Project Memo
TO: Ryan D
.Siats

- USS
cc: 

## uss Rob Wilmuneil Hatch Jason Berzansky Cebert Clarke Darren Gietzen Pat McTiver John Visnesky JenniferWoloshyn 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 3to 7. USS Minntac is evaluating different NOx reduction technologies to achieve this goal. One ofthe NOx reduction technologies being considered involves replacing the existing kiln burner with a Low NOx Burner (LNB). To this end, Minntac is currently pursuing apilot projectto replace the existing burner with a LNB at its No. 7pelletizing line, and has retained the services ofHatch Associates Consultants, Inc. (Hatch) and Coen Company, Inc
. (Coen), a supplierofLow NOx burners. Minnesota Pollution Control Agency (MPCA) has requested Minntac to confirm whether the project would result in an increase in emissions ofthe 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
.

Ifyou disagree with any information contained herein, please advise immediately
. H332571-0000-xx-220·00xx, Rev
.A, Page 1

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## 2. Hatch's Position It is Hatch's position thatthe LNB projectwill not result in an increase in emissions ofany ofthe above listed pollutants. Since USS Minntac plans to continue using theircurrent fuels, fuel mixes and fuel firing rates in conjunction with the LNB, with the exception ofNOx, Hatch does not anticipate any change in the emissions ofapplicable 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 ofAirPollutant 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 differenttype ofburner (standard vs. LNB) in agrate-kiln pelletizer. No such references were found. Hatch strongly believes that agreat majority ofparticulate matter (PM, PM 10 and PM2.s) isgenerated due to handling ofthe 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 contactwith various mechanical components ofthe pelletizer, as well as each other, especially in the rotating kiln. Some raw gas (uncontrolled) PM can be attributed to the type offuel used, e.g. coal, biomass. However, Hatch believes thatthis is comparatively avery small fraction ofthe 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 ofLNB are not anticipated. Also, since the projectdoes not Involve any changes to the gas cleaning (wet scrubberbased) system, it is anticipated thatthere will be no increase in the emissions ofPM, 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 ofdifferenttypes ofburners (standard vs. LNB). No such references were found. S02 is released in the pelletizergas stream from sulfur in the ore, as well as from fuels such as coal. However, since Minntac is notplanning to make any changes to theirore and its processing, fuel use practices orthe wetscrubber based gas cleaning system, Hatch does not anticipate any increase in S02 emissions, clueto the LNB project. 

### 2.3 CO Emissions

ISO9001Hatch 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 ofLNB. 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 thatthe CO emissions are anticipated to be the same with orwithoutthe use of LNB. AP-42, Chapter 1also makes reference to potential for reduced combustion efficiency, resulting in higherCO emissions ifthe LNB is improperly designed. However, as partoftheirassignment, Hatch and Coen are conducting adetailed Computational Fluid Dynamics (CFD) analysis ofthe LNB to ensure thatthe 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

oHatch 2009/11

# ~H Acopy ofthe 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 Areview ofpreviously mentioned AP-42 documentation did not indicate any potential increase in the emissions ofthese pollutants, solely due to the use ofLNB, as compared to the existing burner. 

### 2.5 Sulfuric Acid Mist, Hydrogen Sulfide, Total Reduced Sulfur Compounds Once again, a review ofthe AP-42 documentation did not indicate any potential increase in the emissions ofthese pollutants, solely due to the use ofa LNB. These are sulfur based pollutants, and similarto the S02emissions (since Minntac is not planning any changes to their ore and its processing orfuel use practices), Hatch does not anticipate any increase in !he emissions ofthese 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, ataconite ore processing facility.

GR:ak Attachment: Coen Letter

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

0 Hatch 2009/11