Synergistic mining method for underground mining, separation and filling for a close distance coal seam group

Abstract

A synergistic mining method for underground mining, separation and filling for a close distance coal seam group is applicable to the mining engineering field. Full-mechanized caving mining is carried out for a close distance coal seam group, an underground coal gangue separation system and a filling face are designed according to the yield of gangue in the production process; the gangue produced in the mining process is transported centrally into an underground coal gangue separation chamber, and the separated gangue is transported to the filling face for filling and mining; the gangue produced at the filling face is transported back to the filling face for backfilling after underground washing separation. The method separates nearby and filling at selected locations, reduces the damage and disturbance to the underground rock mass that may be caused by a conventional mining method, and solves problems in treatment of strong dynamic pressure in advance.

1 . A synergistic mining method for underground mining, separation and filling for a close distance coal seam group, comprising the following steps:
 a. designing a fully mechanized caving face ( 1 ), designing a filling face ( 9 ) in an appropriate mining area according to the annual gangue yield in the mining area, and arranging a sectional transportation roadway II ( 8 ) and a sectional ventilation roadway ( 7 ) at both sides of the filling face ( 9 );   b. designing the size of an underground coal gangue separation chamber ( 4 ) and designing an underground coal gangue separation system according to the annual yield of gangue in the mining area, wherein the underground coal gangue separation system comprises a sectional transportation roadway I ( 2 ) in the same direction as the fully mechanized caving face ( 1 ), the tail end of the sectional transportation roadway I ( 2 ) is connected with the underground coal gangue separation chamber ( 4 ) via a mining area transportation roadway I ( 3 ), the underground coal gangue separation chamber ( 4 ) is connected with the sectional ventilation roadway ( 7 ) via a gangue concentration roadway ( 5 ) arranged below the underground coal gangue separation chamber ( 4 ), and the underground coal gangue separation chamber ( 4 ) is connected with the sectional transportation roadway II ( 8 ) via the mining area transportation roadway II ( 6 );   c. mining at the fully mechanized caving face ( 1 ), determining the mining height and caving height of the coal mining machine according to the thickness of the close distance coal seam group and the thickness of the gangue-containing seam, and transporting the coal gangue produced in the mining process through the sectional transportation roadway I ( 2 ) to the mining area transportation roadway I ( 3 );   d. transporting the coal gangue through the mining area transportation roadway I ( 3 ) into the underground coal gangue separation chamber ( 4 ) for coal gangue separation, controlling the obtained gangue to fall into the gangue concentration roadway ( 5 ) by gravity, and finally transporting the gangue to the sectional ventilation roadway ( 7 );   e. filling and mining the filling face ( 9 ) with the coal gangue transported to the sectional ventilation roadway ( 7 ), determining the advance rate of the filling face ( 9 ) according to the requirement for the filling rate in the mine, transporting the coal gangue produced in the mining process at the filling face ( 9 ) through the sectional transportation roadway II ( 8 ) to the mining area transportation roadway II ( 6 ) and finally into the underground coal gangue separation chamber ( 4 ); then repeating step d;   f. repeating steps c, d and e to accomplish the mining in the entire mining area.   
     
     
         2 . The synergistic mining method for underground mining, separation and filling for a close distance coal seam group according to  claim 1 , wherein, the location of the filling face ( 9 ) is selected in a mining area where conditions for fully mechanized caving and integrated coal and gangue mining in the close distance coal seam group are unavailable or in a mining area where the distance between the coal seams in the coal seam group is great and the coal seam group is be mined upward/downward layer by layer or mined in combination. 
     
     
         3 . The synergistic mining method for underground mining, separation and filling for a close distance coal seam group according to  claim 1 , wherein: the annual gangue yield Q is calculated according to the formula Q=L 1 d 1 (ρ 1 h 1  m 1 +ρ 2 h 2  m 2 )+L 2 d 2 ρ 1 h 3  m 1 , where L 1  is the annual advance length of the fully mechanized caving face ( 1 ), d 1  is the width of the fully mechanized caving face ( 1 ), ρ 1  is the apparent density of the coal, h 1  is the total thickness of the close distance coal seam group, m 1  is the primary separation rate of gangue from the raw coal, ρ 2  is the apparent density of the gangue, h 2  is the total thickness of the gangue seams, m 2  is the primary separation rate of the gangue, L 2  is the annual advance length of the filling face ( 9 ), d 2  is the width of the filling face ( 9 ), and h 3  is the mining height of the filling face ( 9 ). 
     
     
         4 . The synergistic mining method for underground mining, separation and filling for a close distance coal seam group according to  claim 1 , wherein, the parameter design of the filling face ( 9 ) is determined according to a formula Q=L 2 d 2 h c ρ 2 , wherein h c  is the fillable height of the filling face ( 9 ). 
     
     
         5 . The synergistic mining method for underground mining, separation and filling for a close distance coal seam group according to  claim 1 , wherein, the total thickness of the gangue seams in the close distance coal seam group involved in the full-mechanized caving mining is not more than 2.0 m, the thickness of each gangue seam is not more than 1.0 m.