Spontaneous Combution And Firing Study On Air Return Workface Of Steep Coal Seam With Pillar Mining Method In Shitun Coal Mine

Based on the three aspects of theory study, laboratory analysis and actual measurement, the paper studied the spontaneous combustion of coal in goaf. On the study of theory, the paper studied the mechanism of spontaneous combustion of coal and rules of coal oxidation in low temperature. Combining document of steep coal seam home and aborad, the paper analyzed the pillar mining method in steep coal seam and concluded the rules of firing of shitun coal mine; On the study of laboratory, the paper studied the absorbed oxygen, weight decreasing, heat flow and analyzed the different effect to absorbed oxygen and heat of different coal size. The paper built mathematic modle of lost coal oxidation of goaf in 1171 workface and calculated the shortest laboratory firing period in low temperature based on the mathematic modle. On the actual measurement, tubes and temperature measuring device were arranged along inlet and return drifts in 1171 workface to measure some parameter of gas composition and temperature of goaf after coal mining. The paper forecatsted spontaneous combustion of lost coal of goaf and acquired the rules of spontaneous combustion and the value of "three zones" of goaf.Based on the study results, the paper advanced effective measurement of spontaneous combustion in goaf before mining using pillar mining in shitun coal mine. Strong theory and actual reality were given to prevent lost coal in goaf from firing.These measurement and study results can ensure the safe mining of 1171 workface using pillar mining in shitun coal mine.