Project Memo 

TO: Ryan D. Siats - USS 

cc: uss 

Rob Wilmuneil 

Hatch 

Jason Berzansky 

Cebert Clarke 

Darren Gietzen 

Pat McTiver 

John Visnesky 

Jennifer Woloshyn 

November 6, 2009 

FROM: Gary Rohekar 

United States Steel Corp. 

USS Minntac-Line 7 NOx Reduction Pilot Project 

Low NOx Burner Pilot Study at USS Minntac 

1. Introduction 

ISO 9001 

United States Steel (USS) Corporation's Mlnntac taconite ore processing and pelletizing facility has 

five grate-kiln type pelletizing lines, numbered 3 to 7. USS Minntac is evaluating different NOx 

reduction technologies to achieve this goal. 

One of the NOx reduction technologies being considered involves replacing the existing kiln burner 

with a Low NOx Burner (LNB). To this end, Minntac is currently pursuing a pilot project to replace 

the existing burner with a LNB at its No. 7 pelletizing line, and has retained the services of Hatch 

Associates Consultants, Inc. (Hatch) and Coen Company, Inc. (Coen), a supplier of Low NOx 

burners. 

Minnesota Pollution Control Agency (MPCA) has requested Minntac to confirm whether the project 

would result in an increase in emissions of the following pollutants: 

• PM • Fluorides 

0 PMIO 0 Sulfuric Acid Mist 

0 PM2.s • Hydrogen Sulfide 

• NOx 0 Total Reduced Sulfur Compounds 

• S02 • MWC Organics 

• co • MWCAcid Gas 

• Ozone (VOC) • MWCMetals 

• Lead • MSW Landfill Gas 

Minntac has requested Hatch to assist them in this task. 

If you disagree with any information contained herein, please advise immediately. 

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2. Hatch's Position 

It is Hatch's position that the LNB project will not result in an increase in emissions of any of the 

above listed pollutants. Since USS Minntac plans to continue using their current fuels, fuel mixes and 

fuel firing rates in conjunction with the LNB, with the exception of NOx, Hatch does not anticipate 

any change in the emissions of applicable pollutants. Substantial reduction in NOx emissions is also 

anticipated. We have based our position on the following: 

2.1 PM, PM10 and PM2.5 Emissions 

Hatch reviewed information provided in USEPA's AP-42 (Fifth Edition, Compilation of Air Pollutant 

Emission Factors, Volume 1: Stationary Point and Area Sources), Section 11.23, which deals with 

Taconite Ore Processing, for any references to differences in PM emission factors due to the use of 

different type of burner (standard vs. LNB) in a grate-kiln pelletizer. No such references were found. 

Hatch strongly believes that a great majority of particulate matter (PM, PM 10 and PM2.s) is generated 

due to handling of the pellets as they are first dried in the travelling grate and then hardened in the 

rotating kiln. Such handling releases all particulate matter, as the pellets come in contact with various 

mechanical components of the pelletizer, as well as each other, especially in the rotating kiln. 

Some raw gas (uncontrolled) PM can be attributed to the type of fuel used, e.g. coal, biomass. 

However, Hatch believes that this is comparatively a very small fraction of the total PM in the raw 

gas. Since no change to the fuel usage practices are planned, changes to raw gas PM emissions solely 

due to use of LNB are not anticipated. Also, since the project does not Involve any changes to the gas 

cleaning (wet scrubber based) system, it is anticipated that there will be no increase in the emissions 

of PM, PMw and PM2.s due to the LNB project. 

2.2 S02 Emissions 

Hatch has reviewed information provided in AP-42, Section 11.23 (Taconite Ore Processing) and 

Chapter 1 (External Combustion Sources), for any references to differences in S02 emission factors, 

solely due to the use of different types of burners (standard vs. LNB). No such references were found. 

S02 is released in the pelletizer gas stream from sulfur in the ore, as well as from fuels such as coal. 

However, since Minntac is not planning to make any changes to their ore and its processing, fuel use 

practices or the wet scrubber based gas cleaning system, Hatch does not anticipate any increase in 

S02 emissions, clue to the LNB project. 

2.3 CO Emissions 

ISO 9001 

Hatch reviewed information provided in AP-42, Section 11.23 and Chapter 1, for any references to 

differences in CO emission factors, solely due to the use of LNB. Table 1.4-1 (Chapter 1) does 

provide information regarding CO emission factors for "uncontrolled" and "controlled- low Nox 

burners" from natural gas combustion. However, the emission factors for both these cases are the 

same, indicating that the CO emissions are anticipated to be the same with or without the use of 

LNB. 

AP-42, Chapter 1 also makes reference to potential for reduced combustion efficiency, resulting in 

higher CO emissions if the LNB is improperly designed. However, as part of their assignment, Hatch 

and Coen are conducting a detailed Computational Fluid Dynamics (CFD) analysis of the LNB to 

ensure that the combustion efficiency is not sacrificed, while achieving maximum NOx reduction. 

Therefore, Hatch anticipates no increase in CO emissions due to the LNB project. 

~ 1'/orklngTogether V' $AillY 

H33257l-OOOO-xx-220-00xx, Rev. A, Page 2 

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~H 

A copy of the letter from Coen, explaining their position as to why the proposed LNB will not result 

in an increase in CO emissions is attached. 

2.4 Ozone (VOC), lead, Fluorides Emissions 

A review of previously mentioned AP-42 documentation did not indicate any potential increase in 

the emissions of these pollutants, solely due to the use of LNB, as compared to the existing burner. 

2.5 Sulfuric Acid Mist, Hydrogen Sulfide, Total Reduced Sulfur Compounds 

Once again, a review of the AP-42 documentation did not indicate any potential increase in the 

emissions of these pollutants, solely due to the use of a LNB. 

These are sulfur based pollutants, and similar to the S02 emissions (since Minntac is not planning any 

changes to their ore and its processing or fuel use practices), Hatch does not anticipate any increase 

in !he emissions of these pollutants due to the LNB project. 

2.6 MWC Organics, MWC Acid Gas, MWC Metals and MSW landfill Gas Emissions 

These pollutants are associated with Municipal Waste Combustor (MWC) and Municipal Solid Waste 

(MSW) landfill, and are not applicable to USS Minntac, a taconite ore processing facility. 

GR:ak 

Attachment: Coen Letter 

ISO 9001 H332571-0000-xx-220-00xx, Rev. A, Page 3 

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