Large mining height gob-side entry retaining method for thick coal seams

Abstract

The invention relates to a large mining height gob-side entry retaining method for thick coal seams, which is suitable for a mine roadway supporting project. When an upper section mining working surface is mined, a roadway side support wall and a pressure buffer wall which are respectively and internally provided with a vent pipeline are built along the edge of a goaf, and a certain horizontal distance L is maintained between the roadway side support wall and the pressure buffer wall, so that gob-side entry retaining can be formed; when a lower section mining working surface is mined, gob-side entry retaining is implemented in a track roadway of the lower section mining working surface, and a flexible film bag on the surface of the roadway side support wall of the upper section gob-side entry retaining behind the working surface is removed; after the stoping of lower section mining working surface is finished, the vent pipelines of the roadway side support wall and the pressure buffer wall of the upper section mining working surface are filled with carbon dioxide, so that the walls are promoted to have a carbonization reaction so as to be broken and decomposed, and mining without coal pillars can be completely realized. The method is beneficial to whole process maintenance of gob-side entry retaining, so that the gob-side entry retaining of the large mining height working surface for the thick coal seams can be realized, the coal mining rate is remarkably improved, and meanwhile, stress concentration of the upper part and the lower part of a wall can be eliminated.

Description

technical field [0001] The invention relates to the technical field of gob-side entry retention, in particular to a gob-side entry retention method suitable for the field of shaft support engineering in thick coal seams and large mining heights. Background technique [0002] Compared with the traditional method of retaining coal pillars for roadway protection, retaining roadway along the gob has obvious technical advantages, such as increasing recovery rate, reducing roadway excavation rate, promoting gas control, eliminating stress concentration, improving the working environment of coal mining face, etc. . In the context of the rapid reduction of non-renewable energy sources, the importance of improving the recovery rate of energy resources is becoming more and more prominent. One of the significant advantages of the gob-side entry retention technology is that by reducing the remaining coal pillars, the coal recovery rate in the mining area can be greatly improved and the...

AI Technical Summary

Problems solved by technology

This has the following four problems: (1) The large temperature difference between the inside and outside of the large-scale filling wall will generate high temperature stress, which will cause damage during the hardening process, and the support efficiency will be low; (2) The filling process is cumbersome and takes up The time is long, which affects the normal coal mining operation of the working face; (3) too much material is used, and a large amount of dust is generated during the mixing process, which deteriorates the working environment; (4) equipment, materials, and manpower are invested more, and the cost is too high

A small number of mining areas have tried to strengthen the conventional gob-side entry retention technology and then applied it to the thick coal seam and large mining height working face, but most of them stopped the application due to poor results

[0004] Most of the coal in our country belongs to the occurrence condition of coal seam groups. The mining of one coal seam will definitely affect other coal seams, especially the concentrated stress on the upper and lower sides of the left coal pillar after mining, which is a hidden danger to the safety of mining space. At the same time, the remaining roadside walls will also cause a certain range of stress concentration, which will greatly interfere with the safe mining of other adjacent coal seams

[0005] In short, the mine pressure in the thick coal seam and large mining height working face is severe, and the maintenance of gob-side entry retention is relatively difficult. At present, there is no method of gob-side entry retention that can adapt to this condition, let alone eliminate the stress concentration of the wall beside the roadway question

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