Experimental study on spontaneous combustion characteristics of coal in Shaqu No.1 coal mine based on programmed temperature rising

YANG Bo; WANG Haoyu; SI Junhong; CHENG Genyin

doi:10.19956/j.cnki.ncist.2024.04.008

Abstract：In order to prevent the coal spontaneous combustion of the 4502 working face of Shaqu No.1 Coal Mine and improve the risk prevention and control ability of coal spontaneous combustion,the programmed tem-perature experiment is designed to simulate coal spontaneous combustion,combined with the single index gas analysis and the composite index gas analysis method,by investigating the changes of O2、CO、CH4、C2 H6、C2 H4 and other gas volume fractions,alkane ratio and alkene-alkyl ratio indexes with temperature,the coal spon-taneous combustion marker gas is optimized,and the critical temperature and dry cracking temperature of coal natural ignition are determined.The spontaneous combustion characteristics of 3+4#coal seam in Shaqu No.1 Coal Mine are studied.The results showed that before the critical temperature,the oxygen consumption rate,CO concentration and φ(C2 H6)/φ(CH4)increased slowly,C2 H6and C3 H8produced a small amount,and the oxygen consumption rate and CO concentration increased exponentially after the critical temperature,while the φ(C2 H6)/φ(CH4)increased abruptly.C2 H4 occurs at 100℃,and the release of alkanes increases signifi-cantly at 100～110℃,after which φ(C2 H4)/φ(CH4)increases regularly,while φ(C2 H4)/φ(C2 H6)and φ(C2 H4)/φ(C3 H8)decrease first and then increase.C2 H2 occurs at 240℃,which is much higher than the cracking temperature.It is concluded that the oxygen consumption rate,CO,C2H4 and C2H2 can be used as the main predictive metrics for coal spontaneous combustion,and the concentrations of C2H6 and C3H8,φ(C2H6)/φ(CH4)and alkene-alkyl ratio can be used as auxiliary means for coal spontaneous combustion,and the critical temperature of 3+4#coal seam coal samples is 75～85℃,and the dry cracking temperature is 100～110℃.