A method of producing a coal mine in which the entire coal seam is extracted

Abstract

The application relates to the field of coal mining, in particular to a mine production method for fully mining coal seams. The method comprises the following steps: establishing a mining, selecting and filling integrated shaft bottom yard, determining the minimum width of a filling body based on the load borne by the filling body, and further determining the minimum width of a large roadway tunneling face, carrying out tunneling and filling work of the large roadway tunneling face from the shaft bottom yard, constructing the large roadway in the filling body formed by filling after the large roadway tunneling face is excavated and mined, and leaving a cut eye on both sides of the filling body; arranging a plurality of longwall faces extending along the inclination along the strike in sequence, and the longwall face adopts advancing mining. The filling mining technology is used to mine the large roadway protection coal pillar region originally set, and the large roadway is reserved in the filling body, which is beneficial to the maintenance of the subsequent large roadway, the cut eye is left on both sides of the filling body, the longwall face directly carries out advancing mining by using the cut eye, and the production time is shortened; no coal pillar is left in the whole mine, the coal seams can be fully mined, and the coal mining efficiency in the mining area is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of coal mining, and more particularly to a mine production method in which all coal seams are extracted. Background Technology

[0002] Longwall fully mechanized coal mining technology is the most commonly used coal mining method currently available. It is highly adaptable to geological conditions, easy to relocate, and easy to master in terms of operation. Common types include strike longwall faces, which are mainly arranged in mining areas, and dip longwall faces, which are mainly arranged in belt zones. Both of these longwall face layouts require the construction of main roadways and the provision of protective coal pillars of appropriate width. Because the service life of main roadways is long, generally 10-30 years, the width of the protective coal pillars is relatively large. Early mines did not plan for these protective coal pillars during construction, resulting in huge resource waste. Taking the double main roadway layout as an example, the total protective coal pillar needs to be about 100m, based on a mining height of 5.0m and a density of 1.3t / m³. 3 The main roadway is 2000m long, resulting in a total coal loss of 1.3 million tons. As the mine's coal resources are depleted, it is necessary to re-mine the protective coal pillars in these main roadways. However, due to the long service life of the main roadways and the insufficient stability of the protective coal pillars, the recovery rate of re-mining is generally less than 30%, and a large amount of coal resources remain in the mine.

[0003] Meanwhile, in order to shorten the construction period, existing mines generally construct main roadways within the coal seam during construction. However, this requires coal with high hardness and strength, otherwise it is difficult to provide support. On the other hand, if traditional construction methods are used in the rock strata, there are problems such as slow tunneling speed, long construction period, and high cost. In addition, the tunneling of rock roadways, as well as the coal mining and coal preparation processes, generate a large amount of gangue and tailings. Thermal power plants generate fly ash, and the accumulation of gangue, tailings, and fly ash on the ground occupies arable land. At the same time, the treatment of wastewater generated by mine production also requires considerable costs. Summary of the Invention

[0004] To address the technical problems of low recovery rates and difficulties in recovering protective coal pillars in existing mines, this invention proposes a mine production method that allows for the complete extraction of coal seams. The protective coal pillars in the main roadway are first recovered using a backfilling mining process, leaving the main roadway within the backfill. Then, a longwall mining face is deployed in the left-out main roadway for longwall mining. This method achieves pillarless mining, and specifically includes the following steps:

[0005] Step 1: Establish an integrated wellbore bottom yard for mining, beneficiation, and charging;

[0006] Step 2: Determine the width of the main roadway face. First, determine the load on the filling material, then compare it with the strength of the filling material to determine the minimum critical width w of the filling material. c The minimum critical width w of the filling material is such that the load on the filling material is equal to the strength of the filling material.c The sum of the widths of the two side cuts and the total width of the main roadway is the minimum critical width w of the main roadway excavation face. j ;

[0007] Step 3: From the bottom of the shaft, proceed with the excavation and backfilling of the main roadway face along the strike. The main roadway is constructed within the backfill formed after the main roadway face has been mined, with cut-outs on both sides of the backfill. The width of the main roadway face is greater than the minimum critical width w determined in Step 2. j ;

[0008] The fourth step is to arrange several longwall working faces extending along the dip in sequence along the strike. The longwall working faces adopt the forward mining method and use the cut-out formed in the third step.

[0009] Fifth, repeat steps three and four to carry out the mining of the entire coal seam.

[0010] As a further optimization of the above scheme, in the first step, in the integrated mining, beneficiation and filling bottom yard, the coal gangue sorting system is used to directly sort the coal mined from the mine underground, separating clean coal and gangue. The gangue is crushed to a suitable particle size by the gangue crushing system; the cementing material storage system stores cementing material; the cementing material, crushed gangue and wastewater are transported to the filling material preparation system for mixing and preparing filling material; a soil silo is also set up to store soil for the adobe.

[0011] As a further optimization of the above scheme, the specific method for determining the second step is as follows:

[0012] The average load P borne by the overburden on the infill body is calculated using the following formula.

[0013]

[0014] In the formula, P is the average load borne by the overburden in MPa; γ is the average unit weight of the overburden in MN / m³. 3 ;w c —Minimum critical width of the infill body, m; β —Angle of rock strata collapse; h k —Thickness of the caving zone, m; h d —Thickness of the water-conducting fracture zone, m; h w —Thickness of the curved and sunken belt, in meters;

[0015] The strength σ of the filling material; when P = σ, the minimum critical width w for the filling material to remain stable can be obtained. c The minimum critical width w c The sum of the widths of the two side cuts and the total width of the main roadway is the minimum critical width w of the main roadway excavation face. j .

[0016] As a further optimization of the above scheme, in the third step, a continuous coal mining machine is used to excavate the coal seam. The excavated coal is transferred by shuttle car to the belt conveyor in the main haulage roadway and then to the coal gangue sorting system in the bottom yard. At a certain distance from the coal mining area, two spaced main haulage formworks are set up along the strike in the middle of the main haulage face. Soil bricks are set up along the strike on both sides of the main haulage face. The main haulage formworks and soil bricks are used to construct the filling retaining wall. The filling retaining wall is spaced at a certain distance from the filling body formed by the previous filling to form a filling space. Filling material is filled in. After the filling material solidifies to the predetermined strength, the main haulage formwork is pulled out.

[0017] As a further optimization of the above scheme, in the third step, the length of the main roadway formwork is greater than the directional length of the filling space, and filling material is injected into the filling space from the filling pipe, wherein the filling pipe enters the return air main roadway from the bottom of the shaft to the filling area.

[0018] As a further optimization of the above scheme, in the third step, the main tunnel formwork is either ∩-shaped or gate-shaped.

[0019] As a further optimization of the above scheme, in the fourth step, the transport roadway is excavated from the transport main roadway to the cut-off point and / or the return air roadway is excavated from the return air main roadway to the cut-off point, the soil in the cut-off point is removed, and the fully mechanized coal mining equipment is arranged.

[0020] As a further optimization of the above scheme, in the fourth step, the roadway excavation face is constructed simultaneously with the coal mining face, and the roadway excavation face is constructed a certain distance ahead of the coal mining area.

[0021] As a further optimization of the above scheme, in the fourth step, the goaf retention technology is adopted for adjacent working faces, so that the transport roadway of the previous working face is used as the transport roadway of the next working face, or the return air roadway of the previous working face is used as the return air roadway of the next working face.

[0022] As a further optimization of the above scheme, in the fourth step, the longwall working surfaces of the shallow wing and the longwall working surfaces of the deep wing are arranged alternately and staggered by a certain distance.

[0023] Invention points and beneficial effects: 1. This invention does not directly excavate the main roadway in the protection coal pillar of the main roadway in the traditional way. Instead, it uses the filling coal mining technology to extract the entire area of ​​the originally set main roadway protection coal pillar area and reserves the main roadway in the filling body. The filling body has high strength, which is conducive to the maintenance of the main roadway in the future. It avoids leaving the main roadway protection coal pillar and greatly improves the coal mining efficiency of the mining area.

[0024] 2. A simple method is presented for calculating the overburden load borne by the backfill and determining the width of the backfill working face during main roadway excavation.

[0025] 3. In the main roadway excavation face, backfilling technology is used to directly leave cut-outs on both sides of the backfill body. The longwall face utilizes these cut-outs for direct forward mining, shortening the commissioning time. Furthermore, the longwall face can simultaneously excavate the roadway and mine coal, resolving the issue of tight mining-excavation succession compared to the traditional method of completely excavating the roadway before mining. Further, the longwall face employs gob-side roadway retention technology, ensuring that no coal pillars are left throughout the mine, allowing for the complete extraction of the coal seam. Attached Figure Description

[0026] When considered in conjunction with the accompanying drawings, the invention will be more fully and better understood, and many of its accompanying beneficial effects will become readily apparent, through the following detailed description. However, the accompanying drawings, which are provided to further illustrate the invention and form part of this invention, and the illustrative embodiments thereof, together with their descriptions, are used to explain the invention and do not constitute an undue limitation thereof, wherein:

[0027] Figure 1 —A schematic diagram of the overall layout of a mine production method for extracting all coal seams according to the present invention;

[0028] Figure 2 —A magnified schematic diagram of the mine bottom yard of a coal seam extraction method according to the present invention;

[0029] Figure 3 —A schematic diagram of the stress on the filling body in a mine production method where all coal seams have been extracted according to the present invention;

[0030] Figure 4 —A magnified schematic diagram of the main roadway excavation face of a mine production method for mining where all coal seams are extracted according to the present invention;

[0031] Figure 5 —A magnified schematic diagram of a longwall working face in a mine production method for extracting all coal seams according to the present invention;

[0032] Attached diagrams: 1-Main transport roadway; 2-Return air roadway; 3-Cut-out; 4-Stop mining line; 5-Return airway; 6-Transport roadway; 7-Main roadway face; 71-Continuous mining machine; 72-Shuttle car; 73-Main roadway formwork; 74-Belt conveyor; 75-Filling pipe; 76-Filling retaining wall; 77-Filling body; 78-Adobe brick; 79-Filling space; 8-Longwall working face; 81-Hydraulic support; 8 2-Drum coal mining machine; 9-Bottom yard; 91-Main shaft; 92-Auxiliary shaft; 93-Coal gangue sorting system; 94-Clean coal; 95-Gangue crushing system; 96-Cementing material storage system; 97-Water sump; 98-Backfill material preparation system; 99-Soil sump; 10-Coal seam; 11-Goaf; 12-Bending subsidence zone; 13-Water-conducting fracture zone; 14-Collapse zone; 15-Grove face. Detailed Implementation

[0033] To better understand the technical content of this invention, specific embodiments are described below in conjunction with the accompanying drawings. Various aspects of this invention are described with reference to the accompanying drawings, which illustrate numerous illustrative embodiments. The embodiments of this invention are not limited to those shown in the drawings. It should be understood that this invention is implemented through any of the various concepts and embodiments described above, as well as the concepts and embodiments described in detail below, because the concepts and embodiments disclosed in this invention are not limited to any particular implementation. Furthermore, some aspects of this invention can be used alone or in any suitable combination with other aspects disclosed in this invention.

[0034] like Figures 1-5 As shown, a coal seam extraction method includes the following steps:

[0035] Step 1: As Figures 1-2 As shown, a construction shaft and an integrated mining, beneficiation, and filling yard are established. The shaft includes a main shaft 91 and an auxiliary shaft 92. The main shaft 91 is mainly used for air intake, coal and material transportation, and pedestrian access, while the auxiliary shaft 92 is mainly used for return air. The integrated mining, beneficiation, and filling yard includes a coal gangue sorting system 93, a cementing material storage system 96, a filling material preparation system 98, and an earthen silo 99. The coal gangue sorting system 93 is used to directly sort the coal mined from the mine underground. The sorted clean coal is placed in the clean coal storage silo 94 and then lifted to the surface through the main shaft 1. The sorted gangue and other gangue produced by the mine are crushed to a suitable size by the gangue crushing system 95. The particle size; the cementing material transported down the main shaft 1 is stored in the cementing material storage system 96, the cementing material including fly ash, cement, early strength agent and other additives; in addition, according to the filling amount requirements of the filling material, when the amount of gangue in the mine is insufficient, urban construction waste can be crushed to a suitable particle size on the ground and then transported down the main shaft to the mine for use in making filling material; the water tank 97 is used to store wastewater generated during the mine production process; the cementing material, crushed gangue and / or urban solid waste, and wastewater in the water tank are transported to the filling material preparation system 98 for mixing to prepare filling material; the soil tank 99 is used to temporarily store soil for the adobe.

[0036] Step 2: Determine the width of the main roadway excavation face 7, that is, determine the width of the main roadway protection and backfill pillars (which function the same as traditional protective coal pillars); for example... Figure 1 , 3As shown, this invention adopts a double-wing zone layout scheme, that is, zones are arranged on both the upper and lower sides of the main roadway. The main roadway is constructed by filling the backfill body 77 formed by backfilling after the main roadway face 7 is mined. When the longwall working faces 8 of the zones on both sides are mined, the backfill body 77 containing the main roadway will bear the maximum overburden load. At this time, the backfill body 77 still needs to maintain sufficient strength and stability to ensure that the longwall working faces 8 in the zones on both sides do not become unstable after mining, so as to ensure the normal service of the main roadway. Therefore, it is necessary to determine the appropriate width of the main roadway face 7, that is, to determine the width of the main roadway protection backfill column.

[0037] In response, this invention proposes a method for easily determining the stability of the filling material 77:

[0038] First, determine the average load of the overburden borne by the backfill body 77: After the longwall working faces on both sides of the backfill body 77 are mined, the rock strata of the caving zone 14 and the water-conducting fracture zone 13 cave to the goaf 11, while the rock strata on the backfill body 77 corresponding to the caving zone and the water-conducting fracture zone do not cave, forming a caving interface between them. The angle between this caving interface and the coal seam plane is the caving angle β. It is assumed that the weight of the rock strata above the backfill body 77 located between the two caving interfaces is borne by the backfill body 77. Figure 2 The solid line inverted trapezoid in the middle, and the weight of the rock strata in the curved subsidence zone within the two vertical planes intersecting the rock strata collapse interface and the bottom surface of the curved subsidence zone 12 are also borne by the filling body 77, such as Figure 2 The solid-line rectangular area on the inverted trapezoid in the middle; assuming that the weight of the above-mentioned rock strata is uniformly applied to the filling body 77, the average load P of the overburden 77 can be calculated.

[0039] Then, determine the strength σ of the filling body 77; when P = σ, the minimum critical width w for the filling body 77 to remain stable can be obtained. c The minimum critical width w c The sum of the widths of the two side cuts (3) and the two main roadways is the minimum critical width w of the main roadway excavation face (7). j ;

[0040] The formula for calculating the average overburden load P borne by the filling body 77 is as follows:

[0041]

[0042] In the formula, P is the average load of the overburden 77 borne by the filling body (MPa); γ is the average unit weight of the overburden (MN / m³). 3 ;w c —Minimum critical width of the infill body, m; β —angle of rock slab collapse; h k —Thickness of the caving zone, m; h d —Thickness of the water-conducting fracture zone, m; h w—Thickness of the curved and sunken belt, in meters.

[0043] Since the strength of the backfill after consolidation is greater than that of the soft coal seam, it is not necessary to construct the main roadway in the rock strata below the coal seam. Compared with soft coal, the width of the protective coal pillar of the main roadway can be reduced, which means that the width of the main roadway face 7 can be reduced to improve the safety of the tunneling and backfilling of the tunneling face. At the same time, more coal resources can be mined through the longwall face, improving the overall coal resource mining efficiency.

[0044] Step 3: As Figure 1 , 4 As shown, the main roadway excavation face 7 is arranged along the direction from the bottom of the shaft yard 9. The width of the main roadway excavation face 7 is greater than the minimum critical width w of the main roadway excavation face determined in the second step. j ;

[0045] The main roadway face 7 is excavated and backfilled, and coal mining and backfilling work is carried out in the direction away from the bottom yard 9. The coal seam 10 is excavated using a continuous coal mining machine 71, and the excavated coal is transferred by a shuttle car 72 to the belt conveyor 74 in the transport roadway 1 and then to the coal gangue sorting system 93 in the bottom yard 9. Two U-shaped or portal-shaped main roadway formwork 73 are set at intervals along the strike in the middle of the main roadway face at a certain distance behind the coal mining area. Soil bricks 7 are set along the strike on both sides of the main roadway face. 8. The vertical main roadway formwork 73 and adobe bricks 78 are used to construct a filling retaining wall 76. A certain distance is maintained between the filling retaining wall 76 and the previously filled filling body 77, forming a filling space 79. The length of the main roadway formwork 73 is greater than the length of the filling space. Filling material is injected into the filling space 79 through the filling pipe 75. After the filling material solidifies to a predetermined strength, the main roadway formwork 73 is pulled out to the next filling space section using a continuous coal mining machine 71 or a shuttle car 72. The positions where the roadway formwork 73 is pulled out form transportation routes. Main roadway 1 and return air main roadway 2 are connected to the previously formed transport main roadway 1 and return air main roadway 2, respectively; the filling pipe 75 enters the return air main roadway 2 from the bottom yard 9 to the filling area 79; before filling, lubricating material is applied or isolation material is laid on the outer surface of the U-shaped or portal-shaped main roadway formwork 73 to separate the filling material from the outer surface of the U-shaped or portal-shaped roadway formwork 73 to facilitate the removal of the filling material after solidification; before filling, isolation material is laid on the outer surface of the adobe 78 to separate the filling material from the outer surface of the adobe 78. The exit is to facilitate the later removal of adobe bricks and prevent filling materials from entering the adobe bricks; the main roadway formwork 73 connects the main roadway with the coal mining area; fresh air enters the transport roadway 1 from the main shaft 91, and then enters the main roadway excavation face 7 from the main roadway formwork 73; exhaust air enters the return air roadway 2 through the main roadway formwork 73 and is discharged to the surface through the auxiliary shaft 92; pedestrians enter the main roadway excavation face 7 through the main shaft 91, transport roadway 1, and main roadway formwork 73 and return along the same route; water generated during production is transported from the main roadway formwork 73 through the return air roadway 2 to the water tank 97.

[0046] In this embodiment, the width of the main roadway excavation face can be selected as 100m, which is equivalent to a short-wall working face. The width of the cut-outs left on both sides is selected as 6m. The width of the filling body 77, which includes the two main roadways, is 88m in total. The two main roadways are evenly arranged in the filling body 77, and the filling body 77 is evenly divided into 3 segments along the dip.

[0047] Step four, as Figure 1 , 5 As shown, several zones extending along the dip direction are arranged perpendicular to the main roadway extension direction, i.e., along the strike direction. Several adjacent dip longwall working faces 8 are arranged in each zone. The dip longwall working faces 8 adopt the forward mining scheme. The longwall working faces in the shallow wing zone are arranged alternately with the longwall working faces in the deep wing zone, staggered by a certain distance. This distance is preferably half the width of the longwall working face.

[0048] For the first longwall face 8 of the zone, the transport roadway 6 is excavated from the transport main roadway 1 to the cut-in 3, and the return air roadway 5 is excavated from the return air main roadway 5 to the cut-in 3. The soil in the cut-in 3 is removed, and fully mechanized coal mining equipment is set up to carry out the coal mining work of the longwall face 8. At the same time, the transport roadway 6 and the return air roadway 5 continue to be excavated. The roadway excavation face 15 of the transport roadway 6 and the return air roadway 5 should be ahead of the coal mining area by a certain distance, generally more than 50m ahead. After the coal seam is mined, the transport roadway 6 or the return air roadway 5 is retained by the goaf retention technology.

[0049] For the continuous longwall working face 8 on one wing of the zone, the transport roadway 6 is excavated from the transport main roadway 1 to the cut-in 3, or the return air roadway 5 is excavated from the return air main roadway 5 to the cut-in 3. The soil in the cut-in 3 is removed. At the same time, the transport roadway 6 excavated by this working face and the return air roadway 5 of the previous working face along the goaf are used to set up fully mechanized coal mining equipment to carry out the coal mining work of the longwall working face 8. At the same time, the transport roadway 6 or the return air roadway 5 is continued to be excavated. The roadway excavation face 15 of the transport roadway 6 or the return air roadway 5 should be ahead of the coal mining area by a certain distance, generally more than 50m ahead.

[0050] That is, if the subsequent working face is adjacent to the transport roadway 6 of the previous working face, the subsequent working face uses the transport roadway 6 left by the previous working face along the goaf as its transport roadway, and it only needs to excavate the return air roadway 5. The next working face after the next working face is adjacent to the return air roadway 5 of the subsequent working face, and uses the return air roadway 5 left by the next working face along the goaf as its return air roadway, and it only needs to excavate the transport roadway 6.

[0051] If the next working face is adjacent to the return air roadway 5 of the previous working face, the next working face uses the return air roadway 5 left by the previous working face along the goaf as its return air roadway, and it only needs to excavate the transport roadway 6. The next working face after the next working face is adjacent to the transport roadway 6 of the next working face, and uses the transport roadway 6 left by the next working face along the goaf as its transport roadway, and it only needs to excavate the return air roadway 5.

[0052] Hydraulic supports 81 are arranged in the longwall working face 8, and a drum coal mining machine 82 is used for coal mining. The coal mined by the drum coal mining machine falls onto a scraper conveyor and is transferred to a belt conveyor in the transport roadway 6, and then to a belt conveyor in the main transport roadway 1, and then to the coal gangue sorting system 93 in the bottom yard 9. Fresh air enters the main transport roadway 1 from the main shaft 91, and then enters the longwall working face 8 from the transport roadway 6. Exhaust air enters the return air roadway 2 through the return air roadway 5 and is discharged to the surface from the auxiliary shaft 92. The pedestrians enter the longwall working face 8 through the main shaft 91, the main transport roadway 1, and the transport roadway 6 and return along the same route. Water generated during the production process is transported to the water tank 97 from the return air roadway 5 and the return air roadway 2.

[0053] In this embodiment, the selected longwall working face width is 260m, including the width of the side roadways. The widths of the transport roadway and return air roadway are both selected as 5m, meaning the width of the roadway excavation face 15 is 5m. The actual width of the longwall working face for mining is 250m. Based on the mine's production boundary, the stop line 4 is located approximately 1260m from the cut-off point, meaning the advance length of the longwall working face is 1260m. Taking a mine production capacity requirement of 3 million tons / year as an example, assuming an actual annual production period of 300 days, then 10,000 tons of coal need to be produced daily. If the average mining height of coal seam 10 is 5m, and the density of soft coal is 1.2 tons / m³, then... 3 Therefore, a daily advance of 6.54m is required. Assuming an advance of 0.8m per cut, the optimal approach is 8 cuts per day, or 6.4m, yielding 9792 tons of coal daily. The remaining coal is mined from the main roadway face 7. Assuming the mine adopts a one-mine-one-face production method, to match the progress of the main roadway excavation with the longwall face mining, the total time required to complete the mining of the two longwall faces 8 on both wings should be greater than the distance of one longwall face width advanced by the main roadway face 7. That is, when the longwall face 8 has mined 1260 × 2 = 2520m, the main roadway face must have mined and filled at least 255m. The total mining time for the two longwall faces is 394 days, corresponding to a minimum daily advance of 0.65m for the main roadway face, yielding 390 tons of coal daily. 9792 + 390 = 10182 > 10000 tons, meeting the mine's production needs.

[0054] Fifth, repeat steps three and four to carry out the mining of coal seam 10 throughout the entire mine.

[0055] Of course, the above description is only a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. It should be noted that any equivalent substitutions or obvious modifications made by those skilled in the art under the guidance of this specification fall within the scope of this specification and should be protected by the present invention.

Claims

1. A method for mine production in which all coal seams are extracted, characterized in that, Includes the following steps: Step 1: Establish an integrated wellbore bottom yard for mining, beneficiation, and charging; Step 2: Calculate the average overburden load P borne by the filling body using the following formula. In the formula, P is the average load borne by the overburden in MPa; γ is the average unit weight of the overburden in MN / m³. 3 ;w c —Minimum critical width of the infill body, m; β —Angle of rock strata collapse; h k —Thickness of the caving zone, m; h d —Thickness of the water-conducting fracture zone, m; h w —Thickness of the curved and sunken belt, in meters; Determine the strength σ of the filling material; when P = σ, the minimum critical width w for the filling material to remain stable can be obtained. c The minimum critical width w c The sum of the widths of the two side cuts and the total width of the main roadway is the minimum critical width w of the main roadway excavation face. j ; Step 3: From the bottom of the shaft, proceed with the excavation and backfilling of the main roadway face along the strike. The main roadway is constructed within the backfill formed after the main roadway face has been mined, with cut-outs on both sides of the backfill. The width of the main roadway face is greater than the minimum critical width w determined in Step 2. j ; The fourth step is to arrange several longwall working faces extending along the dip in sequence along the strike. The longwall working faces adopt the forward mining method and use the cut-out formed in the third step. Fifth, repeat steps three and four to carry out the mining of the entire coal seam. In the third step, a continuous coal mining machine is used to excavate the coal seam. The excavated coal is transferred by shuttle car to the belt conveyor in the main haulage roadway and then to the coal gangue sorting system in the bottom yard. At a certain distance from the coal mining area, two spaced main haulage formworks are set up along the strike in the middle of the main haulage face. Soil bricks are set up along the strike on both sides of the main haulage face. The main haulage formworks and soil bricks are used to construct the filling retaining wall. The filling retaining wall is spaced at a certain distance from the filling body formed by the previous filling to form a filling space. Filling material is then filled in. After the filling material solidifies to the predetermined strength, the main haulage formwork is pulled out.

2. The method for mine production in which all coal seams are extracted according to claim 1, characterized in that: In the first step, in the integrated mining, beneficiation, and filling underground yard, the coal gangue sorting system is used to directly sort the coal mined from the mine underground, separating clean coal and gangue. The gangue is crushed to a suitable particle size by the gangue crushing system. The cementing material storage system stores cementing materials. The cementing material, crushed gangue, and wastewater are transported to the filling material preparation system for mixing and preparing filling materials. A soil silo is also provided for storing soil for the adobe bricks.

3. A mine production method for fully extracted coal seams according to claim 1, characterized in that: In the third step, the length of the main roadway formwork is greater than the directional length of the filling space. Filling material is injected into the filling space from the filling pipe, wherein the filling pipe enters the return air main roadway from the bottom of the shaft to the filling area.

4. A mine production method for fully extracting coal seams according to claim 1 or 3, characterized in that: The main tunnel formwork is either ∩-shaped or gate-shaped.

5. A mine production method for fully extracted coal seams according to claim 4, characterized in that: In the fourth step, the transport roadway is excavated from the main transport roadway to the cut-off point and / or the return air roadway is excavated from the return air roadway to the cut-off point. The soil in the cut-off point is removed and the fully mechanized coal mining equipment is installed.

6. A mine production method for fully extracted coal seams according to claim 5, characterized in that: In the fourth step, the roadway excavation face and the coal mining face are constructed simultaneously, and the roadway excavation face is a certain distance ahead of the coal mining area.

7. A mine production method for fully extracted coal seams according to claim 6, characterized in that: In the fourth step, the goaf retention technique is adopted for adjacent working faces, so that the transport roadway of the previous working face is used as the transport roadway of the next working face, or the return air roadway of the previous working face is used as the return air roadway of the next working face.

8. A mine production method for fully extracted coal seams according to claim 7, characterized in that: In the fourth step, the longwall working surfaces of the shallow wing and the deep wing are arranged alternately and staggered by a certain distance.

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