, 681

, 9 08 $ 6

, 868

, 42 3 $ 2 7

, 32415

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 Cost 2 $14,659,265 $0 $14,659,265

Activated Carbon Injection Capital Cost 2 $3,184,766 $3,625,211 $6,809,977

Other Installation Capital Cost 3 $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) 6 127.5 152.4 279.9

Mercury Emission Reduction w/ ACI (lb/yr) 7 114.8 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 Technol ogies, 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 la bor, 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 o f 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 )Appendix A

Ferroalloys Enhanced Capture Modeling EmissionsEnhanced 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 S heets for the Mercury Control Options22