A coal mining method for steeply inclined coal seams with large dip angle in single roadway arrangement

Abstract

The application discloses a coal mining method for large-inclination steep-inclination coal seam with single-lane arrangement, and belongs to the technical field of coal mining, and comprises the following steps: driving a single-section main lane along a target coal seam floor to a mining area boundary; adopting an isolation wind-blocking wall to separate the section main lane into a transportation and pedestrian channel and a special return air channel; constructing a open-off cut at the mining area boundary, installing a hydraulic coal caving end support at a connection position of a working face lower outlet and the section main lane; adopting a backward mining to a section main lane direction to complete a cycle operation of a single recovery step distance; when the working face retreats to a designed stop mining line position, adopting a concrete sealing wall to block the open-off cut to isolate a goaf; the single-lane dynamic isolation forms independent air inlet and return channels, guarantees that an operation area is always in fresh air flow, adopts remote fracturing to replace traditional blasting to break coal, and adopts the backward mining, so that operation personnel operate in a safe area in the lane all the time, and personal injury accidents caused by coal and rock collapse and impact are fundamentally avoided.

Description

Technical Field

[0001] This invention belongs to the field of coal mining technology, specifically relating to a method for mining coal seams with steep inclination angles arranged in a single roadway. Background Technology

[0002] Steeply inclined coal seams are an important type of coal resource in my country. Nearly one-third of the 20 mines under Sichuan Coal Group are mining steeply inclined coal seams. Currently, the industry has mature mining experience for steeply inclined coal seams with dip angles of 45° to 60°. However, for steeply inclined coal seams with dip angles greater than 60°, there are still industry pain points such as high mining difficulty, high safety risks, high costs, and low efficiency.

[0003] Traditional steeply inclined coal seam mining requires the simultaneous excavation of a dual-roadway system, consisting of a section transport roadway and a section return air roadway. This system involves a large amount of excavation work, high construction costs, and a long construction period. For steeply inclined thin coal seams with a thickness of 0.8-1.5m, or for corner coal seams in aging mines, the dual-roadway layout is extremely uneconomical, and may even be uneconomical to mine. Existing single-roadway layout technology cannot effectively solve the problem of separating transport, pedestrian, and return air functions, which can easily lead to major safety hazards such as airflow short-circuiting, air leakage in goaf areas, and gas accumulation, and cannot meet the requirements of coal mine safety regulations.

[0004] Meanwhile, traditional steeply inclined coal seam mining often employs blasting techniques, which pose a significant safety risk of gas ignition from blasting sparks, making it particularly unsuitable for high-gas mines. Furthermore, personnel and transportation equipment must be located within the working face, exposing workers to direct risks of personal injury from coal and rock collapses and impacts. Existing conventional hydraulic supports are mostly designed for gently inclined coal seams and cannot meet the core requirements of impact protection, precise coal release control, and self-moving in confined spaces under steeply inclined conditions, thus failing to integrate with single-roadway mining systems.

[0005] In summary, the industry urgently needs a low-cost, high-safety, high-efficiency, and highly adaptable method for mining steeply inclined coal seams. Summary of the Invention

[0006] In view of this, the present invention provides a method for mining coal seams with steep inclination angles arranged in a single roadway, in order to solve the above-mentioned problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for mining steeply inclined coal seams with a single roadway arrangement includes the following steps: S1. Mining preparation: Excavate a single section of the main roadway along the bottom of the target coal seam to the boundary of the mining area. Use a movable isolation windbreak wall to divide the main roadway of the section into independent transport and pedestrian passages and a dedicated return air passage. Construct a cutting hole at the boundary of the mining area and install a hydraulic coal discharge end support at the junction of the lower outlet of the working face and the main roadway of the section. S2. Shortwall retreat mining cycle: adopts retreat mining from the boundary of the mining area towards the main roadway of the section to complete the cycle operation of a single mining step. S3. Goaf Sealing: When the working face retreats to the designed stop line position, a concrete sealing wall is used to seal the opening, isolate the goaf, and complete the mining operation.

[0008] Furthermore, the specific operational steps of the shortwall retreat mining cycle in step S2 are as follows: S21. Fracturing drilling construction: Inside the transport pedestrian passage and behind the hydraulic coal discharge end support, a fan-shaped fracturing borehole network is constructed upward along the coal seam, with the boreholes covering the entire inclined length of the working face. S22. Remote fracturing and coal breaking: Hydraulic or gas fracturing is carried out in stages from the upper to the lower end of the working face to induce coal body collapse and breakage; S23. Coal gravity collection: The crushed coal body slides down the coal seam floor under its own weight and collects in front of the hydraulic coal discharge end support at the lower outlet of the working face. S24. Controllable coal discharge and transportation: By remotely controlling and adjusting the opening of the coal discharge port of the hydraulic coal discharge end support, the coal is evenly discharged to the transfer machine in the transportation pedestrian passage and transported out by belt conveyor; S25. Support and System Follow-up: After completing a single mining step, control the hydraulic coal discharge end support to step back one step, temporarily support the exposed roof area after the hydraulic coal discharge end support has retreated, and simultaneously move the isolation windbreak wall forward to maintain the independent structure of the transport pedestrian passage and the dedicated return air passage. S26. Ventilation control: Fresh air flows into the working face through the transport and pedestrian passage, while polluted air is discharged through the return air end of the working face into a dedicated return air passage, forming a directional negative pressure ventilation system.

[0009] Furthermore, in step S1, the isolation windbreak wall is made of bamboo damper panels or precast concrete panels seamlessly joined together. The gap between the damper panels and the roadway roof is sealed with fireproof mud, which has fireproof and moisture-proof properties and can be quickly disassembled and moved forward as the working face advances.

[0010] Furthermore, in step S1, the transport pedestrian passage is equipped with a transfer machine, a belt conveyor, a pedestrian passage and pipelines, which serve the functions of air intake, personnel passage, coal transportation and drainage; the dedicated return air passage is connected to the mining area return air system, which serves the function of return air to the working face, and the isolation windbreak wall prevents air leakage and airflow short circuit in the goaf.

[0011] Furthermore, in step S1, the working surface is a short-walled working surface with an inclined length of no more than 50m.

[0012] Furthermore, the hydraulic coal discharge end support includes a movable base, a supporting top plate, a coal discharge assembly, and a supporting assembly. The supporting top plate is connected to the movable base through the supporting assembly. One end of the coal discharge assembly is connected to the movable base, and the other end is connected to the supporting top plate. The coal discharge assembly is used to adjust the coal discharge angle. An impact-resistant buffer layer is provided on the supporting top plate.

[0013] Furthermore, the support assembly includes a first support rod and a second support rod, both of which are hydraulic telescopic rods. One end of the first support rod is fixedly connected to the movable base, and the other end is hinged to the bottom end of the support top plate. One end of the second support rod is hinged to the movable base, and the other end is hinged to the bottom end of the support top plate.

[0014] Furthermore, the coal discharge assembly includes a coal discharge baffle, which is hinged to the end of the supporting top plate. A coal discharge hydraulic rod is hinged to the bottom end of the coal discharge baffle, and the end of the coal discharge hydraulic rod away from the coal discharge baffle is hinged to the movable base.

[0015] Furthermore, the overall width of the hydraulic coal discharge end support is 1.5-1.75m, which, together with the single-lane isolation windbreak wall, forms a dual channel for transportation and return air.

[0016] Furthermore, in step S2.5, the exposed area of ​​the roof slab is temporarily supported by single hydraulic props in conjunction with metal mesh to shorten the gap between the roof and the ceiling and control the risk of roof collapse; the isolation windbreak wall is moved forward every 3m to maintain the integrity of the dual-channel structure.

[0017] The beneficial effects of this invention are as follows: This invention employs remote hydraulic / gas fracturing to replace traditional blasting coal breaking, completely eliminating the risk of gas explosions caused by blasting sparks, and is particularly suitable for the mining needs of high-gas mines. It utilizes a retreat mining method, allowing workers to operate entirely within a safe area within the roadway, with no personnel working at the working face, fundamentally avoiding personal injury accidents caused by coal and rock collapses and impacts. Only a single section of the main roadway needs to be excavated, eliminating the need for a separate return airway, reducing the amount of roadway excavation work, significantly lowering the cost of excavation materials and labor, shortening the mine construction period, and dynamically isolating each roadway to form independent intake and return air channels, preventing air leakage and airflow short-circuiting in the goaf, ensuring the working area is always in a fresh airflow, effectively preventing gas accumulation, and greatly improving ventilation safety and reliability. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 A process flow diagram of a coal mining method for a single-lane, steeply inclined coal seam. Figure 2 This is a top view of the main lane of the section; Figure 3 for Figure 2 AA section view in the middle; Figure 4 This is a cross-sectional layout diagram of the tunnel. In the figure: 1-Main roadway of section, 11-Transport pedestrian passage, 12-Dedicated return air passage, 2-Isolation windbreak wall, 3-Belt conveyor, 4-Transfer conveyor, 5-Hydraulic coal discharge end support, 51-Mobile base, 52-Roof support, 53-Coal discharge baffle, 531-Coal discharge hydraulic rod, 54-Support assembly, 541-First support rod, 542-Second support rod. Detailed Implementation

[0020] 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.

[0021] See attached document Figure 1-4 This embodiment discloses a method for mining steeply inclined coal seams with a single roadway arrangement, comprising the following steps: S1. Mining preparation: Excavate a single section main roadway 1 along the bottom plate of the target coal seam to the boundary of the mining area. Use a movable isolation windbreak wall 2 to divide the section main roadway 1 into an independent transport and pedestrian passage 11 and a dedicated return air passage 12. Construct a cutting hole at the boundary of the mining area and install a hydraulic coal discharge end support 5 at the junction of the lower outlet of the working face and the section main roadway 1. S2. Shortwall retreat mining cycle: The retreat mining is carried out from the boundary of the mining area towards the main roadway 1 of the section to complete the cycle operation of a single mining step. S3. Goaf Sealing: When the working face retreats to the designed stop line position, a concrete sealing wall is used to seal the opening, isolate the goaf, and complete the mining operation.

[0022] Furthermore, the specific operational steps of the shortwall retreat mining cycle in step S2 are as follows: S21. Fracturing drilling construction: Inside the transportation pedestrian passage 11, behind the hydraulic coal discharge end support 5, a fan-shaped fracturing drilling network is constructed along the coal seam upwards, with the drilling covering the entire inclined length of the working face. S22. Remote fracturing and coal breaking: Hydraulic or gas fracturing is carried out in stages from the upper to the lower end of the working face to induce coal body collapse and breakage; S23. Coal gravity collection: The crushed coal slides down the coal seam floor under its own weight and collects in front of the hydraulic coal discharge end support 5 at the lower outlet of the working face. S24. Controllable coal discharge and transportation: By remotely controlling and adjusting the opening of the coal discharge port of the hydraulic coal discharge end support 5, the coal is evenly discharged into the transfer machine 4 in the transportation pedestrian passage 11 and transported out by the belt conveyor 3; S25. Support and system follow-up: After completing a single mining step, control the hydraulic coal discharge end support 5 to step back one step, temporarily support the exposed roof area after the hydraulic coal discharge end support 5 has retreated, and simultaneously move the isolation windbreak wall 2 forward to maintain the independent structure of the transport pedestrian passage 11 and the dedicated return air passage 12. S26. Ventilation control: Fresh air flows into the working face through the transport and pedestrian passage 11, while polluted air is discharged through the return air end of the working face into the dedicated return air passage 12, forming a directional negative pressure ventilation system.

[0023] In a preferred embodiment, in step S1, the isolation windbreak wall 2 is made of bamboo windbreak panels or precast concrete panels seamlessly joined together. The gap between the windbreak panels and the roadway roof is sealed with fireproof mud, which has fireproof and moisture-proof properties and can be quickly disassembled and moved forward as the working face advances.

[0024] In a preferred embodiment, in step S1, the transport pedestrian passage 11 is equipped with a transfer machine 4, a belt conveyor 3, a pedestrian passage and pipelines, which serve the functions of air intake, personnel passage, coal transportation and drainage; the dedicated return air passage 12 is connected to the return air system of the mining area, which serves the function of return air to the working face, and the isolation windbreak wall 2 prevents air leakage and airflow short circuit in the goaf.

[0025] In a preferred embodiment, in step S1, the working surface is a short-walled working surface with an inclined length of no more than 50m.

[0026] In a preferred embodiment, the hydraulic coal discharge end support 5 includes a movable base 51, a supporting top plate 52, a coal discharge component, and a supporting component 54. The supporting top plate 52 is connected to the movable base 51 through the supporting component 54. One end of the coal discharge component is connected to the movable base 51, and the other end is connected to the supporting top plate 52. The coal discharge component is used to adjust the coal discharge angle. An anti-impact buffer layer is provided on the supporting top plate 52.

[0027] In a preferred embodiment, the support assembly 54 includes a first support rod 541 and a second support rod 542. Both the first support rod 541 and the second support rod 542 are hydraulic telescopic rods. One end of the first support rod 541 is fixedly connected to the movable base 51, and the other end is hinged to the bottom end of the supporting roof plate 52. One end of the second support rod 542 is hinged to the movable base 51, and the other end is hinged to the bottom end of the supporting roof plate 52. Through the telescopic cooperation of the first support rod 541 and the second support rod 542, the support height and support angle of the supporting roof plate 52 can be adjusted to adapt to changes in the roof of a steeply inclined coal seam.

[0028] In a preferred embodiment, the coal discharge assembly includes a coal discharge baffle 53, which is hinged to the end of a supporting top plate 52. A coal discharge hydraulic rod 531 is hinged to the bottom end of the coal discharge baffle 53, and the end of the coal discharge hydraulic rod 531 away from the coal discharge baffle 53 is hinged to a movable base 51. By extending and shortening the coal discharge hydraulic rod 531, the angle of the coal discharge baffle 53 is changed, thereby adjusting the opening of the coal discharge port in real time.

[0029] In a preferred embodiment, the overall width of the hydraulic coal discharge end support 5 is 1.5-1.75m, which, together with the single-lane isolation windbreak wall 2, forms a dual channel for transportation and return air.

[0030] In a preferred embodiment, in step S2.5, the exposed area of ​​the roof is temporarily supported by a single hydraulic prop combined with a metal mesh to shorten the gap between the roof and the ceiling and control the risk of roof collapse; the isolation windbreak wall 2 moves forward every 3m to maintain the integrity of the dual-channel structure.

[0031] The above descriptions are merely specific embodiments of the present invention, and common knowledge regarding the specific structures and characteristics of the solutions is not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

[0032] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0033] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for mining steeply inclined coal seams with a single roadway arrangement, characterized in that, Includes the following steps: S1. Mining preparation: Excavate a single section main roadway (1) along the bottom plate of the target coal seam to the boundary of the mining area. Use a movable isolation windbreak wall (2) to divide the section main roadway (1) into an independent transport and pedestrian passage (11) and a dedicated return air passage (12). Construct a cutting hole at the boundary of the mining area and install a hydraulic coal discharge end support (5) at the junction of the lower outlet of the working face and the section main roadway (1). S2. Short-wall retreat mining cycle: Retreat mining is carried out from the boundary of the mining area to the main roadway (1) of the section to complete the cycle operation of a single mining step. S3. Goaf Sealing: When the working face retreats to the designed stop line position, a concrete sealing wall is used to seal the opening, isolate the goaf, and complete the mining operation.

2. The method for mining steeply inclined coal seams with a single roadway arrangement according to claim 1, characterized in that, The specific operating steps of the shortwall retreat mining cycle in step S2 are as follows: S21. Fracturing borehole construction: Inside the transport pedestrian passage (11) and behind the hydraulic coal discharge end support (5), a fan-shaped fracturing borehole network is constructed along the coal seam upwards, with the boreholes covering the entire inclined length of the working face; S22. Remote fracturing and coal breaking: Hydraulic or gas fracturing is carried out in stages from the upper to the lower end of the working face to induce coal body collapse and breakage; S23. Coal self-flowing and gathering: The crushed coal body slides down the bottom plate of the coal seam by its own weight and gathers in front of the hydraulic coal discharge end support (5) at the lower outlet of the working face; S24. Controllable coal discharge transportation: By remotely controlling and adjusting the opening of the coal discharge port of the hydraulic coal discharge end support (5), the coal is evenly discharged to the transfer machine (4) in the pedestrian passage (11) and transported out by the belt conveyor (3); S25. Support and system follow-up: After completing a single mining step, control the hydraulic coal discharge end support (5) to step back one step, temporarily support the exposed roof area after the hydraulic coal discharge end support (5) retreats, and simultaneously move the isolation windbreak wall (2) forward to maintain the independent structure of the transport pedestrian passage (11) and the dedicated return air passage (12); S26. Ventilation control: Fresh air flows into the working face through the transport pedestrian passage (11), and polluted air is discharged through the working face return air end into the dedicated return air passage (12), forming a directional negative pressure ventilation system.

3. The method for mining steeply inclined coal seams with a single roadway arrangement according to claim 1, characterized in that, In step S1, the isolation windbreak wall (2) is made of bamboo windbreak panels or precast concrete panels seamlessly joined together. The gap between the windbreak panel and the roadway roof is sealed with fireproof mud, which has fireproof and moisture-proof properties and can be quickly disassembled and moved forward as the working face advances.

4. A method for mining steeply inclined coal seams with a single roadway arrangement according to claim 1, characterized in that, In step S1, the transport pedestrian passage (11) is equipped with a transfer machine (4), a belt conveyor (3), a pedestrian passage and pipelines, which are responsible for air intake, personnel passage, coal transportation and drainage. The dedicated return air passage (12) is connected to the return air system of the mining area, which is responsible for the return air function of the working face. The isolation windbreak wall (2) prevents air leakage and airflow short circuit in the goaf.

5. A method for mining steeply inclined coal seams with a single roadway arrangement according to claim 1, characterized in that, In step S1, the working surface is a short-walled working surface with an inclined length of no more than 50m.

6. A method for mining steeply inclined coal seams with a single roadway arrangement according to claim 1, characterized in that, The hydraulic coal discharge end support (5) includes a movable base (51), a supporting top plate (52), a coal discharge assembly, and a supporting assembly (54). The supporting top plate (52) is connected to the movable base (51) through the supporting assembly (54). One end of the coal discharge assembly is connected to the movable base (51), and the other end is connected to the supporting top plate (52). The coal discharge assembly is used to adjust the coal discharge angle. An anti-impact buffer layer is provided on the supporting top plate (52).

7. A method for mining steeply inclined coal seams with a single roadway arrangement according to claim 6, characterized in that, The support assembly (54) includes a first support rod (541) and a second support rod (542). Both the first support rod (541) and the second support rod (542) are hydraulic telescopic rods. One end of the first support rod (541) is fixedly connected to the movable base (51), and the other end is hinged to the bottom end of the support top plate (52). One end of the second support rod (542) is hinged to the movable base (51), and the other end is hinged to the bottom end of the support top plate (52).

8. A method for mining steeply inclined coal seams with a single roadway arrangement according to claim 6, characterized in that, The coal discharge assembly includes a coal discharge baffle (53), which is hinged to the end of the supporting top plate (52). A coal discharge hydraulic rod (531) is hinged to the bottom end of the coal discharge baffle (53), and the end of the coal discharge hydraulic rod (531) away from the coal discharge baffle (53) is hinged to the movable base (51).

9. A method for mining steeply inclined coal seams with a single roadway arrangement according to claim 6, characterized in that, The overall width of the hydraulic coal discharge end support (5) is 1.5-1.75m, which, together with the single-lane isolation windbreak wall (2), forms a dual channel for transportation and return air.

10. A method for mining steeply inclined coal seams with a single roadway arrangement according to claim 2, characterized in that, In step S2.5, the exposed area of ​​the roof is temporarily supported by single hydraulic props and metal mesh to shorten the gap between the roof and the ceiling and control the risk of roof collapse; the isolation windbreak wall (2) moves forward once every 3m to maintain the integrity of the dual-channel structure.

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