U.S. Steel Co rporation Minnesota Ore Operations P.O. Box 417 Mt. Iron , MN 55768



### CERTIFIED MAIL #7006 0 I00 0006 4747 9957 November 30, 2009 Mr. Christopher J. Nelson, P.E. Manager, Metallic Mining Sector Minnesota Pollution Control Agency 520 Lafayette road North Saint Paul , MN 55155-4194 SUBJECT: RE: RE: Selective Catalytic Reduction and Low Temperature Oxidation Pilot Testing Dear Mr. Nelson: United States Steel Corporation, Minnesota Ore Operations- Mirmtac (Minntac) has received the letter dated November 6, 2009, from the Mirmesota Pollution Control Agency (MPCA) regarding additional information on Selective Catalytic Reduction (SCR) and Low Temperature Oxidation (LoTOx) pilot testing. Ji1 its November 6, 2009 letter, the MPCA requested additional information regarding the teclmical feasibility ofSCR including but not limited to:

• Correspondence with Hatch or the solicited pilot test vendors. • Any information on the optimal and feasible temperature for SCR (including dilt-side, clean-side and regenerative) operation. • Data on the potential feasibility of regenerative 

# sqt. • And any information Minntac has about catalyst poisons in the gas stream. The November 6, 2009 letter also detailed the MPCA's position that LoTOx is technically feasible and is required to be pilot tested in accordance with Minntac's Air Emission Operating Permit# 13700005-005. The following is United States Steel Corporation (U. S. Steel) response to the subject letter. 

### Selective Catalytic Reduction (SCR) Pilot Testing

• Attached is correspondence from two SCR vendors declining to bid on NOx reduction testing at Minntac. One vendor has an existing SCR system on an indurating furnace in Europe. The other vendor identifies critical variables that pose significant challenges for SCR. • Optimal operating temperature for the SCR (clean or dirty) is in the range of 600-900°F to facilitate the chemical reaction. Optimal operating temperature for regenerative SCR is often less than 500° F; however, if the flue gas contains more than a few ppm of S03, 

### then the temperature must be increased depending upon the concentration to avoid plugging the SCR catalyst pores. • SCR requires a gas stream with a particulate loading of less than 1.00 grains per dry standard cubic foot (grldscf). At the point in the indurating process were the idealoperating catalyst temperature exists, the pmticulate loading exceeds thi s required parameter. • U. S. Steel will be in a better position to comment on the feasibility of the RSCR following our attendance at Babcock Power's presentation at MPCA on December 15, 2009. • During November 28 and 29 of2000, Minntac completed a stack test to quantify the presence ofselected compounds that may poison a catalyst used as part of SCR. The stack test report, titled 

### Results of the November 28-29, 2000 SCR Catalyst Poison Tests on the Line 7 Waste Gas Stack (SV 151) at the U 

### S. Steel Group-Minnesota Ore Operations Step IIJAgglomerator Facility located in Mt. Iron, Minnesota , was submitted to the MPCA, per Hongming Jiang's request, on Janumy 12, 200 I. The stack test results listed in the test rep01t demonstrate emission rates for arsenic, sulfuric acid mist (as sulfur trioxide), sulfur dioxide, particulate matter and nitrogen oxides (as nitrogen dioxide)

. In conclusion, multiple vendors that offer SCR technology were solicited by U. S. Steel for pilot testing proposals. However, the majority declined to bid and stated that other NOx reduction technologies were more viable for a grate-kiln indurating furnace.


### Low Temperature Oxidation (LoTOx) Pilot Testing MPCA's November 6, 2009 letter requested U. S. Steel to provide the agency with a pilot test schedule for LoTOx by December 1 , 2009. U. S. Steel respectfully requests a meeting with the MPCA to discuss the following issues concerning LoTOx:

• Timing (as it relates to pilot testing other technologies) • Permitting (Air and Water) associated with LoTOx environmental control equipment • Cros s media impacts • Feasibility

U.S. Steel proposes a meeting for December 16, 2009, to discuss the issues listed above. 

### Ifyou have any questions concerning U. S. Steel's r esponse, please do not hesitate to contact Stephani Campbell at (218) 749-7203. Sincerely,

# J:~**ol~ ~~**  General Manager Minnesota Ore Operations United States Steel CorporationAlexander G Parou/Headquarters/USS 04/03/2009 05:06 PM

----- Original Message

----- From: andy.kovalchick Sent: 04/03/2009 04:39PM AST To: Alexander Parou To "Darren Gietzen" <DMGietzen@uss.com> cc bee Subject Fw: RFQ UMO 0486·1 Mlntac Low Nox Reduction System

Cc: paul.yosick@power.alstom.com; Jolm Biddle Subject: RFQ UMO 0486-1 Mi.ntac Low Nox Reduction System

Alex, My name Is Andy Kovalchick. I am the District Sales manager for Alstom In Pittsburgh. It's been quite a while**~ut** you and I have met In the past when I worked for Combustion Engineering and ABB. Probably something to do with Clairton Works. This e-mail is to advise you we have no one to attend the prebid on the 7th as my counterpart, Mr. Josh Klopp, has prior commitments as do both Paul Yoslck and 

### I. Paul indicated to you our rationale for no bidding the project and despite having an operating facility In Europe we feel our chances of success are very slim and the cost of proposal preparation are very high. I had talked with John Biddle about this project several months ago during our terms and conditions discussions. We had even declined back then. For clarity and future Inquiries please forward your Inquiries to me at this e-mail address or to the mailing address below. This will allow for a more timely response. Should you have any questions please call. My office Is In Monroeville and can meet with you at your convenience. Regards, Andy Kovalchlck District Sales Manager Pittsburgh District Office 412-373-6610 office 412-373-2485 fax 412-491-4931 cell 724-283-4999 home

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## MITSUBISHI POWER SYSTEMS MIIIA:isli Pc:ma Syslems Amel'.cos, 'roc./ 100 BoyY.ew Ci'cle, Sule IJX1J I N&hpOrtBeoch. CA 926UJ USA I P h one949.856.81.00 I Fox949.856.4481 Ap rll9, 2009
U.S. Steel
- Headquarters 600 Grant Street Room 2028 Pittsburgh, Pa. 15219 Attention: Mr

. Alex Parou (copy: Mr

. Darren Gietzen)
SUBJECT: Decline to Bid REFERENCE: RFQ
- UM0-0486-1 MINNTAC LOW NO x REDUCTION SYSTEM
Dear Sir,
With reference to above mentioned subject and project, MPSA would li ke to Inform you that we will not be submitting our proposal to your RFQ (ref UM0-0486
- 1). Having attended the pre-bid meeting this week, we now ha ve a better unders tanding of th e Mlnntac's goals and targets , manufac turing process, and at the same time, the challenges th a t SCR, as a technology, wou ld have In Its application. 1) Temperature and layout pose significant chall eng es for SCR. And the same challenges are most likely non-Iss ues for other technologies. An example of this Is how best to extract 100% of the flu e gas and treat th em In the optimal SCR operating range of 600 N 750F

. 2) NOx reduction requirem ent of 70% Is well within th e capab ilities of SNCR and LoTOx. For these reasons, we feel th at SNCR and LoTOx will likely offer better solutions f or your particular application. If you have SCR rela ted questions or If the project parameters change, please le t us know and we will try our bes t to assist. W

e wish the best of luck to US Steel.
Sincere ly, 

## FusatoDana Manager, Contract Administration T

el: 949-856-8416 Cel: 949-275-8368 e-mail : fd ana @ mpshq .com