Gentle dip super-high seam rock cross-cut coal uncovering method

Abstract

The invention discloses a gentle dip super-high seam rock cross-cut coal uncovering method, and is particularly suitable for protruded risk coal seam with small dip angle and large thickness of underground coal mine. When the rock cross cut is tunneled to be the vertical distance of 12 m relative to the coal seam, an inclined rock cross cut is dug on the right side of the rock cross cut; when the inclined rock cross cut is tunneled to be the vertical distance of 7 m relative to the coal seam, a coal bottom road is dug head-on on the inclined rock cross cut; the coal bottom road is parallel to the rock cross cut and tipsily dug along the coal seam. A plurality of drill sites are uniformly arranged in the coal bottom road which is completed; holes are drilled from the drill sites to the coal seam construction hydraulic cutting slot to pre-extract the coal seam gas; when the gas is extracted to reach the standard, the rock cross cut is recovered to tunnel in the original direction; the coal seam is penetrated to enter 2 m of roof, so that the coal uncovering work is completed. By construction of the coal bottom road, the gentle dip long drill holes which restrain the coal uncovering speed are transformed to the coal bottom layer-crossing drill holes, so that the bottleneck problem that the gentle dip super high seam is slow to uncover is solved, safe and quick coal uncovering is realized, and the method can be widely applied.

Description

technical field [0001] The invention relates to a method for uncovering coal at a stone gate of a gently inclined extra-thick coal seam, in particular to a method for quickly uncovering coal in a coal mine with a small downward inclination angle and a large thickness protruding dangerous coal seam. Background technique [0002] Coal and gas outburst (hereinafter referred to as outburst), as one of the most serious disasters in coal mine production, is an abnormal dynamic phenomenon that occurs in gas-bearing coal mass under the combined action of in-situ stress and gas pressure. Among the many outburst accidents, the outburst that occurred when the coal was uncovered in Shimen was the strongest and the most dangerous. If the inclination angle and thickness of the coal seam in the Shimen coal-exposing area are small, the coal-exposing section in Shimen will be too long, and the length of the gas drainage borehole will increase sharply, which will easily cause drill sticking, ...

AI Technical Summary

Problems solved by technology

If the inclination angle and thickness of the coal seam in the Shimen coal-exposing area are small, the coal-exposing section in Shimen will be too long, and the length of the gas drainage borehole will increase sharply, which will easily cause drill sticking, floating drill, hole plugging, and injection holes, etc., eventually. As a result, the drill hole cannot be drilled to the designated position, and there are many blank areas in the outburst elimination area, which brings serious hidden dangers to the safety of coal mining

Due to the difficulty of drainage and slag discharge in long and gently inclined boreholes, and the application of pressure relief and anti-permeability technologies such as hydraulic slotting, gas drainage is limited to low concentration and low flow levels, the pre-pumping time is greatly increased, and the coal uncovering cycle is limited. Prolonged, seriously restricting the normal succession of mine production

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