Cliffs Natural Resources Barr Engineering Co.

Hibbing Taconite Company October 22, 2010

Hibbing, Minnesota

Pellet Indurating Furnace Line 2

Testing performed on 6/3/010

Test Condition: Furnace Line 2 Low Temperature Firing Condition

 NOx Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

SV028 Stack A 1319-1340 1400-1421 1440-1501 1517-1538 1553-1614 1629-1650 1706-1727 1741-1802 1815-1836 1850-1911

Ref. Method lb/hr 55.0 53.1 55.2 52.8 53.1 52.0 53.4 52.8 53.6 52.2

PEM lb/hr 96.7 82.9 83.4 87.6 88.6 88.2 87.2 80.7 81.9 82.6

Difference 41.8 29.7 28.2 34.8 35.4 36.2 33.7 28.0 28.2 30.4

 NOx Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

SV027 Stack B 1319-1340 1400-1421 1440-1501 1517-1538 1553-1614 1629-1650 1706-1727 1741-1802 1815-1836 1850-1911

Ref. Method lb/hr 91.3 84.8 88.9 89.4 88.9 87.2 87.0 88.9 90.6 87.4

PEM lb/hr 121.3 115.9 116.0 116.8 116.2 116.3 115.6 115.5 114.4 115.7

Difference 30.0 31.1 27.0 27.4 27.3 29.2 28.7 26.6 23.9 28.3

NOx Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

SV026 Stack C 1319-1340 1400-1421 1440-1501 1517-1538 1553-1614 1629-1650 1706-1727 1741-1802 1815-1836 1850-1911

Ref. Method lb/hr 125.2 122.7 125.4 125.0 124.8 124.4 126.0 126.9 128.6 125.4

PEM lb/hr 122.3 116.8 116.2 114.9 116.5 115.1 120.2 116.7 119.3 117.7

Difference -3.0 -5.9 -9.1 -10.1 -8.3 -9.4 -5.8 -10.3 -9.3 -7.7

 NOx Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10 

SV025 Stack D 1319-1340 1400-1421 1440-1501 1517-1538 1553-1614 1629-1650 1706-1727 1741-1802 1815-1836 1850-1911

Ref. Method lb/hr 142.9 143.7 144.2 144.4 143.1 144.3 144.6 146.7 144.2 142.9

PEM lb/hr 130.3 120.8 120.3 123.2 123.4 122.7 123.5 123.3 123.6 125.7

Difference -12.7 -22.9 -23.9 -21.2 -19.6 -21.5 -21.2 -23.4 -20.7 -17.2

All Runs
Cliffs Natural Resources Barr Engineering Co.

Hibbing Taconite Company October 22, 2010

Hibbing, Minnesota

Test Condition: Furnace Line 2 Mid Temperature Firing Condition

 Emissions Calculations

6/3/10

SV028- Stack A

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 142,195 140,618 139,459 138,353 138,509 138,171 136,514 137,361 137,217 138,696

NOIx bias corrected ppm 62 62 62 61 63 62 63 62 62 60

Emission Calculations

NOx lb/hr 63.5 62.7 61.9 60.5 62.4 61.6 61.2 61.1 61.1 59.8

SV027 - Stack B

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 175,688 174,442 176,489 176,204 176,314 172,095 176,699 173,831 173,969 175,919

NOIx bias corrected ppm 82 81 82 81 84 83 82 82 83 81

Emission Calculations

NOx lb/hr 103.2 101.6 104.1 102.3 105.9 101.9 104.3 102.7 103.2 101.8

SV026 - Stack C

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 167,086 162,537 161,065 162,548 160,578 158,526 159,209 158,929 158,924 158,805

NOIx bias corrected ppm 123 122 124 122 125 123 123 124 125 122

Emission Calculations

NOx lb/hr 146.7 142.6 142.8 142.4 144.3 139.4 140.5 141.2 142.6 138.9

SV025 - Stack D

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 146,690 148,711 149,968 149,514 150,410 149,036 145,810 146,701 148,019 146,679

NOIx bias corrected ppm 150 151 153 151 154 152 151 152 155 151

Emission Calculations

NOx lb/hr 158.2 161.0 164.1 162.1 166.4 161.9 157.9 159.8 164.8 158.6
Cliffs Natural Resources Barr Engineering Co.

Hibbing Taconite Company October 22, 2010

Hibbing, Minnesota

 Emissions Calculations

06/02/10

SV028 Stack A

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 139,175 140,140 140,388 141,452 139,566 138,712 139,399 137,529 140,546 139,400

NOIx bias corrected ppm 65 65 66 66 64 66 64 66 64 64

Emission Calculations

NOx lb/hr 64.9 64.9 66.2 66.4 64.1 65.2 64.2 64.9 64.5 64.1

SV027 Stack B

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 169,282 174,365 171,680 175,575 171,971 173,488 172,685 172,288 178,830 174,729

NOIx bias corrected ppm 88 87 88 88 85 88 86 88 87 88

Emission Calculations

NOx lb/hr 106.2 108.5 108.4 110.3 105.2 109.3 106.9 108.2 111.6 110.0

SV026 Stack C

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 165,160 163,442 164,097 162,900 162,080 161,471 163,321 165,072 162,470 163,584

NOIx bias corrected ppm 135 133 137 136 134 136 136 137 136 137

Emission Calculations

NOx lb/hr 159.8 155.9 161.1 158.3 155.4 157.8 158.6 162.2 158.3 160.2

SV025 Stack D

Airflow Rates Run 1 Run 2 Run 3 Run 4 Run 5 Run 6 Run 7 Run 8 Run 9 Run 10

DSCFM 152,808 152,569 152,688 153,648 151,408 151,061 148,533 151,250 150,007 149,554

NOIx bias corrected ppm 172 168 174 171 171 173 173 172 171 172

Emission Calculations

NOx lb/hr 188.0 184.1 190.4 188.2 185.4 187.0 183.9 186.9 183.9 184.0

Test Condition: Furnace Line 2 High Temperature Firing Condition