A kind of gently inclined super thick coal seam Shimen coal excavation method

Abstract

The invention discloses a method for uncovering coal in a stone gate of a gently inclined extra-thick coal seam, which is especially suitable for protruding dangerous coal seams with a small inclination angle and a large thickness in a coal mine. When the Shimen is excavated to a vertical distance of 12m from the coal seam, excavate an inclined stone gate on the right side of the Shimen, and when the inclined stone gate is excavated to a vertical distance of 7m from the coal seam, a floor roadway is excavated in front of the Xieshimen. The floor roadway is parallel to the Shimen and excavated along the coal seam . A plurality of drilling sites are evenly arranged in the completed floor roadway, and the coal seam gas is pre-extracted by hydraulic slotting drilling from the drilling site to the coal seam. After the gas drainage reached the standard, Shimen resumed excavation in the original direction, and passed through the coal seam and entered the roof 2m to complete the coal uncovering work. Through the construction of the floor roadway, the present invention transforms the slow-sloping long drilling that restricts the speed of uncovering the coal into the floor-penetrating drilling, which breaks the bottleneck problem of slow coal mining in the gently inclined and extra-thick coal seam, and realizes safe and fast coal mining, which has a wide range of applications. practicality.

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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