Assessment of the Single-Pass Thick-SEAM Longwall Mining Method. Final Report

摘要

The objectives of the project are a review of the foreign experiences in longwall mining of thick seams, an evaluation of the US thick seam reserves, a mine design, equipment specifications, and an economic study for longwall mining in a single pass up to 16 feet in US conditions. The review of foreign experience shows a steady increase in the maximum height of extraction with several examples in the range of 13 to 15 feet. Longwall face equipment is available up to an 18 feet height of extraction, based upon shields support and shearer loader. There are important reserves of thick coal seams which can be mined by a longwall in a single pass (125 billion tons). In US conditions, a retreating face with a 16 foot height of extraction and a double entry system, driven 10 feet high, are proposed. The face stability can be improved by using a two bench face cut in good geological conditions. The economic study compares longwall mining with the room-and-pillar method. Longwall mining 16 feet high coal in a single pass can compete advantageously with room-and-pillar mining. 74 figures, 14 tables. (ERA citation 08:004056)