Analysis of underground extraction techniques for thick coal seams

The problems, technical and nontechnical, which are associated with the mining of thick coal seams are analyzed in this thesis. Mining methods currently practiced abroad are reviewed. A discussion of North American thick-seam mining, based on information gathered from mine-site visits and published literature, is also included. On the basis of an inventory of geologic and mining conditions in the West, four methods are recommended for potential application. An economic evaluation of the proposed methods, on a panel basis, has been conducted. A comparative analysis of the proposed methods with typical conventional and continuous sections is provided. The thesis has arrived at a number of conclusions. Although there are several thick-seam methods practiced abroad, these methods cannot be adapted, for the most part, without variations for U.S. conditions. This is due, mainly to the different economic and political climate of the U.S. However, thick-seam methods can be designed to be economically competitive with methods employed in seams of average thickness. Further, the recovery rates are also acceptable. New equipment, such as shields, should find increased acceptance whereas standard U.S. equipment, such as shuttle cars, will have limited applications.