Risk Analysis And Prevention Of Coal And Gas Outburst In Dongyu Coal Mine

Coal and gas outburst is a major technical problem that threatens the safe production of coal mines for many years.Especially in recent years,with the increasing difficulty of coal mining technology,the gas threat has become more serious.Shanxi Dongyu Coal Industry Co.,Ltd.mainly mines No.3,No.2 and No.4 coal.Because Dongyu Coal Mine is a high gas mine,it identifies the coal seam and gas outburst danger of No.03,2 and No.4 of Dongyu Coal Industry Co.,Ltd.Evaluation can avoid the blindness of gas control work and ensure the safe production of mines.This paper firstly summarizes the production status of Dongyu Coal Industry Co.,Ltd.based on the production profile of Dongyu Coal Industry Co.,Ltd.,including mine development methods,roadway layout and mining methods,etc.,providing basic information for coal and gas outburst.Secondly,the coal and gas outburst identification scheme of Dongyu Coal Industry Co.,Ltd.was formulated,and it was determined that the index method was used to identify the risk of coal and gas outburst in Dongyu coal mine,and the scope of identification was divided according to mine mining.Deployment and measuring point arrangement,the identification range of the three mining areas in the first mining area is divided.In addition,the identification parameters are determined to obtain the type of coal damage;then the gas pressure of the coal seam(P),the solidity coefficient of the coal sample(f)and the sample gas dissipation(ΔP)are released.The initial velocity was directly measured,and the maximum measured gas pressure values of coal seams No.03,2,and 4 were 1.35 MPa,1.48 MPa,and 1.46 MPa.The minimum values of the solidity coefficients of coal samples were 0.51,0.54,and 0.55,respectively.The maximum values of velocity Δp are 19.3,27.8,and 22.7,respectively.The results show that the coal seam gas pressure is similar in the trend along the strike,and is basically in the direction of the trend.With the trend of increasing burial depth,the initial velocity of gas emission(ΔP)and the firmness coefficient(f)of coal taken from different sites are similar and the damage of coal dust is exposed during drilling.Type,coal seam physical and mechanical properties are consistent.According to the current identification status of coal and gas outburst danger in Dongyu coal mine,the basis for judging coal and gas outburst coal seam is expounded,when f≤0.3,p≥0.74MPa or 0.3<f≤0.5,p≥1.0MPa or 0.5<f≤0.8,p≥1.50MPa or p≥2.0MPa,generally determined as the outburst coal seam.