Fully mechanized caving filling mining method for high-gas thick coal seam

Abstract

The invention discloses a fully-mechanized caving filling mining method for a high-gas thick coal seam, and relates to the field of coal seam mining, a gas extraction filling roadway arranged in an overlying rock stratum is adopted to perform gas extraction and filling at the same time, and one-hole multi-purpose drilling is achieved, that is, a hole is drilled in an advanced working face to extract gas, and the gas extraction and filling are performed at the same time. And parallel operations of filling and mining are realized in a drilling and filling manner behind the working face, so that the mining efficiency is improved, and the problem that the mining efficiency is restricted by filling is solved. The gas is extracted through the drill hole, so that the gas concentration of the working face is reduced. Grouting and filling are conducted from top to bottom through the drilled holes, the filling efficiency is improved, and the problem that a traditional filling support is insufficient in height is solved; meanwhile, after the filling slurry is injected into the goaf, a filling body can be formed, namely, an integral supporting structure can be formed, roof contact can be achieved, the bearing performance is high, ground surface subsidence is controlled, and the problem of large-scale subsidence caused by fully mechanized caving mining is solved.

Description

Technical Field

[0001] The invention relates to the field of coal seam mining, and in particular to a fully mechanized caving and backfilling mining method for high-gas thick coal seams. Background Art

[0002] Comprehensive caving mining has high unit yield, high efficiency, low cost, small tunnel excavation volume, and strong adaptability to geology, but it also faces disadvantages such as high coal loss, easy ignition, large coal dust, and easy gas accumulation. The backfill mining method can effectively solve the "three-down" coal pressure problem, reduce the environmental pollution caused by ground gangue accumulation and fly ash, control surface subsidence, and protect ground buildings. However, the current backfill mining of coal mines has the problems of low backfill efficiency, inability to operate backfill and coal mining in parallel, and imperfect back-partitioning technology of the working face.

[0003] At present, many domestic patents change the structure of the support to achieve parallel operation of mining and filling, but this will inevitably lead to an increase in the distance of the top control, and the requirements for working resistance are stringent. It is not well adaptable when encountering special geological conditions, and the filling height is mostly limited by the support filling template, which is not conducive to the release of production capacity. There are also related patents for optimizing the layout of underground tunnels. However, filling is achieved by excavating auxiliary tunnels at the same level, but due to the influence of mining and technology, parallel mining and filling cannot be achieved. Filling will restrict mining efficiency, which is not conducive to the release of production capacity, and the filling rate is low, making it difficult to suppress the sinking of the roof and the collapse of the surface. At the same time, the choice of filling materials is mostly loose, not connected to the top, not easy to compact, and has poor bearing performance. Summary of the invention

[0004] To solve the above technical problems, the present invention provides a fully-mechanized caving and backfilling mining method for high-gas thick coal seams, which realizes parallel operation of backfilling and mining, solves the problem of backfilling restricting mining efficiency and large-scale subsidence caused by fully-mechanized caving and backfilling mining.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a fully mechanized caving and backfilling mining method for high-gas thick coal seams, comprising the following steps:

[0007] Step 1: Arrange the transport lanes and track lanes in the mining area along the direction of the coal seam;

[0008] Step 2: Arrange a gas extraction and filling tunnel parallel to the direction of the coal seam in the overlying rock layer above the working face;

[0009] Step 3: Arrange an inclined lane whose upper end is connected to the gas extraction and filling lane and whose lower end is connected to the transport lane or the track lane, wherein the inclined lane is used for people to walk and transport materials;

[0010] Step 4: transporting the extraction and filling equipment to the rear of the gas extraction and filling tunnel through the inclined tunnel;

[0011] Step 5: At a certain distance in front of the working face, the overburden stratum is drilled to form at least one drilling group, the drilling group includes multiple drilling holes in different directions, each of the drilling holes penetrates the bottom of the overburden stratum, and the multiple drilling holes in each drilling group are coplanarly arranged, and the plane where the multiple drilling holes in each drilling group are located is parallel to the working face, and the coal seam is mined, and gas is extracted by the drilling group and the extraction and filling equipment. As a goaf is formed after the mining of the coal seam, the extraction and filling equipment is used to inject filling slurry into the goaf through the drilling group to form a filling body;

[0012] Step 6: As the working face advances, repeat the work in step 5 until the mining of the coal seam is completed.

[0013] Preferably, in step 2, the gas extraction and filling tunnel is arranged parallel to the strike direction of the coal seam at the center of the overlying rock stratum above the working face.

[0014] Preferably, in step three, two inclined tunnels are provided, the upper and lower ends of one inclined tunnel are respectively connected to the gas extraction and filling tunnel and the transport tunnel, and the upper and lower ends of the other inclined tunnel are respectively connected to the gas extraction and filling tunnel and the rail tunnel.

[0015] Preferably, in step three, the two inclined tunnels are arranged in the same plane, and the plane where the two inclined tunnels are located is perpendicular to the strike direction of the coal seam.

[0016] Preferably, in step four, the extraction and filling equipment includes an extraction pump, a gas transport pipe, a slurry transport pipe and a plurality of extraction and filling pipes. The extraction pump, one end of the gas transport pipe, one end of the slurry transport pipe and the plurality of extraction and filling pipes are transported to the rear of the gas extraction and filling tunnel through the inclined tunnel, and the other end of the slurry transport pipe is located outside the mining area. One end of the gas transport pipe is connected to the extraction pump, and the other end of the gas transport pipe is located outside the mining area.

[0017] Preferably, in step five, one extraction and filling pipe is inserted into each of the boreholes. When gas extraction is required, multiple extraction and filling pipes are connected to the extraction pump, and the extraction pump is turned on for extraction. After the extraction is completed, the multiple extraction and filling pipes are separated from the extraction pump.

[0018] Preferably, in step five, when grouting is required, the plurality of extraction and filling pipes are connected to the slurry transport pipe, and the filling slurry is injected into the goaf through the slurry transport pipe and the extraction and filling pipe.

[0019] Preferably, in step five, after gas extraction and before grouting, the plurality of extraction and filling pipes are connected to the slurry transport pipe, and water is injected into the goaf through the slurry transport pipe and the extraction and filling pipe.

[0020] Preferably, in step five, the overburden stratum is drilled at a distance of 15 m to 20 m in front of the working face to form at least one drilling group.

[0021] Preferably, in step five, the drilling group includes three drill holes, the drill hole located in the middle is vertically arranged, and the two drill holes located on both sides are inclinedly arranged, and the diameter of the drill hole is 150 mm.

[0022] Compared with the prior art, the present invention has achieved the following technical effects:

[0023] The fully mechanized top-caving and backfilling mining method for high-gas thick coal seams of the present invention adopts a gas extraction and backfilling tunnel set in the overlying rock strata to simultaneously perform gas extraction and backfilling, realizing the multi-purpose use of a borehole, that is, drilling a borehole ahead of the working face to extract gas, and backfilling the boreholes behind the working face, realizing the parallel operation of backfilling and mining, improving the mining efficiency, solving the problem that backfilling restricts the mining efficiency, and facilitating the further release of the capacity of fully mechanized top-caving mining. First, gas is extracted through drilling holes to reduce the gas concentration of the working face. Then, grouting and backfilling are performed from top to bottom through drilling holes, which improves the filling efficiency and solves the problem of insufficient height of traditional backfilling supports; at the same time, after the backfill slurry is injected into the goaf, a filling body can be formed, that is, an integral supporting structure can be formed, and it can be connected to the top, with strong bearing capacity, so that the surface settlement is controlled, solving the problem of large-scale subsidence caused by fully mechanized top-caving mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A front view of the tunnel layout of the fully mechanized caving and backfilling mining method for high-gas thick coal seams provided by the present invention;

[0026] Figure 2 A top view of the tunnel layout of the fully mechanized caving and backfilling mining method for high-gas thick coal seams provided by the present invention.

[0027] Explanation of the accompanying reference numerals: 1. Coal seam; 2. Overlying rock stratum; 3. Transport tunnel; 4. Track tunnel; 5. Gas extraction and filling tunnel; 6. Inclined tunnel; 7. Borehole; 8. Filling body. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The purpose of the present invention is to provide a fully-mechanized caving and backfilling mining method for high-gas thick coal seams, which realizes parallel operation of backfilling and mining, solves the problem of backfilling restricting mining efficiency and large-scale subsidence caused by fully-mechanized caving and backfilling mining.

[0030] 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.

[0031] like Figure 1-Figure 2 As shown, this embodiment provides a fully mechanized caving and backfilling mining method for a high-gas thick coal seam 1, comprising the following steps:

[0032] Step 1: Arrange the transport tunnel 3 and the track tunnel 4 of the mining area along the direction of the coal seam 1; specifically, the transport tunnel 3 can also be used for air intake, and the track tunnel 4 can also be used for air return.

[0033] Step 2: Arrange a gas extraction and filling tunnel 5 parallel to the strike direction of the coal seam 1 in the overlying rock stratum 2 above the working face.

[0034] Step three: Arrange an inclined tunnel 6 whose upper end is connected to the gas extraction and filling tunnel 5 and whose lower end is connected to the transport tunnel 3 or the rail tunnel 4. The inclined tunnel 6 is used for people to walk and transport materials.

[0035] Step 4: transport the extraction and filling equipment to the rear of the gas extraction and filling tunnel 5 through the inclined tunnel 6.

[0036] Step 5. At a certain distance in front of the working face, the overlying rock stratum 2 is drilled to form at least one drilling group, the drilling group includes multiple boreholes 7 in different directions, each borehole 7 penetrates the bottom of the overlying rock stratum 2, and the multiple boreholes 7 in each drilling group are coplanarly arranged. The plane where the multiple boreholes 7 in each drilling group are located is parallel to the working face. The coal seam 1 is mined, and gas is extracted by the drilling group and extraction and filling equipment. As a goaf is formed behind the mining of the coal seam 1, the extraction and filling equipment is used to inject filling slurry into the goaf through the drilling group, thereby forming a filling body 8.

[0037] Step 6: As the working face advances, the work in step 5 is repeated until the mining of the coal seam 1 is completed. Specifically, the drilling group is not drilled at one time, but the drilling group is drilled in advance as the working face advances.

[0038] In this embodiment, five gas extraction and filling tunnels arranged in the overlying rock stratum 2 are used for gas extraction and filling, realizing multiple uses of one borehole, that is, gas is extracted by drilling holes ahead of the working face, and filling is carried out by drilling holes behind the working face, thereby realizing parallel operations of filling and mining, improving mining efficiency, solving the problem of filling restricting mining efficiency, and being conducive to further release of comprehensive mining capacity.

[0039] Specifically, gas is first extracted through borehole 7 to reduce the gas concentration of the working face and effectively prevent gas accidents caused by high-intensity mining. Then, grouting is performed from top to bottom through borehole 7 to improve the filling efficiency and solve the problem of insufficient height of traditional filling supports; at the same time, after the filling slurry is injected into the goaf, a filling body 8 can be formed, that is, an integral supporting structure can be formed, and it can be connected to the top with strong bearing capacity, so that the surface settlement can be controlled, and the problem of large-scale subsidence caused by comprehensive mining is solved, which is conducive to the green mining of coal. It can be seen that this method can effectively solve the problems of excessive roof pressure, spontaneous combustion in the well, and excessive gas dust concentration. Under special geological conditions and on the basis of economic feasibility, it has promotion value.

[0040] After the goaf filling technology is adopted in this embodiment, the filling body 8 will maintain the stability of the roof structure together with the coal wall, and part of the roof pressure is transferred to the filling body 8, thereby alleviating the damage of the coal wall. By grouting and filling the goaf, the air leakage in the goaf is blocked, and the spontaneous combustion of coal in the goaf is reduced to a certain extent, that is, because the filling body 8 separates the working face, the spontaneous combustion of the coal in the goaf is reduced.

[0041] Specifically, in step 2, a gas extraction and filling tunnel 5 parallel to the strike direction of the coal seam 1 is arranged at the center of the overburden stratum 2 above the working face. The gas extraction and filling tunnel 5 in this embodiment is located in a stable stratum of the overburden stratum 2.

[0042] In this embodiment, the gas extraction and filling tunnel 5 is set in the overlying rock layer 2, which is less affected by mining. It can ensure that the gas extraction and filling tunnel 5 still has sufficient strength and stability when the top coal is recovered. Even if it is affected by mining, it can maintain its normal use through simple support, thus ensuring the stability of the gas extraction and filling tunnel 5.

[0043] At the same time, the mining operation space and the filling operation space are not in the same layer, and the two do not interfere with each other, so that parallel operations of filling and mining can be achieved, the mining efficiency of the filling working face is improved, and the problem of filling restricting mining efficiency is solved.

[0044] In step 3, an inclined tunnel 6 is arranged near the mining area coal pillar at the mining area boundary. Specifically, two inclined tunnels 6 are provided, and the upper and lower ends of one inclined tunnel 6 are respectively connected to the gas extraction and filling tunnel 5 and the transportation tunnel 3, and the upper and lower ends of the other inclined tunnel 6 are respectively connected to the gas extraction and filling tunnel 5 and the track tunnel 4. By providing two inclined tunnels 6, it is more convenient for operators to carry equipment and materials into the gas extraction and filling tunnel 5, which helps to improve the working environment in the gas extraction and filling tunnel 5.

[0045] In this specific embodiment, the two inclined tunnels 6 are arranged in the same plane, and the plane where the two inclined tunnels 6 are located is perpendicular to the strike direction of the coal seam 1 .

[0046] In step four, the extraction and filling equipment includes an extraction pump, a gas transport pipe, a slurry transport pipe and multiple extraction and filling pipes. The extraction pump, one end of the gas transport pipe, one end of the slurry transport pipe and multiple extraction and filling pipes are transported to the rear of the gas extraction and filling tunnel 5 through the inclined tunnel 6. The other end of the slurry transport pipe is located outside the mining area. The slurry transport pipe is used to transport the prepared filling slurry to the gas extraction and filling tunnel 5. One end of the gas transport pipe is connected to the extraction pump, and the other end of the gas transport pipe is located outside the mining area. The gas transport pipe is used to transport the extracted gas to the outside.

[0047] Specifically, the gas transported from the other end of the gas transport pipe can be stored and utilized at the mine's own gas storage station, or it can be directly connected to the provincial oil and gas pipeline and go through the provincial energy system.

[0048] In step five, a drainage filling pipe is inserted into each borehole 7. When gas extraction is required, multiple drainage filling pipes are connected to the extraction pump, and the extraction pump is turned on for extraction. After the extraction is completed, the multiple drainage filling pipes are separated from the extraction pump.

[0049] In step five, when grouting is required, multiple extraction and filling pipes are connected to the slurry transportation pipe, and filling slurry is injected into the goaf through the slurry transportation pipe and the extraction and filling pipe.

[0050] In this specific embodiment, the filling slurry is a high-concentration cementitious filling slurry.

[0051] In step five, after gas extraction and before grouting, multiple extraction and filling pipes are connected to the slurry transport pipe, and water is injected into the goaf through the slurry transport pipe and the extraction and filling pipe, that is, water is sprayed near the working face to reduce the dust concentration on the working face. After the spraying dust reduction is completed, filling slurry is injected into the goaf through the slurry transport pipe and the extraction and filling pipe.

[0052] The distance of the advance drilling group in front of the working face is determined according to the working conditions. This range is determined after considering the comprehensive factors of gas outflow speed, coalbed methane content, geological conditions, and mine exhaust system. Too small an advance distance may not effectively control the gas concentration, increasing the risk of gas explosion; while too large an advance distance may lead to poor gas extraction effect.

[0053] In this specific embodiment, the overburden stratum 2 is drilled at a distance of 15m to 20m in front of the working face to form at least one drilling group, thereby being able to effectively control the gas concentration and ensure the gas extraction effect.

[0054] In this embodiment, the drilling group includes a plurality of drilling holes 7 with different directions and arranged on the same plane, ensuring that the direction of each drilling hole 7 is evenly distributed in the plane where it is located, so that the filling body 8 can completely fill the entire goaf.

[0055] In step 5, the number of boreholes 7 is reasonably arranged according to the length of the working face. The boreholes 7 should be able to ensure the extraction and filling of the working face. The borehole group in this embodiment includes three boreholes 7. The borehole 7 located in the middle is vertically arranged, and the two boreholes 7 located on both sides are inclined. The diameter of the borehole 7 is 150 mm. It should be noted that the number and diameter of the boreholes 7 can be determined according to the working conditions.

[0056] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A fully mechanized caving and backfilling mining method for high-gas thick coal seams, characterized in that: The following steps are involved: Step 1: Arrange the transport lanes and track lanes in the mining area along the direction of the coal seam; Step 2: Arrange a gas extraction and filling tunnel parallel to the direction of the coal seam in the overlying rock layer above the working face; Step 3: Arrange an inclined lane whose upper end is connected to the gas extraction and filling lane and whose lower end is connected to the transport lane or the track lane, wherein the inclined lane is used for people to walk and transport materials; Step 4: transporting the extraction and filling equipment to the rear of the gas extraction and filling tunnel through the inclined tunnel; Step 5: At a certain distance in front of the working face, the overburden stratum is drilled to form at least one drilling group, the drilling group includes multiple drilling holes in different directions, each of the drilling holes penetrates the bottom of the overburden stratum, and the multiple drilling holes in each drilling group are coplanarly arranged, and the plane where the multiple drilling holes in each drilling group are located is parallel to the working face, and the coal seam is mined, and gas is extracted by the drilling group and the extraction and filling equipment. As a goaf is formed after the mining of the coal seam, the extraction and filling equipment is used to inject filling slurry into the goaf through the drilling group to form a filling body; Step 6: As the working face advances, repeat the work in step 5 until the mining of the coal seam is completed.

2. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 1 is characterized in that: In step two, the gas extraction and filling tunnel is arranged parallel to the direction of the coal seam at the center of the overlying rock layer above the working face.

3. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 1 is characterized in that: In step three, two inclined tunnels are provided, the upper and lower ends of one inclined tunnel are respectively connected to the gas extraction and filling tunnel and the transport tunnel, and the upper and lower ends of the other inclined tunnel are respectively connected to the gas extraction and filling tunnel and the rail tunnel.

4. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 3 is characterized in that: In step three, the two inclined tunnels are arranged in the same plane, and the plane where the two inclined tunnels are located is perpendicular to the strike direction of the coal seam.

5. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 1 is characterized in that: In step four, the extraction and filling equipment includes an extraction pump, a gas transport pipe, a slurry transport pipe and multiple extraction and filling pipes. The extraction pump, one end of the gas transport pipe, one end of the slurry transport pipe and the multiple extraction and filling pipes are transported to the rear of the gas extraction and filling tunnel through the inclined tunnel, and the other end of the slurry transport pipe is located outside the mining area. One end of the gas transport pipe is connected to the extraction pump, and the other end of the gas transport pipe is located outside the mining area.

6. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 5 is characterized in that: In step five, one extraction and filling pipe is inserted into each of the boreholes. When gas extraction is required, multiple extraction and filling pipes are connected to the extraction pump, and the extraction pump is turned on for extraction. After the extraction is completed, the multiple extraction and filling pipes are separated from the extraction pump.

7. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 6 is characterized in that: In step five, when grouting is required, the plurality of extraction and filling pipes are connected to the slurry transport pipe, and the filling slurry is injected into the goaf through the slurry transport pipe and the extraction and filling pipe.

8. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 7 is characterized in that: In step five, after gas extraction and before grouting, the plurality of extraction and filling pipes are connected to the slurry transport pipe, and water is injected into the goaf through the slurry transport pipe and the extraction and filling pipe.

9. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 1 is characterized in that: In step five, the overburden stratum is drilled at a distance of 15 m to 20 m in front of the working face to form at least one drilling group.

10. The fully mechanized caving and backfilling mining method for high-gas thick coal seams according to claim 1 is characterized in that: In step five, the drilling group includes three holes, the hole in the middle is vertically arranged, and the two holes on both sides are inclinedly arranged, and the diameter of the hole is 150 mm.

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