Method for reserving and arranging small coal pillar roadway of coal mine

Abstract

The invention relates to the field of coal mining, in particular to a coal mine small coal pillar roadway reserving and arranging method which comprises the steps that a small coal pillar air return roadway of a next working face is arranged, and stoping is conducted on an upper working face; when the time of a preset distance range away from one end of the main haulage roadway of a goaf of a previous working face formed by stoping reaches a first preset time range, small coal pillar return airway reverse tunneling is performed on the next working face, a large coal pillar roadway is arranged at the position, close to the previous working face, of the next working face, forward tunneling is performed on the large coal pillar roadway, and small coal pillar return airway reverse tunneling is performed on the next working face; the forward tunneling length of the large coal pillar roadway is larger than or equal to the length of an unmined area of an upper working face, forward tunneling is carried out on a small coal pillar return airway in the stoping period of a lower working face, and after a stoping system is formed, stoping is carried out on a large coal pillar. And the coal resource recovery rate and the coal mining efficiency can be improved.

Description

Technical Field

[0001] This application relates to the field of coal mining, and in particular to a method for the retention and arrangement of small coal pillar roadways in coal mines. Background Technology

[0002] In coal mining, working faces are generally laid out in a sequential manner. To ensure roadway stability and safe production, the traditional roadway layout mainly uses large coal pillars for roadway protection, which involves leaving a relatively wide coal pillar between the previous goaf and the roadway to be prepared in this section. This results in a certain degree of waste of mine resources. When using small coal pillar roadway protection technology for coal pillar retention and layout, it solves the drawbacks of the traditional large coal pillar technology to some extent. However, it still has strict application conditions, with high requirements for geological conditions and mining timing. It is necessary to wait for the stress of the adjacent previous goaf to stabilize before construction, which takes a long time and affects coal mining efficiency. Summary of the Invention

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

[0004] Therefore, embodiments of the present invention propose a method for the retention and arrangement of small coal pillar roadways in coal mines, which can improve the coal resource recovery rate and coal mining efficiency.

[0005] The method for reserving and arranging small coal pillar roadways in coal mines according to embodiments of the present invention includes: The previous working face and the next working face are set according to the order of mining, and the previous working face is mined before the next working face. Set up a small coal pillar return airway for the next working face, and set up the small coal pillar return airway on the side of the next working face adjacent to the previous working face; carry out mining of the previous working face, and when the time for the goaf of the previous working face formed by mining to be far away from the end of the main transport roadway reaches the first preset time range, the small coal pillar return airway of the next working face is reversed. The excavation direction of the small coal pillar return airway is the same as the mining direction of the previous working face, and the excavation length of the reverse excavation of the small coal pillar return airway is less than or equal to the length of the goaf of the next working face. A large coal pillar roadway is set up at a position adjacent to the previous working face in the next working face. The large coal pillar roadway is excavated in the forward direction. The length of the forward excavation of the large coal pillar roadway is greater than or equal to the length of the unmined area of ​​the previous working face. When the sum of the forward excavation length of the large coal pillar roadway and the reverse excavation length of the small coal pillar return airway is greater than or equal to the length of the next working face, the large coal pillar roadway and the small coal pillar return airway are connected. The dimension of the large coal pillar roadway in the width direction of the next working face is greater than or equal to the dimension of the small coal pillar return airway in the width direction.

[0006] In some embodiments, a small coal pillar is formed between the return airway of the small coal pillar in the next working face and the previous working face, and a large coal pillar is formed between the large coal pillar in the next working face and the previous working face. The size of the large coal pillar in the width direction of the next working face is greater than the size of the small coal pillar in the width direction of the next working face.

[0007] The method for leaving and arranging small coal pillar roadways in coal mines according to embodiments of the present invention can improve coal resource recovery rate and coal mining efficiency.

[0008] In some embodiments, the small coal pillar has a dimension of 3m to 10m in the width direction of the working face, and the large coal pillar has a dimension of 19m to 100m in the width direction of the next working face.

[0009] In some embodiments, the excavation of the large coal pillar roadway is stopped after the small coal pillar return airway is connected to the large coal pillar roadway.

[0010] In some embodiments, the preset time is 6 to 12 months.

[0011] In some embodiments, when starting the next working face mining, forward excavation of the small coal pillar return airway is carried out from the main transport roadway, and the excavation direction of the forward excavation of the small coal pillar return airway is opposite to the mining direction of the next working face, and the roadway formed by the forward excavation of the coal pillar return airway is collinear with the roadway formed by the reverse excavation.

[0012] In some embodiments, during the reverse excavation of the small coal pillar return airway, the next working face transport roadway and cut-off point are excavated in advance. In some embodiments, the support for the working face transport roadway and the small coal pillar return airway is also included, including: normal anchor mesh support on the solid coal side; anchor mesh and anchor cable reinforcement support on the roof; and filling body roadway sidewall, single unit, and articulated roof beam support on the side near the goaf.

[0013] In some embodiments, the large coal pillar between the return airway and the transport roadway is recovered and mined during the next working face mining. In some embodiments, the goaf is filled and the roadway is reinforced by grouting. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a coal mine small coal pillar return airway according to an embodiment of the present invention.

[0015] Figure 2 This is a schematic diagram of reverse excavation of a small coal pillar return airway in a coal mine, according to an embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of the forward excavation of a large coal pillar roadway according to an embodiment of the present invention.

[0017] Figure 4This is a schematic diagram of the forward excavation of a small coal pillar roadway according to an embodiment of the present invention.

[0018] Figure 5 This is a schematic diagram of the recovery of a large coal pillar in the next working face according to an embodiment of the present invention.

[0019] Figure label: Previous working face 1, Next working face 2, Small coal pillar return airway 3, Transport roadway 4, Goaf of previous working face 5, 6. Small coal pillar, 7. Large coal pillar, 8. Transport roadway, 9. Goaf of the next working face, 10. Large coal pillar roadway. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] The method for reserving and arranging small coal pillars in a coal mine roadway according to an embodiment of the present invention includes: The previous working face 1 and the next working face 2 are set according to the mining sequence, and the previous working face 1 is mined before the next working face 2; the previous working face 1 and the next working face 2 are adjacent and connected.

[0022] Set up a small coal pillar return airway 3 for the next working face 2, and set up the small coal pillar return airway 3 on the side of the next working face 2 adjacent to the previous working face 1; When the previous working face 1 is mined, and the time it takes for the goaf 5 formed by the mining to move away from the end of the main transport roadway 8 by a predetermined distance reaches the first predetermined time range, the next working face 2 is excavated in reverse direction by the small coal pillar return airway 3; the excavation direction of the small coal pillar return airway 3 is the same as the mining direction of the previous working face 1, and the excavation length of the reverse excavation of the small coal pillar return airway 3 is less than or equal to the length of the goaf 9 of the next working face; A large coal pillar roadway 10 is set up at a position adjacent to the previous working face 1 in the next working face 2. The large coal pillar roadway 10 is excavated in the forward direction. The length of the forward excavation of the large coal pillar roadway 10 is greater than or equal to the length of the unmined area of ​​the previous working face 1. When the sum of the excavation length of the large coal pillar roadway 10 and the excavation length of the small coal pillar return airway 3 is greater than or equal to the length of the next working face 2, the large coal pillar roadway 10 and the small coal pillar return airway 3 are connected. The dimension of the large coal pillar roadway 10 in the width direction of the next working face 2 is greater than or equal to the dimension of the small coal pillar return airway 3 in the width direction.

[0023] Specifically, such as Figures 1 to 5As shown, the previous working face 1 is mined first, with the mining direction from front to back. After the previous working face 1 is mined at a preset interval, the overlying roof above the goaf near the working face cut will collapse within a first preset time range, forming a relatively stable goaf and a relatively stable roof above the goaf. For example, if the goaf 5 of the previous working face has not collapsed and stabilized, because the roof of the previous working face 1 is connected to the roof of the next working face 2, the next working face 2 will bear a large stress, forming a high stress peak area. At this time, when mining the small coal pillar return airway 3, it will be subject to stress disturbance, causing deformation of the return airway, requiring strengthened support and pressure relief, and there is a risk of collapse. After the goaf of the previous working face 1 collapses within the first preset time range, forming a relatively stable goaf, The roof of the corresponding part of the next working face 2 in the front-back direction will not be affected by the failure of the previous working face 1 to collapse. As a result, the roof of the corresponding part of the next working face 2 in the front-back direction is relatively stable, which makes it easy to open the face cut and excavate from front to back, and to provide normal support and pressure relief for the small coal pillar return airway 3 without the need for enhanced support and pressure relief.

[0024] When excavating the small coal pillar return airway 3, the excavation proceeds backward from the cut of the previous working face 1, while the reverse excavation direction is from front to back. The excavation direction of the small coal pillar return airway 3 is the same as that of the previous working face 1. As the mining progresses, the length of the stable goaf 5 of the previous working face increases. That is, the length of the preset distance range gradually increases with the advancement of the working face and the time of the goaf. The length of the stable goaf portion formed by the previous working face 1 gradually increases, which allows the reverse excavation of the small coal pillar return airway 3 of the adjacent next working face 2 to continue.

[0025] Alternatively, it can be understood that as the previous working face 1 continues to advance, the length of the preset distance range corresponding to the first preset time range increases accordingly, thereby increasing the excavation length of the small coal pillar return airway 3 of the next working face 2. The length of the preset distance increases with the increase of the excavation length of the previous working face 1 and the extension of time.

[0026] The main transport roadway 8 begins excavation of the large coal pillar roadway 10 from the side adjacent to the previous working face 1 on the next working face 2. The large coal pillar roadway 10 and the small coal pillar roadway 6 are not collinear in the longitudinal direction. The forward excavation length of the large coal pillar roadway 10 is greater than or equal to the length of the unmined area of ​​the previous working face 1, so that the coal pillar between the large coal pillar roadway 10 and the previous working face 1 supports the roof.

[0027] When the total length of the large coal pillar 7 roadway and the small coal pillar 6 roadway is equal to the length of the next working face 2, the two are connected to form a complete roadway system, so as to facilitate the mining of the next working face 2.

[0028] A large coal pillar 7 is reserved between the next working face 2 and the previous goaf as an active load-bearing structure. This absorbs and buffers the enormous pressure from the goaf that has not collapsed and has not formed a stable structure, creating a low-pressure, stable, and safe space during working face mining. This avoids production stoppages caused by roadway disrepair, roof falls, etc.

[0029] The method for leaving and arranging small coal pillars (6) in coal mines according to embodiments of the present invention avoids the peak area of ​​advance support pressure generated during the advancement of the working face by tunneling backwards from the cut-out point of the next working face (2) after the roof of the goaf of the previous working face (1) has collapsed and stabilized. Tunneling in a stable environment where stress has been released significantly reduces the risk of roof collapse and sidewall spalling, avoids high stress concentration areas, and can improve coal resource recovery rate and mining efficiency.

[0030] In some embodiments, a small coal pillar 6 is formed between the return airway 3 of the small coal pillar in the next working face 2 and the previous working face 1, and a large coal pillar 7 is formed between the large coal pillar 7 of the next working face 2 and the previous working face 1. The size of the large coal pillar 7 in the width direction of the next working face 2 is greater than the size of the small coal pillar 6 in the width direction of the next working face 2.

[0031] Specifically, such as Figures 1 to 5 As shown, a small coal pillar 6 is formed between the small coal pillar return airway 3 and the previous working face 1. The width of the small coal pillar 6 in the lateral direction is smaller than that of the large coal pillar 7 in the lateral direction. The smaller width of the small coal pillar 6 in the lateral direction allows the small coal pillar return airway 3 to minimize the width of the coal pillar while ensuring safety, thereby improving the coal resource recovery rate. The large coal pillar 7 is wider to bear the pressure from the goaf after the previous working face 1 is mined. This creates a low-pressure, stable, and safe space for the small coal pillar return airway 3 and the next working face 2. This design avoids the problem of stress superposition during adjacent mining and ensures the stability of the roof.

[0032] The large width of the main coal pillar 7 increases its volume and load-bearing capacity, making the roadway system of the entire upper and lower working faces more stable. It also provides reliable support for the mining of the upper working face 1, reducing roof falls and spalling accidents caused by roof instability in the upper working face 1.

[0033] Furthermore, the small coal pillar 6 has a width of 3m to 10m in the working face, while the large coal pillar 7 has a width of 19m to 100m in the next working face 2. The small coal pillar 6, with a width of 3m to 10m, reduces the space it occupies and increases the mining rate of the working face. For example, if the width of the small coal pillar 6 is reduced from 10m to 5m, the resource recovery rate is directly increased in a longer roadway. The large coal pillar 7, with a width of 19m to 100m, can more effectively bear the enormous pressure from the goaf of the previous working face 1. It absorbs and buffers the pressure from the goaf of the previous working face 1, creating a low-pressure, stable, and safe space for the small coal pillar return airway 3 and the next working face 2. It also avoids the problem of stress superposition during adjacent mining, ensuring the stability of the roof.

[0034] In some embodiments, after the small coal pillar return airway 3 is connected to the large coal pillar roadway 10, the excavation of the large coal pillar roadway 10 is stopped. By connecting the small coal pillar return airway 3 and the large coal pillar roadway 10 to form an integrated mining system, the connected roadway system forms a complete ventilation and transportation channel. Stopping the excavation can ensure the stability and reliability of these channels, providing good conditions for subsequent mining activities and for the mining of the next working face 2.

[0035] In some embodiments, the first preset time range is 6 to 12 months to ensure that the roof of the goaf of the previous working face 1 can fully collapse and reach a stable state, thereby creating a relatively safe and stable environment for the reverse excavation of the small coal pillar return airway 3 of the next working face 2.

[0036] In some embodiments, when the next working face 2 is started for mining, the small coal pillar return airway 3 is advanced forward from the transport roadway 8, and the direction of the forward advancement of the small coal pillar return airway 3 is opposite to the mining direction of the next working face 2. The roadway formed by the forward advancement of the coal pillar return airway is collinear with the roadway formed by the reverse advancement, so as to form a complete return airway, which facilitates the recovery of the large coal pillar 7 and improves the efficiency and coal mining rate of coal mining.

[0037] In some embodiments, during the reverse excavation of the small coal pillar return airway 3, the next working face 2 transport roadway 4 and cut-out are excavated in advance to facilitate the reverse excavation of the small coal pillar return airway 3.

[0038] In some embodiments, the support also includes the support of the working face transport roadway 4 and the small coal pillar return airway 3, the support including: The solid coal side is supported by normal anchor mesh; the roof is reinforced with anchor mesh and anchor cables; and conventional anchor bolts and metal mesh are used on the solid coal side. This support method is suitable for relatively stable solid coal areas and can effectively prevent coal wall spalling and local roof collapse. On the side near the goaf, backfilled roadway sides, single-unit structures, and articulated roof beams are used to reduce the stress impact of the goaf on the roadway and provide additional support.

[0039] Furthermore, during the mining of the next working face 2, the large coal pillar 7 between the return airway and the transport roadway 4 will be recovered and mined. By recovering the coal resources in the large coal pillar 7, the coal resource recovery rate is improved and resource waste is reduced.

[0040] Furthermore, the goaf is filled, and the roadways are reinforced with grout. Grouting can be applied to the return airway and transport roadway 4 of the working face, filling the fissures and voids in the coal and rock mass, enhancing the overall strength of the coal and rock mass, and improving the stability of transport roadway 4 and the return airway. The filling material can effectively fill the goaf, reduce the risk of roof collapse and spalling, and enhance the stability of the roof.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0042] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0043] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0044] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0045] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for reserving and arranging small coal pillar roadways in coal mines, characterized in that, include: The previous working face and the next working face are set according to the order of mining, and the previous working face is mined before the next working face. Set up a small coal pillar return airway for the next working face, and set up the small coal pillar return airway on the side of the next working face adjacent to the previous working face. The previous working face is mined back. When the time it takes for the goaf of the previous working face formed by the back mining to be far away from the end of the main transport roadway reaches the first preset time range, the next working face is excavated in reverse through the small coal pillar return airway. The excavation direction of the small coal pillar return airway is the same as the mining direction of the previous working face, and the excavation length of the reverse excavation of the small coal pillar return airway is less than or equal to the length of the goaf of the next working face. A large coal pillar roadway is set up at a position adjacent to the previous working face in the next working face. The large coal pillar roadway is excavated in the forward direction. The length of the forward excavation of the large coal pillar roadway is greater than or equal to the length of the unmined area of ​​the previous working face. When the sum of the excavation length of the large coal pillar roadway and the excavation length of the small coal pillar return airway is greater than or equal to the length of the next working face, the large coal pillar roadway and the small coal pillar return airway are connected. The width dimension of the large coal pillar roadway in the next working face is greater than or equal to the width dimension of the small coal pillar return airway.

2. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, A small coal pillar is formed between the return airway of the small coal pillar in the next working face and the previous working face, and a large coal pillar is formed between the large coal pillar in the next working face and the previous working face. The dimension of the large coal pillar in the width direction of the next working face is greater than the dimension of the small coal pillar in the width direction of the next working face.

3. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 2, characterized in that, Small coal pillars have a width of 3m to 10m in the working face, while large coal pillars have a width of 19m to 100m in the next working face.

4. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, Once the small coal pillar return airway is connected to the large coal pillar roadway, the excavation of the large coal pillar roadway will be stopped.

5. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, The first preset time is 6 to 12 months.

6. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, When starting the next working face mining, the small coal pillar return airway is advanced forward from the main transport roadway, and the direction of the forward advancement of the small coal pillar return airway is opposite to the mining direction of the next working face, and the roadway formed by the forward advancement of the coal pillar return airway is collinear with the roadway formed by the reverse advancement.

7. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, Also includes: When the small coal pillar return airway is excavated in reverse, the next working face transport roadway and cut-off point are excavated in advance.

8. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, This also includes support for the working face transport roadway and the small coal pillar return airway, the support including: Normal anchor mesh support is used on the side of solid coal; anchor mesh and anchor cable reinforcement support is used on the roof; and the side near the goaf is supported by filling body roadway sidewalls, single units, and articulated roof beams.

9. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, During the next working face mining, the large coal pillar between the small coal pillar return airway and the transport roadway will be recovered and mined.

10. The method for leaving and arranging small coal pillar roadways in coal mines according to claim 1, characterized in that, The goaf is filled, and the roadways are reinforced with grout.

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