Multilift Longwall Mining Methods for Thick Coal Design and Feasibility.
Wilson-JF; Ucciardi-F; Armstrong-W
NTIS: PB/272-460 Available for Reference At Bureau Libraries :329 pages
This report describes the performance of Phase I of a project to design, analyze, and demonstrate a multilift longwall mining method applicable to mining coal seams 12 feet or more thick. A nonsimultaneous multilift operation is the most viable thick seam mining technique for introduction to U.S. coal mining. At the proposed emery, Utah, site, it will result in an increase in coal extraction from 30 pct, with present methods, to at least 50 pct and possibly more. The major technological advance is mining a lower lift under a previously mined upper lift. To accomplish this, entries must be developed and maintained beneath the upper lift gob. This will necessitate the use of steel supports at frequent intervals throughout the lower lift entry system. An economic analysis of the project indicates that while this method will result in a higher-than-average cost per ton for coal mined, the coal would be competitive with current operation in the area.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB/272-460 Available for Reference At Bureau Libraries
Consolidation Coal Company