Explosive Testing of Rock Dust Dispersibility for Coal Dust Explosion Prevention

Abstract

Limestone rock dust is used in many coal mines to inertize coal dust and prevent mine explosions. Since rock dusting creates a nuisance to workers downwind from the dust application, suppliers are offering wet and foam-applied rock dust products. Researchers at the Colorado School of Mines have con- structed a full-size explosion test drift where they can generate controlled explo- sions at defined wind speeds of 30 to 50 m/s, the minimum wind speed that can entrain coal dust and propagate coal dust explosions. Initial results with different wet-applied, that then dried rock dust products suggest that explosive forces break-up clumps of the rock dust, but this wet-applied dust does not disperse as easily as dry-applied dust. Also, hydrophobized rock dust and dust meeting Ger- man specifications disperses more readily. Keywords: