Gas Control During Initial Mining Period Based on Small Angle High-level Borehole

The gas emission is imbalance at mining face during initial mining period, the phenomenon of gas exceeding the limit is easy to occur. According to the characteristic of Xinyuan Coal Mine is that the amount of gas emission is large in the process of closed distance coal seam group mining, the method is proposed that the small angle high-level borehole extraction to control the gas in early mining stage. The application practice of 2219 working face shows that the amount of pure gas extraction is up to 5.25 m³/min, the gas extraction rate is 64.02%, the highest gas concentration of return air is 0.32%, and the highest gas concentration in upper corner is 0.96% during initial mining period, the phenomenon of gas exceed-limit does not appear, this method has achieved effective gas control effect in the early mining stage.