Mining Publication: Extreme Multiple Seam Mining in the Central Appalachian Coalfields
Coal has been mined in the central Appalachian coalfields of southern West Virginia, western Virginia, and eastern Kentucky for more than a century. The dwindling reserve base consists in large part of coal that would have been considered unmineable by earlier generations. Nearly every current operation is working on a property where coal has been extracted in the past from seams either above, below, or both. NIOSH is conducting research aimed at helping mine planners prevent hazardous conditions due to multiple-seam interactions. To date, more than 300 case histories have been collected from underground mines mainly in central Appalachia. This paper focuses on several of the more challenging situations that have been encountered, including: (1) room-and-pillar development 20 ft beneath full-extraction workings at a depth of 1,000 ft of cover (Virginia); (2) pillar recovery 45 ft above full-extraction workings at 900 ft of cover (Virginia); (3) near-simultaneous room-and-pillar mining with pillar recovery with 40 ft of interburden and 1,500-2,000 ft of cover (Kentucky); and (4) longwall mining directly beneath main entries in overlying seams (West Virginia). Some of these operations have been highly successful in overcoming the challenges, other less so. The lessons learned from their experience will help ensure that these and similar difficult reserves can be mined safely.