Method for coal mining by retaining double roadways on coal pillar in pre-filling replacement section

Abstract

The invention discloses a pre-filling replacement section coal pillar double-roadway-reserved coal mining method which comprises the following steps: arranging a transportation uphill and a rail uphill in a coal seam along the inclination direction, pre-digging a transportation gate road and a rail gate road in the coal seam, forming a filling working face after the two gate roads are communicated, and simultaneously arranging the two filling working faces to carry out advancing type stoping, and solid waste material cemented filling is conducted on the goaf of the filling working face, after stoping filling of the two filling working faces is finished, a long-wall working face is formed by penetrating through the two adjacent crossheading of the two filling working faces, and retreating type stoping is conducted. A traditional section protection coal pillar is omitted, and the coal recovery rate is increased; meanwhile, resource utilization of the coal-based solid waste is achieved, and the problems of land resource waste and environmental pollution are solved.

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 pre-dug crossheadings for the first filling face and the second filling face in S2 are the same as the width of the upper mountain protective coal pillar reserved.

[0013] Optionally, the width of the upper mountain 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 crossheading and the second filling face track crossheading 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 crossheading and the third filling face haulage crossheading 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, for the crossheadings on both sides of the goaf in S3, roadway retaining along the goaf is carried out, and the combined support method of "bolt + anchor net + high-strength anchor cable + 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 backfill working face, fills the formed goaf with cemented filling slurry, and then mines the longwall working face between the two backfill 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 that form a part of this application are used to provide a further understanding of this application. The illustrative 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 It is a schematic diagram of the formation process of the first backfill working face and the second backfill working face in the present invention;

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

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

[0032] Figure 4 It is a schematic diagram of the retreating caving method mining of the first longwall working face + the advancing backfilling mining of the third backfill working face in the present invention;

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

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art 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 is set to be 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] Performing roadway retaining work on the first backfilling working face transportation 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 the first backfilling working face transportation gateway 5 and the second backfilling working face track gateway 7 are connected to form the first longwall working face 12 and mined, it further includes:

[0050] While forming the first longwall working face 12, the third backfilling working face track gateway 13 and the third backfilling working face transportation gateway 14 are connected to form the third backfilling working face 15, and the first longwall working face 12 and the third backfilling working face 15 are mined simultaneously.

[0051] Subsequently, according to the working face advancing direction, 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 are successively mined until the coal seam mining is completed.

[0052] Furthermore, in the present invention, when 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 are mined, the "U" - type ventilation method is adopted, and the roadway layout is simple and the maintenance is relatively easy.

[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 the first backfilling working face transportation gateway 5 and the second backfilling working face track gateway 7 on both sides of the goaf 10 are retained along the goaf, the "bolt + anchor mesh + high - strength cable bolt + spraying with coal - based solid waste material" 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] Coal-based solid waste is either coal gangue or fly ash, or a mixture of the two.

[0058] Firstly, coal-based solid waste such as coal gangue and fly ash are selected as the main filling raw materials, which are crushed and screened, and then chemical stabilizers are added and fully stirred to carry out pre-treatment of heavy metals in the coal-based solid waste to reduce and seal it, ensuring zero risk of underground environmental pollution after filling and solving potential environmental pollution problems after coal-based solid waste filling treatment.

[0059] Then, the coal gangue, fly ash and other solid wastes that have been pre-treated for heavy metal reduction are mixed with water in a certain proportion, and curing agents such as cement or slag powder and auxiliary materials such as glass fiber, retarder, and accelerator are added, and the cementitious filling slurry is made after sufficient stirring11.

[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 to increase the strength of the filling body; adding glass fiber can improve the mechanical properties of the slurry; and by adjusting the mass ratio of the accelerator to the retarder, the rheological properties of the slurry can be optimized and the transportation efficiency can be improved.

[0061] Embodiment 1:

[0062] 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, and their lengths are all 40m. 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, and their widths are all 100m. Figure 1 shown.

[0063] 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 70m, 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.

[0064] 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 350m; 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 100m. 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: Simultaneously drive the first filling working face track gateway 4, the first filling working face haulage gateway 5, the second filling working face track gateway 7, and the second filling working face haulage gateway 8 into the coal seam from the haulage rise 1 and the track rise 2. The lengths of all of them are 50 m. When the gateways are driven to the boundary of the upper protective coal pillar 3, the haulage gateways and the track gateways are connected to form the first filling working face 6 and the second filling working face 9 respectively, and the widths of both are 150 m, as Figure 1 shown.

[0075] S2: Carry out 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 80 m, 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.

[0076] 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 haulage gateway 5 and the second filling working face track gateway 7 to form the first longwall working face 12, and its width is 450 m; at the same time, connect the third filling working face track gateway 13 and the third filling working face haulage gateway 14 to form the third filling working face 15, and its width is 150 m, as Figure 3 shown.

[0077] S4: Use the retreating caving method to mine the first longwall working face 12, and at the same time use the advancing filling method to mine the third filling working face 15, and carry out filling and gateway retaining work on the third filling working face 15, as Figure 4 shown;

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

[0079] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention, rather than indicating or implying 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 construed as a limitation to 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 method for mining coal with double lanes in a pre-filled replacement section coal pillar, 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.

2. A method for mining coal with double lanes in pre-filled replacement section coal pillars according to claim 1, characterized in that: 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 as the second filling working face (9), the third filling working face (15), ..., and the Nth filling working face in sequence. The longwall working face between the first filling working face (6) and the second filling working face (9) is defined as the first longwall working face (12), and multiple longwall working faces are defined along the mining direction as the second longwall working face, the third longwall working face, ..., and the Nth longwall working face in sequence.

3. A method for mining coal with double lanes in pre-filled replacement section coal pillars according to claim 1, characterized in that: 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 protective coal pillar (3), wherein the width of the uphill protective coal pillar (3) is 30 to 50 m.

4. A method for mining coal with double lanes in pre-filled replacement section coal pillars according to claim 1, characterized in that: 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); A closed baffle is installed in the goaf (10), and the closed baffle is removed after the cementitious filling slurry (11) solidifies.

5. A method for mining coal with double lanes in pre-filled replacement section coal pillars according to claim 1, characterized in that: 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.

6. A method for mining coal with double lanes in pre-filled replacement section coal pillars 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.

7. A method for mining coal with double lanes in pre-filled replacement section coal pillars 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.

8. A method for mining coal with double lanes in pre-filled replacement section coal pillars 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.

9. A method for mining coal with double lanes in pre-filled replacement section coal pillars according to claim 1, characterized in that: The raw materials of the cementitious filling material slurry (11) in S3 mainly include coal-based solid waste pre-treated for heavy metal reduction.

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