The Spontaneous Combustion Mechanism And Early Prediction Technique Research For The Goaf Of Fully Mechanized Top Coal Caving In Gucheng Coal Mine

75%coal seams in working seams in coal mines in our country belong to combustible seams and spontaneous combustion seams.The spontaneous combustion fires of coal seams bring about great losses to coal mines and even result in serious casualties.So,in face of the mechanism and characteristics of autogenous ignition,coal mines must set up the general concept of fire prevention and build prediction,prevention,forecasting and fire emergency handling four integrated prevention system.The research aims at the spontaneous combustion rule of fully mechanized caving coal face in Gucheng Coal Mine,Dongshan Mining Responsibility Limited Company,Shandong Province and studies the prevention and control technique.The main conclusions are as follows.(1)The natural tendency of coal samples collected type identification was made.The appraisal result of coal samples of 2018 working face for inhaled oxygen is 0.78 cm~3/g,which belongs to the kind of spontaneous combustion and easily spontaneous combustion.(2)According to the result of coal oxidation temperature experiment,the coal seams in Number 3 Well in Gucheng Coal Mine can choose carbon monoxide as spontaneous combustion iconic gas and under high temperature can be supplemented by ethylene as a reference.In general,the appeared ethylene indicates that temperature achieves the ignition point.(3)According to the result of coal oxidation temperature experiment,on the basis of adiabatic oxidation model of oxygen,the shortest spontaneous combustion period of 2018working face is 36 days.(4)The fiber grating temperature observation technique is introduced into the temperature observation in coal mine goaf.In light of coal goaf temperature and gas concentration observations,the spontaneous combustion zone of 2018 working face coal goaf can be divided.The wind side is about 45 to 190 m.The central working face is about 45 to150m.The return air side is between 30 to 100m.(5)Through fully-mechanized caving goaf spontaneous combustion and ground stress distribution relation analysis,it is concluded that the fully-mechanized caving goaf spontaneous combustion is associated with advancing speed.The observation of the goaf gas and temperature shows that according to the current production condition and fire prevention measures,the spontaneous combustion fire will not appear in working face goaf.(Advancing speed is 3 meters every day)The research result has offered a scientific basis for safe production of coal seam working face for No 3 Well of Gucheng Coal Mine and has improved pertinence and effectiveness of the prevention and control technique of No 3 Well coal seam spontaneous combustion in Gucheng Coal Mine and has played a technical support role for Gucheng Coal Mine safety production.