Application of Super-high Pressure Hydraulic Slotting Technology in Exposing Hard Outburst Seam in Crosscut for Outburst Prevention by Gas Pre-drainage

The coal seams in Baijiao Mine are the hard and low-permeability outburst seams and the gas pre-drainage time is generally 4 a to 5 a when the outburst coal seam was exposed in the crosscut. In order to shorten the time for exposing the outburst seam in the crosscut, a complete set of supper-high pressure hydraulic slotting equipment and construction technology was developed and its industrial test was carried out in the heading face in No. 4 crosscut at +300 m level. The practice showed that the super-high pressure hydraulic slotting technology improved the permeability of the coal seam, increased the gas drainage effect, shortened the overall time of exposing the outburst seam in the crosscut by about 4 a, greatly improved the speed of exposing the outburst seam in the crosscut, and while exposing the outburst seam in the crosscut, the gas concentration was not overrun, this thus provided the guarantee for safely and quickly exposing the outburst seam in the crosscut.