Complete non-coal-pillar continuous depressurized mining method for close-distance coal seam groups

Abstract

The invention discloses a complete non-coal-pillar continuous depressurized mining method for close-distance coal seam groups, which is applicable to coal mining engineering. The method comprises the following steps: determining the mining sequence of each coal seam in a coal seam group; when a first coalface of a first mined coal seam is mined, building a filling wall in which a breather pipe is arranged along the edge of a goaf so as to form a gob-side entry retaining, taking the roadway as a transportation roadway when a second coalface is mined, continuing to perform a gob-side entry retaining in a track roadway, breaking and removing a flexible film bag on the surface of the previous gob-side entry retaining behind the coalface, and when the coal recovery of the second coalface is completed, filling carbon dioxide into the breather pipe in the filling wall of the first coalface so as to prompt the filling wall to have a carbonization reaction and then break and disassemble. After a coal seam is completely mined, because a top plate is not supported by a coal-rock pillar, the top plate can move and sink fully, so that the depressurized mining on adjacent coal seams is realized, thereby avoiding the stress concentration produced by the hangover of the filling wall, and facilitating the maintenance for mining spaces, the extraction of gas and the prevention and control of dynamic disasters.

Description

technical field [0001] The invention relates to the technical field of pressure-relief mining, in particular to a continuous pressure-relief mining method suitable for close-distance coal seam groups completely without coal pillars in the field of coal mining engineering. Background technique [0002] Coal-measure strata are mainly the occurrence conditions of coal seam groups composed of multiple coal seams. During the mining process of coal seam groups, multiple coal seams interact with each other, which makes the overlying rock movement and mining stress field more complicated. When the superimposed disturbance is coupled with unfavorable factors such as deep high ground stress, high gas, weak rock formation or hard rock formation, catastrophic accidents will often be caused, such as coal and gas outburst, rock burst, gas explosion, etc. Studies have shown that under the condition of short-distance coal seam group occurrence, reasonable planning of coal seam mining seque...

AI Technical Summary

Problems solved by technology

[0003] However, due to the need to leave a certain width of coal pillars between the working faces, the pressure relief is not sufficient, and the highly concentrated stress on the top and bottom of the coal pillars still brings safety hazards to the adjacent coal seams

In recent years, in order to avoid the adverse effects of such coal pillar stress, the coal mining field is constantly promoting the application of coal pillar-free gobside entry retention technology. This technology achieves the effect of leaving no coal pillars between the working faces, but leaves An artificially filled rock pillar was formed. Although the width of the rock pillar is only a few meters wide, it still forms a large concentrated stress area in the upper and lower adjacent coal seams. When the mining face passes through this area, it still faces the problems of space maintenance and safe mining. major problem

[0004] It can be seen that the technical idea of ​​pressure relief mining for short-distance coal seam groups has been formed, but it is still not possible to fully realize the full pressure relief of adjacent hard-to-mine coal seams by first mining an easy-to-mine coal seam

After the rock pillars with a width of several meters replaced the coal pillars with a width of tens of meters, they are still a safety hazard in the mining of adjacent coal seams

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