To realize the scientific judgment of spontaneous combustion risk in the coal mine, the spontaneous combustion influence factors were analyzed from the three aspects of coal spontaneous combustion tendency, air leakage, and oxygen supply, heat storage and heat dissipation. And the basis for the evaluation of t spontaneous combustion grade was constructed. Combination ordered weighted averaging (COWA) calculation was introduced to optimizes G1 subjective weighting, and a COWA modified G1 combined weighting cloud model was proposed to identify the spontaneous combustion risk in the coal mine. Finally, the rationality of the model was verified with actual cases. The research results show that the spontaneous combustion risk level in the Lingquan coal mine is relatively safe, which is consistent with the actual situation. And the spontaneous combustion tendency of coal is the leading factor affecting spontaneous combustion risk.

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To determine the risk range of remaining coal in the goaf of the higher slice on the seventh mining and fifth face of Lingquan Mine, the beam tube monitoring system was adopted to supervise the temperature and gas content changes in the goaf during the normal mining period of the working face. As per the principle of dividing spontaneous combustion “three zones” (SCTZ), numerical simulation of the distribution of SCTZ in the goaf of the work face was performed. The O2 content and index gas in the goaf were measured and analyzed, and combined with the in-situ measurement outcomes, the distribution of SCTZ in the goaf was determined through the FLUENT numerical modeling program. The outcomes show that the distribution pattern of SCTZ in the goaf of fully mechanized mining face is: the heat dissipation zone is 0–41 m, the oxidation zone is 41–97 m, the suffocation zone is more than 97 m away from the work face, and the increment of temperature is 0.7/°C. Based on the judgement result of SCTZ, the minimum recovery rate of work face is above 3.7 m/d. The use of new polymer materials validly solves the problem of excessive CO in the return air corner of the goaf and prevents self-ignition accidents in the goaf.

Compared with that of equal-length working faces, the mechanical evolution mechanism of overburden rocks in “knife handle”-type mining sites is more complex. The form of roof fracture of knife handle-type mines is more variable, and the stress distribution near the interface is more concentrated, thereby severely threatening the safety of mining. To elucidate the mechanical evolution characteristics of rocks in knife handle-type fully mechanized top-coal caving mining sites, the geological conditions of the 22401 fully mechanized top-coal caving face in Hanjiawa coal mine are investigated. FLAC3D software is used to numerically simulate the abutment pressure, horizontal stress, and vertical displacement of the fully mechanized knife handle top-coal caving face. This provides an effective theoretical and technical framework for subsequent problems, such as mine pressure control, roof management, and support withdrawal under similar mining conditions. The simulation results indicate that when the working face is mined within the range 20–30 m before and after the knife handle caving, the stress distribution is considerably asymmetric, the abutment pressure and horizontal stress are overconcentrated, the maximum vertical stress is 18.41 MPa, and the maximum horizontal stress is 16.45 MPa. Influenced by mining stress and self-weight, the roof subsides and the floor bulges. The maximum sinkage of the roof is 268.9 mm and the maximum bottom drum displacement is 10.01 mm.