A double-heading coal mining method with pre-filled replacement of section coal pillars

Abstract

The present invention discloses a method for mining coal with double lanes in a pre-filled replacement section coal pillar, the method comprising: arranging transport uphill and track uphill along the inclination in the coal seam, pre-digging a transport drift and a track drift in the coal seam, forming a filling working face after connecting the two drifts, arranging two filling working faces for forward mining at the same time, cementing and filling the goaf of the filling working faces with solid waste materials, and after the mining and filling of the two filling working faces are completed, connecting the two adjacent drifts of the two filling working faces to form a longwall working face, and performing backward mining. The present invention eliminates the traditional section protection coal pillar and improves the coal recovery rate; at the same time, it realizes the resource utilization of coal-based solid waste and solves the problems of land resource waste and environmental pollution.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, and in particular to a method for mining coal with double lanes in a pre-filled replacement section coal pillar. Background Art

[0002] As the scale of coal mining continues to increase, coal mining conditions are becoming increasingly complex. At present, coal seam mining is usually divided into multiple sections. In order to reduce the mutual influence between sections, section protection coal pillars are often left. Since these coal pillars play the role of isolating the mining area and supporting the roof, they cannot be mined, resulting in a serious waste of coal resources. Therefore, how to reduce the loss of section coal pillars and improve the coal recovery rate has become a problem that needs to be solved urgently.

[0003] Due to the continuous increase in coal production in recent years, the emission of coal-based solid waste has shown an increasing trend year by year, with coal gangue and fly ash being the most prominent. These solid wastes accumulate on the surface, occupying a large amount of land resources and causing serious damage to the environment. Therefore, how to effectively utilize coal-based solid waste is another problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a method for mining coal with double lanes in a pre-filled replacement section coal pillar, aiming to solve or improve the above technical problems.

[0005] To achieve the above object, the present invention provides a method for mining coal with double lanes in a pre-filled replacement section coal pillar, comprising the following steps:

[0006] S1: Transportation and track uphill are arranged along the dip in the coal seam;

[0007] S2: pre-dig a first filling working face track chute, a first filling working face transport chute, and a second filling working face track chute and a second filling working face transport chute of a preset length into the coal seam, and penetrate the transport chute and the track chute to form a first filling working face and a second filling working face respectively;

[0008] S3: mining the first filling working face and the second filling working face simultaneously to form a goaf, and when the working face advances a preset distance, filling the goaf with cementing filling slurry;

[0009] S4: After the two goafs are filled, the first filling working face transport chute and the second filling working face track chute are connected to form a first longwall working face, and the first longwall working face is mined;

[0010] Optionally, the first mining and filling working face is defined as the first filling working face, and multiple filling working faces are defined along the working face advancement direction as the second filling working face, the third filling working face, ..., the Nth filling working face.

[0011] Optionally, define the longwall face between the first filling face and the second filling face as the first longwall face, and define multiple longwall faces in sequence along the mining direction as the second longwall face, the third longwall face, …, the Nth longwall face.

[0012] Optionally, the lengths of the preparatory headings for the first filling face and the second filling face in S2 are the same as the width of the upper protective coal pillar reserved.

[0013] Optionally, the width of the upper protective coal pillar reserved is 30 - 50 m.

[0014] Optionally, S3 further includes:

[0015] Carry out roadway retaining work on the first filling face haulage gateway and the second filling face track gateway on both sides of the goaf; install a closed baffle in the goaf and remove the closed baffle after the cemented filling slurry solidifies.

[0016] Optionally, S4 further includes:

[0017] While forming the first longwall face, penetrate the third filling face track gateway and the third filling face haulage gateway to form the third filling face, and simultaneously mine the first longwall face and the third filling face.

[0018] Subsequently, according to the advancing direction of the working face, successively mine the fourth filling face, …, the Nth filling face and the second longwall face, the third longwall face, …, the Nth longwall face until the coal seam mining is completed.

[0019] Optionally, the mining method of the filling face is the forward filling method.

[0020] Optionally, the mining method of the longwall face is the retreating caving method.

[0021] Optionally, the width of the filling face is 50 - 150 m.

[0022] Optionally, the width of the longwall face is 250 - 450 m.

[0023] Optionally, roadway retaining is carried out on the gateways on both sides of the goaf in S3, and the combined support method of "bolt + anchor net + high-strength cable bolt + spraying with coal-based solid waste material" is adopted.

[0024] Optionally, the raw materials of the cemented filling slurry in S3 mainly include coal-based solid waste after heavy metal reduction pretreatment.

[0025] The present invention discloses the following technical effects:

[0026] 1. The present invention pre-excavates a transportation gateway and a track gateway of a preset length for the extraction and filling working face, fills the formed goaf with cemented filling slurry, and then extracts the longwall working face between the two filling working faces, eliminating the traditional sectional protective coal pillar, improving the recovery rate of coal resources, and enhancing the economic benefits of coal mining enterprises.

[0027] 2. The cemented filling slurry material in the present invention mainly includes coal-based solid waste, realizing the resource utilization of solid waste, solving problems such as land resource waste and environmental pollution, and providing an innovative idea and method for pillarless mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which form a part of this application, are used to provide a further understanding of this application. The schematic embodiments and descriptions of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0029] Figure 1 is a schematic diagram of the formation process of the first filling working face and the second filling working face in the present invention;

[0030] Figure 2 is a schematic diagram of the simultaneous extraction, filling, and roadway retaining process of the first filling working face and the second filling working face in the present invention;

[0031] Figure 3 is a schematic diagram of the simultaneous formation process of the first longwall working face and the third filling working face in the present invention;

[0032] Figure 4 is a schematic diagram of the extraction process of the first longwall working face by the retreating caving method + the filling process of the third filling working face by the advancing filling method in the present invention;

[0033] In the figures: 1, transportation rise; 2, track rise; 3, rise protective coal pillar; 4, track gateway of the first filling working face; 5, transportation gateway of the first filling working face; 6, first filling working face; 7, track gateway of the second filling working face; 8, transportation gateway of the second filling working face; 9, second filling working face; 10, goaf; 11, cemented filling slurry; 12, first longwall working face; 13, track gateway of the third filling working face; 14, transportation gateway of the third filling working face; 15, third filling working face. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Reference Figures 1 to 4 The present invention provides a method for mining coal with double lanes in a pre-filled replacement section coal pillar, comprising the following steps:

[0037] S1: Transport uphill 1 and track uphill 2 are arranged along the dip in the coal seam;

[0038] S2: Pre-dig a first filling working face track chute 4, a first filling working face transport chute 5, a second filling working face track chute 7, and a second filling working face transport chute 8 of a preset length (30-50 m) into the coal seam, and after penetrating the transport chute and the track chute, form a first filling working face 6 and a second filling working face 9 respectively;

[0039] S3: The first filling working face 6 and the second filling working face 9 are mined simultaneously to form a goaf 10. When the working faces advance a preset distance (60 to 80 m), a cementing filling slurry 11 is filled in the goaf;

[0040] S4: After the two goafs are filled, the first filling working face transport chute 5 and the second filling working face track chute 7 are connected to form a first long wall working face 12, and the first long wall working face 12 is mined;

[0041] The first filling working face 6 and the second filling working face 9 are mined by pre-digging the first filling working face track chute 4, the first filling working face transport chute 5 and the second filling working face track chute 7 and the second filling working face transport chute 8 of preset length, the goaf 10 is filled with cementitious filling slurry 11, and then the first longwall working face 12 is mined, thereby eliminating the traditional section protection coal pillar, helping to control the manifestation of mine pressure on the working face, improving the recovery rate of coal resources, and enhancing the economic benefits of coal mining enterprises.

[0042] Furthermore, the first mining and filling working face is defined as the first filling working face 6, and multiple filling working faces are defined along the working face advancement direction, namely the second filling working face 9, the third filling working face 15, ..., the Nth filling working face.

[0043] Further, the longwall working surface between the first filling working surface 6 and the second filling working surface 9 is defined as the first longwall working surface 12, and multiple longwall working surfaces are defined along the mining direction as the second longwall working surface, the third longwall working surface, ..., the Nth longwall working surface.

[0044] Furthermore, the length of the pre-excavated trenches of the first filling working face 6 and the second filling working face 9 is consistent with the width of the uphill protective coal pillar 3 .

[0045] Furthermore, the width of the upper mountain protection coal pillar 3 reserved is 30 - 50 m.

[0046] In an embodiment of the present invention, when simultaneously mining and backfilling the first backfilling working face 6 and the second backfilling working face 9, it further includes:

[0047] Carrying out roadway retaining work on the first backfilling working face haulage gateway 5 and the second backfilling working face track gateway 7 on both sides of the goaf 10;

[0048] Installing a closed baffle in the goaf 10 and removing the closed baffle after the cemented filling slurry 11 solidifies.

[0049] In an embodiment of the present invention, when forming the first longwall working face 12 by connecting the first backfilling working face haulage gateway 5 and the second backfilling working face track gateway 7 and carrying out mining, it further includes:

[0050] While forming the first longwall working face 12, connecting the third backfilling working face track gateway 13 and the third backfilling working face haulage gateway 14 to form the third backfilling working face 15, and simultaneously mining the first longwall working face 12 and the third backfilling working face 15.

[0051] Subsequently, according to the advancing direction of the working face, successively mining the fourth backfilling working face, …, the Nth backfilling working face and the second longwall working face, the third longwall working face, …, the Nth longwall working face until the coal seam mining is completed.

[0052] Furthermore, in the present invention, the first backfilling working face 6, the second backfilling working face 9, the third backfilling working face 15, and the first longwall working face 12 all adopt the "U"-type ventilation method during mining, with simple roadway layout and relatively easy maintenance.

[0053] In an embodiment of the present invention, the mining method of the first backfilling working face 6, the second backfilling working face 9, and the third backfilling working face 15 is the advancing mining method, and its width is 50 - 150 m.

[0054] In an embodiment of the present invention, the mining method of the first longwall working face 12 is the retreating caving method, and its width is 250 - 450 m.

[0055] In an embodiment of the present invention, when carrying out gob-side entry retaining on the first backfilling working face haulage gateway 5 and the second backfilling working face track gateway 7 on both sides of the goaf 10, the "bolt + anchor mesh + high-strength cable bolt + coal-based solid waste material shotcrete" combined support method is adopted to enhance the stability and bearing capacity of the roadway.

[0056] In an embodiment of the present invention, the raw materials of the cemented filling slurry 11 mainly include coal-based solid waste after heavy metal reduction pretreatment.

[0057] The coal-based solid waste is one or a mixture of two of coal gangue and fly ash.

[0058] First, select coal gangue, fly ash and other coal-based solid wastes as the main filling raw materials, crush and screen them, then add chemical stabilizers and stir well to perform pretreatment on reducing and solidifying heavy metals in the coal-based solid wastes, ensuring zero risk of underground environmental pollution after filling and solving the potential environmental pollution problems after the filling treatment of coal-based solid wastes.

[0059] Then, mix the solid wastes such as coal gangue and fly ash after the pretreatment of heavy metal reduction with water in a certain proportion, add curing agents such as cement or slag powder and auxiliary materials such as glass fiber, retarder and accelerator, and make the cemented filling slurry 11 after sufficient stirring.

[0060] Specifically, the purpose of adding curing agents such as cement or slag powder is to prevent heavy metals from migrating or dissolving in the environment and increase the strength of the filling body; adding glass fiber can improve the mechanical properties of the slurry; by adjusting the mass ratio of the accelerator and the retarder, the rheological properties of the slurry can be optimized and the transportation efficiency can be improved.

[0061] Example 1:

[0062] S1: Simultaneously pre-drive the first filling working face track gateway 4, the first filling working face transportation gateway 5, the second filling working face track gateway 7 and the second filling working face transportation gateway 8 into the coal seam from the transportation rise 1 and the track rise 2, and their lengths are all 40m. When the gateways are driven to the boundary of the rise protective coal pillar 3, the transportation gateways and the track gateways are connected to form the first filling working face 6 and the second filling working face 9 respectively, and their widths are both 100m, as Figure 1 shown.

[0063] S2: Conduct advancing mining on the first filling working face 6 and the second filling working face 9 simultaneously. When the first filling working face 6 and the second filling working face 9 advance 70m, use the cemented filling slurry 11 to fill the goaf 10, and retain the gateways on both sides of the goaf 10, as Figure 2 shown.

[0064] S3: After the mining and filling and gateway retaining of the first filling working face 6 and the second filling working face 9 are completed, connect the first filling working face transportation gateway 5 and the second filling working face track gateway 7 to form the first longwall working face 12, and its width is 350m; at the same time, connect the third filling working face track gateway 13 and the third filling working face transportation gateway 14 to form the third filling working face 15, and its width is 100m, as Figure 3 shown.

[0065] S4: Use the backward caving method to mine the first longwall working face 12, and use the forward filling method to mine the third filling working face 15, and perform filling and lane retention work on the third filling working face 15, such as Figure 4 As shown;

[0066] S5: Repeat S1-S4, and arrange the subsequent fourth filling working face, ..., Nth filling working face and the second longwall working face, the third longwall working face, ..., Nth longwall working face for normal succession mining until all the coal seams are mined.

[0067] Embodiment 2:

[0068] S1: From the transport uphill 1 and the track uphill 2, the first filling working face track chute 4, the first filling working face transport chute 5 and the second filling working face track chute 7, the second filling working face transport chute 8 are pre-excavated into the coal seam at the same time. Their lengths are all 30m. When the chute is excavated to the boundary of the uphill protection coal pillar 3, the transport chute and the track chute are connected to form the first filling working face 6 and the second filling working face 9 respectively. Their widths are all 50m. Figure 1 shown.

[0069] S2: The first filling working face 6 and the second filling working face 9 are simultaneously advanced. When the first filling working face 6 and the second filling working face 9 advance 60m, the goaf 10 is filled with cemented filling slurry 11, and the drifts on both sides of the goaf 10 are retained, such as Figure 2 shown.

[0070] S3: After the first filling working face 6 and the second filling working face 9 are mined and filled, the first filling working face transport chute 5 and the second filling working face track chute 7 are connected to form the first long wall working face 12, whose width is 250m; at the same time, the third filling working face track chute 13 and the third filling working face transport chute 14 are connected to form the third filling working face 15, whose width is 50m. Figure 3 shown.

[0071] S4: Use the backward caving method to mine the first longwall working face 12, and use the forward filling method to mine the third filling working face 15, and perform filling and lane retention work on the third filling working face 15, such as Figure 4 As shown;

[0072] S5: Repeat S1-S4, and arrange the subsequent fourth filling working face, ..., Nth filling working face and the second longwall working face, the third longwall working face, ..., Nth longwall working face for normal succession mining until all the coal seams are mined.

[0073] Embodiment 3:

[0074] S1: From the transport uphill 1 and the track uphill 2, the first filling working face track chute 4, the first filling working face transport chute 5 and the second filling working face track chute 7, the second filling working face transport chute 8 are pre-excavated into the coal seam at the same time. The length of each of them is 50m. When the chute is excavated to the boundary of the uphill protection coal pillar 3, the transport chute and the track chute are connected to form the first filling working face 6 and the second filling working face 9 respectively. The width of each of them is 150m. Figure 1 shown.

[0075] S2: The first filling working face 6 and the second filling working face 9 are simultaneously advanced. When the first filling working face 6 and the second filling working face 9 advance 80m, the goaf 10 is filled with cemented filling slurry 11, and the drifts on both sides of the goaf 10 are retained, such as Figure 2 shown.

[0076] S3: After the first filling working face 6 and the second filling working face 9 are mined and filled, the first filling working face transport chute 5 and the second filling working face track chute 7 are connected to form the first long wall working face 12, whose width is 450m; at the same time, the third filling working face track chute 13 and the third filling working face transport chute 14 are connected to form the third filling working face 15, whose width is 150m. Figure 3 shown.

[0077] S4: Use the backward caving method to mine the first longwall working face 12, and use the forward filling method to mine the third filling working face 15, and perform filling and lane retention work on the third filling working face 15, such as Figure 4 As shown;

[0078] S5: Repeat S1-S4, and arrange the subsequent fourth filling working face, ..., Nth filling working face and the second longwall working face, the third longwall working face, ..., Nth longwall working face for normal succession mining until all the coal seams are mined.

[0079] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0080] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A double - roadway coal mining method for pre - filling and replacing section coal pillars, characterized in that, The filling working face and the long wall working face are arranged alternately in the coal seam, which specifically includes the following steps: S1: Transport uphill (1) and track uphill (2) are arranged along the dip in the coal seam; S2: pre-excavating a first filling working face track chute (4), a first filling working face transport chute (5), a second filling working face track chute (7), and a second filling working face transport chute (8) of a preset length into the coal seam, and after the transport chute and the track chute are connected, a first filling working face (6) and a second filling working face (9) are formed respectively; S3: mining the first filling working face (6) and the second filling working face (9) simultaneously to form a goaf (10); and when the working faces advance a preset distance, filling the goaf (10) with cementitious filling slurry (11); S4: After the two goafs (10) are filled, the first filling working face transport chute (5) and the second filling working face track chute (7) are connected to form a first long wall working face (12), and the first long wall working face (12) is mined; The first mining and filling working face is defined as a first filling working face (6), and multiple filling working faces are defined in the advancing direction of the working face as a second filling working face (9), a third filling working face (15), ..., and an Nth filling working face in sequence, and the longwall working face between the first filling working face (6) and the second filling working face (9) is defined as a first longwall working face (12), and multiple longwall working faces are defined in the mining direction as a second longwall working face, a third longwall working face, ..., and an Nth longwall working face in sequence; In S2, the length of the pre-excavated trenches of the first filling working face (6) and the second filling working face (9) is consistent with the width of the uphill protection coal pillar (3), wherein the width of the uphill protection coal pillar (3) is 30 to 50 m; The S3 further includes: Performing lane retaining work on the first filling working face transport drift (5) and the second filling working face track drift (7) on both sides of the goaf (10); Installing a sealing baffle in the goaf (10), and removing the sealing baffle after the cementing filling slurry (11) solidifies; The S4 further comprises: While forming the first longwall working face (12), the third filling working face track chute (13) and the third filling working face transport chute (14) are connected to form a third filling working face (15), and the first longwall working face (12) and the third filling working face (15) are mined simultaneously; Subsequently, according to the advancement direction of the working face, the fourth filling working face, ..., the Nth filling working face and the second longwall working face, the third longwall working face, ..., the Nth longwall working face are mined in sequence until the coal seam mining is completed.

2. A pre-filled replacement section coal pillar double-heading coal mining method according to claim 1, characterized in that The mining method of the filling working face is a forward filling method, and the mining method of the longwall working face is a backward caving method.

3. A pre-filled replacement section coal pillar double roadway coal mining method according to claim 1, characterized in that, The width of the filling working surface is 50 to 150 m, and the width of the long wall working surface is 250 to 450 m.

4. A pre-filled replacement section coal pillar double-heading coal mining method according to claim 1, characterized in that The tunnels on both sides of the goaf (10) described in S3 are retained along the goaf, and a combined support method of anchor rods + anchor nets + high-strength anchor cables + coal-based solid waste material spraying is adopted.

5. A method for coal mining with double roadways left in a pre-filled and replaced section coal pillar according to claim 1, characterized in that, The raw materials of the cemented filling slurry (11) in S3 mainly include coal-based solid waste after heavy metal reduction pretreatment.

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