Fully mechanized top coal roof multiple segment control exploration method for deeply inclined coal seam

Abstract

The invention provides a head-plate multi-section control mining method for the high inclination-angle coal seam comprehensive top-coal caving. The method is characterized in that two or more sections/working faces are arranged on the same stage of the coal seam, protective or isolating coal pillars are arranged between the sections/working faces; the upper sections/working faces on the same stage is mined firstly when mining the single coal seam; the upper layer of coal is mined firstly when mining the coal seam group; the upper sections/working faces on the same stage of a same coal seam is mined first, and the top-coal is not caved or is caved in control during the mining process; the normal top-coal caving stopping procedure begins mining from the second or lower section/working face; in the course of mining the second or lower section/working face, the protective or isolating pillars on the section/working face of the recovery part can ensure that the gangue slips or rolls into the space formed after the top-coal on the middle or upper areas of the section/working face is caved. The method can improve the top-coal recovering rate of the high inclination-angle coal seam top-coal caving and the output of the working face, and can ensure safe production.

Description

technical field [0001] The invention relates to a multi-section controlled mining method for fully mechanized top-coal caving and roof slab with large dip angle coal seam, and belongs to the technical field of mining. Background technique [0002] High-inclination coal seams are part of medium-inclined and steep-inclined coal seams, generally with an inclination angle of 35°-55°. It is recognized by the international mining community as a difficult coal seam. [0003] When the high-inclination coal seam is mined towards the longwall working face, the rock fracture, movement and mine pressure manifestation along the length of the working face can be divided into three regions, that is, the lower region where the roof movement (mine pressure) appears relatively weak, and the roof movement A restricted central area and an upper area with intense roof activity. Apparently, when top-coal caving is mined in high-inclination coal seams, the top-coal looseness and cavitation are d...

AI Technical Summary

Problems solved by technology

The output of the longwall top-coal caving working face with a large dip angle is mainly from the coal caving openings in the middle and upper areas of the working face. The top coal in the upper area of ​​the working face is emptied, the constituent element "roof" in the "roof-support-bottom" system of the working face is missing, and the "roof-support-bottom" system cannot be formed or formed in the upper part of the working face. "Pseudo-system", it is obvious that the lack of constituent elements of this system or the formation of "pseudo-system" cannot guarantee the stability of the "roof-support-bottom" system of the working face (the interaction system of "support-surrounding rock" cannot be formed), It will inevitably lead to the instability of the support in the local area of ​​the working face, and the phenomenon of toppling, sliding, squeezing and biting of the support will appear, and this phenomenon has a "Domino effect", which will develop from the upper area of ​​the working face to the middle area, so that the work The "roof-bracket-bottom" system in multiple sections of the face was unstable, causing the working face to stop.

What is more serious is that once the "roof-bracket-bottom" system becomes unstable, the breakage and movement of the roof of the working face loses the restraint and control of the bracket, and shock dynamic pressure may appear, causing a catastrophe in the surrounding rock of the working face, resulting in safety hazards. ACCIDENT

From another point of view, in order to maintain the stability of the "roof-support-floor" system of the working face and prevent surrounding rock disasters and safety accidents, it is necessary to control the amount of top-coal discharge at the working face, and the output of the working face will increase. restricted, the top coal recovery rate will inevitably decrease

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