A paste and gangue mixed large-step filling mining method

Abstract

The present invention relates to the technical field of coal mining, and specifically to a method for large-step filling and mining of a mixture of paste and gangue, comprising the following steps: Step 1: Preparation and storage of paste materials, Step 2: Coal mining at the coal mining face, Step 3: Frame pulling and advance support, Step 4: Isolation after the frame, Step 5: Preparation and pumping filling of paste, Step 6: Gangue filling, and Step 7: Dismantling of the isolation wall. The present invention adopts a method of collaborative filling of a mixture of paste and gangue to fill the goaf, which can simultaneously control ground subsidence and gangue consumption, has a high filling rate of the goaf, 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 in large steps, thereby improving the efficiency of filling mining.

Description

Technical Field

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

[0002] Scientifically and rationally solving the problems of "three downs and one up" coal, gangue and other solid waste disposal and mining damage, reducing the impact and damage of the mining industry on the natural, social and living environment, maximizing the use of limited resources, and realizing "green mining" of coal resources are major issues that need to be addressed in my country's mining industry. Among them, the gangue discharged from mining is required not to be lifted to the wellbore, so the gangue can be filled into the goaf for utilization; various 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 lifting the gangue to the wellbore, but the filling rate is low and the control effect of ground subsidence is poor; 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 cannot achieve the effect of not lifting the gangue to the wellbore. The single filling mining method of the existing technology cannot effectively control ground subsidence and gangue consumption at the same time, and also has the defect of low filling mining efficiency, which affects the 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 large-step filling mining method of a mixture of paste and gangue. The goaf is filled in a collaborative filling manner of a mixture of paste and gangue, which can simultaneously control ground subsidence and gangue consumption. The goaf has a high filling rate, good control effect of ground subsidence, and the effect of not lifting gangue into the well is achieved. At the same time, filling mining can be carried out in a large step, thereby improving the efficiency of filling mining.

[0004] To achieve the above-mentioned object, the technical solution of the present invention is: a method for large-step filling of a mixture of paste and gangue, comprising a coal mining face tunnel and a hydraulic support arranged in the coal mining face tunnel, comprising the following steps:

[0005] Step 1: Paste Material Preparation and Storage: The surface filling station crushes and screens the gangue. Gangue powder with a particle size that meets the paste preparation requirements is stored in the finished gangue warehouse. Fly ash and coagulant materials required for paste preparation are stored in silos. Materials for paste preparation are prepared in advance so that the paste can be prepared after the void filling area is formed, ensuring the paste is filled into the void filling area.

[0006] 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 mining the advance channel by the tunnel boring machine and the side loader is to use the scraper conveyor and transfer belt conveyor to achieve the effect of transporting the mined coal out of the coal mining working 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 workers entering the goaf for sealing operations. At the same time, the filling mining step distance can be increased to ensure large-step mining, thereby achieving the effect of large-step mixed filling of paste and gangue.

[0007] Step 3: Coal cutting: Use a coal cutter to cut the coal in 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. 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.

[0008] Step 4: Isolation behind the support: After coal mining and support pulling are completed, the space behind the hydraulic support forms a large-step goaf filling area. A blocking cloth is hung behind the hydraulic support baffle. Isolation walls are built at both ends of the coal mining face tunnel. Isolation walls are also built at intervals within the goaf filling area to divide the goaf filling area into multiple filling spaces. The blocking cloth protects the hydraulic support. By blocking the goaf filling area with the blocking cloth and the blocking wall, slurry leakage can be reduced, the filling rate of the goaf filling area can be increased, and the goaf filling area can be smoothly filled.

[0009] Step 5: Paste Preparation and Pumping: Gangue powder, fly ash, coagulant, and water are mixed in a mixer according to the paste material ratio to form a paste. The paste is pumped into the filling space through a pipeline. The mixer stirs and mixes the gangue powder, fly ash, coagulant, and water to form a paste.

[0010] 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 into 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.

[0011] Step 7: Removal of isolation walls: Multiple filling spaces are mixed and filled with paste and gangue in sequence. After one of the filling spaces is full, the isolation wall between it and the next filling space is removed; after the goaf filling area is full and the paste solidifies to reach the strength, the next coal cutting work cycle is carried out, the filling spaces are filled in sequence and the isolation walls are recycled.

[0012] Furthermore, in the step 1, the crusher of the ground filling station crushes the gangue and screens the gangue through a 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 circulating return crushing system of the ground filling station and is crushed again. The 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.

[0013] Furthermore, in step 2, the coal produced by the coal cutter in the advance tunnel is pushed by the side loader to the scraper conveyor, 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, scraper conveyor, and transfer belt conveyor in sequence.

[0014] Furthermore, in step 3, the corresponding hydraulic supports are gradually pushed and pulled during the coal cutting process by the coal cutter; and the coal generated during the coal cutting process by the coal cutter 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 out, the purpose of which is to ensure the support effect of the hydraulic supports on the coal mining working face tunnels.

[0015] Furthermore, in step 4, the width of the goaf filling area is the step distance of the hydraulic support moving toward the advance channel; the hydraulic support baffle includes an upper baffle and a lower baffle. Since the height of the goaf filling area is relatively high, 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 laid 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 that the goaf filling area can be filled with a mixture of paste and gangue.

[0016] 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 is compacted with coal in a woven bag; the sealing cloths on adjacent hydraulic support baffles are connected with Velcro; this is to avoid leakage of paste when filling the goaf filling area with paste, thereby improving the effect of the sealing cloth in sealing and isolating the goaf filling area.

[0017] Furthermore, 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 pipeline, and then transported to the filling space through an industrial filling pump and filling pipeline. The filling pipeline is hung 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.

[0018] 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 the paste and gangue mixed and synergistically filling the goaf filling area.

[0019] 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 working 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.

[0020] Through the above technical solution, the beneficial effects of the present invention are:

[0021] The present invention adopts a mixed collaborative filling method of paste and gangue to fill the goaf filling area, which can simultaneously control ground subsidence and gangue consumption, 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 being lifted to the well; at the same time, filling and mining can be carried out with a large step distance, achieving the effect of large-step mixed filling of paste and gangue, thereby improving the efficiency of filling and mining.

[0022] The present invention uses a coal cutter to dig an advance channel, and adopts the method of manually driving anchor ropes and hanging nets to carry out advance support for the advance channel in advance, thereby ensuring the safety of the advance channel roof; 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 large-step filling mining, realize the effect of large-step mixed filling of paste and gangue, and improve the efficiency of filling the goaf filling area.

[0023] The sealing cloth of the present invention plays a protective role on the hydraulic support and at the same time 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 separate, seal and isolate the goaf filling area, which can reduce the leakage of slurry, 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

[0024] Figure 1 It is a structural schematic diagram of the process of forming the advance channel and the goaf filling area of ​​the present invention;

[0025] Figure 2 It is a structural schematic diagram of the paste and gangue collaborative filling process of the present invention;

[0026] Figure 3It is a schematic diagram of the structure after the paste and gangue are collaboratively filled in the present invention.

[0027] 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

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0029] like Figures 1 to 3 As shown, a method for large-step filling and mining of a mixture of paste and gangue is applicable to large mining height goafs with a mining face of more than 4 meters. It includes a coal mining face tunnel 1 and hydraulic supports 4 arranged in the coal mining face tunnel 1. In this embodiment, the coal mining face tunnel 1 is a "U"-shaped structure as a whole, which includes interconnected machine tunnels and ventilation 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. Among them, 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:

[0030] 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 coagulant materials required for preparing the paste are stored in silos, where the paste material also includes water. In this embodiment, the coagulant material is cement. The fly ash and coagulant materials required for preparing the paste are respectively pumped into their respective silos by closed powder tankers for storage.

[0031] The crusher at the ground filling station crushes the gangue and screens the gangue through a screening machine. Gangue powder with a particle size of 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.

[0032] Step 2: Step 2: Construction of advance channel: Use the cooperation of comprehensive tunneling machine and side loader to construct the advance channel on the upper part of the coal seam, and carry out advance support of 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 through scraper conveyors and transfer belt conveyors.

[0033] The coal produced by the tunneling machine during the excavation of the advance passage 3 is pushed by the side loader to the scraper conveyor, and then transferred from the scraper conveyor to the transfer belt conveyor for transportation. In this embodiment, the advance passage 3 is 2.5 meters high, 6.2 meters wide, and 260 meters long. The tunneling machine and side loader achieve the purpose of mining coal at the coal mining face and excavating the advance passage 3. Because the composite roof of the large mining height is relatively fragile (the roof is mainly composed of muddy sandstone and gray sandstone), to prevent the roof from collapsing and caving behind the excavation, the tunneling machine and side loader are required to construct the advance passage 3 in the upper half of the 6-meter-high coal seam. The roof of the advance passage 3 is also supported by anchor cables and netting to ensure the stability of the roof behind the excavation and ensure the safety of the roof in the goaf and filling area. The top plate of the advance channel 3 is reinforced by anchoring cables and hanging nets manually to ensure the safety of workers entering the goaf for sealing operations. By reinforcing the top plate of the advance channel 3, the filling mining step distance can be increased, which can 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 using U-shaped steel beams and metal meshes.

[0034] 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 process, the hydraulic support 4 is pushed and pulled 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.

[0035] The coal cutter 2 gradually pushes and pulls the corresponding hydraulic support 4 during coal cutting; and the coal generated during coal cutting by 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. The hydraulic support 4 has a horizontal movement step of 4 meters. In order to improve the efficiency of coal cutting and filling, the coal cutter 2 can continuously move 5 cuts (0.8 meters / cut), and the hydraulic support 4 moves in a large step in the direction of mining. 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.

[0036] 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.

[0037] The width of the goaf filling area 7 is the step distance of the hydraulic support 4 moving toward 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. 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.

[0038] 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 the coal; the sealing cloths on the baffles of adjacent hydraulic supports 4 shall be connected with Velcro.

[0039] In this embodiment, isolation walls are stacked at both ends of the coal mining working face tunnel 1, that is, isolation walls are stacked at the ends of the machine tunnel and the ventilation tunnel, and two isolation walls are stacked at intervals in the goaf filling area 7, and the goaf filling area 7 is divided and sealed 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.

[0040] Step 5: Paste preparation and pumping filling: Gangue powder, fly ash, coagulant material and water are put into a mixer according to the paste material ratio and mixed to form a paste; the paste is pumped to the filling space through a pipeline.

[0041] Gangue powder, fly ash, coagulant material and water are weighed according to the material ratio and then put into the mixer. The fly ash and coagulant material are transported by a screw conveyor to their respective weighing hoppers for weighing. The crushed gangue powder is weighed and transported to the gangue waiting hopper by a belt conveyor. 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 an industrial filling pump and pipeline, stirred again by the underground secondary filling station, and then transported to the filling space through an industrial filling pump and 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. A material distribution valve is installed on the filling pipeline 9, and the paste injection hole is opened on the upper baffle 5.

[0042] Filling paste ratio and demand: The selection and ratio of filling paste is as follows: the finished slurry ratio of 1m³ 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, the cement is 120 kg / m³, the fly ash is 100kg / m³, and the water is 340 kg / m³. The fly ash can be replaced by ball-milled gangue powder. When the actual conditions such as the working face and geological structure change, special ratio experiments need to be carried out again to further optimize the filling material ratio to ensure that the relevant parameters such as paste strength, compaction rate, and setting time meet the requirements.

[0043] 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.

[0044] Step 7: Isolation wall removal: Multiple filling spaces are mixed and filled with paste and gangue in sequence. After one of the filling spaces is full, the isolation wall between it and 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.

[0045] 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; since 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 ensured, the filling and mining step distance can be increased to 4 meters / time, thereby improving the efficiency of filling and mining.

[0046] The embodiments described above are only preferred embodiments of the invention and do not 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: Paste material preparation and storage: The ground filling station crushes and screens the gangue, and the gangue powder with a particle size that meets the requirements for paste preparation is stored in the gangue finished product warehouse; the fly ash and coagulant materials required for paste preparation 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 comprehensive tunneling machine and a side loader, and the roof of the advance channel (3) is supported by anchor cables and nets. The coal and gangue produced by the excavation of the advance channel (3) are transported out by a scraper conveyor and a transfer belt conveyor; Step 3: Coal cutting: Use the coal cutter (2) to cut the coal at the lower part of the coal seam at the advance channel (3). During the coal cutting process, push and pull the hydraulic support (4) in sequence. The hydraulic support (4) moves in large steps in the direction of the advance channel (3). At the same time, continue to construct the next advance channel (3). Step 4: Isolation behind the frame: After the coal mining and frame pulling are completed, the space behind the hydraulic support (4) forms a large-step goaf filling area (7), a blocking 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: Gangue powder, fly ash, coagulant material and water are put into a mixer according to the paste material ratio 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 conveyor (8); Step 7: Dismantling of the isolation wall: Multiple filling spaces are sequentially filled with paste and gangue. When one of the filling spaces is full, the isolation wall between it and the next filling space is dismantled. When the goaf filling area (7) is full and the paste solidifies to reach the required strength, the next coal cutting cycle is carried out.

2. The method for large-step filling of a mixture of paste and gangue according to claim 1, characterized in that: In 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.

3. The method for large-step filling of a mixture of paste and gangue according to claim 1, characterized in that: In 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.

4. The method for large-step filling of a mixture of paste and gangue according to claim 1, 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. The method for large-step filling of a mixture of paste and gangue 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 pieces, the upper and lower pieces, and the two pieces of sealing cloth are adhered to each other using Velcro; 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.

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 is compacted with coal in 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 a mixture of paste and gangue according to claim 1, 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), and the filling pipeline (9) is hung 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 of 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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