Clean and efficient coal mining method

Abstract

The present invention relates to a clean and efficient coal mining method, which is applicable to the field of solid waste treatment in mines. The method is characterized in: the width of short-segment working faces is designed according to the discharge volume of solid wastes produced in a mine, including downhole gangue and surface coal ash; first, two adjacent short-segment working faces are mined and backfilled, and the edges of the filling face and the solid coal side are supported with anchor rods while roadways are retained; the roadways retained at the two short-segment working faces and the coal mass in the middle constitute a long-segment working face mining system; the long-segment working face is mined, the short-segment backfilled working faces at the two sides are mined and backfilled at the same time, and the gangue produced at the long-segment working face is transported to the short-segment working faces to fill, so that a continuous mining system that consists of backfill mining at short-segment working faces and efficient stopping at long-segment working faces is realized. The method provided in the present invention can deal with all surface and downhole solid wastes in a mine, reduces the cost of gangue treatment, and mitigates damages to the ecological environment; besides, the method utilizes solid wastes to fill the gobs to form roadways, eliminates coal pillars and improve resource recovery rate.

1 . A clean and efficient coal mining method, comprising the following steps:
 a. calculating the volume of existing solid wastes produced in a mine, and the solid wastes include downhole gangue, surface gangue, and coal ash;   b. arranging a long-segment working face I for filling solid wastes in the mine in the coal seam in the mine field, arranging short-segment working faces I and II in width of w at the two sides of the long-segment working face I respectively, commissioning the equipment, including coal cutter, hydraulic support and belt conveyer, at the short-segment working faces I and II, mining at the short-segment working faces I and II simultaneously, filling the existing solid wastes in the mine and the gangue produced in the mining, and supporting the edges of the filling face and the solid coal side with anchor rods while retaining roadways at the two sides of the filling face;   c. utilizing a heading machine to excavate open-off cuts between the short-segment working face I and the short-segment working face II after the mining at the short-segment working faces I and II is finished, so that the roadways retained at the short-segment working faces I and II and the open-off cuts constitute a long-segment working face mining system;   d. mining at the long-segment working face I, transporting the mining equipment at the short-segment working face I to a short-segment working face III at the left side to mine, and transporting the mining equipment at the short-segment working face II to a short-segment working face IV at the right side to mine, and transporting the gangue produced in the mining at the long-segment working face I to the short-segment working faces III and IV to fill, letting a gob formed after the mining at the long-segment working face I is finished collapse directly;   e. excavating open-off cuts respectively after the mining at the short-segment working faces III and IV is finished, arranging long-segment working faces II and III respectively, and repeating the step d, so that continuous mining that consists of backfill mining at short-segment working faces, and efficient stopping at the long-segment working faces is realized, and the mining of the entire coal seam in the mine field is completed.   
     
     
         2 . The clean and efficient coal mining method according to  claim 1 , wherein: all short-segment working faces have the same width calculated with a formula w=Q/(2l*h), and w≤60 m, and the specific dimension depends on the quantity Q of the solid wastes, where, l is the length of the short-segment working face, and h is the mining height at the short-segment working face. 
     
     
         3 . The clean and efficient coal mining method according to  claim 1 , wherein: the long-segment working faces have width of 150 m-300 m. 
     
     
         4 . The clean and efficient coal mining method according to  claim 1 , wherein: the roadway retained after the filling of two short-segment working faces has a width of 4-6 m.