System and method for filling goaf by using coal gangue slurry

Abstract

The system comprises a mine body, a coal seam goaf is formed after a working face to be stoped is stoped, the lower terrain side of the coal seam goaf is communicated with a mine system main roadway, a rectangular water pool is formed in the mine system main roadway, the rectangular water pool is communicated with a ground water storage pool through a water drainage pipeline, and the ground water storage pool is communicated with the coal seam goaf through a water drainage pipeline. The rectangular water pool is further communicated with a porous water filtering pipe, the ground water storage pool is sequentially connected with a water purifier and a coal gangue slurrying pool through water pipes, the coal gangue slurrying pool is connected with a coal gangue crushing unit and a grouting pump through material conveying pipelines, the grouting pump is communicated with a coal seam goaf through a grouting pipe, and a stirring machine is arranged in the coal gangue slurrying pool. The invention further discloses a goaf filling method, and the system and method for filling the goaf through the coal gangue slurry solve the problems that in the prior art, a slurry making water source is insufficient, and a large amount of goaf accumulated water is accumulated in the goaf and is not effectively utilized.

Description

Technical Field

[0001] The invention belongs to the technical field of underground filling, and in particular relates to a system for filling a goaf with coal gangue slurry, and also relates to a method for filling a goaf. Background Art

[0002] Coal washing produces a large amount of gangue. If these gangue are not handled properly, they will lead to the occupation of land resources and may also have adverse effects on the ecological environment. Therefore, it is necessary to dispose of the gangue reasonably. Grinding the gangue and mixing it with water to make a slurry to fill the coal seam goaf is an effective way to dispose of gangue. However, the surface water ecological environment in some mines is fragile and the water supply is tight. The mine water inflow generated by the roof sandstone aquifer during coal seam mining is small and cannot meet the water needs of gangue slurry. Taking water from surface rivers and other water sources not only incurs a large amount of water extraction costs, but also aggravates the tense situation of surface water supply to a certain extent. After some working faces were mined and closed, a large amount of water accumulated in the goaf accumulated in the goaf. This water source has not been effectively utilized in mine production, and the large amount of accumulated water accumulated over a long period of time poses a certain threat to the mining of working faces in low-lying areas. In addition, after sedimentation, the gangue slurry filled into the goaf will cause the separation of the gangue debris particles and water, thereby producing some slurry precipitated water. If this water is not properly handled, it will spread to the low-lying areas around the goaf, causing a waste of underground water resources and failing to achieve effective utilization of the slurry precipitated water and the water accumulated in the goaf. Summary of the invention

[0003] The first purpose of the present invention is to provide a system for filling goaf using circulating mine water for pulping, which solves the problems in the prior art of insufficient pulping water and a large amount of water accumulated in the goaf that is not effectively utilized.

[0004] The second object of the present invention is to provide a method for filling a goaf.

[0005] The first technical solution adopted by the present invention is a system for filling goaf with coal gangue slurry, including a mine body, a working face to be mined is arranged in the mine body, a coal seam goaf is formed after the working face to be mined is mined, the lower side of the coal seam goaf is connected with the main tunnel of the mine system, a rectangular water pool is opened in the main tunnel of the mine system, the rectangular water pool is connected with a ground water storage tank through a drainage pipeline, the rectangular water pool is also connected with a porous water filter pipe, the ground water storage tank is connected with a water purifier and a coal gangue slurry making tank in sequence through a water pipe, the coal gangue slurry making tank is connected with a coal gangue crushing unit and a grouting pump respectively through a feed pipeline, the grouting pump is connected with the coal seam goaf through a grouting pipe, and a mixer is arranged in the coal gangue slurry making tank.

[0006] The first technical solution of the present invention is also characterized in that: The working face to be mined is surrounded by four working face tunnels. Intercepting ditches are opened on the sides of the two working face tunnels with lower terrain. High-strength steel filter meshes are laid on the top of the two intercepting ditches. The intersection of the two intercepting ditches is connected to a water collection sedimentation tank. Multiple dense filter meshes are arranged at equal intervals in the water collection sedimentation tank. The dense filter mesh near the outlet of the water collection sedimentation tank is provided with a trapezoidal cross-section water trough filled with gravel fragments. A steel mesh cover is welded on the top of the water collection sedimentation tank. The outlet of the water collection sedimentation tank is connected to a porous water filter pipe, and the porous water filter pipe is connected to a water pipe and a water pump respectively.

[0007] The gangue crushing unit comprises a gangue crusher, and the gangue crusher is connected to a gangue bin through a feeding pipeline.

[0008] The multiple dense filters are all square grids, and the mesh sizes of the multiple dense filters along the trapezoidal cross-section water tank side of the water collection sedimentation tank inlet are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm and 2mm*2mm respectively. Welded steel mesh cover on top of rectangular pool.

[0009] The rectangular pool is connected with a drainage pump through a water pipe, and the drainage pump is connected with a ground water storage tank through a drainage pipeline.

[0010] The inner diameter of the porous water filter pipe is 100~200mm, and a plurality of water filter holes are evenly opened on the wall of the porous water filter pipe, and the aperture φ of the plurality of water filter holes is 1~2mm.

[0011] The second technical solution adopted by the present invention is a method for filling a goaf, which uses a system for filling a goaf with coal gangue slurry, and is specifically implemented in the following steps: S1, before the mining of the working face to be mined, the intercepting ditch and the water collection sedimentation tank are arranged according to the contour line of the coal seam floor. During and after mining, the goaf water intercepted by the two working face tunnels is preliminarily filtered and then drained into the rectangular water pool through the porous water filter pipe; S2, drain the water in the rectangular pool into a ground water storage tank for static sedimentation, and then use a water purifier to further filter and purify it before injecting it into the coal gangue pulping pool through a water pipe; S3, transporting the gangue in the gangue bin to a gangue crusher, crushing it into fine particles and then transporting it to a gangue slurry pool, using a mixer to fully mix water and gangue particles to form gangue slurry; S4, injecting the coal gangue slurry into the coal seam goaf through the grouting pipe to complete the filling.

[0012] The second technical solution of the present invention is also characterized in that: S1 is specifically as follows: before mining the working face to be mined, according to the contour lines of the coal seam bottom, dig ditches along the working face tunnels on both sides of the low-lying terrain of the working face to be mined, and dig a water collection and sedimentation tank at the intersection of the two ditches. The water gushing from the goaf intercepted by the two working face tunnels is converged into the water collection and sedimentation tank, and is initially filtered using multiple dense filter screens and gravel fragments. The water in the water collection and sedimentation tank is then drained into the rectangular water pool through a porous filter pipe.

[0013] S4 is specifically as follows: the gangue slurry is injected into the coal seam goaf through a grouting pipe. The gangue slurry diffuses and fills the gaps in the broken rock blocks under the action of gravity. After the gangue slurry is stabilized, the gangue particles and water are separated, and part of the gangue slurry water is precipitated. The water gushing from the coal seam goaf and the gangue slurry water are collected and precipitated, then discharged to the ground for filtration and purification, and then recycled as a transportation medium for the gangue slurry to complete the filling.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The system and method for filling goaf with coal gangue slurry provided by the present invention collect and utilize the accumulated water in the goaf of the underground working face, avoid taking water from the surface, and are beneficial to the protection of surface ecological water resources.

[0015] (2) The system and method for filling goaf with coal gangue slurry provided by the present invention recycles the water used for making coal gangue slurry, thereby improving the efficiency of water resource utilization.

[0016] (3) The system and method for using coal gangue slurry to fill goaf provided by the present invention can effectively utilize the water in goaf underground, which is polluted by coal slime and has poor water quality, making it difficult to use for production and life in the mine.

[0017] (4) The system and method for filling goaf with coal gangue slurry provided by the present invention inject coal gangue into the goaf underground, which not only avoids occupying the surface space and causing environmental pollution, but also plays a role in supporting the roof of the goaf and slowing down the surface subsidence of the goaf to a certain extent.

[0018] (5) The system and method for filling goaf with coal gangue slurry provided by the present invention have simple connection and convenient movement. They can be moved and arranged along with the mining activities on the working face and have a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a system for filling a goaf with coal gangue slurry according to the present invention; Figure 2 It is a schematic plan view of a system for filling a goaf with coal gangue slurry according to the present invention; Figure 3 It is a schematic diagram of the connection between the drainage pipeline and the rectangular pool in the present invention; Figure 4 It is a partial schematic diagram of the bottom area of ​​the grouting pipe in the present invention; Figure 5 for Figure 4 The enlarged schematic diagram of point A in the middle; Figure 6 It is a schematic diagram of the structure inside the water collection sedimentation tank of the present invention; Figure 7 It is a schematic diagram of the connection between the water collection sedimentation tank and the water pump of the present invention.

[0020] Figure 8 It is a schematic diagram of the process of the goaf filling method of the present invention.

[0021] In the figure, 1. Mine body; 2. Working face tunnel; 3. Intercepting ditch; 4. Coal seam goaf; 5. Water collection sedimentation tank; 6. Working face to be mined; 7. Water pipe; 8. Rectangular water tank; 9. Gravel fragments; 10. High-strength steel filter; 11. Steel mesh cover; 12. Coal gangue silo; 13. Feed pipeline; 14. Coal gangue crusher; 15. Mixer; 16. Coal gangue slurry pool; 17. Injection Slurry pump; 18. Grouting pipe; 19. Grouting pipe stabilizing cover; 20. Water purifier; 21. Encrypted filter; 22. Ground water reservoir; 23. Drainage pipeline; 24. Coal seam; 25. Coal seam bottom rock layer; 26. Multi-porous water filter pipe; 27. Water pipe interface; 28. Water pump; 29. ​​Drainage pump; 30. Collapsed rock; 31. Coal gangue particles; 32. Mine system main tunnel; 33. Gravel fragments screen. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The present invention provides a system for filling a goaf with coal gangue slurry, such as Figure 1 and Figure 2 As shown, the mine body 1 includes a mine body, a working face 6 to be mined is arranged in the mine body 1, a coal seam goaf 4 is formed after the working face 6 is mined, the lower side of the coal seam goaf 4 is connected to a mine system tunnel 32, a rectangular pool 8 is opened in the mine system tunnel 32, a steel mesh cover 11 is welded on the top of the rectangular pool 8, and the rectangular pool 8 is connected to a ground water storage tank 22, wherein, as Figure 3As shown, the rectangular water tank 8 is connected to a drainage pump 29 through a water pipe 7, and the drainage pump 29 is connected to a ground water tank 22 through a drainage pipeline 23; the rectangular water tank 8 is also connected to a porous water filter pipe 26, wherein the inner diameter of the porous water filter pipe 26 is 100-200 mm, and a plurality of water filter holes are evenly opened on the wall of the porous water filter pipe 26, and the aperture φ of the plurality of water filter holes is 1-2 mm. The ground water tank 22 is sequentially connected to a water purifier 20 and a gangue slurry tank 16 through a water pipe 7, and the gangue slurry tank 16 is respectively connected to a gangue crushing unit and a grouting pump 17 through a feed pipeline 13, and the grouting pump 17 is connected to the coal seam goaf 4 through a grouting pipe 18, and a mixer 15 is arranged in the gangue slurry tank 16; the working face 6 to be mined is surrounded by four working face tunnels 2, as shown in FIG. Figure 5 As shown, the two working face tunnels 2 with lower terrain are provided with intercepting ditches 3. The bottom of the water inlet side of the intercepting ditches 3 is a gentle slope of 3-5 degrees. The tops of the two intercepting ditches 3 are paved with high-strength steel filter screens 10. The width of the high-strength steel filter screens 10 paved on the tops of the intercepting ditches 3 is not less than the width of the intercepting ditches 3, and the mesh size of the high-strength steel filter screens 10 is not larger than 50mm. The intersection of the two intercepting ditches 3 is connected to a water collection sedimentation tank 5, as shown in FIG. Figure 6 As shown, a plurality of dense filter screens 21 are arranged at equal intervals in the water collection sedimentation tank 5, and the dense filter screens 21 are all square grids. The mesh sizes of the plurality of dense filter screens 21 along the side of the trapezoidal cross-section water tank of the inlet of the water collection sedimentation tank 5 are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm and 2mm*2mm respectively. The interval of each layer of the dense filter screen 21 is 200~300mm. The dense filter screen 21 near the outlet of the water collection sedimentation tank 5 is provided with a trapezoidal cross-section water tank, and the trapezoidal cross-section water tank is filled with gravel fragments 9, and the particle size of the gravel fragments 9 is between 10~50mm. A steel mesh cover plate 11 is welded on the top of the water collection sedimentation tank 5, as shown in FIG. Figure 7 As shown, the outlet of the water collection sedimentation tank 5 is connected to the porous water filter pipe 26, and the porous water filter pipe 26 is respectively connected to the water pipe 7 and the water pump 28; Figure 1 As shown, the gangue crushing unit includes a gangue crusher 14, and the gangue crusher 14 is connected to a gangue bin 12 through a feed pipe 13. Figure 4 As shown, the mine body 1 also includes a coal seam 24 and a coal seam floor rock layer 25 .

[0024] The present invention also provides a method for filling a goaf, using the above-mentioned system for filling a goaf with coal gangue slurry, which is specifically implemented in the following steps: S1, before the mining of the working face 6 to be mined, the intercepting ditch 3 and the water collection sedimentation tank 5 are arranged according to the contour line of the coal seam floor. During and after mining, the goaf water intercepted by the two working face tunnels 2 is preliminarily filtered and then drained into the rectangular water pool 8 through the porous water filter pipe 26; S1 is specifically as follows: before the working face 6 to be mined is mined, intercepting ditches 3 are built along the sides of the working face tunnels 2 on both sides of the low-lying working face according to the contour lines of the coal seam bottom plate, and high-strength steel filter screens 10 are laid on the intercepting ditches 3. At the intersection of the two intercepting ditches 3, a water collection and sedimentation tank 5 is dug, and the water gushing from the goaf intercepted by the two working face tunnels 2 is converged into the water collection and sedimentation tank 5, and is initially filtered using multiple dense filter screens 21 and gravel fragments 9, and then the water in the water collection and sedimentation tank 5 is drained into the rectangular water tank 8 through a porous water filter pipe 26.

[0025] S2, drain the water in the rectangular pool 8 into the ground water reservoir 22 for static sedimentation, and then further filter and purify it with the water purifier 20 before injecting it into the coal gangue pulping pool 16 through the water pipe; S3, the gangue in the gangue bin 12 is transported to the gangue crusher 14, crushed into fine particles, and then transported to the gangue slurry pool 16, and the water and the gangue particles are fully mixed by the mixer 15 to form a gangue slurry; S4, injecting the coal gangue slurry into the coal seam goaf 4 through the grouting pipe 18 to complete the filling.

[0026] S4 is specifically as follows: the gangue slurry is injected into the coal seam goaf 4 through the grouting pipe 18. The gangue slurry diffuses and fills the gaps in the broken rock blocks under the action of gravity. After the gangue slurry is stabilized, the gangue particles and water are separated, and part of the gangue slurry precipitates water slowly. The goaf water and the gangue slurry precipitate water are collected and precipitated, and then discharged to the ground for filtration and purification, and then recycled as a transportation medium for gangue slurry for filling.

[0027] Example 1 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7 As shown, the mine body 1 includes a coal seam 24 and a coal seam floor rock layer 25. Within the boundary of the mine body 1, the working face 6 to be mined is arranged according to the coal seam floor contour line and the change of the coal seam floor contour line elevation data, so that the mining direction of the working face 6 to be mined is as parallel as possible to the decreasing direction of the coal seam floor contour line elevation data. The mining direction of the working face is gradually advanced toward the side of the mine system main tunnel 32, so that the water flow in the coal seam goaf 4 formed after the mining of the working face 6 to be mined can naturally flow to the side of the mine system main tunnel 32 under the action of gravity.

[0028] Among them, the working face 6 to be mined is surrounded by four working face tunnels 2. According to the undulation of the coal seam floor contour, intercepting ditches 3 are built in the two lower tunnels of the working face 6 to be mined, and covered with high-strength steel filter 10 to prevent the collapsed rock blocks 30 formed by the overlying rock layer falling after the coal seam is mined from entering the intercepting ditch 3, but the water flow in the coal seam goaf 4 can seep into the intercepting ditch 3. The intercepting ditch 3 is built with a width of 150~200mm and a depth of 100~150mm. The width of the high-strength steel filter 10 is not less than the width of the intercepting ditch, and the steel mesh is not larger than 50mm. At the intersection of the two intercepting ditches 3, a water collection sedimentation tank 5 is built. The size of the water collection sedimentation tank 5 is built according to length * width * depth = 3m * 2m * 1.5m. The bottom of the tank on the water inlet side of the intercepting ditch 3 is a gentle slope of 3~5°, so that the water flow can flow by gravity, and at the same time, the impurities such as coal slime carried by the water in the coal seam goaf 4 can be precipitated. The outlet of the water collection sedimentation tank 5 is connected to the porous water filter pipe 26. The dense filter screen 21 is installed in the middle of the water collection sedimentation tank 5. There are 6 layers of filter screens installed. The filter screen is a grid screen. The filter screen apertures are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm, and 2mm*2mm, respectively. The plane interval of each layer of filter screen is 200~300mm, and the aperture gradually decreases from the outlet side of the intercepting ditch 3 to the porous water filter pipe 26. Next to the last layer of filter screen, a trapezoidal cross-section water trough is built. The long side of the trapezoidal cross-section water trough is about 1m deep and the short side is about 0.4m deep. A gravel fragment screen 33 is fixedly connected to one side of the porous filter pipe 26, and then gravel fragments 9 are filled in the trapezoidal cross-section water trough. The particle size of the gravel fragments is between 10 and 50mm. A steel mesh cover 11 is welded on the water collection sedimentation tank 5. The water collection sedimentation tank 5 needs to be dredged regularly, and the dense filter screen 21 also needs to be cleaned regularly to prevent the filter screen from being blocked. A rectangular water pool 8 is built in the main tunnel 32 of the mine system with lower terrain near the coal seam goaf 4. The size of the rectangular water pool can be built according to length * width * depth = 5m * 2m * 1.5m, and a steel mesh cover 11 is welded on the top of the rectangular water pool 8. The porous filter pipe 26 is respectively connected to the water pipe 7 and the water pump 28.

[0029] Among them, the rectangular water pool 8 is connected to a drainage pump 29 through a water pipe 7, and the drainage pump 29 is connected to the ground water reservoir 22 through a drainage pipeline 23. The drainage pump 29 is used to discharge the water in the rectangular water pool 8 through the drainage pipeline 23 to the ground water reservoir 22 for static sedimentation; the rectangular water pool 8 is also connected to a porous water filter pipe 26, wherein the inner diameter of the porous water filter pipe 26 is 100~200mm, and a plurality of water filter holes are evenly opened on the wall of the porous water filter pipe 26, and the aperture φ of the plurality of water filter holes is 1~2mm. The ground water reservoir 22 is connected to a water purifier 20 and a coal gangue pulping pool 16 in sequence through a water pipe 7, and the water in the ground water reservoir 22 is injected into the water purifier 20 through the water pipe 7, and the harmful impurities in the water are further purified to prevent the harmful impurities from being injected into the goaf with the water, thereby escaping underground and polluting the underground working space. The purified water is injected into the coal gangue pulping pool 16 through the water pipe 7 by the water purifier 20. The gangue slurry making pool 16 is connected to the gangue crushing unit and the grouting pump 17 through the feeding pipeline 13, and the grouting pump 17 is connected to the coal seam goaf 4 through the grouting pipe 18. The gangue slurry making pool 16 is provided with a mixer 15. The gangue crushing unit includes a gangue crusher 14. The gangue crusher 14 is connected to the gangue bin 12 through the feeding pipeline 13. The gangue in the gangue bin 12 is passed through the mixing station 15. The coal gangue is transported to the gangue crusher 14 through the feed pipe 13, and the gangue is crushed into gangue particles with a particle size of no more than 5 mm by the gangue crusher 14, and then transported to the gangue slurry pool 16 through the feed pipe 13, and an inorganic colloidal lubricant is added to the gangue slurry pool 16, and then the gangue particles, water and the inorganic colloidal lubricant are fully stirred by the mixer 15 to make a gangue slurry. The inner diameter of the porous water filter pipe 26 is 100-200 mm, and a plurality of water filter holes are evenly opened on the wall of the porous water filter pipe 26, and the aperture φ of the plurality of water filter holes is 1-2 mm. The water pipe interface 27 is respectively installed at the port of the porous water filter pipe 26 and the water pipe 7.

[0030] Example 2 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7 As shown, the mine body 1 includes a mine body, in which a working face 6 to be mined, a coal seam 24 and a coal seam bottom rock layer 25 are arranged. After the working face 6 to be mined is mined, a coal seam goaf 4 is formed. The lower side of the coal seam goaf 4 is connected to a mine system tunnel 32. A rectangular water pool 8 is opened in the mine system tunnel 32. The rectangular water pool 8 is connected to a ground water reservoir 22. The rectangular water pool 8 is also connected to a porous water filter pipe 26. The ground water reservoir 22 is connected to a water purifier 20 and a coal gangue slurry pool 16 in sequence through a water pipe 7. The coal gangue slurry pool 16 is connected to a coal gangue crushing unit and a grouting pump 17 through a feed pipeline 13. The grouting pump 17 is connected to the coal seam goaf 4 through a grouting pipe 18. A mixer 15 is arranged in the coal gangue slurry pool 16.

[0031] Example 3 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7 As shown, the mine body 1 includes a mine body, in which a working face 6 to be mined, a coal seam 24 and a coal seam bottom rock layer 25 are arranged. After the working face 6 to be mined is mined, a coal seam goaf 4 is formed. The lower side of the coal seam goaf 4 is connected with a mine system tunnel 32. A rectangular water pool 8 is opened in the mine system tunnel 32. The rectangular water pool 8 is connected with a ground water reservoir 22. The rectangular water pool 8 is also connected with a porous water filter pipe 26. The ground water reservoir 22 is connected with a water purifier 20 and a coal gangue slurry pool 16 in sequence through a water pipe 7. The coal gangue slurry pool 16 is connected with a coal gangue crushing unit and a grouting pump 17 through a feed pipe 13. The grouting pump 17 is connected with the coal seam goaf 4 through a grouting pipe 18. A mixer 15 is provided in the gangue slurry pool 16, and the working face 6 to be mined is surrounded by four working face tunnels 2. Intercepting ditches 3 are opened on the sides of the two working face tunnels 2 with lower terrain. High-strength steel filter screens 10 are laid on the tops of the two intercepting ditches 3. A water collection sedimentation tank 5 is connected at the intersection of the two intercepting ditches 3. A plurality of dense filter screens 21 are arranged at equal intervals in the water collection sedimentation tank 5. A trapezoidal cross-section water trough is opened on the dense filter screen 21 near the outlet of the water collection sedimentation tank 5. The trapezoidal cross-section water trough is filled with gravel fragments 9. A steel mesh cover plate 11 is welded on the top of the water collection sedimentation tank 5. The outlet of the water collection sedimentation tank 5 is connected to a porous water filter pipe 26, and the porous water filter pipe 26 is respectively connected to a water pipe 7 and a water pump 28.

[0032] Example 4 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7As shown, the mine body 1 includes a mine body, in which a working face 6 to be mined, a coal seam 24 and a coal seam bottom rock layer 25 are arranged. After the working face 6 to be mined is mined, a coal seam goaf 4 is formed. The lower side of the coal seam goaf 4 is connected to a mine system tunnel 32. A rectangular water pool 8 is opened in the mine system tunnel 32. The rectangular water pool 8 is connected to a ground water reservoir 22. The rectangular water pool 8 is also connected to a porous water filter pipe 26. The ground water reservoir 22 is connected to a water purifier 20 and a coal gangue slurry pool 16 in sequence through a water pipe 7. The coal gangue slurry pool 16 is connected to a coal gangue crushing unit and a grouting pump 17 through a feed pipe 13. The grouting pump 17 is connected to the coal seam goaf 4 through a grouting pipe 18. A mixer 15 is arranged in the coal gangue slurry pool 16. The surface 6 is surrounded by four working face tunnels 2. The two working face tunnels 2 with lower terrain are provided with intercepting ditches 3 on their sides. High-strength steel filter screens 10 are laid on the tops of the two intercepting ditches 3. A water collection sedimentation tank 5 is connected at the intersection of the two intercepting ditches 3. A plurality of dense filter screens 21 are arranged at equal intervals in the water collection sedimentation tank 5. A trapezoidal cross-section water trough is provided on the dense filter screen 21 near the outlet of the water collection sedimentation tank 5. The trapezoidal cross-section water trough is filled with gravel fragments 9. A steel mesh cover plate 11 is welded on the top of the water collection sedimentation tank 5. The outlet of the water collection sedimentation tank 5 is connected to a porous water filter pipe 26. The porous water filter pipe 26 is respectively connected to a water pipe 7 and a water pump 28. The coal gangue crushing unit includes a coal gangue crusher 14. The coal gangue crusher 14 is connected to a coal gangue bin 12 through a feed pipeline 13.

[0033] Example 5 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7As shown, the mine body 1 includes a mine body, a working face 6 to be mined, a coal seam 24 and a coal seam floor rock layer 25 are arranged in the mine body 1, a coal seam goaf 4 is formed after the working face 6 to be mined, and a mine system tunnel 32 is connected to the lower side of the coal seam goaf 4, a rectangular pool 8 is opened in the mine system tunnel 32, the rectangular pool 8 is connected to the ground water storage tank 22, the rectangular pool 8 is also connected to the porous water filter pipe 26, and the ground water storage tank 22 is connected in sequence through the water pipe 7 A water purifier 20 is connected to a gangue slurry pool 16. The gangue slurry pool 16 is connected to a gangue crushing unit and a grouting pump 17 through a feed pipe 13. The grouting pump 17 is connected to the coal seam goaf 4 through a grouting pipe 18. A mixer 15 is arranged in the gangue slurry pool 16. The working face 6 to be mined is surrounded by four working face tunnels 2. A water intercepting ditch 3 is opened on the side of the two working face tunnels 2 with lower terrain. The tops of the two water intercepting ditches 3 are both paved with high-strength steel filter screens. 10. The intersection of the two intercepting ditches 3 is connected to a water collection sedimentation tank 5. A plurality of dense filter screens 21 are arranged at equal intervals in the water collection sedimentation tank 5. The dense filter screen 21 near the outlet of the water collection sedimentation tank 5 is provided with a trapezoidal cross-section water tank filled with gravel fragments 9. A steel mesh cover plate 11 is welded on the top of the water collection sedimentation tank 5. The outlet of the water collection sedimentation tank 5 is connected to a porous water filter pipe 26. The porous water filter pipe 26 is respectively connected to a water pipe 7 and a water pump 28. The dense filter screen 21 are all square grids, the gangue crushing unit includes a gangue crusher 14, the gangue crusher 14 is connected to the gangue bin 12 through a feed pipe 13, and the multiple dense filter screens 21 are all square grids. The mesh sizes of the multiple dense filter screens 21 along the side of the trapezoidal cross-section water tank of the inlet of the water collection sedimentation tank 5 are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm and 2mm*2mm respectively.

[0034] Example 6 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7As shown, the mine body 1 includes a working face 6 to be mined, a coal seam 24 and a coal seam floor rock layer 25. After the working face 6 to be mined is mined, a coal seam goaf 4 is formed. The lower side of the coal seam goaf 4 is connected to a mine system tunnel 32. A rectangular water pool 8 is opened in the mine system tunnel 32. The rectangular water pool 8 is connected to a ground water reservoir 22. The rectangular water pool 8 is also connected to a porous water filter pipe 26. The ground water reservoir 22 is connected to a water purifier in sequence through a water pipe 7. 20 and the gangue slurry pool 16, the gangue slurry pool 16 is connected to the gangue crushing unit and the grouting pump 17 through the feeding pipeline 13, the grouting pump 17 is connected to the coal seam goaf 4 through the grouting pipe 18, and the gangue slurry pool 16 is provided with a mixer 15. The working face 6 to be mined is surrounded by four working face tunnels 2. The two working face tunnels 2 with lower terrain are provided with intercepting ditches 3 on the sides. The tops of the two intercepting ditches 3 are both paved with high-strength steel filter screens 10. The two intercepting ditches 3 The intersection is connected to a water collection sedimentation tank 5, in which a plurality of dense filter screens 21 are arranged at equal intervals. The dense filter screen 21 near the outlet of the water collection sedimentation tank 5 is provided with a trapezoidal cross-section water tank, which is filled with gravel fragments 9. A steel mesh cover plate 11 is welded on the top of the water collection sedimentation tank 5. The outlet of the water collection sedimentation tank 5 is connected to a porous water filter pipe 26, which is respectively connected to a water pipe 7 and a water pump 28. The dense filter screens 21 are all square grids, and the coal gangue is crushed. The unit includes a gangue crusher 14, which is connected to a gangue bin 12 through a feed pipe 13. Multiple dense filter screens 21 are all square grids. The mesh sizes of the multiple dense filter screens 21 along the side of the trapezoidal cross-section water trough of the inlet of the water collection sedimentation tank 5 are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm and 2mm*2mm respectively. A steel mesh cover 11 is welded on the top of the rectangular water tank 8.

[0035] Example 7 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7As shown, the mine body 1 includes a working face 6 to be mined, a coal seam 24 and a coal seam floor rock layer 25. After the working face 6 to be mined is mined, a coal seam goaf 4 is formed. The lower side of the coal seam goaf 4 is connected to a mine system tunnel 32. A rectangular water pool 8 is opened in the mine system tunnel 32. The rectangular water pool 8 is connected to a ground water reservoir 22. The rectangular water pool 8 is also connected to a porous water filter pipe 26. The ground water reservoir 22 is sequentially connected to a water purifier 20 and a coal gangue pulping pool 1 through a water pipe 7. 6, the gangue slurry pool 16 is connected to the gangue crushing unit and the grouting pump 17 through the feeding pipeline 13, and the grouting pump 17 is connected to the coal seam goaf 4 through the grouting pipe 18. A mixer 15 is arranged in the gangue slurry pool 16. The working face 6 to be mined is surrounded by four working face tunnels 2. The two working face tunnels 2 with lower terrain are provided with intercepting ditches 3 on the sides. The tops of the two intercepting ditches 3 are both paved with high-strength steel filter screens 10. The intersection of the two intercepting ditches 3 is connected to a water collection sedimentation tank 5. The water collection sedimentation tank 5 has a plurality of internal and external filtration devices. A plurality of dense filter screens 21 are arranged at intervals, and a trapezoidal cross-section water tank is provided on the dense filter screen 21 near the outlet of the water collection sedimentation tank 5, and the trapezoidal cross-section water tank is filled with gravel fragments 9. A steel mesh cover plate 11 is welded on the top of the water collection sedimentation tank 5, and the outlet of the water collection sedimentation tank 5 is connected to a porous water filter pipe 26, and the porous water filter pipe 26 is respectively connected to a water pipe 7 and a water pump 28. The dense filter screens 21 are all square grids. The coal gangue crushing unit includes a coal gangue crusher 14, and the coal gangue crusher 14 is connected to a coal gangue crusher 14 through a feed pipe 13. The coal gangue silo 12 and the multiple dense filter screens 21 are all square grids. The mesh sizes of the multiple dense filter screens 21 along the lateral trapezoidal cross-section water trough side of the water collection sedimentation tank 5 inlet are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm and 2mm*2mm respectively. A steel mesh cover plate 11 is welded on the top of the rectangular water pool 8. The rectangular water pool 8 is connected to a drainage pump 29 through a water pipe 7, and the drainage pump 29 is connected to the ground water storage tank 22 through a drainage pipeline 23.

[0036] Example 8 This embodiment provides a system for filling a goaf with coal gangue slurry, such as Figure 1-7As shown, the mine body 1 includes a mine body, a working face 6 to be mined, a coal seam 24 and a coal seam bottom rock layer 25 are arranged in the mine body 1, a coal seam goaf 4 is formed after the working face 6 to be mined, the lower side of the coal seam goaf 4 is connected to a mine system tunnel 32, a rectangular water pool 8 is opened in the mine system tunnel 32, the rectangular water pool 8 is connected to a ground water reservoir 22, the rectangular water pool 8 is also connected to a porous water filter pipe 26, the ground water reservoir 22 is connected to a water purifier 20 and a coal gangue pulping pool 16 in sequence through a water pipe 7, and the coal gangue pulping pool 16 is connected to a conveying material. The pipeline 13 is respectively connected to the gangue crushing unit and the grouting pump 17, and the grouting pump 17 is connected to the coal seam goaf 4 through the grouting pipe 18. A mixer 15 is arranged in the gangue slurry pool 16. The working face 6 to be mined is surrounded by four working face tunnels 2. The two working face tunnels 2 with lower terrain are provided with intercepting ditches 3 on the sides. The tops of the two intercepting ditches 3 are both paved with high-strength steel filter screens 10. The intersection of the two intercepting ditches 3 is connected to a water collection sedimentation tank 5. A plurality of dense filter screens 21 are arranged at equal intervals in the water collection sedimentation tank 5. The dense filter screens 21 near the outlet of the water collection sedimentation tank 5 are arranged at equal intervals. The net 21 is provided with a trapezoidal cross-section water tank filled with gravel fragments 9, a steel mesh cover 11 is welded on the top of the water collection sedimentation tank 5, the outlet of the water collection sedimentation tank 5 is connected to a porous water filter pipe 26, and the porous water filter pipe 26 is respectively connected to a water pipe 7 and a water pump 28, and the dense filter screens 21 are all square grids. The gangue crushing unit includes a gangue crusher 14, and the gangue crusher 14 is connected to a gangue bin 12 through a feed pipe 13. The multiple dense filter screens 21 are all square grids, and the multiple dense filter screens 21 are arranged along the side of the water collection sedimentation tank 5 in a trapezoidal shape. The mesh sizes of the cross-sectional water tank side are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm and 2mm*2mm respectively. A steel mesh cover 11 is welded on the top of the rectangular water pool 8. The rectangular water pool 8 is connected to a drainage pump 29 through a water pipe 7. The drainage pump 29 is connected to the ground water tank 22 through a drainage pipe 23. The inner diameter of the porous water filter pipe 26 is 100~200mm, and a plurality of water filter holes are evenly opened on the wall of the porous water filter pipe 26. The aperture φ of the plurality of water filter holes is 1~2mm.

[0037] Example 9 This embodiment provides a method for filling a goaf, using the system for filling a goaf with coal gangue slurry provided in the above embodiment, such as Figure 8 As shown, the specific implementation steps are as follows: S1, before the mining of the working face 6 to be mined, the intercepting ditch 3 and the water collection sedimentation tank 5 are arranged according to the contour line of the coal seam floor. During and after mining, the goaf water intercepted by the two working face tunnels 2 is preliminarily filtered and then drained into the rectangular water pool 8 through the porous water filter pipe 26; S2, drain the water in the rectangular pool 8 into the ground water reservoir 22 for static sedimentation, and then further filter and purify it with the water purifier 20 before injecting it into the coal gangue pulping pool 16 through the water pipe; S3, the gangue in the gangue bin 12 is transported to the gangue crusher 14, crushed into fine particles, and then transported to the gangue slurry pool 16, and the water and the gangue particles are fully mixed by the mixer 15 to form a gangue slurry; S4, injecting the coal gangue slurry into the coal seam goaf 4 through the grouting pipe 18 to complete the filling.

[0038] Example 10 On the basis of Example 9, S1 is specifically as follows: before the working face 6 to be mined is mined, according to the contour line of the coal seam bottom plate, intercepting ditches 3 are built along the sides of the working face tunnels 2 on both sides of the low-lying working face, and high-strength steel filter meshes 10 are laid on the intercepting ditches 3. At the intersection of the two intercepting ditches 3, a water collection and sedimentation tank 5 is dug, and the water gushing from the goaf intercepted by the two working face tunnels 2 is converged into the water collection and sedimentation tank 5, and is initially filtered using multiple dense filter meshes 21 and gravel fragments 9, and then the water in the water collection and sedimentation tank 5 is drained into the rectangular water tank 8 through a porous water filter pipe 26.

[0039] S4 is specifically as follows: the gangue slurry is injected into the coal seam goaf 4 through the grouting pipe 18, and the gangue slurry diffuses and fills the gaps in the broken rock blocks under the action of gravity. After the gangue slurry is stabilized, the gangue particles and water are separated, and part of the gangue slurry precipitates water, which returns to S1, and the water gushing from the coal seam goaf 4 and the gangue slurry precipitates water are collected in the water collection sedimentation tank 5 for sedimentation, and then discharged to the ground for filtration and purification, and then recycled as a transportation medium for the gangue slurry to complete the filling.

Claims

1. A system for filling goaf with coal gangue slurry, characterized in that: The invention comprises a mine body (1), wherein a working face (6) to be mined is arranged in the mine body (1), and a coal seam goaf (4) is formed after the working face (6) to be mined is mined, and the lower side of the coal seam goaf (4) is connected to a mine system tunnel (32), and a rectangular water pool (8) is opened in the mine system tunnel (32), and the rectangular water pool (8) is connected to a ground water reservoir (22), and the rectangular water pool (8) is also connected to a porous water filter pipe (26), and the ground water reservoir (22) is connected to a water purifier (20) and a coal gangue slurry pool (16) in sequence through a water pipe (7), and the coal gangue slurry pool (16) is connected to a coal gangue crushing unit and a grouting pump (17) through a feed pipe (13), and the grouting pump (17) is connected to the coal seam goaf (4) through a grouting pipe (18), and a mixer (15) is arranged in the coal gangue slurry pool (16).

2. The system for filling goaf with coal gangue slurry according to claim 1, characterized in that: The working face (6) to be mined is surrounded by four working face tunnels (2). A drainage ditch (3) is opened on the side of the two working face tunnels (2) with lower terrain. The tops of the two drainage ditches (3) are both paved with high-strength steel filter screens (10). The intersection of the two drainage ditches (3) is connected to a water collection sedimentation tank (5). A plurality of dense filter screens (21) are arranged at equal intervals in the water collection sedimentation tank (5). A trapezoidal cross-section water trough is opened near the dense filter screen (21) at the outlet of the water collection sedimentation tank (5). The trapezoidal cross-section water trough is filled with gravel fragments (9). A steel mesh cover plate (11) is welded on the top of the water collection sedimentation tank (5). The outlet of the water collection sedimentation tank (5) is connected to a porous water filter pipe (26). The porous water filter pipe (26) is respectively connected to a water pipe (7) and a water pump (28).

3. The system for filling goaf with coal gangue slurry according to claim 2, characterized in that: The gangue crushing unit comprises a gangue crusher (14), and the gangue crusher (14) is connected to a gangue bin (12) via a material conveying pipeline (13).

4. The system for filling goaf with coal gangue slurry according to claim 3, characterized in that: The plurality of dense filters (21) are all square grids, and the mesh sizes of the plurality of dense filters (21) along the side of the trapezoidal cross-section water tank of the inlet of the water collection sedimentation tank (5) are 15mm*15mm, 10mm*10mm, 8mm*8mm, 6mm*6mm, 4mm*4mm and 2mm*2mm respectively.

5. The system for filling goaf with coal gangue slurry according to claim 3, characterized in that: A steel mesh cover plate (11) is welded on the top of the rectangular water pool (8).

6. The system for filling goaf with coal gangue slurry according to claim 3, characterized in that: The rectangular water pool (8) is connected to a drainage pump (29) via a water pipe (7), and the drainage pump (29) is connected to a ground water storage tank (22) via a drainage pipeline (23).

7. The system for filling goaf with coal gangue slurry according to claim 3, characterized in that: The inner diameter of the porous water filter pipe (26) is 100-200 mm, and a plurality of water filter holes are evenly arranged on the wall of the porous water filter pipe (26), and the diameter φ of the plurality of water filter holes is 1-2 mm.

8. A method for filling a goaf, characterized in that: The system for filling goaf with coal gangue slurry as claimed in any one of claims 1 to 7 is implemented in the following steps: S1, before the mining face (6) is mined, a water interception ditch (3) and a water collection sedimentation tank (5) are arranged according to the contour line of the coal seam floor, and during and after mining, the water gushing from the goaf intercepted by the two working face tunnels (2) is initially filtered, and after filtering, the water is drained into the rectangular water pool (8) through a porous water filter pipe (26); S2, draining the water in the rectangular water pool (8) into a ground water storage tank (22) for static sedimentation, further filtering and purifying the water with a water purifier (20), and then injecting the water into the coal gangue slurry pool (16) through a water pipe; S3, conveying the gangue in the gangue bin (12) to a gangue crusher (14), crushing it into fine particles, and conveying it to a gangue slurry pool (16), using a mixer (15) to fully mix water and the gangue particles to form a gangue slurry; S4, injecting the coal gangue slurry into the coal seam goaf (4) through the grouting pipe (18) to complete the filling.

9. The method for filling a goaf according to claim 8, characterized in that: Specifically, S1 comprises: before the working face (6) to be mined is mined, according to the contour line of the coal seam floor, a diversion ditch (3) is built along the working face tunnels (2) on both sides of the working face (6) in low-lying terrain, and at the intersection of the two diversion ditches (3), a water collection sedimentation tank (5) is excavated, and the water gushing from the goaf intercepted by the two working face tunnels (2) is converged into the water collection sedimentation tank (5), and is initially filtered using a plurality of dense filter screens (21) and gravel fragments (9), and then the water in the water collection sedimentation tank (5) is drained into the rectangular water tank (8) through a porous water filter pipe (26).

10. The method for filling a goaf according to claim 8, characterized in that: The S4 is specifically as follows: the gangue slurry is injected into the coal seam goaf (4) through the grouting pipe (18); the gangue slurry is diffused and filled into the gaps of the broken rock blocks under the action of gravity; after the gangue slurry is stabilized, the gangue particles and water are separated, and part of the gangue slurry precipitates water; the gushing water in the coal seam goaf (4) and the gangue slurry precipitate water are collected and precipitated, and then discharged to the ground for filtration and purification, and then recycled as a transportation medium for the gangue slurry to complete the filling.

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