EXPLOSION HAZARDS IN UNDERGROUND COAL-MINES

A review of the incidence, causes and prevention of coal dust explosio ns is given in this paper. A statistical summary of fire and explosion incidents in Nova Scotia coal mines over the last century is presente d. Techniques for explosion prevention which are discussed include avo idance of ignition sources, use of ventilating air, and rock dusting. Detrimental effects of the presence of methane in mine workings are al so described; these include increases in the maximum explosion pressur e, maximum rate of pressure rise, and inerting requirements of coal du st, as well as a decrease in the lean flammability limit and an enhanc ed ingnitability of coal dust. The significance of provincial (Nova Sc otian) and federal (Canadian) regulations relating to rock dust partic le size are discussed in light of current work being conducted in the authors' laboratory.