Strategy in Reducing Dust in the Coal Mines of the United States.
6th Int Pneumoconiosis Conf Bochum Germany 1983 ILO, Washington, DC, 1983 3:6 pages
This paper describes the strategy and the technical measures used in the United States to control respirable dust in coal mines. Federal law limits the average respirable dust concentration to which each coal miner may be exposed to no more than 2.0 Mg/m3. The allowable dust limit is reduced if the quartz content of the dust exceeds 5 pct. Dust measurements are made in the mines using personal gravimetric dust samplers worn by the miners. The average dust concentration for continuous mining machine operators was reduced from about 6.5 Mg/m3 in 1968 to 1.3 Mg/m3 in 1980. This success was due primarily to improvements in face ventilation. In some mines significant dust reductions have been achieved by use of dust collectors mounted on the mining machines. Control of dust is much more difficult for longwall operations. Some new techniques have been developed that enable mine operators to comply with the 2.0 Mg/m3 dust standard for longwalls. One new technique uses the air entrained by water sprays to divert dust away from the shearer operators and reduces dust exposure by as much as 50 pct. Dust reductions have also been achieved by improvements in longwall face ventilation, more efficient use of water, and modifications in the methods of coal cutting.
6th Int. Pneumoconiosis Conf., Bochum, Germany, 1983, ILO, Washington, DC, V.3, 1984, Pp. 1724-1729