Research On Prevention Technology Of Symbiosis Disaster Of Gas And Residual Coal Spontaneous Combustion Of In High Gassy And Spontaneous Combustible Goaf

With the increasing of coal mining depth and deteriorating of mining conditions,especially in the deep mining stage,the coal mining will face the challenge of high-geostress,high gas content and high temperature underground,which are concluded the “Three High” phenomenon.The more emission of the gas,the more serious of the disaster,and at the same time,the spontaneous combustion of residual coal were easily caused by many factors such as the geothermal gradient.Therefore,the deep coal mining is meeting the common threat of gas and the self-ignition of coal.And the common disaster would be a common pattern in the coming severe and great casualties.However,it is difficult to balance the effort of control of the two disasters.So,in order to effectively prevent and control the symbiotic disaster of gas and spontaneous combustion of residual coal.The coal sample from the 11223 high gas and spontaneous combustion workingface of Panér Coal Mine was taken and conserved with sealed container.Based on the thermogravimetric analysis experiment of coal sample,the activation energy and pre-exponential factor of the coal sample was calculated by the Coast-Redfern method.According to the results of the thermogravimetric analysis,the coal seam of the 11223 workingface could be determined the spontaneous combustion seam.Through theoretical analysis and summarization on the multi-factors interaction between gas and spontaneous combustion of residual coal,a physical model was established combining the 11223 workingface.The parameters including emission terms of gas in this coal seam and adjacent coal seam,three-dimensional porosity and oxygen consumptionrate of coal oxidizing reaction under low temperature condition were compiled by UDF.On the basis,variation of the workingface air volume,layout parameters and extraction parameters for high extraction roadway and Y-type ventilation method and pipe gas drainage method at the upper corner on the interaction between gas extraction effect and distribution of spontaneous combustion region in goaf were analyzed.At the same time,distribution regularity of the spontaneous combustion when carbon dioxide was injected into the gob were researched.Based on the results of numerical simulation,combined with practice of gascontrol and combustion prevention in the Panér coal mine 11223 workingface and Pan Yidong coal mine 12311 workingface,the prevention effect of the practice of gas control and combustion prevention measures was analyzed.Through the mutal verification between theory and practice,theoretical level of awareness for the synergistic prevention of gas and coal spontaneous combustion disasters in gobs was developed.The results can provide reference for prevention of the symbolic disaster with similar conditions.