Coal mining method

Abstract

The invention provides a coal-mining method, which includes the following steps: (1) performing miter cutting to form broom contour with a continuously widening first cutting angle at the left side of the branch entry with a certain distance from the top of the branch entry; (2) performing miter cutting by the coal-mining machine at a proper place of the broom contour with a second cutting angle, and adjusting the cutting angle as the coal-mining machine moves forward for a certain distance to perform excavation work with a first caving angle to form a first cave; (3) performing cutting by the coal-mining machine with the widest cutting angle at the stub position, and widening the cutting angle as soon as possible to perform excavation with a second caving angle to form a second cave. The method realizes ''one cutting and two caves'', and virgin coal is formed between the first cave and the second cave. The technical proposal of the invention is applicable to the boundary coal mining of large-scale coal mines and the mechanized mining of small-scale mines; and the percentage recovery is higher, the coal production speed is improved. Besides, the invention is capable of effectively avoiding the puking accident in large area in branch entries.

Description

technical field [0001] The invention relates to a coal mining method, in particular to a coal mining method using a continuous coal mining machine. Background technique [0002] At present, in the coal industry, due to the difficulty of arranging longwall working faces in irregular blocks such as side coal in the mine field, in order to realize resource recovery, the room and pillar coal mining method is usually used for recovery. The room-and-pillar coal mining method is to mine a coal room of a specified size in the coal seam to realize resource recovery. Coal pillars of a specified size are left on both sides of the coal room to support the roof of the coal room. [0003] With the improvement of mine mechanization, in the process of developing coal fields, the mining equipment used in mines is developing towards heavy-duty. Usually, a large number of foreign advanced continuous coal mining machines are used for roadway excavation, and continuous coal mining machines are a...

AI Technical Summary

Problems solved by technology

It is difficult to meet this distance requirement during on-site operation. Most of the actual operation is more than 10m, and there must be a continuous coal mining machine before each mining tunnel, which causes a long time for cutting and seriously restricts it. recovery speed

[0007] (2) from figure 1 It can be seen from the figure that when the continuous miner is adjusted to an angle of 45 degrees, the branch roadway has been swept away by a distance of 8.5 meters during the oblique cutting process of the continuous coal miner, and all the branch roadways in the goaf have been widened to 8m The above may cause a large area of ​​the roof to fall suddenly, leaving a safety hazard

[0008] (3) A 0.5m thick coal skin is reserved, and the single-pole single-hole coal mining method requires that the rounded corners be enlarged as soon as possible to reduce the length of the branch roadway occupied by the mining tunnel and improve the recovery rate of the branch roadway. In actual operation, it is difficult to control the angle-wiping distance of the coal shearer in a very strict size before entering different mining tunnels. As a result, the coal skin is left too thick and the recovery rate decreases; another situation is No coal skin was left, and the shearer slipped directly into the goaf at the opening of the mining tunnel, causing the mining tunnel to fail

In actual operation, due to the difficulty of operation, the recovery rate of coal pillars in branch lanes is not high, and the recovery speed is slow

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