Roof-cutting self-tunneling coal-pillar-free mining method for coal seam easy to spontaneously combust

Abstract

The invention relates to the technical field of coal mining, in particular to a roof-cutting self-tunneling coal-pillar-free mining method for a coal seam easy to spontaneously combust. The method comprises the following steps of: additionally driving a constant-resistance anchor cable on a roof for reinforcing and supporting; conducting directional pre-splitting blasting joint cutting on the sideroadway roof of a goaf; erecting a single hydraulic prop in a temporary supporting area; arranging a gangue blocking support column close to the side of the goaf behind the stope face, and fixing a first metal net on one side, close to the goaf, of the gangue blocking support column; laying a flexible mold bag on the side, close to the goaf, of the first metal net, laying a second metal net on the side, close to the goaf, of the flexible mold bag, and synchronously laying the flexible mold bags forwards along with forward movement of a coal mining support of the working face; and pouring a quick-setting elastic material into the flexible mold bags. A pre-splitting joint-cutting technology is matched with a constant-resistance anchor cable support to weaken stress transfer of the roof andimprove the dynamic pressure resistance of the roadway; and the quick-setting elastic material capable of generating large deformation is combined with the gangue blocking structure, so that the goodsealing effect of the goaf is ensured while yielding deformation is realized.

Description

technical field [0001] The present application relates to the technical field of coal mining, in particular to a coal pillar-free mining method for spontaneously combustible coal seams with top-cut roofs and self-forming lanes. Background technique [0002] Gobside retaining means that after the working face is mined, no roadway protection coal pillars are left, and certain means are used to maintain and retain the working face of the previous section along the edge of the goaf, as a starting point for the working face of the next section. Down trough, so as to realize the technology of mining without coal pillar. Due to the cancellation of section coal pillars, the goaf and the roadway are connected to each other, which will cause a series of problems such as air leakage and harmful gas overflow in the goaf. Especially for coal seams that are prone to spontaneous combustion, it is very easy to cause spontaneous combustion under the action of fresh air flow in the roadway, ...

AI Technical Summary

Problems solved by technology

In the process of retaining roadways, spraying chemical materials is often used to close the empty area, or although the formed chemical spray layer has a certain deformation ability, but the deformation ability is weak, deformation and cracking will still occur under the action of strong dynamic pressure disturbance, thus losing the empty area closed function

Although the flexible cloth has a certain sealing effect, its impact resistance is too poor, and it is easily damaged under the influence of dynamic pressure in the goaf. Therefore, this method is often used for the spraying seal of gangue gangue in the stable area behind the working face, but it is difficult to apply to the dynamic pressure bearing area with large deformation

[0006] 3. For a class of coal seams that are prone to spontaneous combustion, some existing technologies use walls with anti-deformation capabilities to isolate the empty space and achieve the purpose of support, such as filling high-water materials to form, and after consolidation reaches a certain strength Form a thicker wall structure for support. Although this type of wall has a certain unloading and buffering effect, due to its low strength, it can only adapt to small deformations and cannot adapt to large dynamic pressures.

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