Research On Gas Extraction Technology Of Large Height Mining Face In Zhaozhuang Mine

With the increasing of coal mining scale and the deepening of mining depth year by year, coal seam gas content relatively increases, gas control difficulty also increases further. In the process of coal mining, the working face of broken large mining has thick coal, high speed, and unique degree of gas emission; At the same time, has affect to the broken large mining,adjacent layer and mined-out area are easily to inburst to the working face, are easily goes to gas accumulation during tunnelling and stoping, causes serious difficulties. How to run the broken large mining, height gas, low permeability, and advancing speed of working face gas has become the addressed problem to keep the coal mine safe, high yield and high efficiency production.In 1307 working face case, paper has applied Theoretical Analysis, Field Observation, Numerical Simulation to researcher moving rules of overburden strata of Zhaozhuang mining's 1370 working face, the migration rule of methane and comprehensive controlling methane in this coal face under special condition of Zhaozhuang coal mining with great mining height on the ultra long-distance face. Based on Diffusion Law and Darcy law, we analyze the migration rules of the 1370 working face methane in raw and unloading coal. The result provides basis for forecasting working face gas emission and analyzing comprehensive control scheme of 1307 working face gas. We adopt the scheme of high drainage roadway,bed plate tunnel and gas drainage in current seam for comprehensive treatment of the 1307 working face gas, and adopt field observation of adjacent mining face and numerical simulation of the current face to make a comprehensive comparison and analysis that the caving zone height and crack belt. We can also determine layer selection of high drainage roadway and the distance of horizontal projection in return airway. According to he actual situation of gas Pre-drainage hole in current face, parameters in NO.2 bed plate tunnel is designed, which Provides guarantee for gas pre-drainage, free from dead corner. Analyzing primary mining effect of 1307 working face leads to the conclusions that the average extraction concentration go to the desired goal.The survey shows that the heights of fracture zone that belongs to the ultra long-distance face far outweigh common fully-mechanized face. In the area of Jincheng, That we adopt the scheme of high drainage roadway, bed plate tunnel and gas drainage in current seam for comprehensive treatment of the 1307 working face gas can effectively solve the problem of working face methane.