Explosion hazards in underground coal mines

A review of the incidence, causes and prevention of coal dust explosions is given in this paper. A statistical summary of fire and explosion incidents in Nova Scotia coal mines over the last century is presented. Techniques for explosion prevention which are discussed include avoidance of ignition sources, use of ventilating air, and rock dusting. Detrimental effects of the presence of methane in mine workings are also described; these include increases in the maximum explosion pressure, maximum rate of pressure rise, and inerting requirements of coal dust, as well as a decrease in the lean flammability limit and an enhanced ingnitability of coal dust. The significance of provincial (Nova Scotian) and federal (Canadian) regulations relating to rock dust particle size are discussed in light of current work being conducted in the authors’ laboratory.

Key Words:

• Coal dust
• explosions
• methane
• rock dusting