Steep-coal-seam long wall face non-pillar coal mining method

Abstract

The invention discloses a steel-coal-seam long wall face non-pillar coal mining method. The method comprises the steps of (1) excavating an upper crossheading roadway and a lower crosshead roadway; (2) mounting a constant-resistance large-deformation anchor rod, processing a row of vertical energy-gathering blasting holes, and implementing blasting and presplitting; (3) erecting a column body for supporting a top plate, and arranging a protective layer on the back of the column body; and (4) carrying out recovery, slipping the top plate of a recovery face along a presplitting kerf; (5) withdrawing the column, hanging a net and spraying concrete to form a support layer; (6) mounting a slip-casting constant-resistance long anchor rod, and grouting; (7) forming a roadway automatically in the original crosshead roadway and taking the roadway as the upper crosshead roadway of the next mining face; and (8) repeating the steps (2)-(7). According to the method, the top plate at a worked out section collapses along the presplitting kerf, and meanwhile, a lower crosshead top plate is prevented from being damaged, and small caving waste rocks are prevented from entering the lower crosshead roadway, so that the roadway is automatically formed in the original crosshead roadway.

Description

technical field [0001] The invention relates to a coal seam mining method, in particular to the coal seam mining method of a longwall working face under the condition of a hard roof with a coal seam inclination exceeding 30°. Background technique [0002] In order to improve the advancing speed and high-efficiency production, the fully mechanized mining of high-inclination coal seams has been popularized and applied in my country, and has achieved good economic and technical benefits. However, the gobside roadway maintenance technology corresponding to high-inclination coal seams is seriously lagging behind. At present, the working face of high-inclination coal seam mainly adopts the method of masonry gangue wall next to the roadway to maintain the gob-side roadway for retaining roadway and coal pillar mining. Due to the increase of the inclination angle of the coal seam, after the coal seam is mined, the roof of the stope also has a law of mine pressure that is different fr...

AI Technical Summary

Problems solved by technology

However, this method cannot well solve and realize the coal pillar-free mining under the condition of a hard roof in the longwall working face of a high-inclination coal seam, because:

[0003] If coal pillars are used to maintain the gob-side roadway, if the coal pillars are too small, the coal pillars will not be able to support the pressure of the stope roof, and will not be able to protect the gob-side roadway. At this time, the gob-side roadway will be easily crushed and deformed too much If the coal pillar is too large, although it can support the pressure of the stope roof, it will waste a lot of coal resources and cannot be recovered, resulting in resource loss and waste; Severe disasters such as pressure and other serious disasters, resulting in equipment damage and huge casualties, and huge potential safety hazards

Images