Setting Method of Parallelogram Island Coal Pillar with Retained Roadway in Thin Coal Seam Working Face

Abstract

The invention belongs to the field of thin coal seam mining and provides an arrangement method for parallelogram gob-surrounded pillars of a thin coal seam working face left roadway. The arrangement method comprises the following steps that when an air return way of a working face is driven, parallelogram air return connection roadways are driven at intervals in the side close to the working facetill the air return way is driven to the preset position, and the parallelogram gob-surrounded pillars are reserved between the air return connection roadways; when the working face is pushed forwards, only coal between a transport way of the working face and the edges of the air return connection roadways is recovered, the gob-surrounded pillars between the air return connection roadways are notrecovered, and after the working face is pushed to pass the air return connection roadways, the air return connection roadways also serve as emergency exits; along with the process that the working face is alternately pushed to pass rectangular gob-surrounded pillars and rectangular air return connection roadways, the working face is mined sequentially according to the above steps; and the air return way of the working face serves as an air return way of the next working face, and the next working face is mined. Through the arrangement method, safety of coal mining can be improved, and the arrangement method can be widely applied to the coal mine field.

Description

technical field [0001] The invention belongs to the field of thin coal seam mining, and in particular relates to a method for setting parallelogram-shaped isolated island coal pillars for roadway retention in thin coal seam working faces. Background technique [0002] With the increase of mining intensity in recent years, there are few high-quality medium-thick and thick coal seams left, and a large number of thin coal seams gradually come into people's field of vision. Thin coal seam means that the thickness of the coal seam is less than 1.3m. Because the height of the upper and lower sections of the roadway must meet the requirements of ventilation, material transportation, and pedestrians, the height must be much greater than the thickness of the coal seam. Therefore, the upper and lower sections of the thin coal seam are semi-coal and rock roadways. However, the excavation speed of Banmeiyan Lane is slow, and a large amount of gangue is produced, which increases the diff...

AI Technical Summary

Problems solved by technology

[0004] (1) poor security

Complete gob-side entry retaining can leave no island coal pillars or carry out roadside filling. This method has the problems of air leakage and goaf gas entering the roadway, causing gas to exceed the limit, and there are potential safety hazards. This problem cannot be completely avoided by means of protection and other methods.

[0005] (2) High cost

In order to prevent the occurrence of the above safety hazards, concrete pouring is generally used for roadside support, but there are problems of high material and labor costs

[0006] (3) The process is complicated

The method of concrete pouring needs to wait for the concrete material to cement, so the progress is slow. At the same time, it needs mixing, pipeline transportation, formwork and other processes, and the process is very complicated.

[0007] (4) Poor adaptability

Although gob-side entry can solve the above safety problems, it cannot reduce the amount of gangue and excavation. More importantly, it is difficult to meet the requirements of excavation replacement and entry timing at the same time, which is severely limited in thin coal seam mining.

[0008] In order to solve the problems of large capital investment in the early stage of thin coal seam mining, long return period, poor safety, complex process, and poor adaptability, the invention proposes a parallelogram island coal pillar setting method for partial mining of thin coal seam working faces

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