Coal and water resource coordinated mining system and construction method

Abstract

The present application provides a system and construction method for coordinated mining of coal and water resources, the system comprising: a boundary curtain subsystem, a clean water storage subsystem, a sewage storage subsystem, and a water resource recycling subsystem, wherein the boundary curtain subsystem is arranged in the curtain construction area to block the underground replenishment water outside the mine from flowing into the mine; the clean water storage subsystem and the sewage storage subsystem are both arranged in the goaf, the clean water storage subsystem is connected to the area to be mined to collect and store clean mine water in the area to be mined, and the sewage storage subsystem is connected to the mining area to collect and store mine sewage in the mining area; the clean water storage subsystem and the sewage storage subsystem are both connected to a paste filling material preparation device through a filtering subsystem; the present application can effectively reduce the disturbance of the groundwater system, block the replenishment of dynamic reserves, and realize the underground emission reduction, treatment and utilization of mine water to the greatest extent.

Description

Technical Field

[0001] The present application relates to the technical field of mine resource mining, and in particular to a system and construction method for coordinated mining of coal and water resources. Background Art

[0002] For shallow coal seams in the Shaanxi and Shendong mining areas, the sources of mine water inflow are unconsolidated roof aquifers and bedrock fissure aquifers, while water inflow channels primarily originate from drainage boreholes, water-conducting fracture zones, and primary stratum fissures. Therefore, considering aquifer water quality, water-filling channels, and recharge pathways, it is crucial to reduce disturbances in the groundwater system, block the recharge of dynamic reserves, and maximize the reduction, treatment, and utilization of mine water underground. Summary of the Invention

[0003] In view of this, the purpose of this application is to propose a coal and water resource coordinated mining system and construction method.

[0004] Based on the above objectives, the present application provides a system for coordinated mining of coal and water resources, which is arranged in a mine, and includes:

[0005] Boundary curtain subsystem, clean water storage subsystem, sewage storage subsystem, water resource reuse subsystem;

[0006] The mine is provided with a curtain construction area, a mining area and a goaf area, wherein the curtain construction area is provided on a side close to the periphery of the mine, an area to be mined is formed between the curtain construction area and the mining area, and the goaf area is located on a side away from the curtain construction area;

[0007] The boundary curtain subsystem is arranged in the curtain construction area to block the underground supply water outside the mine from flowing into the mine, so that a closed water-proof space is formed inside the mine;

[0008] The clean water storage subsystem and the sewage storage subsystem are both arranged in the goaf, the clean water storage subsystem is communicated with the area to be mined to collect and store clean mine water in the area to be mined, and the sewage storage subsystem is communicated with the mined area to collect and store mine sewage in the mined area;

[0009] The water resource recycling subsystem includes a paste filling material preparation device, and the clean water storage subsystem and the sewage storage subsystem are both connected to the paste filling material preparation device through a filtering subsystem.

[0010] Based on the same inventive concept, the present application also provides a boundary curtain subsystem construction method, which is applied to the above-mentioned coal and water resource coordinated mining system. The construction method includes:

[0011] Delineating the location of water-rich layers and groundwater recharge areas outside the mine, determining a curtain construction area, and setting construction parameters of the curtain tunnel and the curtain wall according to the determined curtain construction area;

[0012] excavating a curtain tunnel according to the construction parameters, the curtain tunnel being connected to a tunnel provided in the mining area, drilling and constructing a plurality of grouting holes on a side wall of the curtain tunnel on a side close to the periphery of the mine, and performing curtain grouting on the grouting holes to form a curtain wall provided within the periphery of the mine, thereby blocking the grouting holes;

[0013] After the construction of the curtain tunnel and the curtain wall is completed, a water discharge test is carried out to check whether the grouting effect meets the preset standards.

[0014] From the above, it can be seen that the present application provides a coordinated mining system and construction method for coal and water resources, which realizes horizontal reduction and replenishment by setting up a boundary curtain subsystem on the periphery of the mine to reduce the groundwater recharge outside the mine; discharges the static reserve groundwater within the boundary curtain subsystem and stores it in the clean water storage subsystem and sewage storage subsystem in the goaf to realize void area storage; filters the excess mine water stored in the goaf through the filtration subsystem for underground tunnel flushing and preparation of paste filling materials to realize on-site utilization; the present application can effectively reduce the disturbance of the groundwater system, block the recharge of dynamic reserves and realize the underground emission reduction, treatment and utilization of mine water to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in this application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are merely embodiments of this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 This is a schematic diagram of a system for coordinated mining of coal and water resources according to an embodiment of the present application;

[0017] Figure 2 This is a schematic diagram of a filtering subsystem according to an embodiment of the present application;

[0018] Figure 3 This is a three-dimensional schematic diagram of the orientation and inclination of the grouting holes in the embodiment of the present application;

[0019] Figure 4 This is a cross-sectional view of the grouting hole drilled perpendicular to the direction of the tunnel in an embodiment of the present application;

[0020] Figure 5 This is a schematic plan view of a grouting hole according to an embodiment of the present application;

[0021] Figure 6 This is a cross-sectional view of the grouting hole in the embodiment of the present application parallel to the direction of the roadway;

[0022] Figure 7 A schematic diagram of a system for coordinated mining of coal and water resources according to an embodiment of the present application;

[0023] Figure 8 Schematic diagram of the process of constructing the boundary curtain subsystem according to an embodiment of the present application.

[0024] In the figure: 1. Curtain construction area; 2. Mining area; 3. Goaf area; 4. Area to be mined; 5. Boundary curtain subsystem; 51. Curtain tunnel; 52. Grouting hole; 6. Clean water storage subsystem; 7. Sewage storage subsystem; 8. Filtration subsystem; 81. Filter wall one; 82. Filter wall two; 83. Filter wall three; 84. Filter filler one; 85. Filter filler two; 86. Water outlet; 87. Overflow; 9. Paste filling material preparation device; 10. Drilling casing; 11. Clean water pipeline; 12. Clean water branch pipe; 13. Sewage pipeline; 14. Drainage pipeline. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions and advantages of this application more clear, this application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0026] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the usual meanings understood by people with ordinary skills in the field to which this application belongs. The "first", "second" and similar words used in the embodiments of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0027] During mining operations, the mine water underground needs to be discharged. However, the traditional mine water discharge system and drainage system are too crude. The mine water gushing from different channels underground is concentrated in a central water tank, and then discharged to the ground for treatment and utilization. This causes clean mine water to mix with suspended matter mine water, highly mineralized mine water, and acidic mine water. This not only causes pollution of the clean water source in the aquifer, but also increases difficulties in the raw water treatment process and return water utilization.

[0028] In addition, part of the source of discharged mine water is the static reserves within the mining area, and more of it comes from the dynamic reserves that are continuously replenished from the periphery. If a retaining wall can be built on the supply channel to change the groundwater seepage field and make the groundwater move along the periphery of the mining area, the mine water discharged will only be the static reserves within the mining area, which can greatly reduce the damage to groundwater and achieve in-situ protection of water resources.

[0029] Through curtain grouting technology, a retaining wall is built on the aquifer runoff channel, the hydrogeological conditions are artificially modified, and the water supply within the mining range is cut off, thereby reducing the dynamic reserve of the aquifer. However, the existing curtain grouting interception technology generally relies on ground construction, which leads to poor curtain grouting and great construction difficulty.

[0030] To this end, the present application provides a coal and water resource coordinated mining system and construction method.

[0031] This application is based on the principle and concept of "horizontal reduction and supplement, empty area storage, and on-site utilization", and provides technical support for achieving water disaster prevention and control, water resource protection and utilization, and ecological environment improvement.

[0032] See attached Figure 1 , attached Figure 1 This is a plan view of a system for coordinated mining of coal and water resources according to an embodiment of the present application. The technical solution of the present invention is further described in detail below through specific embodiments.

[0033] The present invention provides a system for coordinated mining of coal and water resources, which is arranged in a mine. The system includes:

[0034] Boundary curtain subsystem 5, clean water storage subsystem 6, sewage storage subsystem 7, water resource reuse subsystem;

[0035] The mine is provided with a curtain construction area 1, a mining area 2 and a goaf area 3. The curtain construction area 1 is provided on a side close to the periphery of the mine. An area to be mined 4 is formed between the curtain construction area 1 and the mining area 2. The mining area 2 adopted in this technical solution is a strip-type filling mining area, and the goaf area 3 is a room-and-pillar mining goaf area. The goaf area 3 is located on a side away from the curtain construction area 1.

[0036] The boundary curtain subsystem 5 is arranged in the curtain construction area 1 to block the underground supply water outside the mine from flowing into the mine, so that a closed water-proof space is formed inside the mine;

[0037] The clean water storage subsystem 6 and the sewage storage subsystem 7 are both arranged in the goaf 3. The clean water storage subsystem 6 is connected to the area to be mined 4 to collect and store clean mine water in the area to be mined 4. The sewage storage subsystem 7 is connected to the mining area 2 to collect and store mine sewage generated by spray dust reduction, flushing, a small amount of dripping water, etc. at the mining working face in the mining area 2.

[0038] The water resource recycling subsystem includes a paste filling material preparation device 9 , and the clean water storage subsystem 6 and the sewage storage subsystem 7 are both connected to the paste filling material preparation device 9 through a filtering subsystem 8 .

[0039] Specifically, a boundary curtain subsystem 5 is set on the groundwater recharge channel outside the mine. By setting the boundary curtain subsystem 5, the groundwater seepage field is changed, so that the groundwater moves along the periphery of the mine, effectively reducing the recharge of the peripheral groundwater and realizing "horizontal reduction and recharge";

[0040] Utilize the existing goaf 3 in the mine. In this technical solution, the goaf 3 includes goaf 1 and goaf 2. A clean water storage subsystem 6 is set in goaf 1, and a sewage storage subsystem 7 is set in goaf 2. Clean mine water and mine sewage are stored in different goafs 3, realizing "goaf storage";

[0041] The clean water in the clean water storage subsystem 6 and the sewage in the sewage storage subsystem 7 are filtered for impurities through the provided filtering subsystem 8, and the filtered mine water is supplied to the paste filling material preparation device 9 for preparing the paste filling material, thereby realizing "on-site utilization".

[0042] From the perspective of aquifer water quality, water filling channels, and recharge channels, by setting up this mining system in the mine, the disturbance of the groundwater system can be reduced, the recharge of dynamic reserves can be blocked, and the underground emission reduction, treatment and utilization of mine water can be achieved to the greatest extent.

[0043] In some embodiments, the boundary curtain subsystem 5 includes a curtain alley 51 and a curtain wall;

[0044] The curtain tunnel 51 is arranged between the periphery of the mine and the area to be mined 4, and is connected to the tunnel arranged in the mining area 2. A plurality of grouting holes 52 are arranged on the side wall of the curtain tunnel 51 close to the periphery of the mine. Curtain grouting is performed on the grouting holes 52 to form a curtain wall arranged in the entity outside the mine.

[0045] A curtain tunnel 51 is set up on the periphery of the mine, and the formed curtain tunnel 51 is connected to the tunnel of the equipment in the mining area 2. A to-be-mined area 4 is formed between the curtain tunnel 51 and the mining area 2. A plurality of grouting holes 52 are set on the side wall of the curtain tunnel 51 close to the periphery of the mine. Curtain grouting is performed on the grouting holes 52 to form a curtain wall set in the entity outside the mine, which is used to block the groundwater outside the mine from entering the mine.

[0046] In some embodiments, a drainage hole is provided on the top plate of the solid coal seam in the to-be-mined area 4, and a drilling casing 10 is provided in the drainage hole. The drilling casing 10 is connected to the clean water storage subsystem 6 through a clean water pipe 11, and a pre-filter is provided between the clean water pipe 11 and the drilling casing 10;

[0047] A clean water branch pipe 12 is provided on the pipe body of the clean water pipeline 11. The clean water branch pipe 12 is used to provide production water for the mining area 2. A control valve is provided on the clean water branch pipe 12.

[0048] Through the construction of the curtain tunnel 51, a drainage hole is constructed in the solid coal roof in the area to be mined 4. A drilling casing 10 is set in the drainage hole. The drilling casing 10 is connected to the clean water storage subsystem 6 through the clean water pipeline 11. A pre-filter is installed between the clean water pipeline 11 and the drilling casing 10. The mine water in the drainage hole is automatically discharged into the clean water pipeline 11 by utilizing the height difference. Part of the mine water is discharged into the clean water storage subsystem 6 in the goaf 3 for storage and purification.

[0049] By arranging a clean water branch pipe 12 on the clean water pipeline 11 and arranging a control valve on the clean water branch pipe 12 , the mine water is controlled to be supplied to the mining area 2 .

[0050] The number of drainage holes drilled, the time of drainage and the amount of water discharged need to be dynamically controlled based on the water storage capacity of the goaf 3, underground water use, water used for the preparation of paste filling materials and the mining project plan, so as to achieve timely digestion and utilization in the mine.

[0051] In some embodiments, the paste filling material preparation device 9 is connected to the filtration subsystem 8 through the drainage pipe 14. The clean water stored in the clean water storage system and the mine sewage stored in the sewage storage subsystem 7 are filtered by the filtration subsystem 8. The filtered mine water is supplied to the paste filling material preparation device 9 through the drainage pipe 14.

[0052] The paste filling material preparation device 9 includes a paste filling material mixing station, a filling pump and a filling pipeline. The filtered mine water is transported to the filling material mixing station through the drainage pipe 14 for water supply, and the filling pump transports the stirred filling material to the construction front end through the static filling pipeline for filling.

[0053] It should be noted that the paste filling material preparation device 9 in the present technical solution is a conventional device in the art, which is used to prepare the paste filling material. The present technical solution does not make any improvements, so the specific structure and operation of the paste filling material preparation device 9 will not be described in detail.

[0054] In addition to supplying the paste filling material preparation device 9, the filtered mine water can also be used to flush the tunnels in the mine. A control valve, a pressure regulating valve and a flow meter are set on the drainage pipe 14 to control the water discharge from the drainage pipe 14 and release it as needed.

[0055] The underground sewage formed by spray dust reduction, flushing, and a small amount of dripping water on the working face of the mining area is connected to the sewage storage subsystem 7 through the sewage pipe 13. A water pump is provided on the sewage pipe 13. The water pump is not shown in the accompanying drawings. The water pump is used to collect the underground sewage to the sewage storage subsystem 7.

[0056] In some embodiments, the outlets 86 of both the goaf 1 and the goaf 2 are provided with lower chute. In this technical solution, two filtering subsystems 8 are provided, and the two filtering subsystems 8 are respectively provided in the lower chute of goaf 1 and the lower chute of goaf 2.

[0057] like Figure 2 The filter subsystem schematic diagram shown in FIG. 8 shows that the filter subsystem 8 includes a filter wall 1 81, a filter wall 2 82, and a filter wall 3 83 sequentially arranged along the length of the lower chute. The filter wall 1 81 and the filter wall 2 82 are both honeycomb structures.

[0058] A filter filler 1 84 is provided between the filter wall 1 81 and the filter wall 2 82 , and a filter filler 2 85 is provided between the filter wall 2 82 and the filter wall 3 83 . The filter filler 1 84 used in this technical solution is fine sand, and the filter filler 2 85 is natural zeolite. By providing the fine sand and natural zeolite filling, the impurities in the water can be filtered out.

[0059] The filter wall 3 83 is provided with a water outlet 86 and an overflow outlet 87 , and the water outlet 86 and the overflow outlet 87 are in communication with the drainage pipe 14 .

[0060] Among them, the clean mine water filtered by the filtering subsystem 8 set at a place in the goaf 3 can also be used for flushing the tunnel.

[0061] like Figure 8 The embodiment of the present application further provides a construction method for a boundary curtain subsystem, and the construction method includes the following steps S101 to S103.

[0062] S101: Delineate the water-rich layer and the groundwater recharge area outside the mine, determine the curtain construction area 1, and set the curtain tunnel 51 and the curtain wall construction parameters according to the determined curtain construction area 1.

[0063] Specifically, based on the existing drilling, geophysical exploration, underground water points and other data, the water-rich layer of the solid coal seam roof and the location of the boundary groundwater recharge area are delineated, and then the curtain construction area 1 (curtain belt, curtain tunnel 51 plane position and curtain wall vertical direction layer) is determined; according to the determined curtain construction area 1, the curtain tunnel 51 and curtain wall construction parameters are set, the plane position of the curtain tunnel 51 needs to be arranged along the outer boundary of the mine, the vertical position of the curtain wall is determined by comprehensively determining the water-rich layer based on the drilling, geophysical exploration and water point data, and the thickness of the curtain wall is set to the thickness of the aquifer groundwater recharge channel.

[0064] S102: Excavate a curtain tunnel 51 according to the construction parameters, the curtain tunnel 51 is connected to the tunnel set in the mining area 2, and a plurality of grouting holes 52 are drilled and constructed on the side wall of the curtain tunnel 51 close to the periphery of the mine. Curtain grouting is performed on the grouting holes 52 to form a curtain wall set in the periphery of the mine to block the grouting holes 52.

[0065] The curtain tunnel 51 is excavated according to the set construction parameters. After the excavation construction, the curtain tunnel 51 is used as a drainage tunnel and the mine's later production system. When constructing the curtain tunnel 51, this technical solution adopts an alternating cycle of tunnel excavation and curtain grouting. The specific construction plan can be flexibly adjusted according to the on-site conditions, and no further details will be given here.

[0066] In some embodiments, as Figure 3 The grouting hole orientation and inclination are shown in the three-dimensional diagram. The curtain tunnel 51 is drilled on the side wall near the outer side of the mine shaft to construct multiple grouting hole groups. Figure 5 As shown, the distance between two adjacent grouting hole groups is 40m, and each grouting hole group includes multiple grouting holes 52, such as Figures 4 to 6 As shown, the grouting hole group includes grouting hole 1#, grouting hole 2#, grouting hole 3# and grouting hole 4#, the hole spacing of the four grouting holes is 1.0m, and the horizontal grouting distance of each grouting hole 52 is 50m;

[0067] like Figure 6 As shown, the grouting holes 52 are arranged in a lateral semi-fan-shaped arrangement, and the direction of the grouting holes 52 is inclined by 10° to 25° toward the outer side of the mine.

[0068] In some embodiments, the grouting holes 52 are grouted to block the grouting holes 52 , and there is an overlapping area between the curtain walls formed by grouting two adjacent grouting holes 52 to ensure that there is no gap in the curtain wall after grouting.

[0069] The drilling sequence for grouting holes 52 is to drill holes in the center of the roadway first, then outwards. The initial grouting pressure for the grouting project is 0.6-0.8 MPa, and the normal grouting pressure is 0.8-1.0 MPa. The grouting pressure is dynamically controlled during the grouting process. The grouting material selection for the curtain grouting project is determined by the slurry volume and pressure. Under normal circumstances, cement single slurry is used, starting with thin and then thickening. If the slurry volume is seriously leaking, cement-water glass dual slurry is used. The standard for serious leaking is that the grouting system still does not rise in pressure when the grouting volume exceeds 1.3 times the expected amount. If the cement-water glass dual slurry is still not effective, and the standard for insignificant slurry is that the slurry is still being consumed and the grouting system pressure still does not rise, polyurethane-water glass dual slurry is used.

[0070] Step S103: After the construction of the curtain tunnel 51 and the curtain wall is completed, a water discharge test is performed to check whether the grouting effect meets the preset standards.

[0071] In some embodiments, a surface hydrological observation hole A and a surface hydrological observation hole B are provided outside the boundary of the curtain construction area 1;

[0072] Setting a surface hydrological observation hole C in the area to be mined 4;

[0073] In this technical solution, surface hydrological observation holes A and B are set within 20 to 100 meters outside the mine, and surface hydrological observation hole C is set within the drainage influence radius of the mining area 4.

[0074] A water discharge test is carried out to check whether the grouting effect meets the preset standards by observing the surface hydrological observation hole A, the surface hydrological observation hole B and the surface hydrological observation hole C.

[0075] In some embodiments, during the water discharge test, if the water levels of the surface hydrological observation hole A and the surface hydrological observation hole B remain unchanged, and the water level of the surface hydrological observation hole C drops significantly, then the grouting effect meets the preset standard;

[0076] If the water level of the surface hydrological observation hole A or the surface hydrological observation hole B drops significantly, and the water level of the surface hydrological observation hole C also drops significantly, the grouting effect does not meet the preset standard, and the grouting holes 52 need to be further increased.

[0077] In a specific embodiment, a mine in the southwest of the Yushen Mining District in the Jurassic Coalfield in northern Shaanxi is taken as an example. As the mining area extends eastward, the mining work approaches the spontaneous combustion boundary of the coal seam. The eastern boundary of the mine is affected by the burned rock aquifer in the fire zone and the fissure aquifer in the weathering zone, which seriously threatens the safe production of the mine. In order to ensure the safe production of the mine, the technology described in the present invention is used to liberate the coal resources threatened by water disasters. The specific layout example is shown in the figure below. Figure 7 shown.

[0078] The specific method process is:

[0079] (1) Based on the existing drilling, geophysical and downhole water point data, the top plate water-rich layer and the boundary strong runoff recharge area are delineated, and then the following are determined: Figure 7 The curtain belt, curtain tunnel plane position and curtain wall vertical layer are shown; the curtain tunnel plane position should be arranged along the boundary of the well field, and the vertical position of the curtain wall should be determined by comprehensively determining the water-rich layer based on drilling, geophysical exploration and water-yielding point data, and the thickness should be the thickness of the strong recharge channel of the aquifer, that is, 30m.

[0080] (2) Construct two surface hydrological observation holes A and B in the direction of groundwater recharge outside the mine, and construct one surface hydrological observation hole C inside the mine; the horizontal position of hydrological observation hole A is 22.6m outside the mine boundary, the horizontal position of hydrological observation hole B is 30m outside the mine boundary, and the horizontal position of hydrological observation hole C is within the drainage influence radius inside the mine boundary. The vertical layer of the hydrological observation hole can be drilled within 10m of the coal seam floor, and a water stop casing is inserted in the layer above the aquifer in the grouting section.

[0081] (3) The curtain tunnel constructed outside the mine is used as a drainage tunnel and the mine's later production system. When constructing a certain distance of curtain tunnel, pre-grouting is performed on the side wall of the curtain tunnel along the outside of the mine to form a lateral water-blocking wall. During construction, tunnel excavation and curtain grouting are carried out in alternating cycles.

[0082] During curtain grouting, open the hole → drill → water pressure test → clean the hole → grouting (make slurry, adjust water-cement ratio and pressure) → close the pipe and seal the slurry → sweep the hole and re-inject → construct the next section, repeat the above operations → complete grouting of all sections.

[0083] First, the grouting drilling is constructed. The drilling structure is to first open a Φ133mm hole and insert a Φ108mm casing. After the casing solidifies and passes the pressure test, continue drilling to the final hole with a hole diameter of 75mm.

[0084] The grouting method adopted is underground pure pressure upward grouting and full-section grouting.

[0085] The grouting holes for advance pre-grouting are arranged in a lateral semi-fan shape. Multiple grouting hole groups are drilled on the side wall of the curtain tunnel, with 4 holes in each group. The inclination angles are 10°, 15°, 20°, and 25°, and the corresponding angles with the tunnel centerline are 0°, 5°, 10°, and 15°, respectively, and gradually deviate toward the periphery of the mining area.

[0086] The distance between each grouting hole is 1.0m, the horizontal grouting distance is 50m, and the distance between each group of holes is 40m. The construction sequence of grouting hole drilling is to drill holes in the center of the tunnel first, and then extend outwards.

[0087] The initial grouting pressure of the grouting project is 0.7MPa, and the normal grouting pressure is 0.9MPa. The grouting pressure is dynamically controlled during the grouting process.

[0088] The selection of grouting materials for curtain grouting projects depends on the amount of slurry and pressure. Under normal circumstances, single cement slurry is used, which is thin at first and then thick, and the slurry should be in a water-cement ratio of 1:1~3:1 (mass ratio); if the slurry leakage is serious, cement-water glass double slurry is used. The standard for serious leakage is that the grouting volume is 1.3 times greater than the expected amount, and the grouting system still does not rise in pressure; if the effect of cement-water glass double slurry is still not obvious, and the judgment standard is that the slurry is still being consumed and the pressure of the grouting system still does not rise, polyurethane-water glass double slurry is used.

[0089] The grouting termination standard is that the actual slurry injection volume is greater than or close to the designed injection volume, the grouting pressure increases regularly and reaches the designed final pressure, when the final pressure is reached, the borehole basically does not absorb slurry or the slurry absorption volume is no more than 20L / min, and the final pressure and final volume are maintained for 15 minutes to terminate the grouting of the hole.

[0090] (4) After the construction of curtain tunnel and curtain wall is completed, drill holes for drainage of water on the inner side of the curtain tunnel or in the main tunnel, first check the effect of curtain grouting, and then drain the water after the effect is good.

[0091] After the project is completed, drilling holes will be constructed within the working face to drain water, and the attenuation of the water outlet holes and the changes in the water levels of surface hydrological observation holes A, B, and C will be monitored.

[0092] The method for judging the grouting effect is to conduct a water discharge test in the curtain tunnel or the main tunnel. If, during the water discharge process, the water levels of the hydrological observation holes A and B on the outside of the curtain wall remain unchanged, and the water level of the hydrological observation hole C on the inside of the curtain wall drops significantly, the grouting effect is good; if the water level of the hydrological observation hole A outside the curtain area drops significantly, and the water level of the hydrological observation hole B on the inside of the curtain wall also drops significantly, the grouting effect is poor, and the grouting holes need to be further increased.

[0093] (5) When draining water, a clean water pipe is first installed in the curtain tunnel. A pre-filter is installed between the clean water pipe and the drainage borehole casing. The water from the drainage borehole is automatically discharged into the clean water pipe using the height difference. A portion is used underground, and the remaining portion is discharged into the existing local mining goaf area 1 for storage and purification. A filter wall is constructed in the lower chute of the goaf. The sewage generated by dust suppression spraying, flushing, and a small amount of dripping water on the working face is discharged through the sewage pipe by a pump into the local mining goaf area 2 for storage and purification. The local mining goaf is a room-and-pillar mining goaf, and the roof does not collapse.

[0094] The filter wall consists of three walls: Wall 1, Wall 2, Wall 3 and internal fillings. The internal Wall 1 and Wall 2 have a honeycomb structure for water to enter the filter. The external Wall 3 is installed with overflow holes and drain valves. Walls 1 and 2 are filled with fine sand, and Walls 2 and 3 are filled with natural zeolite. Their function is to filter impurities in the water.

[0095] Since the working face in this area will not be put into production immediately, the water will not be completely drained in a short time. Two drainage boreholes will be constructed first. The drainage time and volume will be dynamically controlled based on the water storage capacity of the goaf, underground water use, water use for paste filling materials, and mining project plan to ensure timely digestion and utilization underground.

[0096] (6) Clean mine water and dirty mine water are stored in different goafs. In terms of utilization time, clean mine water is used first. In terms of utilization method, the purified clean mine water is used for tunnel flushing and preparation of paste filling materials, and the purified sewage is used for preparation of paste filling materials.

[0097] On-site utilization of mine water inside the curtain wall is to collect mine water in the room-and-pillar mining goaf and use it for flushing underground tunnels and mixing strip paste filling materials. The pipeline is equipped with control valves, pressure regulating valves and flow meters to release as needed.

[0098] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. Within the scope of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0099] The embodiments of the present application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of this application.

Claims

1. A system for coordinated mining of coal and water resources, arranged in a mine, characterized in that: The system comprises: Boundary curtain subsystem, clean water storage subsystem, sewage storage subsystem, water resource reuse subsystem; The mine is provided with a curtain construction area, a mining area and a goaf area, wherein the curtain construction area is provided on a side close to the periphery of the mine, an area to be mined is formed between the curtain construction area and the mining area, and the goaf area is located on a side away from the curtain construction area; The boundary curtain subsystem is arranged in the curtain construction area to block the underground supply water outside the mine from flowing into the mine, so that a closed water-proof space is formed inside the mine; The clean water storage subsystem and the sewage storage subsystem are both arranged in the goaf, the clean water storage subsystem is communicated with the area to be mined to collect and store clean mine water in the area to be mined, and the sewage storage subsystem is communicated with the mined area to collect and store mine sewage in the mined area; The water resource recycling subsystem includes a paste filling material preparation device, and the clean water storage subsystem and the sewage storage subsystem are both connected to the paste filling material preparation device through a filtering subsystem; Wherein, the boundary curtain subsystem includes a curtain lane and a curtain wall; The curtain roadway is arranged between the periphery of the mine and the area to be mined, and is connected to a roadway arranged in the mining area. A plurality of grouting holes are arranged on the side wall of the curtain roadway close to the periphery of the mine, and curtain grouting is performed on the grouting holes to form a curtain wall arranged in the periphery of the mine; A lower chute is provided at the water outlet of the goaf, and the filtering subsystem is provided in the lower chute; The filtering subsystem includes a filter wall 1, a filter wall 2 and a filter wall 3 which are sequentially arranged along the length extension direction of the lower chute, and the filter wall 1 and the filter wall 2 are both honeycomb structures; A filter filler 1 is provided between the filter wall 1 and the filter wall 2, and a filter filler 2 is provided between the filter wall 2 and the filter wall 3; The filter wall 3 is provided with a water outlet and an overflow outlet, and the water outlet and the overflow outlet are connected to the drainage pipe.

2. A system for coordinated mining of coal and water resources according to claim 1, characterized in that: include: A drainage hole is provided on the top plate of the solid coal seam in the area to be mined, a drilling casing is provided in the drainage hole, the drilling casing is connected to the clean water storage subsystem through a clean water pipeline, and a pre-filter is provided between the clean water pipeline and the drilling casing; A clean water branch pipe is provided on the pipe body of the clean water pipeline, and the clean water branch pipe is used to provide production water for the mining area. A control valve is provided on the clean water branch pipe.

3. A system for coordinated mining of coal and water resources according to claim 1, characterized in that: include: The paste filling material preparation device is connected to the filtering subsystem through a drainage pipe; The drainage pipeline is also provided with a control valve.

4. A construction method for a boundary curtain subsystem, characterized in that: Applied to a coal and water resource coordinated mining system according to any one of claims 1 to 3, the construction method comprises: Delineating the location of water-rich layers and groundwater recharge areas outside the mine, determining a curtain construction area, and setting construction parameters of the curtain tunnel and the curtain wall according to the determined curtain construction area; excavating a curtain tunnel according to the construction parameters, the curtain tunnel being connected to a tunnel provided in the mining area, drilling and constructing a plurality of grouting holes on a side wall of the curtain tunnel on a side close to the periphery of the mine, and performing curtain grouting on the grouting holes to form a curtain wall provided within the periphery of the mine, thereby blocking the grouting holes; After the construction of the curtain tunnel and the curtain wall is completed, a water discharge test is carried out to check whether the grouting effect meets the preset standards.

5. The construction method of the boundary curtain subsystem according to claim 4, characterized in that: The drilling and construction of a plurality of grouting holes on the side wall of the curtain roadway close to the periphery of the mine shaft includes: A plurality of grouting hole groups are drilled and constructed on the side wall of the curtain tunnel near the periphery of the mine shaft, the spacing between the plurality of grouting hole groups is 40m, each grouting hole group includes a plurality of grouting holes, the hole spacing between each grouting hole is 1.0m, and the horizontal grouting distance of each grouting hole is 50m; The grouting hole is inclined at 10° to 25° toward the periphery of the mine.

6. The construction method of the boundary curtain subsystem according to claim 4, characterized in that: The curtain grouting is performed on the grouting hole to form a curtain wall arranged in the outer body of the mine to block the grouting hole, including: The grouting holes are grouted to block the grouting holes. There is an overlapping area between the curtain walls formed by grouting two adjacent grouting holes to ensure that the curtain wall after grouting has no gaps.

7. The construction method of the boundary curtain subsystem according to claim 4, characterized in that: The water discharge test is to check whether the grouting effect meets the preset standards, including: Set up surface hydrological observation holes A and B outside the boundary of the curtain construction area; Setting a surface hydrological observation hole C in the area to be mined; A water discharge test is carried out to check whether the grouting effect meets the preset standards by observing the surface hydrological observation hole A, the surface hydrological observation hole B and the surface hydrological observation hole C.

8. The construction method of the boundary curtain subsystem according to claim 7, characterized in that: The inspection of whether the grouting meets the preset standards includes: During the water discharge test, if the water levels of the surface hydrological observation holes A and B remain unchanged, and the water level of the surface hydrological observation hole C drops significantly, then the grouting effect meets the preset standards; If the water level of the surface hydrological observation hole A or the surface hydrological observation hole B drops significantly, and the water level of the surface hydrological observation hole C also drops significantly, the grouting effect does not meet the preset standard.

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