Abstract:

When stope caving in working face 22305 of coal seam 2-2, the floating coal in goaf 12306 of overlying 1-2 coal seam got spontaneous combustion, resulting in overrunning of the concentration of CO gas at face 22305 in Bulianta coal mine. With the analysis of the fire area situation, a variety of methods were used for fire regional governing. However, the effects of former ways are not obvious because of the large area of fire, the serious leakage of goaf air and the fast growth of the fire zone et.al. According to the characteristics of the situation, the working face 22305 was closed later and comprehensive measures of filling liquid nitrogen and liquid carbon dioxide from the ground into under goaf were taken. It achieved good results and the high-temperature region of the face 22305 in overlying goaf were effectively controlled, which make the face safe mining after unsealing face 22305.

Key words: Large area of the fire, Overlying goaf, Fire prevention and control, Liquid inert gas, Liquid carbon dioxide