Setting Method of Rectangular Island Coal Pillar in Partial Mining of Thin Coal Seam Working Face with Retained Roadway

Abstract

The invention belongs to the field of thin coal seam mining, and discloses a method for arranging rectangular isolated coal pillars for partially mining and roadway retaining of a thin coal seam working face. The method comprises the following steps of in an air return way of the working face, newly digging rectangular air return crossheadings ahead of the working face in the vertical direction ofthe air return way, and arranging the rectangular isolated coal pillars between the rectangular air return crossheadings; when the working face is advanced forwards, stoping only the partial coal from a haulage gate of the working face to the tail of a scraper conveyor, and after the working face is pushed across one rectangular air return crossheading, taking the rectangular air return crossheading as a safety exit and supporting an old working pedestrian air return access; after the working face is pushed across the next rectangular air return crossheading, supporting the next old workingpedestrian air return access on one side of the next rectangular isolated coal pillar close to the working face; mining the working face in accordance to the above steps; and by taking the air return way of the working face as the air return way of the next working face, mining the next working face. The method can effectively reduce the cost and the process difficulty.

Description

technical field [0001] The invention belongs to the field of thin coal seam mining, and in particular relates to a method for arranging rectangular island coal pillars for partial mining of thin coal seam working faces and retaining lanes. 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 dif...

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 rectangular island coal pillar size setting method for partial mining of thin coal seam working faces.

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