Thick-Seam Mining in the Western United States--Geological Considerations

摘要

Thick coal seams are common in the Western United States. Many seams are over 50 feet thick and are too deep to extract using surface methods. Currently, such deposits are developed using standard 'eastern' mining methods which only extract a few feet of total seam thickness, often rendering the remaining coal unminable with current technology. Novel methods that increase thick-seam recovery have been developed and are currently being used in Europe. These methods--high-face single-pass and multislice longwall, longwall caving, and hydraulic mining--have great potential for use in the United States. Their use requires, among other things, a full evaluation of geologic features common to thick coals. The objective of the report is to present and summarize those features that will affect the introduction of the methods into thick-seam mines in the Western United States.