Although mines in the United States have achieved a high degree of mechanization, mining remains a hazardous occupation. Injuries and fatalities, particularly in underground coal mines, continue to occur. To reduce the risks to miners and improve the efficiency of mining operations, the U.S. Bureau of Mines is conducting research on new mining techniques and methods. This paper describes a few of the numerous research areas pursued by the Bureau. Respirable dust, a major health hazard in underground coal mines, could be reduced by a new cutting technique designed for mining machines. Laboratory investigations have demonstrated a reduction of dust levels by 97 pct and a horsepower reduction of nearly 70 pct using this novel concept. Although groundfalls remain a problem in longwall operations, a method to hydraulically fracture a hanging or cantilevering roof behind the shields is showing promise in relieving the stresses in the face, pillars, and floor. Coal transport at underground mines, a recognized safety hazard, is becoming a major bottleneck toward increasing production. A hoisting concept, an airlift hydrohoisting system, is being researched by the Bureau to address part of the transport problem. The Bureau is also conducting research to improve surface mining operations. Research is underway to provide technology for a low- cost and environmentally acceptable mining system to recover the vast thin-seam coal reserves in the mountainous areas of the Appalachian region in the eastern United States.
6th Korea-USA Joint Worksh Coal Util. Tech, Seoul; Korea Inst. Energy & Resour, 1989, PP. 33-46