Prediction of Coal Spontaneous Combustion in High Gassy Goaf under Stereo Gas Drainage

For accurately predicting the state of coal spontaneous combustion in high gassy goaf,it was understood by analyzing that the high drainage roadway is the most effective place where spontaneous combustion of the residual coal in goaf can be monitored.The volume fraction of the gas from the goaf was calculated in the high drainage roadway,and the volume fractions of CO and ICO corresponding to the different stage of coal spontaneous combustion in the goaf were determined.The results show that when the volume fraction of CO in the high drainage roadway Chdr CO30×10-6 or CO index ICO0.5%,the residual coal in the goaf is in the low-temperature oxidation stage,when Chdr CO≥30×10-6 or ICO≥0.5%,the residual coal in the goaf is in the dangerous stage of coal spontaneous combustion.Some measures must be taken to stop the further expansion of spontaneous combustion.The risk of coal spontaneous combustion in the goaf of No.80501 coal mining face was accurately forecasted,and safety in production was realized.