The location analysis and efficient control of hidden coal spontaneous combustion disaster in coal mine goaf: A case study

Coal spontaneous combustion significantly threatens the mine production safety. This paper focuses on the practical aspects of the disaster within the sealed goaf of Pingmei No. 11 mine. Obtained the characteristic parameters of spontaneous combustion in goaf by arranging high-level drilling field and drilling method. The grey correlation analysis method was applied to analyze the determination index of the effective characterization of the hidden spontaneous combustion area range, and interpolation aided in assessing these indicators before and after the increase amount of N2 injection. All showed that the hidden spontaneous combustion area was determined to be 70–80 m away from the return air side and 10–15 m away from the stop line, and the comprehensive treatment technologies are executed to control the spontaneous combustion hazards, including injecting inert gas to cool the high-temperature area, injecting the aqueous foam to cover the fire source, and plugging leakage to isolation the O2. Finally, the O2 concentration in goaf dropped below 5.0%, and carbon monoxide concentration fell below 0.001% after implementing these methods, effectively controlling the coal spontaneous combustion disaster. The successful management of concealed coal spontaneous combustion disasters offers a valuable reference for identifying and efficiently addressing such incidents in goaf areas.