Application of gas control mode with six gateways per coal mining face to coal mining in seam group

According to the high gas emission from the coal mining face high gas control diffcuty and slow mining speed of the coal mining face was caused by thehigh gas from the adjacent seam unning to the cal minin face in a cloed distance seam group in the mining proc.ss,a gas contol mode with six gateways per coalmining face was provided.That was to say that the gas drainage boreholedrllings were conducted within the six gateways.Belore the coal mining operation ofthe coamining face conducted,the gas pre-crainage of the mining seam was conducted withthe boreholes in and along the seamn of the coal mining face. During the mining process of the cal mining face.the roof and foor boreholes passed through the strata were applied to drain the prssure released gas in the neighboing seans.The gascontrol mode was applied to N. 62210 coal mining face n the protective seam of ×inzhuangailMfne. The resuts showed that during the mining perodof the coal mining face,the gas drainage rate was over S0%. During the mining proc.ss,the max gas volume fracio in the air returning fiow was 0.15%.The month average length of coal minin face reached 140 m and mining speed of coal mining face was highly improved. Therefore.thesaiety problem caused by the gas in the mining procss of the .oal mining face was fundamentally solved.