Abstract
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 (dP/dt)(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 (dP/dt)(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).