Paste and gangue mixed large-step filling mining method

Abstract

The invention relates to the technical field of coal mining, in particular to a paste and gangue mixed large-step filling mining method which comprises the following steps: step 1, paste material preparation and storage, step 2, coal mining on a coal face, step 3, frame pulling and advance supporting, step 4, frame rear isolation, step 5, paste preparation and pumping filling, and step 6, gangue filling. And 7, the isolation wall is dismantled. According to the method, the goaf is filled in a paste and gangue mixed synergistic filling mode, land subsidence and gangue consumption can be controlled at the same time, the goaf filling rate is high, the land subsidence control effect is good, and the effect that the gangue does not rise to the well is achieved; and meanwhile, large-step-pitch filling mining can be carried out, and the filling mining efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, and in particular to a paste and gangue mixed large-step filling mining method. Background Art

[0002] Scientifically and rationally solving the problems of "three down and one up" coal pressure, coal gangue and other solid waste treatment and mining damage, reducing the impact and damage of mining on the natural, social and living environment, making the best use of limited resources, and realizing the "green mining" of coal resources are major issues that need to be urgently solved in my country's mining industry. Among them, the gangue discharge generated by mining is required not to be raised to the well, so the gangue can be filled into the goaf for use; a variety of filling mining methods such as gangue filling and paste filling have emerged. The gangue filling mining method can consume a large amount of gangue and achieve the effect of not raising the gangue to the well, but the filling rate is low and the control effect of ground subsidence is not good; the paste filling mining method has the advantages of high filling rate and good control effect of ground subsidence, but the gangue consumption is small and the effect of not raising the gangue to the well cannot be achieved. The single filling mining method of the existing technology cannot effectively control the ground subsidence and gangue consumption at the same time, and there is also the defect of low filling mining efficiency, which affects the working efficiency of mining. Summary of the invention

[0003] In order to solve the problems in the prior art that the single filling mining method cannot effectively control ground subsidence and gangue consumption and the filling mining efficiency is low, the present invention provides a paste and gangue mixed large-step filling mining method, which adopts the paste and gangue mixed collaborative filling method to fill the goaf, can control ground subsidence and gangue consumption at the same time, has a high filling rate of the goaf, and has a good control effect on ground subsidence, and also achieves the effect of not lifting gangue into the well; at the same time, filling mining can be carried out with a large step, thereby improving the efficiency of filling mining.

[0004] In order to achieve the above object, the technical solution of the present invention is: a paste and gangue mixed large step filling mining method, including a coal mining face tunnel and a hydraulic support arranged in the coal mining face tunnel, including the following steps: Step 1: Preparation and storage of paste materials: The ground filling station crushes and screens the gangue, and the gangue powder with a particle size that meets the requirements for preparing the paste is stored in the gangue finished product warehouse; the fly ash and coagulation materials required for preparing the paste are stored in silos. Prepare the materials used to prepare the paste in advance so that the paste can be prepared after the void filling area is formed, and the effect of filling the void filling area with paste is achieved.

[0005] Step 2: Construction of advance channel: The advance channel is constructed on the upper part of the coal seam by using the cooperation of the tunnel boring machine and the side loader, and the roof of the advance channel is supported by anchor cables and nets. The coal and gangue produced by the excavation of the advance channel are transported out by scraper conveyors and transfer belt conveyors. The purpose of excavating the advance channel by the tunnel boring machine and the side loader is to use the scraper conveyor and the transfer belt conveyor to transport the mined coal out of the coal mining face tunnel; the advance channel is supported in advance by anchor cables and nets to ensure the safety of the roof of the advance channel and the safety of the staff entering the goaf for plugging operations. At the same time, the filling mining step distance can be increased to ensure large step distance mining, thereby achieving the effect of large step distance mixed filling of paste and gangue.

[0006] Step 3: Coal cutting: Use a coal cutter to cut the coal at the lower part of the coal seam at the advance channel. During the coal cutting process, the hydraulic supports are pushed and pulled in sequence, and the hydraulic supports move in large steps toward the advance channel. At the same time, the construction of the next advance channel (3) is continued. The purpose of forming the goaf filling area is achieved by the movement of the hydraulic supports toward the advance channel.

[0007] Step 4: Isolation behind the frame: After coal mining and frame pulling are completed, the space behind the hydraulic support forms a large-step goaf filling area. A plugging cloth is hung behind the baffle of the hydraulic support. Isolation walls are piled up at both ends of the coal mining working face tunnel, and isolation walls are piled up at intervals in the goaf filling area to divide the goaf filling area with stacked isolation walls into multiple filling spaces. The plugging cloth protects the hydraulic support. By plugging the goaf filling area with the plugging cloth and the isolation wall, the phenomenon of slurry leakage can be reduced, the filling rate of the goaf filling area is improved, and the goaf filling area can be filled smoothly.

[0008] Step 5: Paste preparation and pumping filling: Gangue powder, fly ash, coagulation material and water are put into a mixer according to the paste material ratio to mix and stir to form a paste; the paste is pumped to the filling space through a pipeline. The gangue powder, fly ash, coagulation material and water are mixed by the mixer to form a paste.

[0009] Step 6: Gangue filling: While the paste is being filled, the gangue is thrown into the filling space through a suspended gangue conveyor. The paste and gangue are mixed and used to fill the goaf filling area. The simultaneous filling of the two can consume a large amount of gangue solid waste, thereby achieving the effect of not lifting the gangue from the well; at the same time, the filling rate of the goaf filling area is high, and the control effect of ground subsidence is good.

[0010] Step 7: Removal of isolation walls: Multiple filling spaces are mixed and filled with paste and gangue in turn. When one of the filling spaces is full, the isolation wall between the next filling space is removed; when the goaf filling area is full and the paste solidifies to reach strength, the next coal cutting work cycle is carried out, the filling spaces are filled in turn and the isolation walls are recycled.

[0011] Furthermore, in the step 1, the crusher of the ground filling station crushes the gangue and screens the gangue through a screening machine. Gangue powder with a particle size less than 5 mm enters the gangue finished product bin, and gangue with a particle size greater than 5 mm enters the crusher through the circulating return crushing system of the ground filling station and is crushed again. Gangue whose particle size does not meet the requirements for preparing the paste is crushed again by the crusher, which can ensure the quality of the paste preparation.

[0012] Furthermore, in step 2, the coal produced by the coal cutter in the advanced tunnel is pushed to the scraper conveyor by the side loader, and then transferred from the scraper conveyor to the transfer belt conveyor for transportation. The mined coal is transported out of the coal mining face tunnel through the side loader, the scraper conveyor and the transfer belt conveyor in sequence.

[0013] Furthermore, in step 3, the corresponding hydraulic supports are gradually pushed and pulled during the coal cutting by the coal cutter; and the coal generated during the coal cutting by the coal cutter is also pushed by the side loader to the scraper conveyor, and then transferred from the scraper conveyor to the transfer belt conveyor for transportation, the purpose of which is to ensure the supporting effect of the hydraulic supports on the coal mining working face tunnels.

[0014] Furthermore, in step 4, the width of the goaf filling area is the step distance of the hydraulic support moving in the direction of the advance channel; the hydraulic support baffle includes an upper baffle and a lower baffle. Due to the high height of the goaf filling area, the sealing cloth is divided into two pieces, upper and lower, and the two pieces of sealing cloth are glued together with Velcro; the sealing cloth is tightly attached to the upper baffle and the lower baffle, and the sealing cloth is spread from the top beam of the hydraulic support along the upper baffle and the lower baffle to the bottom plate. The purpose is to enable the sealing cloth to protect the hydraulic support and at the same time to seal the goaf filling area, so as to fill the goaf filling area with a mixture of paste and gangue.

[0015] Furthermore, in step 4, the sealing cloth leaves a margin of no less than 500 mm above the top beam of the hydraulic support, and a straw mat is used to fill the gap; the sealing cloth leaves a margin of no less than 500 mm on the bottom plate of the hydraulic support, and a woven bag is used to compact the coal; the sealing cloths on adjacent hydraulic support baffles are connected with Velcro; this is to avoid leakage of paste when filling the paste into the goaf filling area, thereby improving the effect of the sealing cloth in sealing and isolating the goaf filling area.

[0016] Furthermore, in step 5, gangue powder, fly ash, coagulant material and water are weighed according to the material ratio and then put into the mixer; the prepared paste is transported to the underground secondary filling station through an industrial filling pump and a pipeline, and then transported to the filling space through an industrial filling pump and a filling pipeline. The filling pipeline is suspended on the hydraulic support, and a paste injection hole is opened on the baffle of the hydraulic support. The purpose of transporting the paste to the underground secondary filling station is to stir the paste again to avoid solidification of the paste during long-distance transportation.

[0017] Furthermore, in step 6, the gangue in the underground gangue bin is thrown into the filling space through the air lane belt conveyor and the suspended gangue belt conveyor; the suspended gangue belt conveyor is suspended on the hydraulic support, and a feeding port is opened on the baffle of the hydraulic support. The air lane belt conveyor and the suspended gangue belt conveyor play the role of transporting the gangue, so that the gangue is filled into the goaf filling area through the feeding port through the air lane belt conveyor and the suspended gangue belt conveyor, thereby achieving the effect of paste and gangue mixed and synergistically filling the goaf filling area.

[0018] The process flow of the present invention is: preparation and storage of paste materials → coal mining pull frames and advance support at the coal mining face to form a large-step goaf filling area → isolation and sealing of the goaf filling area → preparation of paste at the ground filling station → paste pumping and gangue transportation and mixed filling of the goaf filling area → mining of the remaining coal body below the advance channel → next working cycle.

[0019] Through the above technical solution, the beneficial effects of the present invention are: The present invention adopts a mixed and coordinated filling method of paste and gangue to fill the goaf filling area, which can control ground subsidence and gangue consumption at the same time. The filling rate of the goaf is high and the control effect of ground subsidence is good. The simultaneous filling of the two can consume a large amount of gangue solid waste, and achieve the effect of no gangue lifting to the well. At the same time, filling and mining can be carried out in a large step distance, achieving the effect of large-step mixed filling of paste and gangue, thereby improving the efficiency of filling and mining.

[0020] The present invention uses a coal cutter to dig an advance channel, and adopts the method of manually driving anchor cables and hanging nets to carry out advance support for the advance channel in advance, thereby ensuring the safety of the roof of the advance channel; while ensuring the safety of workers entering the goaf to carry out plugging operations, the step distance of filling mining can be increased, so as to achieve the purpose of filling mining with a large step distance, realize the effect of mixing filling paste and gangue with a large step distance, and improve the efficiency of filling the goaf filling area.

[0021] The sealing cloth of the present invention plays a protective role on the hydraulic support and also plays a sealing role on the goaf filling area, so that the goaf filling area can be filled with a mixture of paste and gangue; the sealing cloth and the isolation wall can separate, seal and isolate the goaf filling area, which can reduce the phenomenon of slurry leakage, improve the filling rate of the goaf filling area, and ensure that the goaf filling area can be filled smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the process of forming the advanced channel and the goaf filling area of ​​the present invention; Figure 2 It is a schematic diagram of the structure of the paste and gangue in the collaborative filling process of the present invention; Figure 3 It is a schematic diagram of the structure after the paste and gangue are collaboratively filled in the present invention.

[0023] The numbers in the attached figure are: 1 is the coal mining face tunnel, 2 is the coal cutter, 3 is the advance channel, 4 is the hydraulic support, 5 is the upper baffle, 6 is the lower baffle, 7 is the goaf filling area, 8 is the suspended gangue belt conveyor, and 9 is the filling pipeline. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments: like Figure 1 to Figure 3 As shown, a paste and gangue mixed large-step filling mining method is suitable for large mining height goafs with a mining face of more than 4 meters, including a coal mining face tunnel 1 and a hydraulic support 4 arranged in the coal mining face tunnel 1. In this embodiment, the coal mining face tunnel 1 is an overall "U"-shaped structure, which includes interconnected machine tunnels and air tunnels. The length of the coal mining face tunnel 1 is 260 meters. The number of hydraulic supports 4 that play a supporting role inside the coal mining face tunnel 1 is 149, of which 3 ZCG13000-30 / 65D filling transition hydraulic supports are arranged at both ends of the coal mining face tunnel 1, and 143 ZC13000-30 / 65D filling hydraulic supports are arranged in the middle of the coal mining face tunnel 1. The following steps are included: Step 1: Preparation and storage of paste materials: The ground filling station crushes and screens the gangue, and the gangue powder with a particle size that meets the requirements for preparing the paste is stored in the gangue finished product warehouse; the fly ash and coagulation materials required for preparing the paste are stored in silos, where the paste material also includes water. In this embodiment, the coagulation material is cement, and the fly ash and coagulation materials required for preparing the paste are respectively driven into their respective silos by closed powder tank trucks for storage.

[0025] The crusher at the ground filling station crushes the gangue and screens the gangue through a screening machine. Gangue powder with a particle size less than 5 mm enters the gangue finished product bin, and gangue with a particle size greater than 5 mm enters the crusher through the circulating return system of the ground filling station for further crushing.

[0026] Step 2: Step 2: Construction of advance channel: Use the cooperation of multi-purpose tunneling machine and side loader to construct the advance channel on the upper part of the coal seam, and carry out advance support for the top plate of the advance channel by anchoring cables and hanging nets. The coal and gangue produced by excavating the advance channel are transported out by scraper conveyor and transfer belt conveyor.

[0027] The coal produced by the advance channel 3 excavated by the tunnel boring machine is pushed to the scraper conveyor by the side loader, and then transferred from the scraper conveyor to the transfer belt conveyor for transportation. In this embodiment, the height of the advance channel 3 is 2.5 meters, the width is 6.2 meters, and the length is 260 meters. The tunnel boring machine and the side loader achieve the purpose of mining coal at the coal mining face and excavating the advance channel 3. Since the composite roof of the large mining height is relatively broken (the roof is mainly mud sandstone and gray sandstone), in order to prevent the roof behind the frame from falling and collapsing, the tunnel boring machine and the side loader are required to construct the advance channel 3 in the upper half of the 6-meter-high coal seam, and the roof of the advance channel 3 is supported by anchor cables and nets to ensure the stability of the roof behind the frame and achieve the safety of the roof in the goaf filling area. The top plate of the advance channel 3 is reinforced by anchoring cables and hanging nets manually to ensure the safety of the workers entering the goaf for sealing operations. The filling mining step distance can be increased by reinforcing the top plate of the advance channel 3 to ensure large-step mining, thereby achieving the effect of 7 large-step mixed filling of paste and gangue in the goaf filling area. The anchoring cables and hanging nets are reinforced by the combination of U-shaped steel beams and metal nets.

[0028] Step 3: Coal cutting: Use the coal cutter 2 to cut the coal in the lower part of the coal seam at the advance channel 3. During the coal cutting, push and pull the hydraulic support 4 in sequence, and the hydraulic support 4 moves in large steps toward the direction of the advance channel 3; at the same time, continue to construct the next advance channel 3.

[0029] The corresponding hydraulic support 4 is gradually pushed and pulled during the coal cutting process by the coal cutter 2; and the coal generated during the coal cutting process by the coal cutter 2 is also pushed by the side loader to the scraper conveyor, and then transferred from the scraper conveyor to the transfer belt conveyor for transportation. The horizontal movement step of the hydraulic support 4 is 4 meters. In order to improve the coal cutting and filling efficiency, the coal cutter 2 can continue to move 5 knives (0.8 meters / knives), and the hydraulic support 4 moves in a large step in the mining direction. By pushing and pulling the hydraulic support 4, the purpose of forming a 4m step in the goaf filling area is achieved, thereby achieving the effect of large-step mixed filling of paste and gangue.

[0030] Step 4: Isolation behind the frame: After coal mining and frame pulling are completed, the space behind the hydraulic support 4 constitutes a large-step goaf filling area 7, and a sealing cloth is hung behind the baffle of the hydraulic support 4. Isolation walls are stacked at both ends of the coal mining working face tunnel 1, and isolation walls are stacked at intervals in the goaf filling area 7 to divide the goaf filling area 7 with stacked isolation walls into multiple filling spaces.

[0031] The width of the goaf filling area 7 is the step distance of the hydraulic support 4 moving in the direction of the advance channel 3, that is, the width of the goaf filling area 7 is 4 meters; the baffle of the hydraulic support 4 includes an upper baffle 5 and a lower baffle 6. Since the height of the goaf filling area 7 is relatively high, the sealing cloth is divided into two pieces, upper and lower, and the two sealing cloths are glued together with Velcro. In this embodiment, 10*3 meters / piece of sealing cloth are hung on the upper baffle 5 and the lower baffle 6; the sealing cloth is tightly attached to the upper baffle 5 and the lower baffle 6, and the sealing cloth is spread from the top beam of the hydraulic support 4 along the upper baffle 5 and the lower baffle 6 to the bottom plate.

[0032] The sealing cloth shall leave a margin of no less than 500 mm above the top beam of the hydraulic support 4, and use straw mats to fill the gap; the sealing cloth shall leave a margin of no less than 500 mm on the bottom plate of the hydraulic support 4, and use woven bags to compact coal; the sealing cloths on the baffles of adjacent hydraulic supports 4 shall be connected with Velcro.

[0033] In this embodiment, isolation walls are piled up at both ends of the coal mining working face tunnel 1, that is, isolation walls are piled up at the ends of the machine tunnel and the ventilation tunnel, and two isolation walls are piled up at intervals in the goaf filling area 7, and the goaf filling area 7 is divided and blocked into three filling spaces by four isolation walls; the isolation walls are composed of woven bags filled with coal, and the isolation walls are reinforced by single hydraulic pillars and thick wooden boards, that is, the thick wooden boards are installed on the outside of the isolation walls, and two groups of hydraulic pillars are installed on the outside of the thick wooden boards, one group of hydraulic pillars is installed vertically, and the other group supports the vertically installed hydraulic pillars, and the hydraulic pillars are DW28~45 single columns.

[0034] Step 5: Paste preparation and pumping filling: according to the paste material ratio, gangue powder, fly ash, coagulant material and water are put into a mixer and mixed to form a paste; the paste is pumped to the filling space through a pipeline.

[0035] Gangue powder, fly ash, coagulant material and water are weighed according to the material ratio and then put into the mixer. Fly ash and coagulant material are transported to their respective weighing hoppers by screw conveyors for weighing. The crushed gangue powder is weighed and transported to the gangue waiting hopper by belt conveyors. Water is pumped into the water weighing hopper by a water pump for weighing. The weighing of all materials is controlled by computer automation. The prepared paste is transported to the underground secondary filling station through industrial filling pumps and pipelines, stirred again by the underground secondary filling station, and then transported to the filling space through industrial filling pumps and filling pipelines 9. The filling pipelines 9 are suspended on the hydraulic support 4, and a paste injection hole is opened on the baffle of the hydraulic support 4. A material distribution valve is installed on the filling pipeline 9, and the paste injection hole is opened on the upper baffle 5.

[0036] Filling paste ratio and demand: The selection and ratio of filling paste is as follows: 1m³ finished slurry ratio contains 0.3-0.45t of water, 1.0-1.6t of gangue, 0.1-0.2t of fly ash and 0.15-0.2t of cement. The ratio needs to be adjusted according to the comprehensive cost of gangue and fly ash and the geological conditions of the roof and floor. In this embodiment, the gangue is 1400 kg / m³, cement is 120 kg / m³, fly ash is 100kg / m³ and water is 340 kg / m³, of which fly ash can be replaced by ball-milled gangue powder. When the actual conditions such as the working face and geological structure change, it is necessary to redo a special ratio experiment to further optimize the ratio of the filling materials and ensure that the relevant parameters such as the paste strength, compaction rate and setting time meet the requirements.

[0037] Step 6: Gangue filling: While the paste is being filled, the gangue is thrown into the filling space through the suspended gangue-feeding belt conveyor 8; the gangue in the underground gangue bin is thrown into the filling space through the air lane belt conveyor and the suspended gangue-feeding belt conveyor 8, and the gangue may fall to the lower layer of the filling space due to its weight; the suspended gangue-feeding belt conveyor 8 is suspended on the hydraulic support 4, and a feeding port is opened on the baffle of the hydraulic support 4, a valve is installed at the feeding port, and the feeding port is opened on the upper baffle 5.

[0038] Step 7: Removal of isolation wall: Removal of isolation wall: Multiple filling spaces are mixed and filled with paste and gangue in turn. After one of the filling spaces is full, the isolation wall between the next filling space is removed; after the goaf filling area 7 is full and the paste solidifies to reach strength, the next coal cutting work cycle is carried out.

[0039] The present invention complements the advantages and disadvantages of paste filling and gangue filling, and filling the two at the same time can consume a large amount of gangue solid waste; because the top plate of the advance channel 3 is supported in advance by anchoring cables and hanging nets, the safety of the top plate of the advance channel 3 is guaranteed, and the filling and mining step distance can be increased to 4 meters / time, thereby improving the efficiency of filling and mining.

[0040] The embodiments described above are only preferred embodiments of the invention and are not intended to limit the scope of implementation of the invention. Therefore, any equivalent changes or modifications made according to the technical solutions described in the patent scope of the present invention should be included in the scope of the patent application of the present invention.

Claims

1. A method for large-step filling of a mixture of paste and gangue, comprising a coal mining face tunnel (1) and a hydraulic support (4) arranged in the coal mining face tunnel (1), characterized in that: The following steps are involved: Step 1: Preparation and storage of paste materials: The ground filling station crushes and screens the gangue, and the gangue powder with a particle size that meets the requirements for preparing the paste is stored in the gangue finished product warehouse; the fly ash and coagulation materials required for preparing the paste are stored in silos; Step 2: Construction of the advance channel: The advance channel (3) is constructed on the upper part of the coal seam by using a multi-purpose excavator and a side loader, and the top plate of the advance channel (3) is supported by anchor cables and nets. The coal and gangue produced by excavating the advance channel (3) are transported out by means of a scraper conveyor and a transfer belt conveyor; Step 3: Coal cutting: The coal cutting machine (2) is used to cut the coal at the lower part of the coal seam at the advanced channel (3). During the coal cutting, the hydraulic support (4) is pushed and pulled in sequence, and the hydraulic support (4) moves in large steps in the direction of the advanced channel (3); at the same time, the construction of the next advanced channel (3) is continued; Step 4: Isolation behind the frame: After coal mining and frame pulling are completed, the space behind the hydraulic support (4) forms a large-step goaf filling area (7), a plugging cloth is hung behind the baffle of the hydraulic support (4), isolation walls are piled up at both ends of the coal mining working face tunnel (1), and isolation walls are piled up at intervals in the goaf filling area (7) to divide the goaf filling area (7) into multiple filling spaces; Step 5: Paste preparation and pumping filling: according to the paste material ratio, gangue powder, fly ash, coagulation material and water are put into a mixer and mixed to form a paste; the paste is pumped to the filling space through a pipeline; Step 6: Gangue filling: While the paste is being filled, the gangue is thrown into the filling space through a suspended gangue-throwing belt conveyor (8); Step 7: Removal of isolation wall: Multiple filling spaces are sequentially mixed with paste and gangue, and when one of the filling spaces is full, the isolation wall between the next filling space is removed; when the goaf filling area (7) is full and the paste solidifies to reach the strength, the next coal cutting work cycle is carried out.

2. A paste and gangue mixed large-step filling mining method according to claim 1, characterized in that: In the step 1, the crusher of the ground filling station crushes the gangue and screens the gangue through the screening machine. The gangue powder with a particle size less than 5 mm enters the gangue finished product bin, and the gangue with a particle size greater than 5 mm enters the crusher through the circulation return system of the ground filling station and is crushed again.

3. The method for large-step filling of paste and gangue mixture according to claim 1 is characterized in that: In the step 2, the coal produced by the coal cutter (2) excavating the advance channel (3) is pushed to the scraper conveyor by the side loader, and then transferred from the scraper conveyor to the transfer belt conveyor for transportation out.

4. The method for large-step filling of paste and gangue mixture according to claim 1 is characterized in that: In step 3, the corresponding hydraulic supports (4) are gradually pushed and pulled during the coal cutting process of the coal cutter (2); and the coal generated during the coal cutting process of the coal cutter (2) is also pushed to the scraper conveyor by the side loader, and then transferred from the scraper conveyor to the transfer belt conveyor for transportation.

5. A paste and gangue mixed large-step filling mining method according to claim 4, characterized in that: In step 4, the width of the goaf filling area (7) is the step distance of the hydraulic support (4) moving in the direction of the advance channel (3); the baffle of the hydraulic support (4) includes an upper baffle (5) and a lower baffle (6); due to the high height of the goaf filling area (7), the sealing cloth is divided into two upper and lower pieces, and the two pieces of sealing cloth are adhered to each other using Velcro; the sealing cloth is closely attached to the upper baffle (5) and the lower baffle (6), and the sealing cloth is spread from the top beam of the hydraulic support (4) along the upper baffle (5) and the lower baffle (6) to the bottom plate.

6. A paste and gangue mixed large-step filling mining method according to claim 5, characterized in that: In step 4, the sealing cloth is left with a margin of not less than 500 mm above the top beam of the hydraulic support (4), and a straw mat is used to fill the gap; the sealing cloth is left with a margin of not less than 500 mm on the bottom plate of the hydraulic support (4), and coal is compacted with a woven bag; the sealing cloths on the baffles of adjacent hydraulic supports (4) are connected by Velcro.

7. The method for large-step filling of paste and gangue mixture according to claim 1 is characterized in that: In step 5, the gangue powder, fly ash, coagulant material and water are weighed according to the material ratio and then put into the mixer; the prepared paste is transported to the underground secondary filling station through an industrial filling pump and a pipeline, and then transported to the filling space through an industrial filling pump and a filling pipeline (9); the filling pipeline (9) is suspended on the hydraulic support (4), and a paste injection hole is opened on the baffle of the hydraulic support (4).

8. The method for large-step filling mining with a mixture of paste and gangue according to claim 1, characterized in that: In step 6, the gangue in the underground gangue bin is thrown into the filling space through the air lane belt conveyor and the suspended gangue belt conveyor (8); the suspended gangue belt conveyor (8) is suspended on the hydraulic support (4), and a feeding port is opened on the baffle of the hydraulic support (4).

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