A method and device for roughing in a coal and gangue underground and high-position dry backfilling in a goaf

Abstract

This invention discloses a method and apparatus for underground coarse selection of coal gangue and high-level dry backfilling of goaf in top-coal caving mining, belonging to the field of underground coal gangue disposal technology. The invention separates gangue with a particle size >50mm from the raw coal by installing an underground coarse selection device in the working face transport roadway. The separated coal is transported out of the mine via the lower layer of a double-layer belt conveyor, while the gangue is transferred to a gangue disposal roadway located above the goaf via the upper layer belt conveyor. A suspended belt conveyor in the gangue disposal roadway is equipped with a high-speed gangue disposal device at the end, which uses a self-propelled tracked trolley to continuously move the disposal point, evenly distributing the gangue to the goaf for backfilling. This invention achieves integrated underground closed-loop operation of "mining-selection-backfilling," reducing solid waste at the source, and has significant advantages such as simplified process, low cost, no water requirement, high disposal efficiency, no groundwater pollution, and environmental friendliness.

Description

Technical Field

[0001] This invention relates to the field of underground coal gangue disposal and green mining technology. Specifically, it relates to an integrated method and dedicated device for underground roughing, long-distance transportation and high-level dry backfilling of coal gangue in top coal caving mining processes. Background Technology

[0002] Top-coal caving mining technology has become the mainstream method for mining thick and extra-thick coal seams in my country due to its outstanding advantages such as high output, high efficiency, simple roadway layout, and strong adaptability to coal seam thickness. However, during the implementation of this technology, the complex top coal crushing mechanism and the difficulty in precisely controlling the coal discharge process result in a large amount of roof gangue and interbedded gangue being mixed into the raw coal, with gangue production rates generally reaching 15% to 30%. If these coal gangue generated during mining are hoisted to the surface using traditional methods, it not only drastically increases the energy consumption and cost of hoisting and transportation, but more seriously, the gangue piles formed by surface discharge will occupy land, release harmful gases, pollute water sources, and cause major ecological and environmental problems such as spontaneous combustion. This has become a core bottleneck restricting top-coal caving mining from becoming a green mine.

[0003] Currently, there are two main technical approaches for handling top coal caving gangue: The first is the "surface washing + slurry backfilling" model, where the gangue is lifted to the surface for washing, crushing, and grinding to produce a high-concentration slurry, which is then pumped into the goaf through surface boreholes. This method has a long process chain, huge equipment investment, high operating costs, and enormous water consumption. Furthermore, the moisture in the slurry can soften the coal seam floor and affect working face safety. The second is the "underground dry separation + waste roadway gangue removal" model, where gangue is simply sorted underground and then backfilled into waste roadways. However, this method is limited by the finite volume of waste roadways, resulting in a very low gangue disposal rate, which cannot meet the gangue removal needs of continuously high-production working faces. Therefore, there is an urgent need to develop a new in-situ disposal technology that enables high-efficiency, low-cost, large-capacity, and safe and reliable handling of top coal caving gangue without escaping to the surface. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a scientifically designed, coherent, economical and environmentally friendly method and device for underground roughing of coal gangue and high-level dry backfilling of goaf in top coal caving mining. It aims to fundamentally solve the technical problems of large output, difficult disposal and serious environmental pollution of gangue in top coal caving mining, and achieve the goal of green mining integrating "mining-benefiting-backfilling".

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides a method for underground coarse selection of coal gangue and high-level dry backfilling of goaf in top coal caving mining, characterized by comprising the following steps: The first step is the mining of the working face and the transportation of raw coal: the top coal caving mining process is adopted. The coal mining machine (9) cuts the coal, and the top coal (2) is discharged through the coal discharge port (5) of the top coal caving support (7). The cut coal and the discharged top coal are mixed and transported out by the front chute (8) and the rear chute (6) to form raw coal, which is then transported to the underground coarse separation equipment (11). The second step is underground coarse selection of coal and gangue: the raw coal enters the underground coarse selection equipment (11) for sorting, the sorted coal is transported to the main transportation system, and the sorted gangue (3) is transferred to the belt conveyor in the gangue discharge roadway. The third step is the transfer of coal gangue: the sorted gangue (3) is transported by the transfer belt conveyor (14) in the transfer roadway (16) to the hanging belt conveyor (19) in the gangue discharge roadway (17) above the goaf. The fourth step is high-level backfilling of the goaf: the gangue (3) is transported by the hanging belt conveyor (19) in the gangue discharge roadway (17) to the ultra-long distance high-speed gangue disposal device (41) at the front end of the goaf, and then thrown into the goaf by the high-speed gangue disposal machine (1) at its rear end. The throwing angle and speed of the high-speed gangue disposal machine (1) are adjusted to control the throwing trajectory of the gangue, and the gangue disposal machine (1) is moved along the gangue discharge roadway (17) by the self-propelled tracked trolley (20) to evenly throw the gangue (3) into the goaf, thus achieving dry backfilling.

[0006] Preferably, the downhole coarsening equipment (11) adopts roller screening technology, which can control the separation of gangue with a block size of 50mm or more as gangue (3).

[0007] The present invention also provides an underground roughing and high-level dry backfilling device for top coal caving mining gangue in implementing the method of claim 1 or 2, characterized in that it includes a coal mining device, a sorting device, a transfer device, and an ultra-long-distance high-speed gangue dumping device (41) connected in sequence; the coal mining device includes a coal mining machine (9), a top coal caving support (7), a front chute (8), and a rear chute (6); the sorting device is a well located at the intersection of the underground working face transport roadway (10) and the centralized transport roadway (31). The lower coarse selection equipment (11) includes a double-layer belt conveyor (22), a transfer belt conveyor (14) in the transfer tunnel (16), and a suspended belt conveyor (19) arranged in the waste disposal tunnel (17). The ultra-long distance high-speed waste disposal device (41) includes a self-moving tracked trolley (20), a suspended sliding belt conveyor (42), a fixed pulley block (26), a moving crossbeam (28), a chain (29), a manned pedal (43), and a high-speed waste disposal machine (1).

[0008] Preferably, the double-layer belt conveyor (22) adopts a belt conveyor structure with two independently driven upper and lower layers. The upper layer is a gangue conveyor belt conveyor for conveying gangue (3), and the lower layer is a coal conveyor belt conveyor (24) for conveying coarse coal.

[0009] Preferably, the suspended belt conveyor (19) is suspended from the top plate of the waste rock dumping roadway (17) by a chain (29), and its middle or rear part is mounted on the ultra-long distance high-speed waste rock dumping device (41).

[0010] Preferably, the ultra-long-distance high-speed waste rock disposal device (41) includes a self-propelled tracked trolley (20), a suspended sliding belt conveyor (42), a fixed pulley block (26), a movable crossbeam (28), a chain (29), a personnel board (43), and a high-speed waste rock disposal machine (1); wherein, the self-propelled tracked trolley (20) is a tracked chassis with self-drive and walking functions, which is used to support the belt conveyor frame and drive the high-speed waste rock disposal machine (1) to move back and forth along the waste rock disposal tunnel; the suspended sliding belt conveyor (42) 2) The device is suspended in the air by the fixed pulley block (26), the movable crossbeam (28) and the chain (29) to realize the lateral sliding of the ultra-long distance high-speed coal throwing device (41); the manned pedal (43) is connected to the reserved interface on the side of the suspended sliding belt conveyor (42) through the handrail. The manned pedal is used for operators to inspect and maintain key parts; the high-speed coal throwing machine (1) does not contact the ground and is suspended in the air by the suspended sliding belt conveyor (42).

[0011] Preferably, the high-speed gangue throwing machine (1) is installed below the discharge port (36) of the suspended sliding belt conveyor (42), and includes a hopper (37), an electric drum (38) and a gangue throwing belt (39). The initial velocity and trajectory of the gangue are controlled by adjusting the rotation speed of the electric drum (38) and the elevation angle of the gangue throwing belt (39).

[0012] Preferably, it also includes a local ventilation system, which is composed of a local ventilation fan (23), an air outlet (21), an air duct (32) and an air door (15) to continuously supply air to the waste rock dumping tunnel (17) and the filling operation area.

[0013] Preferably, a camera (34) and a sensor (35) are respectively installed in the middle section of the suspended sliding belt conveyor (42), on the top of the self-propelled crawler trolley (20), at the end of the suspended sliding belt conveyor (42) and at the discharge port (36). The camera (34) integrates a searchlight and video monitoring, and is used to provide lighting, monitor the gangue transportation status, trolley position, filling effect and feeding flow in real time, and connect to a remote monitoring system. The sensor (35) is used to monitor gas concentration and harmful gases.

[0014] Preferably, the waste rock dumping lane (17) is arranged in a single row or a double row. When arranged in a double row, each of the two waste rock dumping lanes is equipped with an independent suspended belt conveyor (19) and a high-speed waste rock dumping device (41) for ultra-long distance conveying. The present invention achieves the following technical effects compared to the prior art: 1. Revolutionary simplification of process flow: The traditional lengthy path of "lifting gangue to the well - surface processing - secondary backfilling" has been completely abandoned, realizing an integrated closed-loop operation of "downhole extraction - immediate sorting - in-situ backfilling", which greatly reduces the complexity of the system and the difficulty of operation and management.

[0015] 2. Significant economic and social benefits: It eliminates the huge energy consumption and equipment investment required for processes such as gangue hoisting, surface transportation, crushing, grinding, pulping, and pumping, while also saving a large amount of valuable water resources and cementing materials. Taking a caving coal mine with an annual output of 3 million tons as an example, it is estimated that it can save tens of millions of yuan in comprehensive costs annually.

[0016] 3. Enhanced safety and efficiency in mining: The three major processes of "coal mining," "sorting," and "backfilling" can be carried out in parallel without interference, ensuring continuous and efficient advancement of the working face. The timely backfilling of gangue effectively controls roof collapse in the goaf, improves stress distribution in the mining area, reduces the risk of dynamic pressure disasters, and enhances the stability of the support system.

[0017] 4. Excellent environmental benefits: It achieves "zero emissions" of gangue at the source, completely eliminating the risks of land occupation, air pollution, water pollution and spontaneous combustion caused by the storage of gangue on the ground. It is a model technology for practicing the concept that "green mountains and clear waters are invaluable assets".

[0018] 5. Reliable and controllable filling effect: Through the adjustable throwing parameters of the high-speed gangue throwing machine and the precise movement of the self-propelled trolley, the gangue can be filled in the goaf at a long distance, uniformly and in layers. With the help of pressure monitoring, the filling density and support effect can be effectively guaranteed. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a plan view of the single-row coal mine roadway arrangement in Embodiment 1 of the present invention.

[0021] Figure 2 This is a plan view of the double-row coal seam layout in Embodiment 2 of the present invention.

[0022] Figure 3 This is a cross-sectional schematic diagram of the overall construction process of the present invention, showing the spatial relationship from coal mining, transportation, sorting to backfilling.

[0023] Figure 4 This is a cross-sectional schematic diagram of the waste rock removal and backfilling operation in the waste rock removal tunnel in this invention.

[0024] Figure 5 This is a detailed structural diagram of the ultra-long-distance high-speed waste rock disposal device of the present invention.

[0025] Figure 6 This is a detailed diagram of the sliding structure of the ultra-long-distance high-speed waste rock disposal device in this invention.

[0026] In the diagram: 1-High-speed gangue dumper; 2-Top coal; 3-Gangue; 4-Roof collapse gangue; 5-Coal discharge port; 6-Back chute; 7-Top coal discharge support; 8-Forward chute; 9-Coal mining machine; 10-Working face transport roadway; 11-Underground coarsening equipment; 12-Centralized track roadway; 13-Centralized return air roadway; 14-Transfer belt conveyor; 15-Air door; 16-Transfer roadway; 17-Gangue discharge roadway; 18-Anchor cable; 19-Suspended belt conveyor; 20-Self-propelled crawler trolley; 21-Air outlet; 22-Double-layer belt conveyor 23-Local ventilation fan; 24-Coal conveyor belt; 25-Connecting roadway; 26-Fixed pulley block; 27-Roof; 28-Moving crossbeam; 29-Chain; 30-Belt guardrail; 31-Centralized transport roadway; 32-Ventilation duct; 33-Coal seam; 34-Camera; 35-Sensor; 36-Discharge port; 37-Hopper; 38-Electric roller; 39-Rotary rock throwing belt; 40-Anchor bolt; 41-Long-distance high-speed rock throwing device; 42-Suspended sliding belt conveyor; 43-Personnel board. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1: Single-row coal mine roadway layout Reference Figure 1 , Figure 3 , Figure 4 , Figure 5 and Figure 6This embodiment provides a complete method for high-level dry backfilling of goaf using a single waste rock dumping tunnel, as well as an apparatus system for applying this method. The specific implementation steps are as follows: System layout and equipment installation: In the top-coal caving mining face, the top-coal caving support 7 is rationally arranged according to the thickness of the coal seam 33 and geological conditions to ensure that its support strength covers the entire working face. The coal mining machine 9 is installed in front of the support and arranged along the length of the working face. The front conveyor 8 and the rear conveyor 6 are installed at the front and rear of the support, respectively. Near the intersection of the working face transport roadway 10 and the centralized transport roadway 31, an underground coarsening device 11 is installed. In this embodiment, roller screening technology is preferred, which can control the separation of gangue with a block size of 50mm or more as gangue 3. Below the discharge end of the coarsening device 11, a double-layer belt conveyor 22 is installed, with the upper layer being a gangue transport belt conveyor and the lower layer being a coal transport belt conveyor 24. Starting from the upper discharge end of the double-layer belt conveyor 22, a transfer belt conveyor 14 arranged at an incline is connected. This belt conveyor is located in the transfer roadway 16 and directly connects to the gangue discharge roadway 17 located above the goaf and parallel to the working face. Inside the waste rock disposal tunnel 17, after the roof support is reinforced by anchor cables 18 and anchor bolts 40, the main body of the suspended belt conveyor 19 is suspended below the roof 27 using chains 29. The middle and rear parts of this belt conveyor are mounted on the ultra-long distance high-speed waste rock disposal device 41. A high-speed waste rock disposal machine 1 is installed below the end discharge port 36 of the suspended sliding belt conveyor 42. At the same time, a local ventilation fan 23 is installed in the transport tunnel 10, which supplies air to the waste rock disposal tunnel 17 through the ventilation duct 32 and the air door 15. The polluted air enters the centralized return air tunnel 13 through the air outlet 21.

[0030] Step 1: Working Face Mining and Raw Coal Transportation The coal mining machine 9 is started, allowing it to reciprocate along the guide slipper of the working face. The rotating drum cuts the coal seam 33, and the cut coal falls onto the front conveyor 8. Simultaneously, the tail beam and insert plate of the top coal caving support 7 are operated to open the coal caving outlet 5, allowing the top coal 2 above the support and a small amount of roof gangue 4 that naturally collapses during the coal caving process to fall together onto the rear conveyor 6. The front conveyor 8 and the rear conveyor 6 synchronously transport the mixed raw coal (including coal and gangue) to the working face transport roadway 10, and then feed it into the feed inlet of the underground coarsening equipment 11 via a transfer conveyor.

[0031] Step 2: Coal and gangue coarse separation underground The underground coarse separation equipment 11 (roller screen) operates under the drive of a roller screen motor. Raw coal forms a layer on the screen surface. Fine coal particles smaller than 50mm pass through the rollers and become undersize, falling into the lower coal conveyor belt 24 of the double-layer belt conveyor 22. These are transported to the coal bunker at the bottom of the mine and eventually lifted to the surface for further processing. Gangue 3, with a particle size larger than 50mm, cannot pass through the rollers and becomes oversize, exiting from the other end of the screen surface and falling into the upper gangue conveyor belt 22. This achieves the initial separation of coal and gangue underground.

[0032] Step 3: Long-distance transportation of coal gangue The upper-level gangue conveyor belt transports gangue 3 to its terminal and unloads it onto the transfer conveyor belt 14 in the transfer roadway 16. Since the transfer roadway 16 is an inclined connecting roadway from the transport level to the high-level gangue discharge roadway 17 above the goaf, the transfer conveyor belt 14 inside it has a large inclination angle and strong lifting function, which continuously and stably transports the gangue upwards, and finally unloads it to the receiving end of the suspended conveyor belt 19 in the gangue discharge roadway 17.

[0033] Step 4: High-level backfilling of the goaf with waste rock. The suspended belt conveyor 19 starts, transporting the gangue 3 to the ultra-long-distance high-speed gangue throwing device 41 at its rear. The gangue falls into the hopper 37 of the high-speed gangue throwing machine 1 through the discharge port of the suspended sliding belt conveyor 42 of the ultra-long-distance high-speed gangue throwing device 41. The two electric rollers 38 of the high-speed gangue throwing machine 1 drive the gangue throwing belt 39 to rotate at a set speed (e.g., 800-1200 rpm), while the discharge angle of the gangue throwing belt 39 (e.g., 30°-45°) is pre-adjusted. The falling gangue is thrown out at high speed by the gangue throwing belt 39, gaining a large initial velocity and flying towards the depth of the goaf along the designed parabolic trajectory. At the same time, the self-propelled tracked trolley 20 moves slowly backward (towards the goaf) along the gangue dumping roadway 17 under remote control. Because the suspended sliding belt conveyor 42 is fixed on the trolley, the movement of the trolley drives the belt conveyor and its end-mounted high-speed waste rock dumping machine 1 to move synchronously, thus continuously changing the waste rock landing point. Through the continuous or step-by-step movement of the trolley, the high-speed waste rock dumping machine 1 can evenly scatter and cover the entire length of the goaf. By adjusting the throwing parameters, the accumulation of waste rock in the width direction of the goaf can be controlled. This process is repeated to achieve dry filling of the goaf.

[0034] Process monitoring and safety assurance: Throughout the operation, cameras 34, integrated with searchlights and video surveillance, are positioned in the middle section of the suspended sliding belt conveyor 42, on top of the self-propelled tracked trolley 20, and near the discharge port 36. These provide illumination and capture images in real time, transmitting them to the ground control center via the underground ring network. Operators can clearly see the status of the waste rock transport, the trolley position, and the effect of waste rock dumping and backfilling. Sensors 35 on top of the discharge port 36 monitor and detect methane concentration and harmful gas content in real time. Local ventilation fans 23 operate continuously to ensure sufficient airflow in the waste rock discharge tunnel 17, effectively diluting and expelling dust and potential methane. Air dampers 15 ensure correct airflow direction and prevent short circuits, providing a safe and reliable environment for personnel and equipment.

[0035] like Figure 1-6 The method for coking and backfilling the goaf in the underground coal gangue during top coal caving mining relies on a set of sequentially connected coal mining equipment, sorting equipment, transfer equipment, and ultra-long distance high-speed gangue dumping equipment 41. Specifically, the coal mining device includes a coal mining machine 9, a top coal caving support 7, a front conveyor 8 and a rear conveyor 6; the sorting device is an underground coarsening device 11 located at the intersection of the underground working face transport roadway 10 and the centralized transport roadway 31; the transfer device includes a lower coal transport belt conveyor 24 and an upper gangue transport belt conveyor of a double-layer belt conveyor 22 for coal transport, a transfer roadway 16 for gangue transport and a transfer belt conveyor 14 therein, and a suspended belt conveyor 19 arranged in the gangue discharge roadway 17; the ultra-long distance high-speed gangue throwing device (41) includes a self-moving tracked trolley (20), a suspended sliding belt conveyor (42), a fixed pulley block (26), a moving crossbeam (28), a chain (29), a manned pedal (43), and a high-speed gangue throwing machine (1). In addition, the system is also equipped with local ventilation fans 23, air outlets 21, air ducts 32 and air dampers 15 to ensure ventilation safety in the work area.

[0036] The underground coarsening equipment 11 preferably employs roller screening technology, whose separation principle is based on the particle size difference between coal and gangue. By setting the roller screening size to 50mm (which can be adjusted within the range of 40-60mm according to the characteristics of the coal seam interbedded with gangue), materials with a particle size ≤50mm are transported out of the mine as roller screen undersize (i.e., coarse coal), while gangue 3 with a particle size >50mm is transported as roller screen oversize and used for backfilling. This setup can effectively separate most of the gangue in the raw coal, ensuring the quality of the separated coal while improving the gangue capture rate.

[0037] The double-layer belt conveyor 22 adopts a structure with two independently driven belt conveyors. The upper layer is a gangue conveyor, used to receive and transport the gangue 3 discharged from the coarse separation equipment 11; the lower layer is a coal conveyor 24, used to receive and transport the sorted coarse coal. The two belt conveyors operate in the same direction but are isolated from each other, achieving effective separation of coal and gangue after sorting.

[0038] The transfer tunnel 16 is an inclined tunnel, with its lower end connected to the bottom centralized transport tunnel 31 and its upper end connected to the top waste rock discharge tunnel 17. A transfer belt conveyor 14, which acts as a conveyor belt, is installed in the transfer tunnel 16 to continuously and stably transport the waste rock 3 from the upper layer of the double-layer belt conveyor 22 to the waste rock discharge tunnel 17 along the inclined tunnel.

[0039] The suspended belt conveyor 19 consists of a belt conveyor body and a suspension mechanism. The suspension mechanism is a chain 29 fixed to the roof of the waste rock dumping roadway 17, allowing the belt conveyor body to be suspended in the middle of the roadway space via the chain 29, with belt guardrails 30 on both sides. A section of the belt conveyor near the goaf is mounted on the ultra-long distance high-speed waste rock dumping device 41. The suspended sliding belt conveyor 42 is mounted on a self-propelled tracked trolley 20 and suspended in the air via a fixed pulley block 26, a movable crossbeam 28, and a chain 29. This allows the belt conveyor section and its end-of-line high-speed waste rock dumping machine 1 to move synchronously with the trolley, enabling flexible adjustment of the waste rock dumping operation point.

[0040] The self-propelled tracked trolley 20 is a tracked chassis with autonomous driving force and walking function. It is equipped with a belt conveyor support frame to support part of the frame of the suspended sliding belt conveyor 42. By controlling the trolley to move back and forth along the waste rock dumping roadway 17, it can drive the high-speed waste rock dumping machine 1 to perform fixed-point or continuous waste rock dumping operations at different locations in the goaf.

[0041] The high-speed gangue throwing machine 1 is not in contact with the ground and is suspended below the discharge port of the suspended sliding belt conveyor 42. Its structure mainly includes a hopper 37, two electric rollers 38, and a gangue throwing belt 39. Gangue 3 falls from the discharge port of the suspended belt conveyor 19 into the hopper 37 of the high-speed gangue throwing machine 1, and then enters the gangue throwing belt 39, which is driven and speed-controlled by the two electric rollers 38. By adjusting the rotation speed and discharge angle of the gangue throwing belt 39, the initial velocity and trajectory of the gangue can be controlled, thereby achieving uniform and long-distance throwing and accumulation of gangue in the goaf.

[0042] To ensure effective ventilation and a safe working environment, this invention incorporates a comprehensive local ventilation system. This system comprises a local ventilation fan 23, an air outlet 21, a ventilation duct 32, and an air damper 15, ensuring uninterrupted airflow and compliant air quality in the waste rock dumping roadway 17 and the goaf filling area. The local ventilation fan 23 is installed at the fresh air inlet, continuously supplying air to the waste rock dumping roadway 17 and the filling work area to dilute and expel harmful gases such as dust and methane. The air outlet 21 is located at the end of the waste rock dumping roadway 17, guiding polluted air smoothly towards the return air system. The ventilation duct 32 is arranged along the roadway roof and connects the local ventilation fan 23 to the work area, guiding and delivering fresh air to the filling work area. The air damper 15 is located in the key connecting roadway 25 or the ventilation transition section, used to adjust the airflow direction and volume, preventing airflow short-circuiting and ensuring an effective ventilation path. The ventilation system, in conjunction with the roadway layout, enables the orderly flow of air from the centralized transport roadway 31 through the transfer roadway 16 to the waste rock disposal roadway 17, with the waste air ultimately being discharged through the centralized return air roadway 13.

[0043] To ensure safe equipment operation and controllable filling process, cameras 34 and sensors 35 are installed at the following key locations: a camera 34 is installed in the middle section of the suspended sliding belt conveyor 42 to monitor the real-time transport status of the gangue; a camera 34 is installed on the top of the self-propelled tracked trolley 20 to monitor the trolley's position and operation; a camera 34 is installed on the top of the rear end of the suspended sliding belt conveyor 42 to observe the filling effect of the goaf; and a sensor 35 is installed on the top of the discharge port 36 of the suspended sliding belt conveyor 42 to monitor methane concentration and harmful gases. All cameras are equipped with searchlights to provide illumination for underground operations. All monitoring signals can be connected to a remote monitoring system, thereby achieving automated monitoring and intelligent scheduling of the entire transfer and filling process.

[0044] To ensure the filling effect, the waste rock dumping tunnel 17 can be arranged in a single row or double row (e.g., Figure 1 , Figure 2 (As shown). When a double-row arrangement is adopted, simultaneous filling on both sides can be achieved, thereby effectively improving the efficiency of gangue processing. The top of the gangue disposal tunnel 17 is supported by anchor cables 18 to ensure the stability of the tunnel.

[0045] Example 2: Double-row coal mine roadway layout Reference Figure 2 When the working face is long (e.g., exceeding 250 meters) or the gangue production rate is extremely high (e.g., exceeding 25%), the gangue dumping and backfilling capacity of a single gangue dumping tunnel may not fully meet the requirements for rapid backfilling. Therefore, this invention provides an embodiment of a double-row gangue dumping tunnel layout.

[0046] The main difference between this embodiment and Embodiment 1 is that two parallel waste rock dumping roadways 17 are arranged above the goaf, connected by a connecting roadway 25 to ensure flexibility in ventilation and transportation. Each waste rock dumping roadway 17 is independently equipped with a complete filling device, including its own suspended belt conveyor 19 and a high-speed waste rock dumping device 41 for ultra-long distance transport. The waste rock 3 separated by the underground coarse separation equipment 11 can be evenly distributed to the waste rock transportation system of the two waste rock dumping roadways via a transfer belt conveyor 14 and a matching material distribution device (such as a reversible belt or a material distribution chute). The two waste rock dumping roadways can carry out waste rock dumping operations simultaneously, realizing synchronous filling of the goaf on both sides.

[0047] This double-row arrangement can double the backfilling capacity of the gangue, significantly shorten the distance of delayed backfilling at the working face, and ensure timely and effective support for the roof. It is especially suitable for the green mining requirements of ultra-high mining height and ultra-long working faces. The specific operating steps, equipment working principles, and monitoring and ventilation measures are the same as in Example 1, and will not be repeated here.

[0048] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for underground coarse selection of coal gangue and high-level dry backfilling of goaf in top coal caving mining, characterized in that, Includes the following steps: The first step is the mining of the working face and the transportation of raw coal: the top coal caving mining process is adopted. The coal mining machine (9) cuts the coal, and the top coal (2) is discharged through the coal discharge port (5) of the top coal caving support (7). The cut coal and the discharged top coal are mixed and transported out by the front chute (8) and the rear chute (6) to form raw coal, which is then transported to the underground coarse separation equipment (11). The second step is underground coarse selection of coal and gangue: the raw coal enters the underground coarse selection equipment (11) for sorting, the sorted coal is transported to the main transportation system, and the sorted gangue (3) is transferred to the belt conveyor in the gangue discharge roadway. The third step is the transfer of coal gangue: the sorted gangue (3) is transported by the transfer belt conveyor (14) in the transfer roadway (16) to the hanging belt conveyor (19) in the gangue discharge roadway (17) above the goaf. The fourth step is high-level backfilling of the goaf: the gangue (3) is transported by the hanging belt conveyor (19) in the gangue discharge roadway (17) to the ultra-long distance high-speed gangue disposal device (41) at the front end of the goaf, and then thrown into the goaf by the high-speed gangue disposal machine (1) at its rear end. The throwing angle and speed of the high-speed gangue disposal machine (1) are adjusted to control the throwing trajectory of the gangue, and the gangue disposal machine (1) is moved along the gangue discharge roadway (17) by the self-propelled tracked trolley (20) to evenly throw the gangue (3) into the goaf, thus achieving dry backfilling.

2. The method for underground coarse selection of coal gangue and high-level dry backfilling of goaf in top coal caving mining according to claim 1, characterized in that, The downhole coarse separation equipment (11) adopts roller screening technology, which can control the separation of gangue with a block size of 50mm or more, as gangue (3).

3. A device for underground roughing of coal gangue and high-level dry backfilling of goaf in top-coal caving mining for implementing the method described in claim 1 or 2, characterized in that, The system includes a coal mining device, a sorting device, a transfer device, and a high-speed gangue throwing device for ultra-long distance transportation (41) connected in sequence. The coal mining device includes a coal mining machine (9), a top coal caving support (7), a front chute (8), and a rear chute (6). The sorting device is an underground coarse sorting device (11) set at the intersection of the underground working face transport roadway (10) and the centralized transport roadway (31). The transfer device includes a double-layer belt conveyor (22), a transfer belt conveyor (14) in the transfer roadway (16), and a suspended belt conveyor (19) arranged in the gangue dumping roadway (17). The high-speed gangue throwing device for ultra-long distance transportation (41) includes a self-moving tracked trolley (20), a suspended sliding belt conveyor (42), a fixed pulley block (26), a moving crossbeam (28), a chain (29), a manned pedal (43), and a high-speed gangue throwing machine (1).

4. The underground roughing and high-level dry backfilling device for top coal caving mining gangue as described in claim 3, characterized in that, The double-layer belt conveyor (22) adopts a belt conveyor structure with two independently driven layers. The upper layer is a gangue conveyor belt conveyor for conveying gangue (3), and the lower layer is a coal conveyor belt conveyor (24) for conveying coarse coal.

5. The underground roughing and high-level dry backfilling device for top coal caving mining gangue as described in claim 3, characterized in that, The suspended belt conveyor (19) is suspended from the top plate of the waste rock dumping roadway (17) by a chain (29), and its middle or rear part is mounted on the ultra-long distance high-speed waste rock dumping device (41).

6. The underground coarse selection and high-level dry backfilling device for top coal caving mining gangue as described in claim 3, characterized in that, The ultra-long distance high-speed waste rock disposal device (41) includes a self-propelled tracked trolley (20), a suspended sliding belt conveyor (42), a fixed pulley block (26), a moving crossbeam (28), a chain (29), a personnel board (43), and a high-speed waste rock disposal machine (1); wherein, the self-propelled tracked trolley (20) is a tracked chassis with self-drive and walking functions, which is used to support the belt conveyor frame and drive the high-speed waste rock disposal machine (1) to move back and forth along the waste rock disposal tunnel; the suspended sliding belt conveyor (42) The device is suspended in the air by the fixed pulley block (26), the movable crossbeam (28) and the chain (29) to achieve the lateral sliding of the ultra-long distance high-speed coal throwing device (41); the manned pedal (43) is connected to the reserved interface on the side of the suspended sliding belt conveyor (42) through the handrail. The manned pedal is used for operators to inspect and maintain key parts; the high-speed coal throwing machine (1) does not contact the ground and is suspended in the air by the suspended sliding belt conveyor (42).

7. The underground roughing and high-level dry backfilling device for top coal caving mining gangue as described in claim 3, characterized in that, The high-speed gangue throwing machine (1) is installed below the discharge port (36) of the suspended sliding belt conveyor (42), and includes a hopper (37), an electric drum (38) and a gangue throwing belt (39). The initial velocity and trajectory of the gangue are controlled by adjusting the rotation speed of the electric drum (38) and the elevation angle of the gangue throwing belt (39).

8. The underground roughing and high-level dry backfilling device for top coal caving mining gangue as described in claim 3, characterized in that, It also includes a local ventilation system, which consists of a local ventilation fan (23), an air outlet (21), an air duct (32) and an air door (15) to continuously supply air to the waste rock dumping tunnel (17) and the filling operation area.

9. The underground roughing and high-level dry backfilling device for top coal caving mining gangue as described in claim 3, characterized in that, Cameras (34) and sensors (35) are respectively installed in the middle section of the suspended sliding belt conveyor (42), on the top of the self-propelled crawler trolley (20), at the end of the suspended sliding belt conveyor (42) and at the discharge port (36). The camera (34) integrates a searchlight and video monitoring, and is used to provide lighting, monitor the gangue transportation status, trolley position, filling effect and feeding flow in real time, and connect to the remote monitoring system. The sensor (35) is used to monitor the gas concentration and harmful gases.

10. The underground roughing and high-level dry backfilling device for top coal caving mining gangue as described in claim 3, characterized in that, The waste rock dumping lane (17) can be arranged in a single row or in a double row. When arranged in a double row, each of the two waste rock dumping lanes is equipped with an independent suspended belt conveyor (19) and a high-speed waste rock dumping device for ultra-long distance transportation (41).

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