Hibbing Taconite Company

Table 1: Facility-wide Potential to Emit Calculations for NOx and SO2

SV EU EU_Desc Tput_Hr Tput_Hr_Note Tput_Ann Tput_Ann_Note Units Pollutant Unc lbs/hr Unc tons/yr PTE lbs/hr PTE tons/yr

SV 021-024 EU 020 Pellet Indurating Furnace Line 1 140 [101] 1,226,400 [102] MM Btu NOx 4.7651 [103] 667 [105] 2,922 [106] [107] 667 [108] 2,922 [109]

SV 021-024 EU 020 Pellet Indurating Furnace Line 1 140 [101] 1,226,400 [102] MM Btu SO2 2 [104] 280 [105] 1,226 [106] [107] 280 [108] 1,226 [109]

SV 025-028 EU 021 Pellet Indurating Furnace Line 2 140 [101] 1,226,400 [102] MM Btu NOx 4.7651 [103] 667 [105] 2,922 [106] [107] 667 [108] 2,922 [109]

SV 025-028 EU 021 Pellet Indurating Furnace Line 2 140 [101] 1,226,400 [102] MM Btu SO2 2 [104] 280 [105] 1,226 [106] [107] 280 [108] 1,226 [109]

SV 029-032 EU 022 Pellet Indurating Furnace Line 3 140 [101] 1,226,400 [102] MM Btu NOx 4.7651 [103] 667 [105] 2,922 [106] [107] 667 [108] 2,922 [109]

SV 029-032 EU 022 Pellet Indurating Furnace Line 3 140 [101] 1,226,400 [102] MM Btu SO2 2 [104] 280 [105] 1,226 [106] [107] 280 [108] 1,226 [109]

Total NOx: 2,001.3 8,765.9 2,001.3 8,765.9

Total SO2: 840.0 3,679.2 840.0 3,679.2

Notes:

[101] Maximum hourly throughput = Design capacity of emission unit:

Pellet Indurating Furnace Line 1 140 MM Btu/hr

Pellet Indurating Furnace Line 2 140 MM Btu/hr

Pellet Indurating Furnace Line 3 140 MM Btu/hr

[102] Maximum annual throughput = Maximum hourly throughput x 8,760 hrs/yr.

[103] NOx emissions depend on the fuel being fired but not on the pellet production rate. Worst-case emission factor is selected:

AP-42, "Natural Gas Combustion" (7/98), Table 1.4-1 for "Large Wall-fired Boilers (> 100 MM Btu/hr)": 280 lbs/MM cf 0.2745 lbs/MM Btu, converted from fuel units (lbs/MM cf) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 6 oil fired, normal firing": 47 lbs/M gallons 0.3133 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 5 oil fired, normal firing": 47 lbs/M gallons 0.3133 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 4 oil fired, normal firing": 47 lbs/M gallons 0.3133 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 2 oil fired, normal firing": 24 lbs/M gallons 0.1714 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

Stack Test results, averaged over four stacks: EU 020 Furnace 1 3.5671 lbs/MM Btu Test [13] 5/1/2007

3.1007 lbs/MM Btu Test [23] 6/22/2010

EU 021 Furnace 2 3.6950 lbs/MM Btu Test [13] 5/2/2007

4.7651 lbs/MM Btu Test [23] 6/10/2010

EU 022 Furnace 3 2.9107 lbs/MM Btu Test [13] 5/8/2007

3.1001 lbs/MM Btu Test [23] 6/16/2010

[104] SO2 emissions depend on the fuel being fired and the pellet production rate. Emission factor is based on existing permit limit:

AP-42, "Natural Gas Combustion" (7/98), Table 1.4-2": 0.6 lbs/MM cf 0.0006 lbs/MM Btu, converted from fuel units (lbs/MM cf) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 6 oil fired, normal firing": 15.7 lbs/M gallons 0.1047 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 5 oil fired, normal firing": 15.7 lbs/M gallons 0.1047 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 4 oil fired, normal firing": 15 lbs/M gallons 0.1000 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

AP-42, "Fuel Oil Combustion" (5/10), Table 1.3-1 for "Boilers > 100 MM Btu/hr), No. 2 oil fired, normal firing": 14.2 lbs/M gallons 0.1014 lbs/MM Btu, converted from fuel units (lbs/M gallons) using the heat content in [110]

Limit in permit 13700061-004, page A-11 (which includes 0.75 lbs/MM Btu for the contribution of SO2 from the pellets): 2 lbs/MM Btu

Stack Test results, averaged over four stacks: EU 020 Furnace 1 0.2397 lbs/MM Btu Test [7] 6/14/2005

0.5558 lbs/MM Btu Test [23] 6/22/2010

EU 021 Furnace 2 0.3626 lbs/MM Btu Test [5] 6/23-24/2004

0.6204 lbs/MM Btu Test [23] 6/10/2010

EU 022 Furnace 3 0.3650 lbs/MM Btu Test [7] 6/22-23/05

0.7590 lbs/MM Btu Test [23] 6/16/2010

where sulfur content of fuel oil is based on a limit in permit 13700061-004, page A-11: 0.1 % sulfur

[105] Max. Uncontrolled Emissions (lbs/hr) = Max. Hourly Throughput (units/hr) x Uncontrolled Emission Factor (lbs/unit).

[106] Max. Uncontrolled Emissions (tons/yr) = Max. Annual Throughput (units/yr) x Uncontrolled Emission Factor (lbs/unit) / 2,000 (lbs/ton).

[107] APCD used in this process is not effective in controlling this pollutant.

[108] Max. Controlled Emissions (lbs/hr) = Max. Uncontrolled Emissions (lbs/hr) x ((100-Control Eff.)/100).

[109] Max. Controlled Emissions (tons/yr) = Max. Uncontrolled Emissions (tons/yr) x ((100-Control Eff.)/100).

[110] Fuel heat contents:

No. 6 (residual), No.5 and No. 4 fuel oil 150 MM Btu/M gallons #6 fuel oil (from AP-42, May 2010, Table 1.3-2 footnote d)

No. 2 (distillate) fuel oil 140 MM Btu/M gallons #6 fuel oil (from AP-42, May 2010, Table 1.3-2 footnote d)

Natural gas 1,020 MM Btu/MM cf (from AP-42, July 1998, Table 1.4-1 footnote a)

Emission Factor Max. Controlled Emissions

(lbs/Unit) (%) (lbs/hr) (tons/yr)

Control Efficiency

(lbs/hr) (tons/yr)

Stack ID Emission Unit Throughput Pollutant Max. Uncontrolled Emissions

(Units/hr) (Units/yr)

ID Description Maximum Units

File: C:\PROGRA~1\Documentum\CTS\docbases\ProDocbase\config\temp_sessions\4767632496047191667\09000064810c3524.xlsx

Sheet: PTE Page 1 of 1 Print Date: 8/13/2012