Experimental study on early prediction index gas for spontaneous combustion

A spontaneous combustion and oxidation simulation experiment involving coal samples from the fully mechanized top coal caving face 2308 of Getting Coal Mine was performed using a self-developed spontaneous combustion test bed. The aim was to determine the production law of spontaneous combustion products in Getting Coal Mine and provide a basis for establishing an early prediction index system for spontaneous combustion in the goaf. The law governing changes in the concentrations of CO, C2H4, and other gases with temperature in the process of coal sample heating was analyzed, and the index gas of coal sample spontaneous combustion was optimized. The experimental results showed that the shortest spontaneous combustion period was 54 days. The coal samples produced CO at a lower temperature. The absolute amount of CO production increased monotonously during the entire oxidation process, but the increase was uneven under different temperature conditions, and there was a sudden temperature point. C2H4 appeared for the first time at 110 °C, increased monotonously from 110 to 163 °C, and then fluctuated after 163 °C. Finally, CO and C2H4 were selected as the main index gases to predict spontaneous coal combustion in Getting coal mine, and C2H6 and C2H4/C2H6 were used as auxiliary index gases.