Technical And Economic Analysis Of Safe And Efficient Mining In Gas Outburst Coal Seam

There are many shortcomings in the traditional mining method of coal seam with gas outburst.Therefore,it is of great practical significance to find a safe and efficient mining method suitable for gas outburst coal seam and realize scientific mining.Taking Linhua coal mine in Guizhou Province as the research object,this paper puts forward the technical method system of gob side entry retaining,layer by layer drainage and non rock bottom drainage,which is suitable for safe and efficient mining of gas outburst coal seam.The technical feasibility and economic rationality of the system are studied by theoretical analysis,numerical simulation,cost analysis and industrial test.The system can not only alleviate the tension of mining connection,improve the recovery rate of coal resources,maintain the stability of surrounding rock,but also greatly reduce the amount of rock tunnel excavation,reduce the cost of tons of coal,and produce huge economic benefits.The main research contents and achievements are as follows:(1)This paper puts forward a technical method system(L-H method for short)of gob side entry retaining,layer by layer drainage and no rock bottom drainage,and establishes a coal seam mining area model of gas outburst,introduces the specific content and implementation technology of this method in detail.(2)Taking the No.2 Mining Area of No.9 coal seam of Linhua coal mine as the research object,combined with the specific geological conditions,the technical scheme and technical parameters of cutting the roof and retaining the roadway and drawing along the seam are designed;the technical feasibility of "L-H method" is analyzed,the economic cost is calculated,and the economic feasibility is verified.(3)Analyze and summarize the effect of "L-H method".Through the observation of mine pressure,it is concluded that the implementation of roof cutting and pressure relief technology has a good control effect on the surrounding rock of the roadway;the gas extraction effect can reach 1.8 times of the original extraction scheme,and reach the national outburst prevention standard of<8m3/t;while ensuring safety,it also creates huge economic benefits.(4)Through the industrial test of Linhua coal mine in recent one year,the applicability of "L-H method" proposed by the team for gas outburst coal seam is verified,and the purpose of technical applicability,safety,reliability,economic rationality is realized.