BART SO2 Data: MN Facilities Summary

Taconite Pellet Production Skillings Mining Review (July 2007)

2006 Updates, long tons USS Minntac Hibbing Taconite USS KeeTac Northshore Unite Taconite Minorca Mine

Total material moved 89,133,615 51,327,000 ######### 29,900,000 17,026,000

Crude ore mined 49,243,592 29,800,000 ######### 13,200,000 8,407,000

Stripping ratio 0.81 0.72 0.67 1.27 1.03

Acid pellets made 2,922,274 8,300,000 5,199,546 5,100,000 4,300,000

Fluxed pellets made 11,587,477 2,831,000

Pellet chips 39,000 MN total:

Total production 14,509,751 8,300,000 5,199,546 5,100,000 4,300,000 2,870,000 40,279,297

Best yr pellests fired 16,520,764 8,747,774 5,472,238 5,100,000 5,879,858 71,170,000 44,133,176

Best Year 1979 1988 2000 2006 1981 July 1977 thru 2006

Skillings Mining Review (July 2006)

2005 Updates, long tons USS Minntac Hibbing Taconite USS KeeTac Northshore Unite Taconite Minorca Mine

Total material moved 86,000,000 49,500,000 ######### 27,100,000

Crude ore mined 52,000,000 29,800,000 ######### 14,700,000

Stripping ratio 0.65 0.66 0.72 0.84

Acid pellets made 8,500,000 5,334,392 4,900,000 4,900,000

Fluxed pellets made 15,097,304 2,761,000

Pellet chips 38,000 MN total:

Total production 15,097,304 8,500,000 5,334,392 4,900,000 4,900,000 2,799,000 41,530,696

SO2 emissions, ton/yr USS Minntac Hibbing Taconite USS KeeTac Northshore Unite Taconite Minorca Mine

lbSO2/LT 0.421 0.207 0.0864 0.186 0.123 Suggested BART limit for natural gas firing (and gas-wood co-firing at Minntac).

0.364 *

4.43 Estimated PTE for coal-pet-coke-gas co-firing at UTac Line 2.

SO2, tpy 3,054 ~ 859 946 * 220 6,483 ** 177 Sum: 11,739 ton SO2/yr

not including SO2 due to coal at Minntac not including SO2 due to coal at Minntac

~ Lack of coal firing stack test results led to the exclusion of SO2 due to coal for Minntac. Minntac will install SO2 CEMS for all 5 furnaces.

* KeeTac has an SO2 emission limit of 951 ton/yr, calculated as a 12-month rolling sum, in its Title V permit.

The emission factor given here represented the worst run during the 2006 stack test (coal firing for all test runs of various pH settings).

** United Taconite Line 2 can emit a wide range of SO2, depending on how solid fuels are blended. Line 1 is fired with natural gas only.

Two-third of the pellets made in 2006 are assumed to be from Line 2. If both lines were to be fired with natural gas only, 400 tpy of SO2

is expected.

Why look at SO2 facility-by-facility?

Ratio of suggested limits (Minntac/Mittal): 3.42

Ratio of 2006 productions (Minntac/Mittal): 5.06

Multiplication of the above two numbers: 17.3

Ratio of SO2, tpy numbers (Minntac/Mittal): 17.3

Remarks: Mittal makes less tonnage, has lower sulfur greenball, and is thus expected to emit less SO2.

Staff: HJ; File: 09000064814f5ac8; Page 1 of 1; 11:16 AM, 1/22/2014
BART SO2 Data: HibTac

SO2 ppm Statistics SO2 lb/LT

6.2 Median 0.10502

5.0 1st quartile 0.08455

2.3 Minimum 0.07307

13.9 Maximum 0.17614

8.6 3rd quartile 0.12708

5.6 Harmean 0.10220

6.2 Geomean 0.10636

6.7 Average 0.11107

2.73 Stdev 0.03662

12.1 Upper data 0.20686

7.3 UCL mean 0.14494

6.7 mean 0.11107

6.1 LCL mean 0.07720

1.2 Lower data 0.01528

* Based on test runs from 1994-2005, when furnaces were fired with natural gas.

SO2 ppm SO2 lb/LT SO2 lb/LT for oil-firing

5.2 <gas-fired> 0.07307 Upper data 0.32702 0.36704

5.2 0.08238 UCL mean 0.22913 0.25717

5.4 0.17614 mean 0.17559 0.19708

6.0 0.08672

5.0 0.10502 Multiplier: 1.5809 1.7743

5.0 0.11291 Basis: ppm data lb/LT data

5.2 0.14125

5.7

5.1 0.19708 No. 6 oil-firing: Ultra low S No. 2 oil-firing: 0.11140

4.1 0.10220 ore SO2 after ctrl: ore SO2 after ctrl: 0.11107

6.5 0.09487 fuel SO2 after ctrl: fuel SO2 after ctrl: 0.00033

6.5 0.14731 fuel SO2 unctrl: ultra low S fuel SO2 unctrl: 0.00052

4.9 35.6% apparent ctrl effcy:

5.6

5.1 oil-fired SO2 ppm

5.0 11.7

4.3 13.3

5.0 14.5

7.0 12.2

3.5 12.1

3.9 12.1

8.0 10.6

5.3 6.7

5.6 10.0

8.1 7.1

7.9 7.8

8.5 8.8

11.4

9.6

9.7

11.0

11.8

0

5

10

15

SO2 ppm

Hibbing Taconite Company

0.06

0.08

0.10

0.12

0.14

0.16

0.18

SO2 lb/LT

Stack Test Results

Staff: HJ; File: 09000064814f5ac8; Page 1 of 1; 11:16 AM, 1/22/2014
BART SO2 Data: Northshore

May 1994 stack testing at Furnace 12 (both hood exhaust and waste gas stacks) and Furnace 11 (only waste gas stacks)

F12 h.e. F12 w.g. Stack 1104 Stack 1105 Stack 1205 STP temp: 68 deg F

Production rate, LT/h 242 240 205 204 270 STP press: 14.696 psia

Natural gas, MMscf/hr 0.144 0.145 0.0885 0.0885 (Jan '95 test) Temp conv: 459.67 0 deg F

MMBtu/LT pellets 0.595 0.604 0.432 0.434 R universal: 10.73 psia*ft3/R/lbmol

MW(SO2) 64.06 lb/lb mole

Test/Run Date Hours Flow, dscfm SO2, ppm SO2, lb/hr For MW, see http://webbook.nist.gov/chemistry/

F12 hood exhaust inlet (Electric ON)

1/1 5/24/1994 0953-1051 235,033 4 9.38

1/2 5/24/1994 1148-1246 237,667 12 28.5

1/3 5/24/1994 1328-1452 234,018 12 28.0 SO2, lb/hr, flow corrected

Average 235,573 9.33 21.9 17.3

F12 hood exhaust inlet (Electric OFF)

7/1 5/24/1994 1523-1621 229,235 14 32.0

7/2 5/24/1994 1643-1741 227,040 14 31.7

7/3 5/24/1994 1808-1906 227,251 14 31.7 SO2, lb/hr, flow corrected

Average 227,842 14.0 31.8 26.2

F12 hood exhaust stack (Electric ON) Hood exhaust stacks:

2/1 5/24/1994 0954-1052 62,062 4 2.48 6.17 lb SO2/hr

2/2 5/24/1994 1149-1247 61,536 4 2.46 0.0255 lb SO2/LT pellets

2/3 5/24/1994 1329-1453 61,812 2 1.23 SO2 ctrl stck/inlet flow 78.5% hood exhaust in furnace

Average 61,803 3.33 2.06 64.3% 78.7% 1.73 multiplier for h.e. stacks

F12 hood exhaust stack (Electric OFF)

6/1 5/24/1994 1524-1622 63,577 1 0.63

6/2 5/24/1994 1644-1742 62,321 3 1.87

6/3 5/24/1994 1809-1907 61,825 4 2.47 SO2 ctrl stck/inlet flow

Average 62,574 2.67 1.66 81.1% 82.4%

Test/Run Date Hours Flow, dscfm SO2, ppm SO2, lb/hr

F12 waste gas inlet (Electric ON)

8/1 5/25/1994 0928-1026 240,245 6 14.4

8/2 5/25/1994 1113-1211 233,917 6 14.0

8/3 5/25/1994 1258-1356 213,505 6 12.8 SO2, lb/hr, flow corrected

Average 229,222 6.00 13.7 7.56

F12 waste gas inlet (Electric OFF)

9/1 5/25/1994 1433-1531 226,198 7 15.8

9/2 5/25/1994 1600-1658 227,633 7 15.9

9/3 5/25/1994 1726-1824 237,012 3 7.09 SO2, lb/hr, flow corrected

Average 230,281 5.67 12.9 6.96

F12 waste gas stack (Electric ON) Waste gas stacks:

10/1 5/25/1994 0929-1027 64,551 2 1.29 1.69 lb SO2/hr

10/2 5/25/1994 1114-1212 62,729 < 1 < 0.63 0.0070 lb SO2/LT pellets

10/3 5/25/1994 1259-1357 62,059 < 1 < 0.62 SO2 ctrl stck/inlet flow 7.85 lb SO2/hr <= Furnace

Average 63,113 1.33 0.84 77.7% 55.1% 0.0325 lb SO2/LT pellets

21.5% waste gas in furnace

F12 waste gas stack (Electric OFF) 0.0864 final lb SO2/LT pellets

12/1 5/25/1994 1434-1532 61,671 < 1 < 0.62 0.0650 just for comparison

12/2 5/25/1994 1600-1658 61,752 < 1 < 0.62

12/3 5/25/1994 1727-1825 61,258 < 1 < 0.61 SO2 ctrl stck/inlet flow

Average 61,560 < 1 < 0.61 82.4% 53.5%

Test/Run Date Hours Flow, dscfm SO2, ppm SO2, lb/hr

No. 1104 pelletizer waste gas stack (Electric ON)

15/1 5/26/1994 0814-0913 69,427 < 1 < 0.69

15/2 5/26/1994 0959-1058 66,236 < 1 < 0.66

15/3 5/26/1994 1144-1242 68,343 3.1 2.1

Average 68,002 1.70 1.16

No. 1105 pelletizer waste gas stack (Electric ON) 3.58 lbSO2/hr

16/1 5/26/1994 0811-0912 73,739 4 2.9 0.0175 lbSO2/LT pel.

16/2 5/26/1994 0956-1057 73,133 4 2.9

16/3 5/26/1994 1141-1241 71,070 2 1.4 Waste gas stacks

Average 72,647 3.33 2.43 lbSO2/hr lbSO2/LT

1.53 0.0057

Test/Run Date Hours Flow, dscfm SO2, gr/dscf SO2, lb/hr 1.69 0.0070

No. 1205 pelletizer waste gas stack Method 6 3.58 0.0175

4/1 1/11/1995 0840-0940 65,952 0.0014 0.79 UPL 2-tail 95% 7.94 0.0423

4/2 1/11/1995 1022-1125 63,717 0.0011 0.60

4/3 1/11/1995 1153-1253 61,936 0.0017 0.90

Average 63,868 0.0014 0.76

Test/Run Date Hours Flow, dscfm SO2, ppm SO2, lb/hr

No. 601 pelletizerstack

5/1 10/10/1995 1239-1339 52,507 4 2.10 108.4 LT/h, low bound

5/2 10/10/1995 1424-1524 52,961 1.6 0.85 111 LT/h, high bound

5/3 10/10/1995 1605-1705 52,937 0.6 0.32 109.7 LT/hr, ave

Average 52,802 2.07 1.09 0.0297 lb SO2/LT for Furnace 6

Staff: HJ; File: 09000064814f5ac8; Page 1 of 1; 11:16 AM, 1/22/2014
BART SO2 Data: United Taconite

May 3, 2005, Methods 6C & 7E stack testing at Line 1 (SV 046)

Post EERP Run 2 Run 3 Run 4 Average STP temp:

GB feed to grate, LT/h 254 261 259 258 STP press:

Fired pellets made, LT/h 221 229 226 225 Temp conv:

Natural gas, MMBtu/hr 154 117 120 130 R universal:

Calc MMBtu/LT pel 0.697 0.511 0.531 0.580 MW(SO2)

Stack gas flow, acfm 393,960 407,396 397,581 399,646 MW(NOx)

Stack gas flow, scfm 330,867 341,961 334,885 335,904 For MW, see

Stack gas flow, dscfm 285,297 291,795 289,690 288,927

SO2, ppm, zero, initial 1.3 1.7 -0.03 L1 SO2 limit, lb/LTp.

final 1.7 -0.03 -0.10 Upper data 0.186

upscale, initial 48.1 49.3 48.3 UCL mean 0.107

final 49.3 48.3 47.8 mean 0.0291

Calibration gas value 50.5 50.5 50.5 LCL mean -0.049

Measured value 2.1 2.4 2.0 Lower data -0.127

Corrected value, ppm 0.64 1.65 2.17 1.49

SO2, lb/hr 1.83 4.80 6.26 4.30 Barr gave:

lb SO2/LT pellets 0.00827 0.0209 0.0277 0.0190 0.0188

lb SO2/MMBtu 0.0119 0.0410 0.0522 0.0350 0.0369

NOx, ppm, zero, initial 2.0 1.7 1.50

final 1.7 1.5 2.2

upscale, initial 240 234 233

final 234 233 237

Calibration gas value 246 246 246

Measured value 301 310 291

Corrected value, ppm 313 327 305 315

NOx, lb/hr 640 684 633 652

lb NOx/LT pellets 2.89 2.99 2.80 2.89

lb NOx/MMBtu 4.15 5.85 5.28 5.09

Pre-EERP stack test, 12/28/04 12/30/2004 data Average

254 251 250 230 230 243 LT GB feed to grate/hr

221 219 217 200 200 211 LT pellets/hr

196 191 193 171 166 183 MMBtu/hr

0.887 0.872 0.889 0.855 0.830 0.867 Calc MMBtu/LT pel

366,346 395,012 397,058 393,719 388,265 388,080 Stack gas flow, acfm

312,852 336,666 338,220 335,115 330,752 330,721 Stack gas flow, scfm

276,989 296,047 296,000 293,576 292,005 290,923 Stack gas flow, dscfm

1.5 1.2 1.0 SO2, ppm, zero, initial

1.2 1.0 0.4 final

46.7 48.2 46.8 upscale, initial

48.2 46.8 47.4 final

50.5 50.5 50.5 Calibration gas value

4.8 5.5 6.2 Measured value

3.8 4.8 6.0 4.85 Corrected value, ppm

10.4 14.1 17.7 14.1 SO2, lb/hr

0.0473 0.0646 0.0815 0.0644 lb SO2/LT pel.

0.0533 0.0741 0.0916 0.0730 lb SO2/MMBtu

1.7 3.1 5.4 -34.0 -27.0 NOx, ppm, zero, initial

3.1 5.4 4.0 -27.0 -42.0 final

452 449 457 442 434 upscale, initial

449 457 455 437 430 final

461 461 461 461 461 Calibration gas value

683 684 685 562.8 562.1 Measured value

700 698 695 582 590 653 Corrected value, ppm

1390 1481 1474 1224 1234 1361 NOx, lb/hr

6.29 6.76 6.79 6.12 6.17 6.43 lb NOx/LT pel.

7.09 7.76 7.64 7.16 7.43 7.41 lb NOx/MMBtu

Nov. 21, 1997, Methods 6C & 7E stack testing at Line 1 (SV 046)

Run 2 Run 3 Run 4 Average

GB feed to grate, LT/h 254 269 269 264

Fired pellets made, LT/h 213 226 226 222

Natural gas, MMBtu/hr 146 146 154 149

Calc MMBtu/LT pel 0.685 0.646 0.681 0.671

Stack gas flow, acfm 375,633 374,973 375,303

Stack gas flow, scfm 319,703 319,052 319,378

Stack gas flow, dscfm 282,378 283,006 282,692 282,692

SO2, ppm, zero, initial 0.6 0.2 2.10

final 0.2 2.1 1.70

upscale, initial 50.0 50.7 51.3

final 50.7 51.3 50.7

Calibration gas value 55.4 55.4 55.4

Measured value 0.8 1.3 1.9

Corrected value, ppm 0.44 0.17 0.00 0.305

SO2, lb/hr 1.25 0.47 0.00 0.860 Barr gave:

lb SO2/LT pellets 0.00587 0.00208 0.0000 0.0040 0.0041

Staff: HJ; File: 09000064814f5ac8; Page 1 of 4; 11:16 AM, 1/22/2014
BART SO2 Data: United Taconite

lb SO2/MMBtu 0.00856 0.00322 0.0000 0.00589 0.00597

NOx, ppm, zero, initial 0.5 2.4 1.20 Barr for 5/3/2006:

final 0.5 1.1 1.1 0.0308

upscale, initial 86.6 438 439 0.0599

final 217 437 438

Calibration gas value 448 448 448

Measured value 414 401 330

Corrected value, ppm 423 411 337 374

NOx, lb/hr 856 833 682 757

lb NOx/LT pellets 4.02 3.68 3.02 3.35

lb NOx/MMBtu 5.86 5.70 4.43 5.07

Nov. 21, 1997, Performance testing at Stack 2A (to be continued on bottom of Page 4)

Parameter 2A-Run 1 2A-Run 2 2A-Run 3 2A-Average

Test period 1838-1935 2009-2119 2148-2254

Grate GB feed, LT/hr 583 583 583 583

Fired pellets, LT/hr 489 489 489 489

Coal-coke, ton/hr 7.01 7.01 7.01 7.01

Fuel rate, million Btu/hr 185 185 185 185

Calc MMBtu/LT pellets 0.378 0.378 0.378 0.378

Stack gas flow, acfm 380,571 379,325 377,326 379,074

Fuel Stack gas flow, scfm 329,975 328,706 326,832 328,504

13166 Btu/lb as rec'd Stack gas flow, dscfm 296,681 295,241 291,402 294,441

2.05% sulfur as rec'd SO2, ppm, zero, initial 5.2 5.1 1.7

4.45% moisture as rec'd final 5.1 1.7 2.8

upscale, initial 89.9 219.9 219.0

9.9% moisture for GB final 90.1 219.0 226.6

0.008% sulfur for GB Calibration gas value 225.0 225.0 225.0

0.003% S - fired pelletsMeasured value 139.4 187.0 149.7

Corrected value, ppm 141.6 191 150 161

SO2, lb/hr 419 563 437 473

lb SO2/LT pellets 0.86 1.15 0.894 0.968

lb SO2/MMBtu 2.270 3.050 2.368 2.563

Staff: HJ; File: 09000064814f5ac8; Page 2 of 4; 11:16 AM, 1/22/2014
BART SO2 Data: United Taconite

Common parameters June 9, 2004, Performance testing at Line 2 (Stack 2A, SV 048; Stack 2B, SV 049)

68 deg F Parameter 2A-Run 1 2A-Run 2 2A-Average 2B-Run 1 2B-Run 2 2B-Run 3 2B-Average Furnace Total

14.696 psia Test period 1630-1741 1802-2014 0920-1034 1138-1247 1325-1438

459.67 0 deg F Grate GB feed, LT/hr 607 602 605 592 592 599 594

10.73 psia*ft3/R/lbmol Fired pellets, LT/hr 520 506 513 518 503 514 512 512

64.06 lb/lb mole 50-50 coal-coke, ton/hr 6.53 7.59 7.06 7.70 9.2 7.5 8.13

46.01 lb/lb mole Fuel rate, million Btu/hr 185 215 200 218 261 213 231

http://webbook.nist.gov/chemistry/ Calc MMBtu/LT pellets 0.356 0.425 0.391 0.421 0.518 0.414 0.451 Stack gas flow

Stack gas flow, acfm 397,032 397,045 397,039 379,591 382,952 384,234 382,259 779,298 801,246 acfm

Fuel data, 50-50 coal-coke Stack gas flow, scfm 339,626 339,877 339,752 326,693 330,568 330,222 329,161 668,913 694,725 scfm

14172 Btu/lb as received Stack gas flow, dscfm 288,068 290,068 289,068 289,041 285,155 286,704 286,967 576,035 618,977 dscfm

2.34 % Sulfur as received SO2, ppm, zero, initial 0.0 3.0 0.0 3.0 3.0

1.33 % Moisture as received final 3.0 0.0 3.0 3.0 3.0

upscale, initial 91.0 91.0 92.0 90.0 90.0

9.74 % Moisture for greenball final 91.0 90.0 90.0 90.0 90.0

0.003 % Sulfur for greenball Calibration gas value 93.0 93.0 93.0 93.0 93.0

0.002 % Sulfur for fired pellets Measured value 114.2 119.0 97.8 102.8 91.0 SO2 data

Corrected value, ppm 117 123 120 100 107 94 100 f.w. ave 110 192 ppm

Line 2 1998 sulfur balance: SO2, lb/hr 337 355 346 289 303 269 287 633 1,185 lb/hr

0.0499 LT chips/LT wet GB lb SO2/LT pellets 0.647 0.702 0.675 0.557 0.603 0.523 0.561 1.24 2.27 lb/LT

2.34E-04 lb S/lb chips lb SO2/MMBtu 1.82 1.65 1.73 1.32 1.16 1.27 1.25 2.99 4.66 lb/MMBtu

3.38E-05 lb S/lb pellets NOx, ppm, zero, initial 2.0 2.0 1.0 0.0 0.0

7.45E-05 lb S/lb wet GB final 2.0 2.0 0.0 0.0 1.0

upscale, initial 94.0 94.0 95.0 93.0 93.0

min 312,852 final 94.0 93.0 93.0 93.0 93.0

max 341,961 Calibration gas value 94.0 94.0 94.0 94.0 94.0

min 200 Measured value 98.0 97.0 84.0 83.0 83.0 SO2 data

max 229 Corrected value, ppm 98.1 97.6 98 83.9 83.9 83.8 84 f.w. ave 91 115 ppm

min 117 NOx, lb/hr 202 203 203 174 171 172 173 375 509 lb/hr

max 196 lb NOx/LT pellets 0.389 0.401 0.395 0.336 0.341 0.335 0.337 0.732 0.97 lb/LT

lb NOx/MMBtu 1.09 0.943 1.02 0.797 0.657 0.810 0.755 1.77 2.00 lb/MMBtu

L1 SO2 limit, lb/million Btu

Upper data 0.151 Dry GB feed, LT/hr 548 543 534 534 541

UCL mean 0.092 Sulfur from feed, lb/hr 36.8 36.5 35.9 35.9 36.3

mean 0.044 Sulfur from fuel, lb/hr 306 355 360 431 351

LCL mean -0.004 Total sulfur input, lb/hr 342 392 396 466 387

Lower data -0.063 Dust & chips, LT/hr 30.3 30.0 29.5 29.5 29.9

Sulfur from chips, lb/hr 15.9 15.7 15.5 15.5 15.7

Barr Sulfur from pellets, lb/hr 23.3 22.7 23.2 22.5 23.0

UPL 0.149 Sulfur @ scr inlet, lb/hr 303 353 358 428 349 Line 2 ave:

SO2 @ scr inlet, lb/hr 606 707 715 857 697 716

SO2 ctrl efficiency 11.7% c.f. 15.4% by Barr

April 18, 2001, Title V performance testing at Line 2 (Stack 2A, SV 048; Stack 2B, SV 049)

Parameter 2A-Run 1 2A-Run 2 2A-Run 3 2A-Average 2B-Run 1 2B-Run 2 2B-Run 3 2B-Average Furnace Total

Barr gave: Test period 0840-1058 1150-1300 1326-1432 1610-1719 1745-1855 1930-2042

0.0650 Grate GB feed, LT/hr 599 627 653 626 669 652 646 656

0.0736 Fired pellets, LT/hr 491 512 535 513 548 534 529 537 525

Coal-coke, ton/hr 8.87 8.58 8.78 8.74 8.76 8.95 9.02 8.91

Fuel rate, million Btu/hr 256 248 253 252 253 258 260 257

Fuel Calc MMBtu/LT pellets 0.522 0.483 0.474 0.493 0.461 0.484 0.492 0.479

14431 Btu/lb as rec'd Stack gas flow, acfm 404,891 408,456 412,388 408,578 391,209 396,477 390,318 392,668 801,246

3.53% sulfur as rec'd Stack gas flow, scfm 352,674 355,012 356,838 354,841 338,410 343,361 337,881 339,884 694,725

1.04% moisture as rec'd Stack gas flow, dscfm 316,850 317,286 319,219 317,785 299,949 304,402 299,225 301,192 618,977

SO2, ppm, zero, initial 0.8 4.8 4.1 5.8 6.4 5.0

10.0% moisture for GB final 8.0 4.1 6.5 6.4 11.3 6.4

0.005% sulfur for GB upscale, initial 234.0 233.0 233.6 232.1 233.0 238.0

0.002% S - fired pellets final 238.5 233.6 232.6 233.0 234.2 234.4

Calibration gas value 240.0 240.0 240.0 240.0 240.0 240.0

Measured value 205.9 193.3 203.6 175.4 179.4 171.2

Corrected value, ppm 209 198 209 205 179 182 172 178 f.w. ave 192

SO2, lb/hr 659 627 665 651 537 553 514 535 1,185

lb SO2/LT pellets 1.343 1.224 1.244 1.27 0.980 1.036 0.972 0.996 2.27

lb SO2/MMBtu 2.58 2.53 2.63 2.58 2.12 2.14 1.98 2.08 4.66

NOx, ppm, zero, initial 0.9 1.8 0.9 0.4 1.2 0.2

final 1.8 0.9 2.1 1.2 3.2 -0.4

upscale, initial 96.2 94.2 95.8 95.5 93.8 95.9

final 94.2 95.8 94.7 93.8 94.0 99.6

Calibration gas value 96.0 96.0 96.0 96.0 96.0 96.0

Measured value 116.3 131.1 124.5 103.4 100.6 103.9

Corrected value, ppm 118 133 126 126 105 103 102 103 f.w. ave 115

NOx, lb/hr 267 302 288 286 226 225 219 223 509

lb NOx/LT pellets 0.544 0.590 0.539 0.558 0.412 0.421 0.413 0.415 0.973

lb NOx/MMBtu 1.04 1.221 1.137 1.13 0.892 0.870 0.840 0.867 2.00

Dry GB feed, LT/hr 539 564 588 602 587 581

Sulfur from feed, lb/hr 60.4 63.2 65.8 67.4 65.7 65.1

Staff: HJ; File: 09000064814f5ac8; Page 3 of 4; 11:16 AM, 1/22/2014
BART SO2 Data: United Taconite

Sulfur from fuel, lb/hr 626 606 620 618 632 637

Total sulfur input, lb/hr 687 669 686 686 698 702

HJ: Dust & chips, LT/hr 29.9 31.3 32.6 33.4 32.5 32.2

0.0624 Sulfur from chips, lb/hr 15.7 16.4 17.1 17.5 17.1 16.9

Sulfur from pellets, lb/hr 22.0 23.0 24.0 24.6 23.9 23.7

Sulfur @ scr inlet, lb/hr 649 630 645 644 657 661 Line 2 ave:

SO2 @ scr inlet, lb/hr 1298 1259 1289 1288 1313 1323 1295

SO2 ctrl efficiency 8.47%

c.f. 10.4% by Barr

Nov. 21, 1997, Performance testing at Stack 2A (Continued from Page 2)

Parameter 2A-Run 1 2A-Run 2 2A-Run 3 2A-Average

NOx, ppm, zero, initial 0.5 0.1 1.7

final 0.1 1.7 1.9

upscale, initial 90.7 90.0 92.5

final 90.0 92.5 91.1

Calibration gas value 89.9 89.9 89.9

Measured value 88.2 103.9 89.2

Corrected value, ppm 87.8 102.5 87.3 92.5 Line 2 ave:

NOx, lb/hr 187 217 182 195 1.94 lb SO2/LT pellets

lb NOx/LT pellets 0.381 0.443 0.373 0.399 0.79843589

lb NOx/MMBtu 1.010 1.174 0.987 1.057 2.11450484 UPL 4.43

UCL 3.12

Dry GB feed, LT/hr 525 525 525 Average 1.81

Sulfur from feed, lb/hr 97.4 97.4 97.4 LCL 0.506

Sulfur from fuel, lb/hr 287 287 287 LPL -0.801

Total sulfur input, lb/hr 384 384 384

Dust & chips, LT/hr 29.1 29.1 29.1

Sulfur from chips, lb/hr 15.2 15.2 15.2

Sulfur from pellets, lb/hr 37.1 37.1 37.1

Sulfur @ scr inlet, lb/hr 332 332 332 LT pellets/hr scfm MMBtu/hr

SO2 @ scr inlet, lb/hr 664 664 664 min 489 666,319 185

SO2 ctrl efficiency cannot be determined.... max 548 700,199 261

Staff: HJ; File: 09000064814f5ac8; Page 4 of 4; 11:16 AM, 1/22/2014
BART SO2 Data: Minntac

Test date lb SO2/LT pellets Remarks SO2, ppm dscfm Pellets, LT/hr lb SO2/LT

9/5/2000 0.302 L7; pre-ported; gas-fired; fluxed pellet production Line 3, 4/7/2004

11/28/2000 0.356 L7; pre-ported; gas-fired; fluxed pellet production 39.8 242000 202.4 0.475

2/20/2001 0.209 L7; pre-ported; gas-fired; fluxed pellet production 48.1 230000 202.7 0.544

8/2/2001 0.231 L7; post-ported; gas-fired; fluxed pellet production 42.5 243000 202.8 0.508

8/30/2001 0.243 L7; post-ported; gas-fired; fluxed pellet production Line 4, 4/6/2004

6/20/2002 0.209 L7; post-ported; gas-fired; no purge; fluxed pellet production 11.8 416400 482.5 0.102

12/26/2006 0.322 L3; post-scrubber; gas-fired; fluxed pellet production 10.5 419800 477.4 0.0921

12.8 419600 470.7 0.114

6/20/2002 0.208 L7; post-ported; gas-fired; nitrogen purge; fluxed pellet production Line 6, 4/8/2004

20.6 338700 438.0 0.159

4/8/2004 0.154 L6; post-ported; coal-gas co-firing; fluxed pellet production 19.4 348200 437.8 0.154

18.8 346800 439.2 0.148

4/6/2004 0.103 L4; gas-fired; acid pellet production

4/7/2004 0.509 L3; pre-scrubber; gas-fired; acid pellet production Statistics lb SO2/LT pellets

Median 0.243

Based on the top 7 stack tests listed above: 1st quartile 0.220

UPL 0.421 Minimum 0.209

UCL 0.322 Line 3 Line 4 Line 5 Maximum 0.356

Average 0.267 Pellets fired, LT/hr 275 426 426 3rd quartile 0.312

LCL 0.213 Suggested limit, lb SO2/hr 116 180 180

LPL 0.114 Pre-005 applicability, lb/hr 200 161 161 Harmean 0.257

R. haze modeling, 1/24/05 234 182 182 Geomean 0.262

Average 0.267

Stdev 0.0588

0.0

0.1

0.2

0.3

0.4

lb SO2/LT pellets

Natural Gas Firing

Staff: HJ; File: 09000064814f5ac8; Page 1 of 1; 11:16 AM, 1/22/2014
BART SO2 Data: Mittal

June 2007 Method 7E Compliance Test - Fluxed Pellet Prod.

Stack Run Test date Run time SO2 ppmd SO2,lb/hr Flow dscfmPellets LT/hr MMBtu/hr EF lb/LT EF lb/MMBtu

A 1 6/19/2007 0955-1104 1.82 2.87 158,260 355.8 185 0.0081 0.0156

2 6/19/2007 1140-1253 2.91 4.46 153,770 355.8 185 0.0125 0.0242

3 6/19/2007 1322-1428 1.72 2.72 158,517 355.8 185 0.0076 0.0147

Average 2.15 3.35 156,849 355.8 185 0.0094 0.0182

B 1 6/19/2007 1504-1609 2.25 3.41 151,982 377.6 184 0.0090 0.0186

2 6/19/2007 1635-1739 2.57 3.87 151,013 377.6 184 0.0103 0.0211

3 6/19/2007 1800-1904 1.64 2.55 155,850 377.6 184 0.0068 0.0139

Average 2.15 3.28 152,948 377.6 184 0.0087 0.0179

C 1 6/20/2007 0610-0715 1.40 2.02 144,738 375.0 183 0.0054 0.0111

2 6/20/2007 0740-0845 2.05 3.03 148,192 375.0 183 0.0081 0.0166

3 6/20/2007 0914-1014 1.98 3.23 163,645 375.0 183 0.0086 0.0177

4 6/20/2007 1051-1154 1.61 2.37 147,541 375.0 183 0.0063 0.0130

Average 1.76 2.66 151,029 375.0 183 0.0071 0.0146

D 1 6/20/2007 1305-1412 < 1.00 1.40 140,311 360.9 182 0.0039 0.0077

2 6/20/2007 1444-1547 1.47 2.09 142,776 360.9 182 0.0058 0.0115

3 6/20/2007 1612-1717 0.88 1.27 144,318 360.9 182 0.0035 0.0069

Average 1.12 1.59 142,468 360.9 182 0.0044 0.0087

Furnace total or flow-wt. average: 1.81 10.9 603,295 367.3 183 0.0296 0.0593

June 17, 1997, Engineering Test on the Indurating Furnace (MPCA review letter, 8/12/1997)

Stack SO2, lb/hr

A 13.9 max-min 10.5 0.0406

B 7.3 average 8.13 0.0213

C 7.9 (m-m)/ave 1.29 0.0231

D 3.4 0.0099

Sum 32.5 c.f. June 2007

Fuel 183 from 169 - 195 Mcf/hr of nat. gas. 0.18 lb SO2/million Btu 0.0593

Production 342 from 325 - 360 LT pellets/hr. 0.0950 lb SO2/LT pellets 0.0296

This is not stated in the MPCA review letter.

corrected 0.123 lb SO2/LT

margin 22.6% for compliance

June 29, 1994, Engineering Test on Indurating Furnace Stack D (MPCA review letter 5/15/1997)

Stack SO2, lb/hr

D 0.89 0.0192

Fuel 192 Mcf/hr of natural gas. 0.0224

Production 380 LT pellets/hr. Furnace/D

Staff: HJ; File: 09000064814f5ac8; Page 1 of 1; 11:16 AM, 1/22/2014
BART SO2 Data: Grate-kiln solid streams

1998 EVTAC sulfur balance

11/19/97 11/20/97 11/20/97 11/18/97 11/18/97 11/19/97

Line 1 Line 1 Line 1 Line 2 Line 2 Line 2

Wet GB feed, LT/hr 280 210 281 585 615 605

Dry GB feed, LT/hr 252 189 251 527 554 546

Fired pellets made, LT/hr 235 176 236 492 517 508

Dust & chips collected, LT/hr 13.9 10.2 11.8 28.9 30.8 30.3

Dust & chips / wet GB, lb/lb 0.0496 0.0486 0.0420 0.0494 0.0501 0.0501

lb sulfur/hr from GB 44.8 36.9 64.4 118.6 91.0 90.9

lb sulfur/hr from pellets 19.6 13.1 17.5 34.3 39.6 41.4

lb sulfur/hr from dust & chips 2.8 2.7 3.0 15.0 16.2 15.9

Moisture in green ball, % 10.0 10.0 10.7 9.91 9.92 9.75

Sulfur in GB, lb S/lb dry GB 7.94E-05 8.72E-05 1.15E-04 1.00E-04 7.33E-05 7.43E-05

Sulfur in pellets, lb S/lb pellets 3.72E-05 3.32E-05 3.31E-05 3.11E-05 3.42E-05 3.64E-05

Sulfur in chips, lb S/lb chips 8.99E-05 1.18E-04 1.13E-04 2.32E-04 2.35E-04 2.34E-04

S in chips / S in pellets 2.42 3.56 3.43 7.44 6.87 6.44

GB feed

GB recycle

Staff: HJ; File: 09000064814f5ac8; Page 1 of 3; 11:16 AM, 1/22/2014
BART SO2 Data: Grate-kiln solid streams

1994 Minntac sulfur balance

11/3/93 3/30/94 4/12/94 4/13/94 4/1/94 4/4/94 4/11/94 3/11/94 3/15/94

Acid L6 Acid L4 Acid L4 Acid L4 Acid L4 Acid L4 Acid L4 Fluxed L6 Fluxed L6

464 510 550 446 415 504 567 500 500

421 465 501 404 376 458 514 455 454

418 464 500 408 380 460 518 433 432

14 7 8 3 3 5 5 15 15

0.0302 0.0137 0.0145 0.0067 0.0072 0.0099 0.0088 0.0300 0.0300

109 115 124 132 127 139 179 148 143

47 27 24 14 14 26 61 52 40

4 2 2 1 1 2 2 5 5

9.17 8.89 8.92 9.37 9.30 9.19 9.37 9.02 9.19

1.15E-04 1.10E-04 1.11E-04 1.46E-04 1.51E-04 1.36E-04 1.56E-04 1.45E-04 1.41E-04

5.02E-05 2.60E-05 2.14E-05 1.53E-05 1.64E-05 2.52E-05 5.26E-05 5.36E-05 4.13E-05

1.28E-04 1.28E-04 1.12E-04 1.49E-04 1.49E-04 1.79E-04 1.79E-04 1.49E-04 1.49E-04

2.54 4.91 5.21 9.71 9.05 7.08 3.40 2.78 3.60

510 560 605 480 440 540 605 550 550

46 50 55 34 25 36 38 50 50

Staff: HJ; File: 09000064814f5ac8; Page 2 of 3; 11:16 AM, 1/22/2014
BART SO2 Data: Grate-kiln solid streams

3/16/94 7/25-26/00

Fluxed L6 NSPC Ph2

500 885

454

432 628

15 2.47

0.0300 95% Chebyshev (Mean,Sd) UCL 0.0482 0.00279

148

43

5

9.16

1.45E-04

4.44E-05 Lo data LCL mean mean UCL mean Up data

1.49E-04 5.65E-05 1.32E-04 1.56E-04 1.80E-04 2.55E-04

3.35 -0.0822 3.85 5.11 6.37 10.3

550

50

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