External support replacement type room type coal pillar recycling method

Abstract

The invention discloses an external support replacement type room type coal pillar recycling method. In a process of recycling a room type coal pillar, a cementing material wall is poured at the periphery of the room type coal pillar with a width-height ratio less than 0.6 by utilizing a single prop bag hanging manner; a room type coal pillar resource is recovered under a supporting and rock overlying condition of a cementing filling material wall; after recovery is finished, a goaf of the room type coal pillar is filled by utilizing a cementing filling material; after the cementing filling material is stably condensed, a single prop is recycled; a mechanical model of the cementing filling material wall in a single supporting and rock overlying phase is established based on a Winkler's beam theory, so as to obtain displacement and stress conditions of a roof of the cementing filling material wall in a supporting phase. A theoretical pouring width of the cementing filling material wallis obtained according to a first strength theory of the roof and a extreme strength criterion of the cementing filling material wall. According to the method provided by the invention, room type mining remained coal pillars can be effectively recycled, and wastes of coal resources are reduced; the rock overlying above the coal pillars can keep stable, and a series of problems are avoided.

Description

technical field [0001] The invention belongs to the technical field of coal pillar recovery, and in particular relates to an external support replacement type room-type coal pillar recovery method, and is especially suitable for the replacement support recovery of room-type coal pillars with an aspect ratio less than 0.6 left over from coal mining in coal mines. Background technique [0002] Room-type coal pillar mining is widely used in Northwest my country, mainly concentrated in Shaanxi, Inner Mongolia, Shaanxi and other provinces where the resources are widely distributed, the geological structure is simple, and the coal seams are shallow. The room-type coal pillar mining method has the advantages of low production cost, high efficiency, and easy management, but the coal recovery rate is low, and the coal pillar has the risk of cascading instability and disasters. The safe recovery of room-type coal pillars can improve the utilization rate of coal resources and prevent s...

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Problems solved by technology

[0003] The traditional coal pillar recovery methods in China include split column recovery and warehouse wing recovery, etc. These recovery methods are low in efficiency and low in mechanization; while the existing coal pillar recovery methods of filling, such as comprehensive mechanized filling recovery and throwing filling Recycling and other methods require high investment in equipment and filling materials, making it difficult to popularize

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