The Researches And Applications Of Gas Drainage On Steep-Inclined Thick-Seam

China’s rich in coal resources, and the gas reserve in coal seam is also considerable. Generally, China’s coal seams are buried deeply under the earth, and well versed in mining is adopted by almost all of coal mine.Exploitation of coal comes with the problem of methane gas.The technology of gas drainage can not ony meet the needs of mine safety, but also provide us with clean energy. Coal resources in xinjiang accounted for about40.6%of the whole country, but most coal seams exist in large dip angle. The DaHuangShan coal mine of company of Xinjiang yuxin belongs to the steep-inclined thick coal seam with high-meathane gas, the gas drainage technology of the mine of steep-inclined thick coal seam was studied and discussed in this paper.The characteristics of the pore and crack, and storage characteristics of gas in coal seam were studied in this paper.By the introduction of the concept of porous media, the law of gas migration in coal seam and gob are studied. Coal mined-out area, the gap size and porosity of fracture degree will directly affect the effecience of gas drainage. Under the U-shaped ventilation condition, the enrichment characteristics of goaf is studied which can provide a theoretical basis for the gas drainage., The analysis of mechanics experiment of Coal and rock sampling from+735mining face field can provide the goaf caving characteristics of overlying coal rock and methods of roof managing. According to the date above, the Three-Area’s distribution of the testing area roof and floor can be calculated with the numerical simulation. According to the collection of the mine geological data and mechanical analysis of experimental zone of coal and rock from mining place, the mathematical model was established, and calculated by Flac software.It is concluded that the height of the crack zone is10m, fracture zone height is about29m. According to the fact of DaHuangShan mines, the necessity and feasibility of gas drainage of the mine was studied, and the establishment of gas drainage system is necessary, During the drivage, alternative step drillings were used to pre-drainage the gas in front of the virgin field coal seam which was80metres away from drillings, and the problem of gas outburst was solved at the same time.Before mining, drainaging the gas of the whole seam by bedding boring at the tunnel which have been digged, drainaging area should cover all seam.due to the characteristics of the coal seam low-permeability,the method of gas drainaging with high negative and low flow was used. During mining, the top corner gas of mining place was drainaged by the negative pressure pipe, and goaf gas behind the stents30m away and the old goaf gas were drainaged by the layer-through borehole. Aafter these basic measures were applied,the emission of gas from minging place reduced, the lowest from around4m3/min, the gas concentrated in upper corner stable at0.4%-0.6%. The problem of gas was effectively solved, The gas of+735mining place drainaging rate reached59.17%.