A Method of Reducing the Width of Stopped Coal Pillars in Extra-thick Coal Seams by Combining Masonry and Filling

Abstract

The invention discloses a method for decreasing the width of an ultra-thick coal seam stopping coal pillar through combination of building and filling. Slurry filling serves as a main measure, as for the coal mining procedure, non-caving coal mining and caving coal mining are conducted through a coal cutter alternately, and the coal resource recovery rate is increased. The method comprises the following steps that firstly, a grouting pipeline is arranged; when an ultra-thick coal seam coal face moves to the position of an original designed stopping line, a conveyor starts working, an insertion board of the conveyor is unfolded, a coal discharging outlet is closed, coal is conveyed through a front scraper conveyor, a rear scraper conveyor does not convey the coal, and a coal non-discharging procedure is started; along with the forward conduction of the coal mining and support advancing procedure, a wall is built behind the rear scraper conveyor, and wall building is conducted along with advancing of a support; the coal face continues to move forwards, the insertion board is retracted, and a coal discharging procedure is started; when the distance of the conveyor along with the support advancing and pushing of the working surface is 2 / 3 the direct top caving pace, the coal non-discharging procedure is started again; a closed area is formed behind the working surface, slurry is injected into the closed area till the closed area is filled with the slurry; and the steps are conducted repeatedly till filling of the working surface is completed.

Description

technical field [0001] The invention relates to a method for reducing the width of a stopped coal pillar in an extra-thick coal seam by combining masonry and filling, and belongs to the technical field of coal mining. Background technique [0002] Due to geological conditions, roadway layout, production system and other reasons, the coal mining face can be mined indefinitely along the direction of the coal seam. In order to ensure the safety of mine production, a production stop line is artificially set at this time to restrict its forward mining. When the working face advances to this position, coal mining will stop, the equipment will be withdrawn, and the goaf will be closed. At this time, the coal pillars between the production stop line and the main road are discarded, resulting in a waste of coal resources. Taking the 8105 working face of Tashan Mine as an example, the coal pillars stopped up to 230m, resulting in a great waste of coal resources. [0003] Coal resour...

AI Technical Summary

Problems solved by technology

Judging from the existing patent publications, there are relatively few technical measures to reduce the stoppage of mining coal pillars. From the perspective of related content, it is mainly to reduce the impact of mining stress by filling the old roadway in advance with the working face. The special conditions of extra-thick coal seams are seldom involved

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