Control Technology Of Methane Gas Emission In 15# Seam In Duan Wang Coal Mine

DuanWang mine is high gas mine,and absolute gas emission is 60-70 m³/min,and relative gas emission is 22.17m³/t.The mine high gas working face are mainly concentrated in 15#coal seam.Following 15#coal seam mining,the mine gas emission increased obviously.150403 working face in mine mining deepest part,The absolute gas quantity in tunneling and mining is 9m³/min and 47.98m³/min respectively.Working face advancing speed slowly.Gas has the period of king safe production of coal mine caused great threat.This article in view of the period of the king of coal mine gas control problem,for 15#coal seam gas emission and gas control technology system research.（1）Basic parameters measured by 15#coal seam gas:540 m depth area of coal seam gas pressure and gas content is 0.67MPa and 10.00m³/t respectively.Gas adsorption constants a and b 54.64 nd 0.23 respectively.For the coal seam permeability coefficient is 0.082 m²/MPa^2.d.Hundreds of meters drilling attenuation coefficient for the gas flow is 0.18d^-1.So 15#coal seam is low permeability coal seam,belong to the more difficult to smoke extracting seam.（2）Predicting the 15#coal seam gas emission during mining face.The mined-out area of coal seam,adjacent layer and absolute gas emission is 10.8 m³/min、5.9 m³/min and 6.7 m³/min respectively.Poured out of total is 23.4 m³/min.Considering unbalanced gas emission coefficient of 1.3,So total of working face gas emission is30.4 m³/min.（3）According to the principle of drawing method of determination of the gas emission rate.Results showed that the goaf gas emission of working face and 65.12%of total gas emission,coal wall flow gas proportion is 34.88%.So the goaf gas emission source mainly.（4）In 150403 working face as a case,studying the gas extraction mainly and the ventilation system management comprehensive gas control technology of system.Gas extraction technology is mainly the bedding drilling drainage of coal seam and the high drilling comprehensive extraction.The bedding drilling main drainage before mining face of coal seam gas,high drilling main extraction goaf during mining face.The ventilation system management technology mainly includes:Upper and lower corner hanging ram,on the installation of feng shui spray in upper corner,corner buttress bag and control the speed of cutting coal and so on.Effectively with the extraction technology of gas control.（5）Through the application of the working face comprehensive gas control technology.Middle and late of mining face,Working face gas extraction rate increased to 60%above,Return the gas concentration drops below 0.8%.Caused by gas overrun alarm and the number of power outages are greatly reduced.Daily production raw coal from 1000 tons increase to 2000 tons,ensuring the safety of mine production,and increasing productivity.