Comprehensive Control Measures for Spontaneous Combustion of Coal Pillars in Close Distance Compound Coal Seams

Taking spontaneous combustion and control process of residual coal pillars in close distance compound coal seams of Dongrong 2^# Coal Mine as research background, the position of spontaneous combustion is judged by the change characteristics of index gases in closed zone and the arrangement of close distance coal seam group. A control idea of plugging, inerting and cooling is proposed. These mainly include plugging air leakage channel by drillings in a dedicated fire extinguishing tunnel, high-flow injection of liquid nitrogen by pre-buried pipeline, and infusion of a large quantity of foam retardant into flame locations by drillings. The results show that C₂H₂,C₂H₄ gradually disappear in the spontaneous combustion zone, and the concentration of CO falls greatly.