A layering and partially filling coal mining method of thick seams

[0020] An embodiment of the present invention will be further described below in conjunction with accompanying drawing:

[0021] The thick coal seam layered partial filling coal mining method of the present invention, its coal mining step is as follows:

[0022] a. To extract the geological conditions of the coal seam, according to the range and protection level of the surface building groups, and based on the determination of the traditional mining area range, the surface building groups are within the protection range of the filling zone, and the "buildings, water bodies, railways and major The protection level requirements of the Coal Pillar Retention and Pressure Coal Mining Regulations in Shaft Roadway are used as the standard to determine the coal filling and mining range under the mine; b. According to the thickness of the coal seam, the coal seam 5 is divided into upper and lower layers, and the top of the coal seam 5 is the roof 3, The bottom is the bottom plate 7;

[0023] c. Determine the mining width of the upper layered coal seam, establish a working face 4 on the upper layered coal seam and carry out backfill mining, such as figure 1 and figure 2 As shown, the paste filling strips 2 and mining strips 6 are alternately divided in the working face 4, the distance between the paste filling strips 2 is the filling step 1, and the divided paste filling strips 2 are mined in sequence. Fill the paste filling strip in time every time it is advanced 2 to 4m, each time filling a step distance 1, when the filling of the paste filling strip 2 divided by the upper layered coal seam is completed, the mining strip 6 can be filled Carry out excavation back mining, also carry out paste filling to mining strip 6 during back mining, coal mining and filling parallel operation,

[0024] d. After the upper layered coal seam is mined and the filling paste is solidified and stable, take samples on site to test the strength of the backfilled paste in the upper layered coal seam after solidification. When the test results meet the requirements of maintaining the stability of the filling paste, judge the strength of the backfilled paste after solidification qualified, such as image 3 and Figure 4 The above layered coal seam backfill paste 16 is used as the false roof of the working face to mine the lower layered coal seam, and the width of the lower layered coal seam paste filling strip 2 and the mining strip 6 are determined, and the width of the filling strip 2 is 25~50m , the mining width 6 is 3~12 m, the paste filling strips 2 are divided alternately in the working face, and the divided paste filling strips 2 and the mining roadway 6 are mined in sequence, and the working face advances every time 2~4m Fill the paste filling strip in time. When the paste filling strip is mined and filled, wait for the filling body in the paste filling strip to solidify to form filling areas 8, 10, 12, 14, and take samples of the solidified filling body Inspection, when the stable numerical value of the filling paste is met, it is judged that the backfill paste has reached the design strength, and after reaching the strength of supporting the false roof of the upper layer and the rock formation, the recovery strip 6 between the two paste filling strips 2 can be sequentially Excavation mining is carried out, and the working face 2 is arranged in the mining strip. The goaf formed after mining is not processed, and an unfilled area 9, 11, 13, 15 is formed. With the advancement of the working face, the scope of the goaf gradually expands. , the subsidence of the false roof of the filling body in the goaf is controlled due to the support of the filling body in the lower stratified strip. Mining with 2.

[0025] The filling material used is a paste mixture of crushed coal gangue, fly ash or slag, cementitious material and water; the mass ratio of coal gangue, flyash or slag and filling cementitious material to water is 150:2 :30.