[1]School of Safety Engineering;
North China Institute of Science and Technology;
Sanhe 065201;
China;
[2]School of Safety Science and Engineering;
Henan Polytechnic University;
Jiaozuo 454003;
China;
[2]School of Safety Science and Engineering;
Henan Polytechnic University;
Jiaozuo 454003;
China;
[1]School of Safety Engineering;
North China Institute of Science and Technology;
Sanhe 065201;
China;
Gas drainage; Risk assessment; Air leakage; Oxidation zone; Spontaneous combustion;