May9, 2012 

Attn: Compliance Tracker, AE-17J 

Ai1; Enforcement and Compliance Assurance Branch 

U.S. Enviromnental Protection Agency 

Region 5 

77 W. Jackson Boulevard 

Chicago, Illinois 60604 

10)~ © ~ o w ~rm lffi MAY 1'.0 2012 lYJ 

ruRENFORCEMENTBRANCH 

U.S. EPA REG!ON 5 

ArcelorMittal 

Re: ArcelorMittal Minorca Mine Inc. Response to Clean Air Act Section 114 Request to 

Provide Information Regarding Best Available Retrofit Technology (BART) Compliance 

This letter and the enclosed data disks are the response of ArcelorMittal Minorca Mine Inc. (refened to 

herein as "Minorca" or "we") to the "Request to Provide Infonnation Requested Pursuant to Clean Air 

Act" (the "Request"), regarding the iron ore processing facility located at 5950 Old Highway 53 North, 

which we received on April 12, 2011. The Request required a response within 15 days of receipt. Upon 

receipt of the request, Minorca asked for and received an extension, making this response due by May 9

1

h. 

The extension was approved by Molly DeSalle, EPA's contact person for this response. Minorca hereby 

provides this timely r"esponse to the Request, with the understandings and clarifications noted herein. 

Minorca has given careful consideration to this Request and each of its questions to ensure that its 

response is accurate and properly tailored to the infmmation EPA has requested. Most of the information 

requested is public infom1ation that has been submitted previously to a regulatory agency, so Minorca is 

not requesting that any pmiion of this response be considered Confidential Business Information. 

This response restates each of the questions in the Request and provides a narrative explanation of the 

responsive infom1ation. Responsive documents are referenced in the nanative and included on the data 

disks enclosed with this letter. The disks are organized by numbered folders that correspond to the 

questions below. Each disk is labeled with the company name, folders contained on that disk, and the 

date of response. Documents responsive to multiple questions are identified in the nanative response to 

each question, and are included on the disks under the question to which the documents are most 

responsive. The documents provided have been scanned for viruses using Microsoft Forefront Endpoint 

Protection software. 

If you have any questions or concerns about the infonnation provided, please direct your questions to 

Minorca's counsel, Douglas McWilliams, at Douglas.McWilliams@squiresanders.com. 
U.S. Envirom11ental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 ArcelorMitta I 

Page 2 

1. Provide process flow diagrams for both the taconite iron ore mmmg and the taconite pellet 

manufacturing process. Include in th.e description, at minimum, b~formation on the following: 

mining operations, ore transfer and storage, course ore crushing, fine ore crushing, ore 

classification screens, ore storage bins, grinding rod/ball mills, separation, thickeners, balling 

drums/pellet formation, indurating furnace, pellet cooling and storage, and the process boilers. 

lllclude a detailed narrative process description. and photographs to explain the indurating furnace 

process. For each photograph, provide a coded diagram/map to clearly identifY the location of the 

image in the photograph. Photographs must correspond to each of the process stages described. 

Responsive documents are included in Folder 01. The folder includes the following ftles: 

• Document 1-1 is a facility brochure which provides an overview of the facility history and 

operation overview, including a facility process flow diagram and description of each process 

unit. A more detailed description of the indurating furnace process is provided in the nanative 

response below. 

• Document 1-2 contains a schematic indurating furnace including an indication of the air flow 

directions and recycling throughout the various zones. This schematic is being provided in 

lieu of photographs because Minorca does not possess cunent photographs of the indurating 

furnace that would be useful in this context. The schematic is am1otated with letters referenced 

in the process description below. Minorca's indurating furnace is a straight grate furnace that 

is capable of producing up to approximately 3.2 million long tons per year (LTPY). It was 

manufactured by Dravo and startup occmTed in 1977. The indurating fum ace contains 8 

preheat burners (10 MMBtu/hr each), 2 upper burners (60 MMBtulhr each), and 2 lower 

bumers (60 MMBtulhr each). The lower bumers are not cunently in use. The fumace is fueled 

by natural gas, and is capable of combusting distillate oil as a backup for the upper and lower 

burners. Before the feed enters the furnace, a "heat1h layer" 3 inches deep is laid on the grate 

before "green balls" are placed on top. The hearth layer is made of pre-fired pellets. The heat1h 

layer protects pallet car sidewalls and grate bars fi·om extreme heat encountered in firing and 

preheat zones. 

The following description cmTesponds to lettered sections of the indurating fumace as shown in 

Document 1-2 ofMinorca's section 114 response. 

Zone A. First, the green balls enter the updraft drying zone. The wann air fi·om the 2nd 

cooling zone (Zone F) flows up fi·om below the green balls for initial drying. The 

hood exhaust fan draws the warm-moist air from the updraft drying zone and some 

air from the firing zone (Zone D) and sends it to the scrubbers. 

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U.S. Environmental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 ArcelorMittal 

Page 3 

Zone B. 

Zone C. 

Zone D. 

Zone E. 

Zone F. 

Next, the green balls enter the downdraft drying zone. Hot air from the firing zone 

supplies the downdraft drying zone. The hot air passes down the pellet bed 

completing the drying process. The gas is exhausted to the indurator gas scrubber 

stacks by the windbox exhaust fan. 

Green balls then enter the preheat zone. Eight (8) preheat burners provide the 

energy input required to calcine fluxstone in the green balls. Hot air from tl).e 1st 

cooling zone (Zone E) is recycled to the preheat burner down-comers providing 

combustion and heating air. The windbox exhaust fan discharges gas from the 1st 

half of the preheat zone to the stacks. The second half of the preheat zone is 

exhausted by the windbox recoup fan. The gas fl:om the windbox recoup fan is used 

in the downdraft drying zone. 

Next, the green balls enter the firing zone. Hot air fiom the 1st cooling zone is 

recycled to two combustion chambers. The hot air is used for combustion and 

heating. Each chamber has a bumer in the roof (the "upper burners") to heat the 

recycled air before it flows down through the bed of green balls. There are bumers 

located at the bottom of the combustion chambers (the "lower burners") that 

currently are not in use. Here, the green balls are transformed from magnetite to 

hematite by a process called induration. The green balls are dried and heated at 

approximately 18% oxygen and 2450of. The green ball is referred to as a pellet 

after induration is completed. A windbox recoup fan collects the hot air and sends it 

to the downdraft drying zone from step B. 

The fired pellets then go to the 1st cooling zone. The cooling air fans draws 

ambient air and sends it up through the pellets for cooling. The heated air from the 

1st cooling zone is recycled into the firing zone burner ducts and the preheat burner 

ducts in Zone C. 

The pellets then enter the 2nd cooling zone. The cooling air fans draws ambient air 

and again, sends it up through the pellets for cooling. The heated air from the 2nd 

cooling zone is recycled through the updraft drying fan into the updraft drying 

section from Zone A. 

Jaime Baggenstoss (Enviromnental Engineer) and Adam Sersha (Process Engineer) of ArcelorMittal 

Minorca Mine, with the assistance of Be·au Thurman of Ban Engineering, provided infonnation for 

this response. 

2. For the time period January 1, 2010 toDecember 31, 2011, provide manufacturing specification 

and operating data to demonstrate operating parameters for the facility's indurating furnace. 

Operating parameters and data must include, at a minimum: flue gas composition, entrance 

. 3. 
U.S. Envirom11ental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 

r~ ArcelorM itt a I 

Page4 

temperature, exit air temperature, preheat zone temperature, burner temperature, pellet 

residence time, and air flow rate. 

Two documents summarizing indurating fumace data are included in Folder 02. 

• Document 2-1 contains flue gas composition, pellet residence time, and air flow rate data. Flue 

gas composition and the air flow rate were derived fi:om two recent stack tests conducted in 

2011. Pellet residence time was approximated based on the average speed of the fumace belt 

and length of the furnace between the entrance of the preheat zone and the exit of the firing 

zone. 

• Document 2-2 contains temperature data. Data was collected fiom thennocouples within the 

furnace and reflect the pre-drying temperature, temperature at the start and end of the pre-heat 

zone, and temperature at the entrance to the combustion chambers. A diagram of the 

thermocouple locations is included in this document. 

Jaime Baggenstoss (Enviromnental Engineer) and Adam Sersha (Process Engineer) of ArcelorMittal 

Minorca Mine provided infonnation for this response. 

3. For the time period January 1, 2007 to December 31, 2011, provide records of the natural gas 

used by the indurating furnace at the facility. 

Document 3-1 is a spreadsheet containing monthly natural gas usage and is included in Folder 03. 

Natural gas usage information is calculated monthly based on purchase records. 

Jaime Baggenstoss (Enviromnental Engineer) and Adam Sersha (Process Engineer) of ArcelorMittal 

Minorca Mine provided infom1ation for this response. 

4. For the time period January 1, 2007 to December 31, 2011, if coal was used as a fuel source at 

the facility, provide documentation of the average sulfur content for coal used by the indurating 

furnace at the facility. 

Minorca does not use coal as a fuel source and therefore has no infom1ation responsive to this request. 

5. If not already provided to EPA in Mittal's February 16, 2012 Section 114 Information Request 

Response, provide copies of all stack test conducted on any emissions unit for any reason, and 

include all test runs, even if a full test series was not completed. Identify the emissions unit, 

specify the date of the test, test method used, and the filter temperature during the time of the 

test, if applicable. Provide all calculations relative to the stack test, and provide copies of the full 

test report, including the section describing the process parameters and production or 

processing rates at the time of the test, as well as copies of any reports of visible emission 

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U.S. Environmental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 

r~ ArcelorMittal 

Page 5 

observations conducted during each test. For each test during which the source was not 

·.operating at the maximum design capacity, provide an explanation why production was limited. 

As stated in EPA's 114 request, only those stack tests which were not provided in the previous 114 

request regarding MACT compliance are included in this response. EPA clarified that it was not 

seeking full test repmts for pmticulate tests, and that Minorca should submit only summary pages 

identifying the unit, method, and test results for these tests. Accordingly, only summary pages are 

included for particulate tests. Full test repmts are included for stack tests of other pollutants. Minorca 

does not operate continuous opacity monitors, and therefore any opacity data collected dming stack 

testing is included in the stack test reports. 

Nine stack test repmts are included in Folder 05: 

• Document 5-T is a 2005 stack test report for NOx emissions from the Indurating Fumace. 

Process operating data during the stack test is provided in Appendix F. This test was not 

conducted at maximum design capacity because the facility air pennit only requires that 

production be maintained at greater than 340 LT/hour during testing and the maximum design 

capacity is approximately 400 LT/hour. 

• Documents 5-2a to 5-2g contains NOx, S02 and CO test data from an incomplete study in 

2006. A fonnal test repmt was never created, and therefore the only data available fiom these 

tests is raw data that was not verified. Available process data is included in the attached 

documents. 

• Document 5-3 contains the summary pages from a 2006 stack test repmt for several Taconite 

MACT particulate compliance tests. This test was not conducted at maximum design capacity 

because the facility air permit only requires that production be maintained at greater than 340 

LT/hour during testing and the maximum design capacity is approximately 400 LT/hour. 

Minorca has also included a notice of compliance letter from MPCA for tllis stack test 

(Document 5-3a), as the itlitial test repmt does not contain an analysis of complim1ce under the 

special compliance demonstration provisions of the Taconite MACT rule. The MPCA letter 

confirms that Minorca demonstrated compliance with the Taconite MACT emission limits. 

• Document 5-4 is a 2007 stack test report for the Indurating Furnace for particulate matter, 

NOx, S02 and CO. Process operating data during the stack test is provided in Appendix F. This 

test was not conducted at maximum design capacity because the facility air pennit only 

requires that production be maintained at greater than 340 LT/hour during testing and the 

maximum design capacity is approximately 400 LT/hour. 

• Document 5-5 is the 2008 report for the 7 -day stack NOx stack test on the Indurating Fumace. 

Process operating data during the stack test is provided in Appendix F. Because this was a 

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U.S. Envirom11ental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 

,.~ 

ArcelorMittal 

Page 6 

multi-day stack test to assess variability under nonnal operating conditions, testing was not 

perfonned at the maximum production rate. 

• Document 5-6 is the 2008 report for the 7-day stack S02 stack test on the Indurating Furnace. 

Process operating data during the stack test is provided in Appendix F. Because this was a 

multi-day stack test to assess vatiability under nonnal operating conditions, testing was not 

perfonned at the maximum production rate. 

• Document 5-7 is a 2009 report for. an S02 stack test on the Indurating Furnace. Process 

operating data during the stack test is provided in Appendix F. The stack test was conducted to 

detennine S02 emissions dming nonnal operation and therefore was not conducted at the 

maximum production rate. 

• Document 5-8 is a 2009 report for a NOx stack test on the Indurating Fumace. Process 

operating data dming the stack test is provided in Appendix F. The stack test was conducted to 

dete1mine NOx emissions during normal operation and therefore was not conducted at the 

maximum emission rate. 

• Document 5-9 is a 2011 report for an S02 stack test on the Indurating Fumace. Process 

operating data dming the stack test is provided in Appendix F. This test was not conducted at 

maximum design capacity because the facility air permit only requires that production be 

maintained at greater than 340 LT/hour during the testing and the maximum design capacity is 

approximately 400 LT/hour. 

• Document 5-10 is a 2011 report for the stack NOx stack test on the Indurating Fumace. Process 

operating data during the stack test is provided in Appendix F. This test was not conducted at 

maximum design capacity because the facility air pennit only requires that production be 

·maintained at greater than 340 LT/hour during the testing and the maximum design capacity is 

approximately 400 LT/hour. 

• Document 5-11 contains the summary pages from a stack test report for several particulate 

compliance tests. These tests were operating at high production rates (approximately 90% of 

the maximum capacity or greater) but may not have been at the maximum design capacity 

because raw material quality can impact the maximum production rates. The facility air 

pennit only requires that production be maintained at greater than 340 LT/hour during testing 

and the maximum design capacity is approximately 400 LT/hour. 

Jaime Baggenstoss (Envirom11ental Engineer) of ArcelorMittal Minorca Mine provided information 

for this response. 

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U.S. Environmental Protection Agency 

Attn: Compliance Tracker, AE-1 7J 

May 9, 2012 ArcelorMittal 

Page? 

6. Provide an electronic Excel workbook with the complete nitrogen oxide (NOx) and sulfur 

dioxide (S02) facility-wide potential to emit calculations. Include in the response a written 

description of how each column in the Excel workbook is generated. 

Minorca's potential to emit calculations for NOx and S02 are in Document 6,.1 and are included in 

Folder 06. References are outlined in a separate tab within the spreadsheet and give an explanation of 

how each calculation was conducted. The potential to emit for the indurating furnace will change 

when the BART limits for NOx and S02 become effective. For the S02 potential to emit, we 

presumed maximum use ofNo. 2 fuel oil in the firing zone bumers even though this is not a normal 

operating condition. PTE calculations do not include emissions from insignificant sources. 

Jaime Baggenstoss (Environmental Engineer) of ArcelorMittal Minorca Mine and Erik Boleman of 

Ban Engineering provided information for this response. · 

7. The facility's Best Available Retrofit Technology report, available on the Minnesota Pollution 

Control Agency Regional Haze website ("BART report"), discusses the low efficiency of the 

facility's wet scrubber for S02• Provide all documentation, including reports and studies, to 

determine the current S02 efficiency of all water scrubbers at the facility. Additionally~ provide 

all documents, including reports and studies, completed for technical feasibility of efficiency 

upgrades for each scrubber. 

Several documents regarding wet scrubber S02 removal efficiency are included in Folder 07. 

• Document 7-1 is an Evaluation of Mitmesota Taconite Wet Scrubbers at Minntac, Keetac, 

HibTac, and UTac by Jolm Engesser (Minnesota Department of Natural Resources). Page 6 of 

Engesser's report contains infonnation on scmbber S02 efficiency and page 11 contains 

desc1iptions of the scmbbers. Minorca's scrubbers are most like Utac's Line 2 scrubbers. 

• Document 7-2 is a copy ofMPCA's fonn GI-05A (July 2007). 1. Table GI-05A.l shows a high 

efficiency wet scrubbers used for particulate control with an S02 removal efficiency of 30%. 

• Document 7-3 is a memo written by Ban Enginee1ing which explains a statistical analysis of 

S02 data from the 7-day stack test conducted in March 2008. 

• Document 7-4 is a memo written in 2007 to explain the source of sulfur from each of 

Minorca's processes. Minorca does not have any site-specific data to support the control 

efficiencies indicated in this memorandum, which are based on a conversation with John 

Engesser in 2007. 

Jaime Baggenstoss (Enviromnental Engineer) of ArcelorMittal Minorca Mine, Erik Boleman of Ban 

Engineering and Jack Ke1medy of Ban Engineering provided infom1ation for this response. 

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U.S. Environmental Protection Agency 

Attn: Compliance Tracker, AE-17 J 

May 9, 2012 

,.~ 

ArcelorMittal 

Page 8 

8. The BART report discusses the technical feasibility of low NOx burnet·s and a variety of 

selective catalytic reduction (SCRs) systems. Pt·ovide all documentation, including reports and 

studies, to determine the technical feasibility of low NOx burners and SCRs at the facility's 

indurating furnaces. 

Several documents regarding low NOx burners and SCRs are included in Folder 08. 

• Document 8-1 is an email summary of a phone conversation with representatives of DanieliCorus who had recently completed a major NOx study and low-NOx bumer retrofit at a 

straight-grate taconite induration furnace in the Netherlands. Note that at the time of this email 

8/2/2006, this teclmology was detem1ined to be "not available" for taconite indurating fumaces 

because there is only one facility using the technology and the teclmology has not been sold 

outside of their company. 

• Document 8-2 contains an MPCA report prepared by Barr Engineering entitled, "Potential 

Impacts of the Federal Regional Haze and Best Available Retrofit Teclmology Rules on the 

Taconite Industry in Minnesota" from 2003. Pages 45, 60, and 65 contain the most relevant 

info1mation to Low NOx Bumers. Pages 46 and 63-65 contain the most relevant information 

to SCR. 

• Document 8-3 is an internal Barr Engineering email indicating a 10% NOx reduction at a 

different facility with low-NOx bumers ins~all ed on the preheat section. 

• Document 8-4 contains a proposal and preliminary data from EPS Teclmologies, Inc. 

investigating use of a catalyst referred to as CFD 24-7. A final sununary and analysis was 

never completed for this study because Minorca did not have confidence in the testing or 

preliminary results produced by EPS Teclmologies. To the best ofMinorca's knowledge, this 

company and product are no longer in existence and the proposed technology was not 

investigated fmiher. 

Jaime Baggenstoss (Environmental Engineer) of ArcelorMittal Minorca Mine and Erik Boleman of 

Barr Engineering provided infonnation for this response. 

9. The BART report discusses the technical feasibility of overfire air and induced· flue gas 

technology. Provide all documentation, including reports and studies, to determine the technical 

feasibility of overfire air and induced flue gas technology at the facility's indurating furnace. 

Infonnation responsive to this question is included in response to Question 8 in Folder 08, Docwnent 

8-2. Pages 45, 60, and 65 of this document contain the most relevant information to induced flue gas 

recirculation. The Minorca BART report only addresses overfire air in Appendix D where it is 

designated as not technically feasible. The principle behind overfire air is to stage the addition of air 

to limit the peak flame temperature and excess oxygen in the combustion zone to limit the fom1ation 

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U.S. Environmental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 

Page 9 

ArcelorMitta I 

ofNOx. P1imary air is added at the bumer to allow combustion to occur at nearly stoichiometric ratios 

of oxygen. This limits the amount of oxygen which is available to react with nitrogen and fonn NOx. 

Overfire air is added above the primary flame zone to allow complete combustion to occur in the 

presence of a small amount of excess oxygen. However, Minorca's indurating fumace does not have 

a primary combustion zone that can be controlled to near stoichiometric ratios. Oxygen levels in the 

fumace are in the 15% to 20% range, well above stoichiometric combustion conditions. Therefore 

overfire air was detennined to be not technically feasible. 

Erik Boleman of BatT Engineering and Jack Kennedy of Ban Engineering, under the direction of 

Jaime Baggenstoss (Environmental Engineer) of ArcelorMittal Minorca Mine, provided information 

for this response. 

10. Identify the manufacturer, including the contact information, for all low NOx burners, SCR, 

scrubber, overfire air, and induced flue gas technologies considered technically feasible for use 

at the facility. 

The manufacturer company names, contacts, email addresses, and phone numbers are provided below 

for wet walled electrostatic precipitators (WWESP), secondary scrubbers, and SCR with conventional 

reheat. Low NOx bumers were also identified as technically feasible in the preheat section of the 

fumace, however these controls are already installed at Minorca and therefore were not considered 

futiher in the BART analysis. 

Control Manufacturer Contact Contact Email Contact Phone 

Teclmology Name 

WWESP Dun Rodney Roden y.P em1ington@durrusa. com 407.822.9203 

Pennington 

Secondary STS Hal Taylor taylor@stsconsultants.com 847.279.2541 

Wet Scrubber Consultants 

SCR Babcock Bob Harold BHarold@babcock2ower.com 508.854.3941 

Power 

SCR Com1etech Elizabeth GoveyEM@Carmetech.com 919.620.3000 

Govey 

Jack Ke1medy of Barr Engineering, under the direction of Jaime Baggenstoss (Enviromnental 

Engineer) of ArcelorMittal Minorca Mine, provided infonnation for this response. 

11. For the time period January 1, 2002, to the date of the receipt of this letter, provide all 

documentation, including engineering studies or mass balance studies, conducted to determine 

emissions of NOx from each waste-gas stack at all indurating furnaces at the facility . 

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U.S. Enviromnental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 . 

Page 10 

ArcelorMittal 

• Document 11-1 is an internal ArcelorMittal presentation addressing benefits of relocating 

indurating bumers in the Firing Zone of the fumace. 

• Docwnent 11-2 is the ESA Computational Fluid Dynamic Modeling Repmi for predicting 

NOx emissions from bumer changes. 

• Document 11-3 is MPCA's approval letter to ArcelorMittal approving the "altemate method" 

for monitoring NOx emissions. 

Jaime Baggenstoss (Enviromnental Engineer) of ArcelorMittal Minorca Mine, Erik Boleman of Barr 

Engineering and Jack Ke1medy of Barr Engineering provided infom1ation for this response. 

12. Provide an electronic Excel workbook listing the following information from the NOx and/or 

S02 continuous emission monitoring system (CEMS) from the date the CEMS were installed to 

present. Provide the information on an hourly basis, where applicable. The Excel workbook 

must include the following: 

a) CEMS indentifying name or marl<:er; 

b) CEMS location; 

c) Pollutant monitored; 

d) Date and time; 

e) NOx I S02 emissions rate in pounds per million British thermal units (lb/mmBtu); 

f) Raw NOx I S02 in ppm; 

g) NOx I S02 emissions in pounds per hour; 

b) Flow rate in actual cu.bic feet per minute (ACFM); and 

i) Furnace temperature in °F. 

Minorca does not own or operate continuous em1sswns monitors (CEMS) and therefore has no 

infonnation responsive to this request. 

13. Provide written explanation and supporting documents of how the facility could use NOx CEMS 

for process optimization. 

Minorca has not conducted an evaluation on how a NOx CEMS could be used for process 

optimization. Minorca cannot respond to this request without engaging in speculation, and therefore 

has no infonnation responsive to this question with an adequate foundation for reliability. The section 

of the BART report which relates to process optimization with a NOx CEMS or other parametric 

monitoring (page 33) was written in response to MPCA's guidance for BART analyses, which was 

based on the experience of the electric utility industry. A taconite indurating furnace is different from 

a utility boiler as it petiains to NOx generation and NOx variability. Minorca's NOx emissions are 

p1imarily a function of thennal NOx and, based on the design of the furnace and the existing 

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Attn: Compliance Tracker, AE-17J 

May 9, 2012 

Page 11 

ArcelorMittal 

equipment, we expect there are few, if any, adjustments that can be made to reduce peak flame 

temperature to reduce NOx without impacting furnace productivity and quality. 

Adam Sersha (Process Engineer) of ArcelorMittal Minorca Mine, Erik Boleman of Barr Enginee1ing 

and Jon Maki of Barr Engineering provided information for this response. 

14. For the period January 1, 2002, to the date of the receipt of this letter, provide NOx emissions 

data from the indurating furnace for each day, and also for a thirty-day rolling average. 

Data on daily NOx emissions and thirty day rolling averages would require a Continuous Emissions 

Monitoring System (CEMS). Minorca does not own or operate CEMS and therefore has no 

infonnation responsive to this request. 

15. Identify all NOx emission sources and factors contributing to NOx emissions at the facility's 

indutating furnace, including but not limited to, the burners. 

The three mechanisms by which NOx production occurs in an indurating furnace are thennal, fuel, and 

prompt NOx. Thennal NOx occurs when nitrogen contained in air oxidizes at high temperatures. This 

occurs primarily in the flame zone of the burners and is a function of high temperature and excess 

oxygen. The majmity of them1al NOx is fonned during gas combustion, and occurs when high 

temperatures cause 0 2 to dissociate to 0, which can fonn NO through the following reaction: N2 + 0 

= NO + N. Water dissociation or fuel combustion can also produce OH and fonn NO through the 

following reaction: N + OH = NO + H. 

Fuel NOx occurs when nitrogen contained in the fuel oxidizes dming combustion. This is most 

common with coal, oil, and wood combustion, and is also driven by temperature and 0 2 concentration. 

Prompt NOx makes up a small fi·action of the NOx fmmed during gas combustion. Prompt NOx occurs 

at the bumers as turbulent diffusion mixes fuel and air and creates eddies ideal for NO formation. 

Erik Boleman of BaiT Engineering, Jack Kennedy of Barr Engineering and Energy Systems 

Associates provided information for this response. 

16. Identify all persons, including employees, consultants, representatives of the taconite industry, 

or representative of air pollution control manufacturers, who assisted in the preparation, or 

were consulted for the purpose of preparing, the BART repoi·t. 

The following personnel at BaiT Enginee1ing contributed to the BART report: 

• Anthony Widboom 

• Anita Dickson 

• Andrew Skoglung 

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U.S. Environmental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 

Page 12 

• Anthony Shoberg 

• Beth Havlik 

• Bradley Johnson 

• Cherie Lemer 

• Colin J oln1son 

• Erik Boleman 

• George Pruclmofski 

• Joel Trinkle 

• Jeannette Y anta 

• J olm Kennedy 

• Lori Yalch 

• Michael Hansel 

• Marilyn Lindquist 

• Susan Nelson 

• Suzanne Johnson 

• Teresa Kinder 

• Timothy Russell 

ArcelorMittal 

Erik Boleman, George Pruclmofski, Jolm Kennedy, and Michael Hansel maintained primary 

responsibility for the contents of the report. 

The following manufacturers were consulted for pmposes of preparing the BART report: 

• Kenneth Gardner (Metso) 

• Jan Weekes (Outokumpu) 

• Peter Zmmeveld (Danieli) 

• Koen Meijer (Danieli) 

• Bob Schreiber (Schreiber, Y onley, and Associates) 

• Bob Harold (Babcock Power) 

• Elizabeth Govey (Cormtech) 

• Hal Taylor (STS Consultants) 

• Rodney Pennington (Durr) 

The following Minorca employees were consulted for purposes of preparing the BART repmi: 

• Gus Josephson (retired employee) 

• Jon Maki (former employee) 

Jaime Baggenstoss (Enviromnental Engineer) of ArcelorMittal Minorca Mine and Erik Boleman of 

Barr Engineering provided information for this response. 

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U.S. Environmental Protection Agency 

Attn: Compliance Tracker, AE-17J 

May 9, 2012 

Page 13 

Sincerely, 

~~(\~ 

Jonathan Holmes 

Vice President/Operations Manager 

Enclosure 

cc: Supervisor, Air Quality Compliance Dete1mination 

Minnesota Pollution Control Agency 

520 Lafayette Road North 

Saint Paul, Minnesota 55155-4194 

Rich Zavoda 

Jaime Baggenstoss 

Douglas McWilliams 

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ArcelorMittal