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Title: First North American longwall in pitching seams proven feasible. [Colorado]

Journal Article · · Min. Eng. (Littleton, Colo.); (United States)
OSTI ID:6807692

There are 1.4 Gt (1.5 billion st) of recoverable coal under less than 914 m (3,000 ft) of cover in Colorado in pitching seams. Snowmass Coal Co., in cooperation with the US Department of Energy, introduced the longwall mining method in pitching seams to North America. This venture is a coal mining research program directed toward the profitable production of coal under difficult mining conditions as found in pitching seams of the western US. Snowmass Coal classifies pitching seams into the following categories for longwall on the strike in seams 3 m (10 ft) or less thick: Flat = 0 to 10/sup 0/: Normal continuous mines and shuttle cars work efficiently. Slight = 10/sup 0/ to 22/sup 0/: The maximum pitch that rubber tired equipment will function. Moderate = 22/sup 0/ to 40/sup 0/: The angle of repose of mined coal. Steep = 40/sup 0/ to 60/sup 0/: The limit of safe use of this roof support. Vertical = over 60/sup 0/. The longwall roof support covered here will work in all pitches except vertical. The shearer and conveyor will work in flat through moderate conditions. Longwalling across strike with this equipment in seam pitch over 60/sup 0/ could be accomplished with an inclined face. Development of the first longwall panel began in 1979 and was completed in 1981. The longwall equipment was installed and mining began on Aug. 11, 1981. Snowmass' performance shows that the capacity of a longwall operating on moderate pitch, up to 45/sup 0/, should be the same as a flat seam longwall. With equipment now available, pitching seam longwall is not only feasible, but cost competitive. The actual roof support method of troika concept has excellent maneuverability, good support, and low maintenance. The shearer has proven power to operate on moderate pitching seams.

Research Organization:
Snowmass Coal Co., Snowmass Operations, Carbondale, CO
OSTI ID:
6807692
Journal Information:
Min. Eng. (Littleton, Colo.); (United States), Vol. 35:12
Country of Publication:
United States
Language:
English