Evaluation of underground mining technology for western thick coal seams. Preprint No. 75-F-341. [Recommendations for mining thick, pitching coal seams deep underground]

Deep mining of thick coal seams offers both a challenge and and opportunity to the U. S. coal industry. The conditions that may be encountered and the hazards that may have to be overcome during such mining are described briefly. As an aid to mine design, selected foreign practices were critically reviewed to determine their applicability to American conditions. Bearing in mind that immediate extraction procedures must use existing equipment, manpower and technology, two methods were proposed. It is necessary to examine, in depth, the economics, production and detailed engineering of the proposed methods. Though costs are not quantified yet, for thick seam mining to be widely practiced, the coal must be competitive in the energy market. It is heartening to note that there are several research projects, including demonstrations, underway to examine the technical and economic feasibilities, of this subject. (auth)