Research On Gas Migration Law In Mechanized Mining Face With High Gas

Mine gas is an important factor for damaging safety production.Gas disaster is one of the worst coal mine disasters.As the mechanization level of continuous improvement,the mining depth increases,exploitation of growing strength,the gas emission will further increase and gas disaster management is increasingly becoming focus of coal mine disaster prevention. By researching the law of gas migration on mechanized mining face of high-gas coal mine, the thesis is helpful to guide the coal mine gas-management and coal mine safety. It has a certain theoretical and practical significance.This thesis systematically discusses the coal seam conditions and mining conditions which impact the gas emission of the face and mining goaf,and study the mechanism of gas emission and gas migration.We have made a field measurement and determinated the gas concentration on the mechanized mining face in Ato Hai mine. According to analysis and summary the measured data,the gas sources,gas migration and distribution of gas concentration of mechanized mining face and mining goaf are geology condition. The main conclusions are as follows:the gas emission of ming goaf gas comes mainly from the upper and lower close-layers, losing coal, un-mining coal seam, and surrounding rock. Along the vertical direction of face mining, the gas concentration tended to increase. The gas concentration presents a distribution trend as "higher, high, low, high, higher" from coal wall to mining goaf. Along the mining face, gas concentration increases from the inlet-air side to the return-air side.The high concentrations gas gushing from the deep goaf, meet the air leakage seepage carrying large amounts of gas at the upper corner, the existence of comprehensive mining support resulted the upper corner of bad ventilation, and also resulted accumulation of local gas lamellar, this is the direct cause of gas concentration in the upper corner is high and overrun. So, the upper corner gas control is the key of fully mechanized mining face gas control.In this paper identifies the best place to drawing out methane in fully mechanized mining goaf is about 60~80m away from the face, if considering the use of the gas drainage, the best place to drawing out methane is 100m away form the face, at this location the drainage concentration of gas is close to 30%.Based on these results, this paper presents a number of specific gas control measures for fully mechanized mining face and applies these to Ato Hai 1209 coal mine, which achieves good results.