| 211130 |
Sulfur recovered from natural gas |
| 212114 |
Bituminous coal, lignite, or anthracite beneficiating (e.g., cleaning, crushing, screening, washing, sizing) |
| 212114 |
Bituminous coal, lignite, or anthracite surface mine site development for own account |
| 212114 |
Bituminous coal, lignite, or anthracite surface mining and/or beneficiating |
| 212114 |
Brown coal mining and/or beneficiating |
| 212114 |
Coal beneficiating plants (e.g., cleaning, crushing, screening, washing) |
| 212114 |
Coal stripping (except on a contract, fee, or other basis) |
| 212114 |
Coal, bituminous, lignite, or anthracite, surface mining and/or beneficiating |
| 212114 |
Coal, brown, mining and/or beneficiating |
| 212114 |
Culm bank recovery, bituminous coal, lignite, or anthracite (except on a contract basis) |