Design optimization in underground coal systems. Interim report, October--December 1976. [31 refs]

Technical Report · Tue Mar 01 04:00:00 EST 1977

DOI:https://doi.org/10.2172/7297017· OSTI ID:7297017

Lucas, J. R. ^[1]

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1. ed.

The thicker, shallower, and geologically superior coal seams in the eastern U.S. are being mined, and surface operations of the western U.S. are being subjected to increasing pressure from environmentalists. In order to meet demand as more accessible surface seams are exhausted, the coal industry is starting to mine seams of over 2000 in depth and less than 30 in. in thickness. The Longwall Mining System is the natural choice to mine deep and thin coal seams as it operates largely independently of the overburden rock stress. Also the need for increasing productivity without a corresponding cost increase is causing many coal producers to look at longwall mining systems as a means of achieving this end. The consistent increase in the utilization of longwall mining systems in the U.S. illustrates the excellent potential of this technique for the future. Because of roof conditions, not all deep seams are suitable for longwall mining. In deep seams not adaptable to longwall mining, the room-and-pillar method appears reasonable as room-and-pillar mining is more adaptable to varying seam conditions than longwall mining. When a conventional pillar design is used, the seam may prove uneconomical to mine due to the low extraction ratios at great depth. The yield-pillar concept offers an alternative method of pillar design as this method makes it possible to raise the extraction ratio in room-and-pillar mines at great depths.

• Research Organization: Virginia Polytechnic Inst. and State Univ., Blacksburg (USA). Dept. of Mining and Minerals Engineering
• OSTI ID: 7297017
• Report Number(s): FE-1231-7
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600 -- Coal
Lignite
& Peat-- Properties & Composition
012000* -- Coal
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CARBONACEOUS MATERIALS
COAL
COAL DEPOSITS
COAL MINES
COAL MINING
DIMENSIONS
ENERGY SOURCES
FORECASTING
FOSSIL FUELS
FUELS
LONGWALL MINING
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MECHANICAL STRUCTURES
MINES
MINING
PLANNING
ROCK MECHANICS
ROOFS
ROOM AND PILLAR MINING
SAMPLING
SIMULATION
SUPPORTS
THICKNESS
UNDERGROUND MINING