Determination of index gas of coal spontaneous combustion prediction and analysis of CO sources in working faces
Using a combination of experimental analysis and on-site observation,the spontaneous combustion tendency and shortest igni-tion period of coal seams in the No.7 well of Sikeshu in Wusu,Xinjiang were studied,and the indicator gas for spontaneous combustion was determined.The source of carbon monoxide in the working face was analyzed.Research suggests that the A5 coal seam in the mine should use CO as the predictive index gas for the initial stage of spontaneous combustion,and olefins as the auxiliary index gas to deter-mine the degree of coal spontaneous combustion.Using CO as an index gas for predicting spontaneous combustion in the range of 30 ℃~130℃,the appearance of CO indicates that the coal has undergone oxidation reaction.Using olefins as an index gas to determine the degree of coal spontaneous combustion in the range of 130 ℃~200 ℃,the presence of ethylene and ethane indicates that the coal tem-perature has reached 130 ℃,and the presence of propane indicates that the coal temperature has reached 150 ℃.The CO in A504 working face of the mine mainly comes from the oxidation of residual coal in the goaf of this working face(accounting for 88%),and a part of it comes from two ultra strong deep hole pre splitting blasting in the working face(accounting for 12%).The research results provide a reliable basis for the prevention and control of natural combustion in mines.