Experimental data revealing explosion characteristics of methane, air, and coal mixtures.

Whenever air and gases mix with pulverised coal, explosions are possible. Such explosions constitute a primary category of safety concerns during coal bed methane mining. This study investigated the explosion parameters and characteristics of methane-air-coal dust mixtures by using an XKWB-1 sealed explosion system. Maximum explosion pressure ( P max ), maximum explosion pressure rise rate (d P /d t ) max , and explosion index ( K ) were recorded and calculated. Findings showed that relative to the maximum explosion pressure of an air-methane gas mix P max-G , that of a gas-dust mixture P max-GD was elevated when a 7.0 vol% methane-air mixture coexisted with 500.0 g m -3 of coal dust in the explosion. P max-GD decreased as C G increased and increased as V ad increased for a methane-air-coal dust mixture. Both P max-GD and (d P /d t ) max-GD increased first, but were diminished with an increase in C D . The C opt values of five coal samples of HC, KZD, DFS, TC, and YMZ were 400.0, 500.0, 500.0, 500.0, and 600.0 g m -3 , respectively. Based on the coal dust explosion pathways, the effects of coal dust volatility on the explosion characteristics were analysed. Finally, with respect to 7.0 vol% methane, the data showed that the explosion index of a gas K g was consistently lower than the explosion index of a gas-dust mixture K m ; that is, K g < K m .