Coal mine caving combined longwall fully mechanized mining method

Abstract

The present application provides a kind of coal mine collapse filling combined longwall fully mechanized mining method, first, first caving method mining area, caving transition area, filling mining area, filling transition area and second caving method mining area are determined in turn along the advancing direction of working face.Then lay out filling pipeline.When working face advances to first caving method mining area and second caving method mining area, caving method is used for mining.When working face advances to caving transition area, caving filling combined method is used for mining, which reduces the number of working face moving and improves the recovery efficiency.When working face advances to filling mining area, full filling method is used for mining, which recovers the protected body under the pressure of coal and improves the recovery rate of mine.When working face advances to filling transition area, caving filling combined method is used for mining, which solves the problem of mine working face connection arrangement and realizes efficient and green mining.

Description

Technical Field

[0001] This invention relates to the field of coal mine fully mechanized mining technology, and in particular to a coal mine longwall mining method combining cross-filling and filling. Background Technology

[0002] With the development of mechanized longwall mining technology in coal mines, the advancing length of the working face is getting longer and longer in order to achieve safety, high output and high efficiency. When there are buildings and structures that need to be protected above the working face, protective coal pillars are usually left. When the working face is mined back to the protective coal pillar, mining stops and it is necessary to cut another hole across the protective coal pillar. The working face is moved, which seriously affects the mining efficiency and the mine recovery rate. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0004] Therefore, the present invention provides a method for combined longwall mining with cross-flow mining in coal mines, comprising:

[0005] Along the advancing direction of the working face, the first caving mining area, the caving-to-backfilling transition area, the backfilling mining area, the backfilling-to-caving transition area, and the second caving mining area are determined in sequence. The location and extent of the backfilling mining area are determined based on the location and protection level of the protected body above the working face.

[0006] A filling pipeline is laid out, the discharge end of which can extend to the caving-to-filling transition zone and the filling mining zone;

[0007] When the working face advances to the first caving method mining area, caving method is used for mining.

[0008] When the working face advances to the collapse-to-filling transition zone, the first support assembly is installed on the top plate, the rear tail beam of the hydraulic support is lifted, and the filling bag is suspended on the top plate and filled with support material.

[0009] As the working face advances to the backfilling mining area, a second support assembly is continuously installed on the roof as the hydraulic support moves forward, and backfill bags are suspended on the roof and filled with support material.

[0010] When the working face advances to the filling-to-collapse transition zone, a third support assembly is installed on the top plate, and the rear tail beam of the hydraulic support is lowered.

[0011] When the working face advances to the second caving method mining area, caving method is used for mining.

[0012] According to the coal mine caving and filling combined longwall mining method provided by the present invention, when the working face advances to the filling-to-caving transition zone, the method further includes:

[0013] Hydraulic fracturing is performed on the area above the working face.

[0014] According to the coal mine caving-filling combined longwall mining method provided by the present invention, when the working face advances to the caving-filling transition zone, the method includes: setting a first support assembly on the roof, lifting the rear tail beam of the hydraulic support, and hanging filling bags on the roof and filling them with support materials.

[0015] The rear tail beam of the hydraulic support is raised to half its height, and a filling bag of half its height is suspended on the top plate behind the hydraulic support and filled. As the hydraulic support moves forward, the filling bag is continuously suspended on the top plate and filled, and the height of the filling bag gradually increases.

[0016] According to the coal mine longwall mining method with backfilling provided by the present invention, the step of determining the backfilling mining area includes:

[0017] The scope of the protective coal pillar is determined based on the location of the protected object and the level of protection.

[0018] Along the advancing direction of the working face, the area extending 20 meters forward and backward from the protective coal pillar is defined as the backfilling mining area.

[0019] According to the coal mine caving-filling combined longwall mining method provided by the present invention, determining the caving-filling transition zone includes:

[0020] The distance extended outward from the rear of the filling mining area by a distance equal to or greater than two cycles of pressing step distance is defined as the caving-to-filling transition zone.

[0021] According to the coal mine caving-filling combined longwall mining method provided by the present invention, determining the caving-filling transition zone includes:

[0022] The area is expanded outward from the front of the filling mining area by a distance equal to or greater than one cycle of pressing step distance, and the expanded area is defined as the filling-to-collapse transition zone.

[0023] The coal mine longwall mining method with combined backfilling and filling provided by the present invention further includes, before laying the backfilling pipeline:

[0024] The following structures are constructed: working face transport level roadway, section main transport roadway, section auxiliary transport roadway, working face return air level roadway, and section return air roadway.

[0025] According to the coal mine longwall mining method provided by the present invention, the first support component includes a high-strength polyester fiber mesh and anchor cables.

[0026] According to the coal mine longwall mining method provided by the present invention, the second support component includes anchor cables.

[0027] According to the coal mine longwall mining method provided by the present invention, the third support component includes a high-strength polyester fiber mesh.

[0028] The coal mine longwall mining method combining caving and filling provided by this invention firstly defines, along the advancing direction of the working face, a first caving mining zone, a caving-to-filling transition zone, a filling mining zone, a filling-to-caving transition zone, and a second caving mining zone. The location and extent of the filling mining zone are determined based on the location and protection level of the protected structure above the working face. Then, filling pipelines are laid, with the discharge end of the filling pipelines extending to the caving-to-filling transition zone and the filling mining zone. When the working face advances to the first and second caving mining zones, caving mining is carried out. When the working face advances to the caving-to-filling transition zone, a first support assembly is installed on the roof, the rear tail beam of the hydraulic support is raised, and filling bags are suspended from the roof and filled with supporting materials. When the working face advances to the filling mining zone, as the hydraulic support moves forward, a second support assembly is continuously installed on the roof, and filling bags are suspended from the roof and filled with supporting materials. When the working face advances to the caving transition zone, a third support assembly is installed on the roof, and the rear tail beam of the hydraulic support is lowered. The coal mine caving-caving combined longwall mining method provided by this invention recovers the coal under the protected body through caving mining, improving the mine recovery rate. By combining caving and caving methods along the same working face advancement direction, it reduces the number of working face relocations and improves recovery efficiency. Simultaneously, the combined caving-caving method solves the problem of continuous working face layout in mines, achieving efficient and green mining. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this 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 some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic flowchart of the coal mine longwall mining method with combined cross-filling and full-wall mining provided by the present invention;

[0031] Figure 2 This is a schematic diagram of the working face division in the coal mine longwall mining method with combined coal filling and excavation provided by the present invention;

[0032] Figure 3 This is a schematic diagram of the working face layout structure in the coal mine longwall mining method with combined coal filling and excavation provided by the present invention;

[0033] Figure 4 This is a schematic diagram of the mining of the first caving method mining area in the coal mine caving and longwall mining method provided by the present invention;

[0034] Figure 5 This is a schematic diagram of the mining of the transition zone between caving and backfilling in the coal mine caving and backfilling combined longwall mining method provided by the present invention;

[0035] Figure 6 This is a schematic diagram of the backfilling mining area in the coal mine longwall mining method provided by the present invention. Figure 1 ;

[0036] Figure 7 This is a schematic diagram of the backfilling mining area in the coal mine longwall mining method provided by the present invention. Figure 2 ;

[0037] Figure 8 This is a schematic diagram of the mining of the transition zone from filling to caving in the coal mine longwall mining method provided by the present invention;

[0038] Figure 9 This is a schematic diagram of the second caving method mining area in the coal mine caving and longwall mining method provided by the present invention.

[0039] Figure label:

[0040] 100. Protected body; 200. First caving mining area; 300. Caving to backfilling transition zone; 400. Backfilling mining area; 500. Backfilling to caving transition zone; 600. Second caving mining area; 710. Main haulage roadway of the section; 720. Auxiliary haulage roadway of the section; 730. Return airway of the section; 740. Return airway of the working face; 750. Transport airway of the working face; 800. Backfilling pipeline; 900. Working face; 1000. Hydraulic support; 1110. Anchor cable; 1120. High-strength polyester fiber mesh; 1200. Backfilling bag. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0042] The following is combined Figures 1-9 The present invention describes a coal mine longwall mining method combining cross-flow and filling.

[0043] Embodiments of the present invention provide a method for combined longwall mining with cross-filling in coal mines, comprising the following steps:

[0044] In step S100, the first caving mining area 200, the caving-to-filling transition area 300, the filling mining area 400, the filling-to-caving transition area 500, and the second caving mining area 600 are determined sequentially along the advancing direction of the working face 900. The location and extent of the filling mining area 400 are determined based on the location and protection level of the protected body 100 above the working face 900.

[0045] In this step, the location and extent of the backfill mining zone 400 are first determined based on the position and protection level of the protected body 100 above the working face 900. The area in front of and behind the backfill mining zone 400 is designated as the first caving mining zone 200 and the second caving mining zone 600, respectively. The area between the front side of the first caving mining zone 200 and the rear side of the backfill mining zone 400 is designated as the caving-to-backfilling transition zone. The area between the front side of the backfill mining zone 400 and the rear side of the second caving mining zone 600 is designated as the backfilling-to-caving transition zone 500. Therefore, along the advancing direction of the working face 900, the zones are sequentially: first caving mining zone 200, caving-to-backfilling transition zone 300, backfill mining zone 400, backfilling-to-caving transition zone 500, and second caving mining zone 600.

[0046] Step S200: Lay out the filling pipeline 800. The discharge end of the filling pipeline 800 can extend to the caving-to-filling transition zone 300 and the filling mining zone 400.

[0047] In this step, the filling pipeline 800 is used to transport support materials to the area that needs to be filled. The discharge end of the filling pipeline 800 can extend to various positions in the caving-to-filling transition zone 300 and the filling mining zone 400. As the working face 900 advances, it can continuously fill the caving-to-filling transition zone 300 and the filling mining zone 400 with support materials to support the roof or falling gangue.

[0048] Step S300: When the working face 900 advances to the first caving method mining area 200, the caving method is used for mining.

[0049] In this step, since the first caving mining area 200 does not affect the protected body 100 above the working face 900, the first caving mining area 200 is mined using the caving method. After the hydraulic support 1000 moves forward, the roof behind the hydraulic support 1000 collapses, and the collapsed gangue and other debris fill the goaf.

[0050] Step S400: When the working face 900 advances to the collapse-to-filling transition zone 300, the first support assembly is installed on the top plate, the rear tail beam of the hydraulic support 1000 is lifted, and the filling bag 1200 is suspended on the top plate and filled with support material.

[0051] The caving-to-filling transition zone 300 is the intermediate area between the first caving mining zone and the filling mining zone 400. It adopts a combination of caving and filling to achieve the transition from full caving mining to full filling mining.

[0052] In this step, the first support assembly may include a high-strength polyester fiber mesh 1120 and anchor cables 1110. When the working face 900 advances to the caving-to-filling transition zone 300, the high-strength polyester fiber mesh 1120 is first laid on the roof above the front top beam of the hydraulic support 1000, and anchor cables 1110 are simultaneously installed on the roof to reinforce it and prevent it from breaking and scattering after mining. Then, filling bags 1200 are suspended from the roof in the space below the rear tail beam, and the filling bags 1200 are filled with support material. In this way, when the hydraulic support 1000 moves forward, the collapsed roof will not scatter under the support of the high-strength polyester fiber mesh 1120 and anchor cables 1110, and will ultimately be supported by the filling bags 1200 filled with support material. As the working face 900 continues to advance, the support height gradually increases to the mining height, and then enters the filling mining zone 400.

[0053] Step S500: When the working face 900 advances to the backfill mining area 400, as the hydraulic support 1000 moves forward, the second support component is continuously installed on the roof, and the backfill bag 1200 is suspended on the roof and the backfill bag 1200 is filled with support material.

[0054] The second support component may include anchor cables 1110. The backfill mining zone 400 is mined using a fully backfilling method. When the working face 900 advances to the backfill mining zone 400, anchor cables 1110 are first driven into the roof to reinforce it. At this point, the support height of the backfill bags 1200, combined with the height reached by the backfill bags and the reinforcement of the anchor cables 1110, prevents the roof from collapsing. As the working face 900 continues to advance, backfill bags 1200 are continuously suspended onto the roof behind the hydraulic support 1000, and support materials are filled into the backfill bags 1200 to support the roof. For example, every 1.6 to 3.2 meters the working face 900 advances, backfill bags 1200 are suspended, support materials are filled into the backfill bags 1200, and the backfilling pipeline 800 is cleaned, until the backfill to collapse transition zone 500 is reached.

[0055] Step S600: When the working face 900 advances to the filling-to-collapse transition zone 500, the third support assembly is installed on the top plate, and the rear tail beam of the hydraulic support 1000 is lowered.

[0056] The backfill-to-caving transition zone 500 is an intermediate area for the transition from the backfill mining zone 400 to the second caving mining zone 600. It adopts a reinforced caving method to achieve the transition from full backfilling to full caving mining.

[0057] In this step, when the working face 900 advances to the filling-to-collapse transition zone 500, a high-strength polyester fiber mesh 1120 is laid above the front guard plate of the hydraulic support 1000. For example, it can be a high-strength polyester fiber mesh. At this time, the filling bag 1200 is no longer suspended. As the hydraulic support 1000 moves forward, the roof collapses. Due to the fixation of the high-strength polyester fiber mesh, the collapsed gangue falls as a whole and blocks the front side of the filling bag 1200 in the filling mining area 400.

[0058] Step S700: When the working face 900 advances to the second caving method mining area 600, the caving method is used for mining.

[0059] In this step, after the working face 900 advances to the second caving mining area 600, this area has no impact on the protected body 100 above, so the caving method is continued for mining. As the hydraulic support 1000 moves forward, the roof behind collapses to fill the goaf.

[0060] The coal mine longwall mining method combining caving and backfilling provided by this invention recovers 100 mm of coal under protection through backfilling mining, thereby improving the mine recovery rate. By employing a combined roof management method of caving and backfilling along the 90 mm advance direction of the same working face, the number of times the 90 mm working face needs to be moved is reduced, improving recovery efficiency. Simultaneously, the combined caving and backfilling roof management method solves the problem of continuous 90 mm working face layout in mines, achieving efficient and green mining.

[0061] The roof management method provided by this invention can not only effectively control rock strata movement, protect the surface protected body 100%, and improve the recovery rate of coal seams under "three-under" pressure, but also significantly improve the efficiency of backfilling mining and reduce backfilling mining costs, thus having wide applicability in this technical field. Furthermore, this invention can consume solid waste such as coal gangue, construction waste, and fly ash, resulting in significant environmental, economic, and social benefits.

[0062] In some embodiments provided by the present invention, when the working face 900 advances to the filling-to-collapse transition zone 500, in order to make the roof of the goaf collapse, the rock strata in the area above the working face 900 can be hydraulically fracturing.

[0063] Specifically, as the working face advances to 900 meters and enters the transition zone 500 meters from filling to collapse, hydraulic fracturing boreholes can be drilled above the working face 900 meters. The fracturing method employs a backward fracturing approach, meaning fracturing is performed sequentially from the bottom of the borehole to the borehole opening. The fracturing interval is generally 2–3 meters, with each fracturing session lasting approximately 30 minutes. Fracturing is terminated when the distance to the borehole opening is less than 10 meters. Each borehole undergoes 10–15 fracturing cycles. Through fracturing, the roof collapses, preventing large-area roof overhang.

[0064] In some embodiments of the present invention, when the working face 900 advances to the collapse-to-filling transition zone 300, the following steps are included: setting up a first support assembly on the top plate, lifting the rear tail beam of the hydraulic support 1000, and suspending the filling bag 1200 on the top plate and filling it with support material.

[0065] The rear tail beam of the hydraulic support 1000 is raised to half its height. A filling bag 1200 with half its height is suspended on the top plate behind the hydraulic support 1000 and filled with supporting material. As the hydraulic support 1000 moves forward, the filling bag 1200 is continuously suspended on the top plate and filled with supporting material, and the height of the filling bag 1200 gradually increases.

[0066] In this step, as the working face 900 advances, it enters the caving-to-filling transition zone 300. Under the suspension of anchor cable 1110, hydraulic support 1000 raises the rear tail beam. After the working face 900 has mined two cuts of coal, filling bags 1200 are suspended from below the rear tail beam towards the roof. Due to the influence of caving rock behind, the rear tail beam cannot be fully raised. At this point, the rear tail beam is raised to half its height, and cylindrical filling bags 1200 (e.g., φ1.5m×1.5m) are suspended behind the support at half its height. High-water filling material is injected into the filling bags 1200 to support the goaf. After mining two more cuts, the cylindrical filling bags 1200 are suspended again, with the height of the filling bags 1200 increased by 30% from the previous level, such as φ2.0m×1.5m cylindrical filling bags 1200. This cycle continues until the filling height is the mining height.

[0067] In some embodiments of the present invention, determining the backfill mining area 400 includes the following steps:

[0068] Step S110: Determine the range of the protective coal pillar based on the location and protection level of the protected body 100.

[0069] Specifically, the protective coal pillar is located directly below the protected body 100, and the extent of the protective coal pillar can be calculated according to relevant regulations and specifications.

[0070] Step S120: Along the advancing direction of the working face 900, the area between 20 meters forward and backward of the protective coal pillar range is defined as the filling mining area 400.

[0071] Specifically, based on the location and extent of the protective coal pillar, the area extends outward by 20 meters both forward and backward along the advancing direction of the working face 900, and this area is designated as the filling mining area 400.

[0072] In some embodiments of the present invention, determining the caving-to-fill transition zone 300 includes the following steps:

[0073] Step S130: Expand the back of the filling mining area 400 by a distance equal to or greater than the step distance of two cycles, and define the expanded area as the caving-to-filling transition zone 300.

[0074] Specifically, the distance of the step distance, which is extended backward and outward from the rear edge of the backfill mining area 400 by two cycles, for example, can be 30 to 50 meters. This area is defined as the caving-to-backfill transition zone 300.

[0075] In some embodiments of the present invention, determining the filling-to-collapse transition zone 500 includes the following steps:

[0076] Step S140: Expand the backfill mining area 400 outward by a distance equal to or greater than the pressure step distance of one cycle, and define the expanded area as the backfill-to-collapse transition zone 500.

[0077] Specifically, the front edge of the backfill mining area 400 is extended forward and outward by a distance equal to or greater than one cycle, for example, 20 to 30 meters. This area is designated as the backfill-to-collapse transition zone 500.

[0078] In some embodiments of the present invention, the following steps need to be performed before laying the filling pipeline 800:

[0079] Step S800: Open the working face transport level roadway 750, the section main transport roadway 710, the section auxiliary transport roadway 720, the working face return air level roadway 740, and the section return air roadway 730.

[0080] The mined coal enters the coal transportation system via the working face transport roadway 750 and the section main transport roadway 710. The materials required for the working face 900 are transported to the working face 900 via the section auxiliary transport roadway 720 and the working face transport roadway 750. The polluted air generated at the working face 900 enters the mine ventilation system via the working face return air roadway 740 and the section return air roadway 730.

[0081] In some embodiments of the present invention, the filling material in the filling bag 1200 has a 28-day strength greater than or equal to 2 MPa, an 8-hour strength greater than 0.1 MPa, and a slump greater than or equal to 260 mm.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for combined longwall mining and coal filling in coal mines, characterized in that, include: Along the advancing direction of the working face, the first caving mining area, the caving-to-backfilling transition area, the backfilling mining area, the backfilling-to-caving transition area, and the second caving mining area are determined in sequence. The location and extent of the backfilling mining area are determined based on the location and protection level of the protected body above the working face. A filling pipeline is laid out, the discharge end of which can extend to the caving-to-filling transition zone and the filling mining zone; When the working face advances to the first caving method mining area, caving method is used for mining. When the working face advances to the collapse-to-filling transition zone, the first support assembly is installed on the top plate, the rear tail beam of the hydraulic support is lifted, and the filling bag is suspended on the top plate and filled with support material. As the working face advances to the backfilling mining area, a second support assembly is continuously installed on the roof as the hydraulic support moves forward, and backfill bags are suspended on the roof and filled with support material. When the working face advances to the filling-to-collapse transition zone, a third support assembly is installed on the roof and the rear tail beam of the hydraulic support is lowered. The third support assembly includes a high-strength polyester fiber mesh, which is laid above the front guard plate of the hydraulic support. In the filling-to-collapse transition zone, filling bags are no longer suspended. As the hydraulic support moves forward, the roof collapses, and the high-strength polyester fiber mesh fixes the collapsed gangue, causing it to fall as a whole and block the front side of the filling bags in the filling mining area. When the working face advances to the second caving method mining area, caving method is used for mining.

2. The coal mine longwall mining method according to claim 1, characterized in that, When the working face advances to the filling-to-collapse transition zone, the method further includes: Hydraulic fracturing is performed on the area above the working face.

3. The coal mine longwall mining method according to claim 1, characterized in that, When the working face advances to the collapse-to-filling transition zone, the process includes: installing a first support assembly on the top plate, lifting the rear tail beam of the hydraulic support, and suspending filling bags on the top plate and filling them with support materials. The rear tail beam of the hydraulic support is raised to half its height, and a filling bag of half its height is suspended on the top plate behind the hydraulic support and filled. As the hydraulic support moves forward, the filling bag is continuously suspended on the top plate and filled, and the height of the filling bag gradually increases.

4. The coal mine longwall mining method combining cross-filling and full-wall mining according to claim 1, characterized in that, The backfilling mining area was identified, including: The scope of the protective coal pillar is determined based on the location of the protected object and the level of protection. Along the advancing direction of the working face, the area extending 20 meters forward and backward from the protective coal pillar is defined as the backfilling mining area.

5. The coal mine longwall mining method according to claim 1, characterized in that, Determining the caving-to-fill transition zone includes: The distance extended outward from the rear of the filling mining area by a distance equal to or greater than two cycles of pressing step distance is defined as the caving-to-filling transition zone.

6. The coal mine longwall mining method combining cross-flow and filling as described in claim 1, characterized in that, Determining the filling-to-collapse transition zone includes: The area is expanded outward from the front of the filling mining area by a distance equal to or greater than one cycle of pressing step distance, and the expanded area is defined as the filling-to-collapse transition zone.

7. The coal mine longwall mining method according to claim 1, characterized in that, Before laying the filling pipeline, the following is also included: The following structures are constructed: working face transport level roadway, section main transport roadway, section auxiliary transport roadway, working face return air level roadway, and section return air roadway.

8. The coal mine longwall mining method according to claim 1, characterized in that, The first support component includes a high-strength polyester fiber mesh and anchor cables.

9. The coal mine longwall mining method combining cross-filling and full-wall mining according to claim 1, characterized in that, The second support component includes anchor cables.

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