Coal mining method

Abstract

The invention provides a coal mining method. The coal mining method comprises the following steps: 1, analyzing the characteristics of a coal seam to be mined, determining the structural strength sigma e of paste, and designing the step pitch L of the filled paste and the height H of the filled paste; 2, pre-mining the coal seam to be mined to form a first area to be mined and a second area to be mined, and arranging a roadway to form an air inlet and return system; thirdly, a heading machine is arranged to conduct primary mining on the first to-be-mined area and the second to-be-mined area in sequence, anchor rod or anchor cable supporting is conducted on a top plate in the mining process, and mined goaf roadways are blocked; fourthly, the goaf roadway is filled with paste; and 5, repeating the step 3 to the step 4 until the mining of the coal seam to be mined is completed. The problem that in the prior art, when a deep coal mine is mined, a coal seam falls off easily, and the mining efficiency is reduced is solved.

Description

Technical Field

[0001] The invention relates to the technical field of mining, and in particular to a coal mining method. Background Art

[0002] In recent years, with the frequent and in-depth mining activities in China, the mining area has gradually shifted to the deep strata, which not only significantly increased the difficulty of mining operations, but also aggravated the problem of ground collapse, posing a major threat to the ecological environment and the lives of surrounding residents. Ground collapse after coal mining not only affects the stability of the surface and the fertility of the soil, but may also lead to environmental problems such as water pollution and frequent geological disasters, seriously affecting sustainable development. In addition, long-term mining has led to the depletion of shallow resources. In the face of the development of deep resources, the high production costs and complex safety challenges it brings have become key factors restricting the development of the mining industry. Existing mining technologies, such as the longwall full-span method, are mainly characterized by a long mining face, and the coal seam roof and its overlying rock strata will naturally collapse after mining to release pressure, but this method often leads to increased uncontrollability of rock strata destruction, an expansion of the scope of ground subsidence, and a more serious impact on surface buildings and natural ecology. Especially under deep mining conditions, the fracturing and collapse of overlying rock strata not only affect the mining efficiency, but also increase the ventilation, drainage and support costs of the mine, posing a challenge to the economic benefits and safe production of mining enterprises.

[0003] As can be seen from the above, in the prior art, there is a problem that coal seam shedding is prone to occur during deep coal mining, which reduces mining efficiency. Summary of the invention

[0004] The main purpose of the present invention is to provide a coal mining method to solve the problem of coal seam shedding and reduced mining efficiency in the prior art during deep coal mining.

[0005] In order to achieve the above object, the present invention provides a coal mining method, comprising: Step 1: Analyze the characteristics of the coal seam to be mined and determine the structural strength σ of the paste e , design the step distance L of the filled paste and the height H of the filled paste; Step 2: pre-mine the coal seam to be mined to form a first area to be mined and a second area to be mined, and arrange tunnels to form an air inlet and return system; Step 3: arrange the tunneling machine to mine the first area to be mined and the second area to be mined in turn, and support the roof with anchor rods or anchor cables during the mining process, and seal the mined tunnels; Step 4: fill the gouged tunnels with paste; Step 5: Repeat steps 3 to 4 until the mining of the coal seam to be mined is completed.

[0006] Furthermore, in step three, arranging the tunneling machines to mine the first area to be mined and the second area to be mined in sequence includes: arranging multiple tunneling machines, wherein the multiple tunneling machines mine the first area to be mined for a preset distance at a step distance L, then stop, and move to the second area to be mined for mining, and stop after mining the preset distance; adjusting the working content of the tunneling machines, selecting one of the multiple tunneling machines to perform a secondary bottom closing to open up multiple mining tunnels formed by the single mining of the first area to be mined and the second area to be mined to form multiple goaf tunnels.

[0007] Furthermore, step three also includes temporarily blocking the mining tunnel, wherein a reserved coal seam is provided at one end of the mining tunnel, and a sealing member is provided at the other end of the mining tunnel to block the other end of the mining tunnel so as to avoid the tunnel boring machine during the secondary bottoming; and / or a reserved coal seam is provided at one end of the mining tunnel, and a sealing member is provided at the other end of the mining tunnel, and the sealing member is connected to the goaf tunnel to seal the other end of the mining tunnel.

[0008] Furthermore, step three also includes pre-burying a filling pipe in the goaf before blocking the goaf, and the filling pipe is movably arranged in the goaf.

[0009] Furthermore, adjusting the working content of the tunnel boring machine also includes setting at least one of the multiple tunnel boring machines in one of the first area to be mined and the second area to be mined, and setting the remaining tunnel boring machines in the other of the first area to be mined and the second area to be mined.

[0010] Furthermore, when the tunneling machine is mining in the first area to be mined or the second area to be mined, the tunneling speed of the tunneling machine is V1, and the speed of the tunneling machine during the secondary bottoming is V2, wherein V1 is less than V2.

[0011] Furthermore, filling the paste into the goaf in step 4 includes injecting the paste into the goaf in stages.

[0012] Furthermore, in step 1, the filling strength σ e The height H is determined by the following calculation formula: Where: H is the height of the cemented filling body, m; σe is the self-supporting strength of the cemented filling body, MPa; a is the empirical coefficient; the filling step distance L is determined by the following calculation formula: Where: e - Self-supporting strength of filling body, MPa; γ c -Bonding filling body bulk density, MN·m -3 ; H-height of cemented filling body, m; L-filling step distance, m.

[0013] Furthermore, step five also includes bottom closing and filling of the coal seam to be mined.

[0014] Furthermore, step three also includes pre-burying an exhaust pipe in the goaf tunnel.

[0015] The technical solution of the present invention is applied to a coal mining method, comprising: Step 1: Analyze the characteristics of the coal seam to be mined and determine the structural strength σ of the paste e , design the step distance L of the filled paste and the height H of the filled paste; Step 2: pre-mine the coal seam to be mined to form a first area to be mined and a second area to be mined, and arrange tunnels to form an air inlet and return system; Step 3: arrange the tunneling machine to mine the first area to be mined and the second area to be mined in turn, and support the roof with anchor rods or anchor cables during the mining process, and block the mined tunnel; Step 4: fill the mined tunnel with paste; Step 5: repeat steps 3 to 4 until the mining of the coal seam to be mined is completed, by dividing the coal seam to be mined into two areas In the mining area, the first area to be mined and the second area to be mined are mined in turn, and the goaf tunnels are sealed and filled with paste in time, which can effectively ensure the support of the coal seam roof, avoid the risk of breakage, collapse and even surface deformation of the coal seam in the mining area, and ensure the mining efficiency. The mining of the coal seam and the filling of the paste are carried out separately without interfering with each other, which further ensures the mining efficiency and solves the problem of coal seam shedding and reducing mining efficiency in deep coal mining in the prior art. At the same time, the method of filling with paste after mining can improve the safety of the mining process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A flow chart showing a coal mining method in a specific embodiment of the present invention; and

[0018] Figure 2 A schematic structural diagram of mining a first area to be mined in a specific embodiment of the present invention is shown;

[0019] Figure 3 A schematic structural diagram of secondary mining of the first area to be mined in a specific embodiment of the present invention is shown;

[0020] Figure 4 A schematic diagram of the structure of injecting paste into a goaf tunnel in a specific embodiment of the present invention is shown;

[0021] Figure 5 A schematic diagram of the structure of mining a goaf tunnel in a first area to be mined in a specific embodiment of the present invention is shown;

[0022] Figure 6 It shows a schematic structural diagram of multiple mining and filling of the first area to be mined in a specific embodiment of the present invention;

[0023] Figure 7 A structural schematic diagram of a coal mining method in a specific embodiment of the present invention is shown.

[0024] The above drawings include the following reference numerals:

[0025] 10. Paste; 20. First area to be mined; 30. Second area to be mined; 40. Roadheader; 50. Reserved coal seam; 60. Goaf tunnel; 70. First tunnel; 80. Second tunnel; 90. Third tunnel; 100. Air duct; 110. Filling pipe; 120. Sealing piece; 130. Fan; 140. Coal transport direction; 150. Air intake direction; 160. Exhaust direction. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0028] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0029] Obviously, the above-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 ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0030] In order to solve the problem in the prior art that coal seam shedding easily occurs during deep coal mining, reducing mining efficiency, the present invention provides a coal mining method.

[0031] like Figure 1 As shown, the coal mining method includes: Step 1: Analyze the characteristics of the coal seam to be mined and determine the structural strength σ of the paste 10 e, design the step distance L of the filled paste 10 and the height H of the filled paste 10; step two: pre-mine the coal seam to be mined to form a first area to be mined 20 and a second area to be mined 30, and arrange tunnels to form an air inlet and return system; step three: arrange the tunneling machine 40 to mine the first area to be mined 20 and the second area to be mined 30 in turn, and support the roof with anchor rods or anchor cables during the mining process, and seal the mined tunnel 60; step four: fill the mined tunnel 60 with paste 10; step five: repeat steps three to four until the mining of the coal seam to be mined is completed.

[0032] By dividing the coal seam to be mined into two areas, mining the first area 20 to be mined and the second area 30 to be mined in turn, and timely sealing and filling the goaf tunnel 60 with paste 10, the support of the coal seam roof can be effectively guaranteed, avoiding the risk of breakage, collapse and even surface deformation of the coal seam in the area to be mined, ensuring the efficiency of mining, and the mining of the coal seam and the filling of the paste 10 are carried out separately without interfering with each other, which further ensures the efficiency of mining. At the same time, the method of filling the paste 10 after the mining is completed can improve the safety during the mining process.

[0033] In this embodiment, in step 3, arranging the tunneling machine 40 to mine the first to-be-mined area 20 and the second to-be-mined area 30 in sequence comprises: arranging multiple tunneling machines 40, wherein the multiple tunneling machines 40 mine the first to-be-mined area 20 at a step distance L, then stop, and transfer to the second to-be-mined area 30 for mining, and stop after mining the preset distance. Adjust the working content of the tunneling machine 40, and select one of the multiple tunneling machines 40 to perform secondary bottoming to open up multiple mining tunnels formed by the first to-be-mined area 20 and the second to-be-mined area 30 to form multiple goaf tunnels 60.

[0034] Specifically, a plurality of tunnel boring machines 40 are arranged at intervals along the first area to be mined 20 or the second area to be mined 30, and move from one end of the first area to be mined 20 or the second area to be mined 30 toward the other end for mining, and stop tunneling at a position 5 m away from the other end, then withdraw from the mined area and temporarily block the opening position of the mined area.

[0035] like Figures 2 to 7 As shown, a first tunnel 70 is provided at the top of the first area to be mined 20, and the first tunnel 70 is used to discharge the dirty air generated during the mining process. The plugging member 120 is used to block the opening of each area to be mined. During the opening process, one end of the air duct 100 is connected to the fan 130, and the other end is provided on the tunneling machine 40 and moves with the tunneling machine 40. The air duct 100 is used to discharge the dirty air generated during the mining process of the tunneling machine 40, as shown in FIG. Figures 2 to 7As shown in the exhaust direction 160, the dirty wind is discharged from the first tunnel 70, and the clean wind enters the area to be mined from the second tunnel 80 or the third tunnel 90, thereby forming a complete flow path in the entire coal seam to be mined. The clean wind enters the coal seam to be mined from the second tunnel 80 or the third tunnel 90 along the air inlet direction 150, takes away the dust generated by the excavation of the tunneling machine 40, and is discharged along the exhaust direction 160, so as to prevent a large amount of smoke and dust from being generated during the mining process and interfering with the mining progress.

[0036] In this embodiment, step three also includes temporarily blocking the mining tunnel, a reserved coal seam 50 is provided at one end of the mining tunnel, and a sealing member 120 is provided at the other end of the mining tunnel to block the other end of the mining tunnel so as to avoid the tunnel boring machine 40 during the secondary bottoming; and / or a reserved coal seam 50 is provided at one end of the mining tunnel, and a sealing member is provided at the other end of the mining tunnel, and the sealing member is connected to the goaf tunnel 60 to seal the other end of the mining tunnel.

[0037] Specifically, the plugging member 120 is movably arranged at one end of the mining tunnel, so that the tunnel boring machine 40 can be avoided when the mining tunnel is mined into the goaf tunnel 60. The movably arranged manner of the plugging member 120 is quick to operate and convenient for recycling. Of course, a seal can also be used to seal the opening of the mining tunnel. Optionally, the seal is a concrete layer. The manner in which the seal is arranged can improve the sealing effect of the mining tunnel to prevent the reserved coal seam 50 from collapsing due to air flow, thereby causing deformation of the mining tunnel and avoiding safety accidents. When the concrete layer is used to seal the mining tunnel, the tunnel boring machine 40 opens both the seal and the reserved coal seam 50 to form the goaf tunnel 60, and the mined coal seam is transported out along the coal transportation direction 140.

[0038] Furthermore, the coal seam 50 is reserved as a wind wall for regulating the air volume, which is opened up when the second bottom pulling is carried out to form full negative pressure ventilation in the mining lane. The negative pressure ventilation method can improve the exhaust effect.

[0039] In this embodiment, the length of the blocking member 120 or the sealing member is smaller than the width of the mining tunnel, thereby saving materials required for construction.

[0040] like Figures 4 to 7 As shown, step three also includes pre-burying a filling pipe 110 in the goaf tunnel 60 before blocking the goaf tunnel 60 , and the filling pipe 110 is movably arranged in the goaf tunnel 60 .

[0041] Specifically, the filling tube 110 extends along one end of the goaf 60 and the length of the filling tube 110 extending into the goaf 60 should not be too long. After the filling of the paste 10 is completed, the filling tube 110 needs to be slowly withdrawn and transferred to another goaf 60. The withdrawal of the overly long filling tube 110 takes too long. The plugging member 120 is provided with an escape notch for avoiding the filling tube 110, so as to facilitate the withdrawal of the filling tube 110. Furthermore, the plugging member 120 is a structure cast at both ends of the goaf 60, thereby sealing both ends of the goaf 60 to prevent the injected paste 10 from flowing out. Optionally, an outer ring is provided at the outer end of the filling tube 110, and the plugging member 120 is formed to the outer side of the outer ring. When the filling tube 110 is withdrawn, the outer ring remains in the sealing position.

[0042] In this embodiment, adjusting the working content of the tunnel boring machine 40 also includes setting at least one tunnel boring machine 40 among the multiple tunnel boring machines 40 on one of the first area to be mined 20 and the second area to be mined 30, and the remaining tunnel boring machines 40 on the other of the first area to be mined 20 and the second area to be mined 30.

[0043] Specifically, there are three tunneling machines 40, and two of them are used to complete a tunneling operation on the first area to be mined 20 and the second area to be mined 30 in turn. After the tunneling operation is completed, one end of the mining tunnel is temporarily blocked, and then the third tunneling machine 40 starts a secondary bottoming operation, so that at least one of the multiple tunneling machines 40 performs a secondary bottoming operation.

[0044] It should be noted that excavation refers to the excavation of a preset distance of coal seams by the excavator 40 in the first to-be-mined area 20 or the second to-be-mined area 30 to form a reserved coal seam 50. Secondary bottoming refers to the excavation of the reserved coal seam 50 by the excavator 40 to form a goaf roadway 60.

[0045] In this embodiment, when the tunneling machine 40 is mining in the first area 20 to be mined or the second area 30 to be mined, the tunneling speed of the tunneling machine 40 is V1, and the speed of the tunneling machine 40 during the secondary bottoming is V2, wherein V1 is less than V2.

[0046] Specifically, by limiting the speed of excavation and secondary bottom closing of the roadheader 40, it is possible to achieve that two roadheaders 40 are excavating and one roadheader 40 is performing secondary bottom closing at the same time in any time period. Preferably, the secondary bottom closing speed V2 is twice the excavation speed V1. It can be understood that when two roadheaders 40 are excavating in the area to be mined and excavating to half of the area to be mined, the third roadheader 40 has completed the secondary bottom closing of one goaf tunnel 60, so that when two roadheaders 40 complete the excavation of two mining tunnels, the third roadheader 40 has completed the secondary bottom closing of two goaf tunnels 60, so that the construction speed can be greatly improved and the requirements of the "Safety Regulations" are met.

[0047] like Figure 3 As shown, after completing the primary mining in the first area to be mined 20 and the second area to be mined 30, there are always two tunneling machines 40 in excavation, and one tunneling machine 40 is performing secondary bottom closing. After completing the secondary bottom closing, both ends of the goaf tunnel 60 are sealed and filled with paste 10 through the pre-buried filling pipe 110.

[0048] In this embodiment, filling the paste 10 into the goaf tunnel 60 in step 4 includes injecting the paste 10 into the goaf tunnel 60 in stages.

[0049] Specifically, the staged filling method is adopted to divide the entire filling process into two steps. The gradual filling method can avoid the excessive amount of the paste 10, which causes the paste 10 to exceed the area to be mined after solidification or form a large squeeze on both sides of the goaf 60. Optionally, the paste 10 is first filled to a height of 1.5 to 2.5 m below the goaf 60, and after the paste 10 filled in the lower part is initially solidified, the goaf 60 is continued to be filled until the paste 10 reaches the upper area to the top, and the length of the paste 10 after the filling is completed is adapted to the length of the entire area to be mined.

[0050] In this example, the paste 10 strength σ in step 1 e The height H is determined by the following calculation formula: Where: H is the height of the paste 10, m; σe is the self-supporting strength of the paste 10, MPa; a is the empirical coefficient; the filling step distance L is determined by the following calculation formula: Where: e - Self-supporting strength of paste 10, MPa; γ c -Paste 10 bulk density, MN·m -3 ; H-paste 10 height, m; L-filling step distance, m.

[0051] The strength height and step distance of the paste 10 to be filled are designed by the above formula to ensure the construction effect.

[0052] In this embodiment, step five also includes bottom closing and filling of the coal seam to be mined.

[0053] Specifically, bottom closing is secondary bottom closing, and secondary bottom closing does not require a roof support process. Compared with excavation, the secondary bottom closing surface at the same working position has one less support process. Judging from the time spent on each process, the support process accounts for about half of the time spent on a single operation cycle. Therefore, the secondary bottom closing advancement speed is about twice the excavation speed. Before filling the paste 10, the paste 10 is formed on the ground and transported to the goaf 60 through the filling pipe 110. The filling pipe 110 is made of wear-resistant material to reduce losses during use.

[0054] In this embodiment, step three also includes pre-burying an exhaust pipe in the goaf tunnel 60 .

[0055] Specifically, when the paste 10 is filled, the paste 10 condenses and occupies the space inside the goaf 60 , and the air in the goaf 60 is discharged through the exhaust pipe.

[0056] Using the coal mining method of the present invention, each area to be mined is a working face. Figure 1 The right side in the horizontal direction is the cut eye. During the mining process, the overburden load needs to be slowly and evenly transferred to the paste 10. The design divides the entire coal seam mining process into three stages: the first stage is the first round of coal seam mining and the filling stage of the goaf roadway 60. The design mines adjacent working faces in sequence, and leaves a strip coal pillar of a certain size between the two strip empty areas, and starts filling after mining. In order to ensure good ventilation of the working face, a continuous mining machine is used as a tunneling machine 40 for mining, and a forward layout is used for filling until the entire working face is mined and filled. The second stage is the multi-round coal pillar mining and goaf roadway 60 filling stage, and filling is carried out after mining. In order to ensure good ventilation of the working face, a forward layout is also used for filling until the entire working face is mined and filled; the third stage is the completion of the paste 10 filling mining stage. At this time, after multiple rounds of continuous mining machine strip mining and goaf filling, the coal body of the coal seam is recovered.

[0057] Specifically, starting from the first mining, as mining progresses, a paste 10 is constructed at a certain distance in the coal body along the strip arrangement direction. When the spacing of the paste 10 is smaller than the initial fracture step of the old roof, if the spacing of the paste 10 is larger than the initial spanning step of the direct roof, the direct roof will break and may fall. The initial spanning step of the direct roof is generally related to the strength of the direct roof rock layer, the layer thickness, and the degree of development of joints and fissures. Before the initial spanning of the direct roof, bending deformation will occur, which is generally larger than the deformation of the old roof, so delamination between the direct roof and the old roof is prone to occur. After the direct roof spans and breaks, the volume will expand, and its morphology and mechanical properties are equivalent to those of a bulk body. The broken direct roof rock blocks will accumulate in the unfilled strips, and the height of the accumulation will be higher than the original thickness of the direct roof. If the immediate roof that has fallen fills the unfilled goaf 60, the gangue in the coal seam that has fallen will produce horizontal pressure on the paste 10 on both sides, changing the stress state of the paste 10 from a uniaxial stress state to a biaxial stress state, thereby improving the bearing capacity of the paste 10, and the bending deformation of the old roof will be very small, only a few cracks will be generated, and the layered structure will still be maintained. If the immediate roof that has fallen does not fill the unfilled goaf 60, the old roof will produce a larger bending deformation. When the spacing of the paste 10 is greater than the initial fracture step of the old roof, as the comprehensive mining face advances forward, the immediate roof will first cross and fall, and the old roof will be in a suspended state. At this time, the old roof can be regarded as a "plate" structure. According to the thin plate theory, as the bending moment increases, the old roof will break when it reaches the strength limit.

[0058] Furthermore, the working face is divided into a group at a certain distance parallel to the cut, and each group is mined and filled in four rounds. EBZ160 or EBZ200 type comprehensive excavator is used to drop coal, shovel truck is used to load coal, secondary transport, scraper or rubber wheel truck is used to transport coal, the roof of the goaf roadway is managed by the full filling method of 60, and the goaf is retained in the return roadway.

[0059] From the above description, it can be seen that the above embodiment of the present invention achieves the following technical effects: The coal mining method comprises: Step 1: Analyze the characteristics of the coal seam to be mined, determine the structural strength σ of the paste 10 e, design the step distance L of the filled paste 10 and the height H of the filled paste 10; step 2: pre-mine the coal seam to be mined to form a first area to be mined 20 and a second area to be mined 30, and arrange the tunnel to form an air inlet and return system; step 3: arrange the tunneling machine 40 to mine the first area to be mined 20 and the second area to be mined 30 in turn, and support the roof with anchor rods or anchor cables during the mining process, and block the mined tunnel 60; step 4: fill the mined tunnel 60 with paste 10; step 5: repeat steps 3 to 4 until the mined area is completed The mining of the coal seam can effectively ensure the support of the coal seam roof by dividing the coal seam to be mined into two areas, mining the first area 20 to be mined and the second area 30 to be mined in turn, and timely sealing and filling the goaf 60 with paste 10, thereby avoiding the risk of breakage, collapse and even surface deformation of the coal seam in the mining area, ensuring the mining efficiency, and the mining of the coal seam and the filling of the paste 10 are carried out separately without interfering with each other, which further ensures the mining efficiency. At the same time, the filling of the paste 10 after the mining is completed can improve the safety during the mining process.

[0060] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0061] It should be noted that the terms "upper", "lower", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A coal mining method, characterized in that: include: Step 1: Analyze the characteristics of the coal seam to be mined and determine the structural strength σ of the paste (10) e , designing the step distance L of the filled paste (10) and the height H of the filled paste (10); Step 2: pre-mining the coal seam to be mined to form a first mining area (20) and a second mining area (30), and arranging tunnels to form an air inlet and return system; Step 3: Arranging a tunnel boring machine (40) to mine the first to-be-mined area (20) and the second to-be-mined area (30) in sequence, supporting the roof with anchor rods or anchor cables during the mining process, and sealing the mined tunnel (60) after the mining is completed; Step 4: filling the paste (10) into the goaf tunnel (60); Step 5: Repeat steps 3 to 4 until the mining of the coal seam to be mined is completed.

2. The coal mining method according to claim 1, characterized in that: The step 3 of arranging the roadheader (40) to mine the first to-be-mined area (20) and the second to-be-mined area (30) in sequence comprises: Arranging a plurality of the roadheaders (40), wherein the plurality of roadheaders (40) mine the first to-be-mined area (20) at a step distance L, then stop after mining a preset distance, and move to the second to-be-mined area (30) for mining, and stop after mining the preset distance; The working content of the tunnel boring machine (40) is adjusted, and one of the plurality of tunnel boring machines (40) is selected to perform secondary bottom closing to connect the plurality of mining tunnels formed by the first to-be-mined area (20) and the second to-be-mined area (30) through one mining operation to form a plurality of goaf tunnels (60).

3. The coal mining method according to claim 2, characterized in that: The step three also includes temporarily blocking the mining tunnel. A reserved coal seam (50) is provided at one end of the mining tunnel, and a plugging member (120) is provided at the other end of the mining tunnel to plug the other end of the mining tunnel so as to avoid the tunneling machine (40) during secondary bottoming; and / or A reserved coal seam (50) is arranged at one end of the mining tunnel, and a sealing member is arranged at the other end of the mining tunnel. The sealing member is connected to the goaf tunnel (60) to seal the other end of the mining tunnel.

4. The coal mining method according to claim 3, characterized in that: The step three also includes pre-burying a filling pipe (110) in the goaf tunnel (60) before blocking the goaf tunnel (60), and the filling pipe (110) is movably arranged in the goaf tunnel (60).

5. The coal mining method according to claim 3, characterized in that: The work content of adjusting the tunnel boring machine (40) also includes setting at least one of the multiple tunnel boring machines (40) on one of the first area to be mined (20) and the second area to be mined (30), and the remaining tunnel boring machines (40) are set on the other of the first area to be mined (20) and the second area to be mined (30).

6. The coal mining method according to claim 3, characterized in that: When the tunneling machine (40) is mining in the first area to be mined (20) or the second area to be mined (30), the tunneling speed of the tunneling machine (40) is V1, and the speed of the tunneling machine (40) when performing secondary bottoming is V2, wherein V1 is less than V2.

7. The coal mining method according to claim 1, characterized in that: Filling the paste (10) into the goaf tunnel (60) in step 4 includes injecting the paste (10) into the goaf tunnel (60) in stages.

8. The coal mining method according to claim 1, characterized in that: The paste (10) in step 1 has a strength σ e The height H is determined by the following calculation formula: Wherein: H is the height of the paste (10), m; σe is the self-supporting strength of the paste (10), MPa; a is the empirical coefficient; The filling step distance L is determined by the following calculation formula: Where: e - the self-supporting strength of the paste (10), MPa; γ c - Bulk density of the paste (10), MN·m -3 ; H-height of the paste (10), m; L-filling step, m.

9. The coal mining method according to claim 1, characterized in that: The step five also includes bottom closing and filling of the coal seam to be mined.

10. The coal mining method according to any one of claims 1 to 9, characterized in that: The step three also includes pre-burying an exhaust pipe in the goaf tunnel (60).

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