Fire detection and control of overlying goaf in close-distance coal seam mining

The distance between layers of close-distance coal seam is very small, the phenomenon of air leakage is prominent in the process of coal seam mining, and the coal is prone to spontaneous combustion. In view of the abnormal situation that a large amount of CO gushing in the early stage of mining in Haizemiao Coal Mine, the overlying surface area of the panel working face in the mine was detected by the isotope radon measurement method for fire detection, a total of 4 high temperature abnormal regions with a total area of 2 100 m² were detected. Fire prevention and extinguishing technical measures such as dynamic monitoring of coal spontaneous combustion and injecting glue in goaf were worked out. After the implementation of the measures, the volume fraction of CO in the air return and upper corner decreased to the normal level in the working face, it indicated that the spontaneous combustion of coal was effectively controlled, which provided a guarantee for the safe mining in the working face.