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U.S. Department of Energy
Office of Scientific and Technical Information

Multislice mining for thick Western coal seams. Information Circular/1990

Technical Report ·
OSTI ID:5992712
Multislice mining methods were analyzed by the U.S. Bureau of Mines to determine their application to Western U.S. thick coal seams; ground control, geology and costs were considered. Multislice mining is used in widely varying seam conditions worldwide, including flat seams too thick to mine in a single pass, pitching thick seams, and seams containing a rock parting. Longwall multislice methods predominate, but room-and-pillar variants also exist. The initial use of the method in western seams is planned at a deep Colorado mine, where a rock parting will be used to separate two slices mined by longwall. Ground control and spontaneous combustion are major hazards associated with multislice mining. A well-consolidated upper slice gob can reduce ground control problems and provide a seal against spontaneous combustion. Geologic analysis indicates that the consolidation of the gob depends on the composition of the upper slice roof, the presence of water, and sufficient overburden pressure. A geologically competent intermediate rock parting can also reduce ground control problems and seal against spontaneous combustion.
Research Organization:
Bureau of Mines, Denver, CO (USA). Denver Research Center
OSTI ID:
5992712
Report Number(s):
PB-91-160929/XAB; BUMINES-IC--9239
Country of Publication:
United States
Language:
English