Topical Subjects
- Coal preparation plants--Equipment and supplies.3
- Coal preparation plants--West Virginia--Fairmont.1
- Coal preparation plants--West Virginia--Middleton.1
- Coal preparation plants--West Virginia--Owings.1
- Coal preparation plants--West Virginia.1
- Coal preparation plants.3
- Coal preparation.2
- Coal trade--Accidents.1
- Coal trade--Quality control.1
- Coal--Geology.3
- Coal--Testing.1
- Coal--Transportation--Pennsylvania.1
- Coal--Transportation--West Virginia--Owings.1
- Coal--Transportation--West Virginia.1
- Coal--Transportation.8
- Coal-mining machinery--Ohio--Georgetown.1
- Coal-mining machinery.26
- Coal.3
- Conveying machinery.1
- Core drilling.1