Fully mechanized coal mining face three-in-one drilling fluidization filling green mining method

Abstract

The invention discloses a three-in-one drilling fluidized filling green mining method for a fully mechanized coal mining face. Comprising the following steps that a ground filling pump station is arranged on the ground, a filling chamber is arranged underground, and a ground filling system is responsible for filling work of a separation layer area and conveying filling materials to the underground filling chamber; and an underground filling system needs to fill the fissure zone and the caving zone. The method comprises the following steps: firstly, determining the layer position of separation grouting, the arrangement of separation drill holes, the separation grouting amount and other key conditions for implementing separation grouting filling mining according to factors such as separation occurrence time, separation space and separation development conditions; for a fissure zone and a caving zone, the height and filling amount parameters of the caving zone need to be determined. And finally, the filling system is designed, and the matching relation of the underground filling system in time and space is mainly considered. And the three-in-one filling can support the overlying strata, so that the safety of underground workers is protected, and the ground building is protected from being damaged.

Description

Technical Field

[0001] The invention relates to the technical field of coal filling mining, and in particular to a three-in-one drilling fluidized filling green mining method for a fully mechanized working face. Background Art

[0002] In recent years, as the main energy source for my country's rapid economic development, coal mining has been huge in scale, causing some mines to enter the recession period ahead of schedule, and the remaining coal is mostly "three-down" resources that cannot be mined by conventional methods, which seriously affects the sustainable development of mining areas. In order to solve the problems caused by mining, my country has begun to introduce and use subsidence reduction mining methods, but ordinary subsidence reduction mining methods cannot effectively solve the problem of protecting ground buildings. For example, the traditional strip mining method will cause a large number of coal pillars to be left underground, resulting in a large waste of resources. This mining method has long been eliminated by my country's coal mines; some filling mining methods, such as separation grouting filling mining and caving area grouting filling mining, have limited subsidence reduction effects and are difficult to meet the mining needs of surface buildings without migration. Therefore, a single subsidence reduction mining method can no longer meet the requirements of the maximum surface subsidence.

[0003] Chinese invention patent: Publication number "CN117868973A", titled "A method for distributed filling of goaf", discloses a method for distributed filling of goaf, including completing the coal seam recovery operation and underground support body construction operation of the first mining branch section along the mining direction in the comprehensive mining face; completing the coal seam recovery operation of the first mining section connected to the first mining branch section; completing the coal seam recovery operation and underground support body construction operation of the second mining branch section connected to the first goaf space; completing the coal seam recovery operation of the second mining section connected to the second mining branch section; and so on, until the underground support body construction operation of all mining branches in the comprehensive mining face and the coal seam recovery operation of all mining sections are completed, and multiple underground support bodies and goaf spaces are obtained; and the goaf space is subjected to ground grouting filling operation through grouting drilling. This technical solution combines underground support body filling and ground grouting filling, realizes step-by-step filling of goaf, and effectively avoids the problems of long filling time and low coal mining efficiency caused by one-time overall filling underground. However, this technical solution does not take into account the impact of the backfill mining method on ground subsidence and cannot meet the requirements for reducing subsidence.

[0004] Chinese invention patent: Publication number is "CN116575917A", and the name is "A combined process of recovery, filling and carbon storage integration", which discloses a combined process of recovery, filling and carbon storage integration. The working face cycle step is determined by the measured data of the mine pressure of the comprehensive mining working face. When the recovery interval of the comprehensive mining working face reaches the filling step, a filling tarpaulin is set behind the hydraulic support, and the filling pipeline pumps the filling paste to the filling area along the support beam; when the paste fills the filling area, supercritical carbon dioxide is injected into the filling paste; wait for the supercritical carbon dioxide to fully react and solidify with the filling paste. This technical solution realizes the simultaneous implementation of the working face filling mining and carbon dioxide storage, makes full use of the abandoned space after coal mining, realizes the maximum utilization of the abandoned goaf, forms a new joint mining process, meets the goal of green mining, and has important practical significance. However, this technical solution does not consider the impact of the filling mining method on ground subsidence, and cannot meet the requirements of subsidence reduction. Summary of the invention

[0005] In order to solve the problem that the single subsidence reduction mining method in the above-mentioned prior art cannot meet the maximum surface subsidence requirement, the present invention proposes a three-in-one drilling fluidized filling green mining method for a fully mechanized working face, which uses fluidized filling materials to fill the goaf, fracture zone and caving zone (three-in-one). This filling method can greatly reduce ground subsidence and protect ground buildings from being damaged.

[0006] The present invention is achieved through the following technical solution: comprising the following steps:

[0007] S1. Determine whether there is a key layer based on the overlying rock layer of the main coal seam;

[0008] S2. Analyze the migration law of the overlying strata of the main coal seam during the mining process to obtain the grouting filling layer position, the layout of the grouting filling boreholes, the grouting amount in the separation zone, and the grouting amount in the fracture zone and the caving zone;

[0009] S3, respectively selecting filling materials for filling the delamination zone, the fracture zone and the caving zone;

[0010] S4, excavate the development tunnel and preparation tunnel of the filling working face, first excavate the return air uphill, the track uphill, and the transport uphill, then excavate the filling working face track tunnel, the next working face track tunnel, and the filling working face transport tunnel, so that the filling working face track tunnel and the next working face track tunnel are connected to the track uphill respectively, and the filling working face transport tunnel is connected to the transport uphill, and a connecting tunnel is set between the next working face track tunnel and the filling working face transport tunnel, and finally lay the filling pipeline;

[0011] S5. Establish a filling chamber near the filling working face during transportation up the mountain;

[0012] S6. A filling pump station in the separation zone is set up on the ground at the middle position between the direction and inclination of the filling working face, and an underground filling pump station is set up near the auxiliary shaft of the industrial square;

[0013] S7, drilling according to the drilling point;

[0014] S8. The filling working face is mined according to the conventional procedures; the filling pump station in the abscission zone transports the filling materials to the filling area of ​​the abscission zone through the filling pipeline of the abscission zone, and the filling of the abscission zone begins when the filling working face is advanced to the predetermined position; the filling chamber transports the super-high water material to the filling area of ​​the fracture zone and the filling area of ​​the caving zone through the filling pipeline of the fracture zone and the filling pipeline of the caving zone respectively for filling;

[0015] S9. Repeat step S8 until the coal seam recovery in the entire mining area is completed.

[0016] As a further preference, the step S1 comprises the following steps:

[0017] S11. The first rock layer is directly determined from the mined coal seam, and the position of the hard rock layer in the overlying rock layer is determined from the deep to the shallow. According to the composite beam principle, the formula for determining the position of the key layer can be derived:

[0018]

[0019] Where: h i , γ i 、E i are the thickness, bulk density and elastic modulus of the i-th rock layer, respectively. The calculation starts from the first rock layer above the coal seam. When the above inequality is satisfied, the m+1-th rock layer is a hard rock layer.

[0020] S12, according to the formula k=1,2,…,n to obtain the breaking distance l of each hard rock layer k ,

[0021] Where: h k is the thickness of the kth hard rock layer, m; σ k is the tensile strength of the kth layer of hard rock, MPa; q k is the load borne by the kth layer of hard rock, MPa, q k The calculation formula is as follows:

[0022]

[0023] Where m k The number of soft rock layers controlled by hard rock layers; h k,j , γ k,j 、E k,jare the thickness, bulk density, and elastic modulus of the jth rock layer in the soft rock layer group controlled by the kth hard rock layer, in units of m and MN / m respectively. 3 , GPa;

[0024] S13, determining whether there is a key layer;

[0025] Calculate the breaking distance l of each hard rock layer starting from the hard rock layer with the largest burial depth k <l k+1 Is it true? If l appears k > k+1 , then add the load borne by the k+1th hard rock layer to the kth hard rock layer, and recalculate the breaking distance of the kth hard rock layer. If the recalculated breaking distance of the kth hard rock layer is smaller than the breaking distance of the k+1th hard rock layer, then take l k = l k+1 , continue to compare, if the breaking distance of the kth hard rock layer is smaller than the breaking distance of all the hard layers above it, then the kth hard rock layer is the key layer and can be filled by delamination grouting; otherwise, there is no key layer and delamination grouting cannot be performed.

[0026] As further preferred, step S2 comprises the following steps:

[0027] S21. According to the timing of the occurrence of the delamination, the delamination space, and the delamination development, the layer position for delamination grouting, the arrangement of the delamination drilling holes, and the delamination grouting amount are obtained.

[0028] The layer for grouting of separation layer is the separation layer below the (sub) key layer above the height of the water-conducting fracture zone of the mining coal seam + the thickness of the isolation layer, and the burial depth is not less than 0.3 times the mining depth;

[0029] Spacing l of filling boreholes in the separation zone: The mining working face is simulated by numerical simulation software or similar simulation test methods, and the state of the key layer is observed as the coal seam advances; when the key layer breaks, the distance the filling working face advances is the spacing l of the ground separation grouting boreholes;

[0030] Step 22: According to the formula Get the height H of the fall zone k , where M is the thickness of the coal seam, according to the height of the caving zone H k Obtain the filling volume of the fracture zone and the caving zone.

[0031] As a further preference, the filling material for the delamination zone in step S3 is a slurry made of fly ash, sand and gangue powder as main solid materials at a water-cement ratio of 2:1, and the filling material for the fracture zone and the caving zone is an ultra-high water material.

[0032] As a further preference, the ultra-high water content material is a mixture of ultra-high water content A material and ultra-high water content B material.

[0033] As a further preferred embodiment, step S7 comprises the following steps:

[0034] According to the development of the separation layer, the separation layer filling boreholes are set in the separation layer filling area in the filling area, and the spacing l of the separation layer filling boreholes is obtained by step S21; the boreholes of the fracture zone are driven into the upper part of the filling area from the track level of the next working face, and the drilling depth is determined according to the height H of the caving zone in step S22. k It is obtained that the drill hole of the caving zone is driven into the caving zone from the bottom of the track lane of the next working face. The drill hole has a horizontal elevation angle and is located below the drill hole of the fracture zone.

[0035] As a further preference, the elevation angle of the drill holes in the fracture zone is 3° to 5°, and the spacing is 300 to 500 mm.

[0036] As a further preference, the spacing between the drill holes in the caving zone is less than twice the effective diffusion radius of the ultra-high water material.

[0037] As a further preference, in the step S8, the filling method of the fracture zone and the caving zone is filling as mining proceeds; and the filling method of the separation zone is filling at a fixed time and at a fixed point.

[0038] As a further preference, in step S8, the fracture zone and the caving zone are filled first, and then the delamination zone is filled.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The present invention combines the idea of ​​backfilling mining and fills the delamination zone, fissure zone, caving zone and goaf zone generated during the mining process of the mine, which can minimize ground subsidence, thereby reducing surface subsidence and building damage, reducing the occurrence of secondary disasters, and protecting surface water and soil and building facilities.

[0041] 2. The present invention can dispose of coal-based solid wastes such as fly ash on a large scale, reduce their storage and landfill on the surface, reduce the risk of environmental pollution, and has important practical significance.

[0042] 3. The three-in-one filling designed by the present invention can support the overburden, protect the safety of underground workers, and protect the ground buildings from being damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is the layout diagram of the working face tunnel in the present invention.

[0044] Figure 2 for Figure 1 Middle AA section view.

[0045] Figure 3 for Figure 1Middle BB cross-section.

[0046] Indicated in the figure:

[0047] 1. Return air up the mountain; 2. Track up the mountain; 3. Transport up the mountain; 4. Filling working face track tunnel; 4', next working face track tunnel; 5. Filling working face transport tunnel; 6. Filling working face; 7. Super-high water filling materials; 8. Super-high water A material filling pipeline; 9. Super-high water B material filling pipeline; 10. Filling chamber; 11. Connecting tunnel; 12. Fracture zone filling pipeline; 13. Spalling zone filling pipeline; 14. Filling drilling holes in the abscission zone; 15. Filling in the abscission zone; 16. Filling pump station in the abscission zone; 17. Filling pipeline in the abscission zone; 18. Surface buildings; 19. Spalling zone filling area; 20. Fracture zone filling area. DETAILED DESCRIPTION

[0048] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments thereof, which are given by way of example only with reference to the accompanying drawings.

[0049] The three-in-one drilling fluidized filling refers to a mining method that fills the delamination zone, fracture zone, and caving zone of the fully mechanized mining face. The filling body and the overlying rock strata can form a common bearing structure, further reducing ground subsidence and effectively protecting ground buildings.

[0050] like Figure 1 The following is the layout diagram of the three-in-one filling working face tunnel. Figure 2 and Figure 3 They are Figure 1 The filling working surface 6 separates the filling area and the working area, and the filling area includes the abscission zone filling area 15, the caving zone filling area 19 and the fracture zone filling area 20.

[0051] The underground filling process is as follows: the filling material starts from the underground filling pump station and passes through the auxiliary shaft, transported up the mountain 3, filling chamber 10, ultra-high water A material filling pipeline 8 and ultra-high water B material filling pipeline 9, connecting tunnel 11, fracture zone filling pipeline 12 and caving zone filling pipeline 13, and finally fills the caving zone filling area 19 and the fracture zone filling area 20. The filling material for underground filling is preferably ultra-high water material, which is a mixture of ultra-high water material A and ultra-high water material B. The ultra-high water material A and ultra-high water material B enter the connecting tunnel 11 from the ultra-high water material A filling pipeline 8 and the ultra-high water material B filling pipeline 9 respectively. The two ultra-high water materials are mixed in the connecting tunnel 11, and then the fracture zone filling area 20 and the caving zone filling area 19 are filled respectively through the fracture zone filling pipeline 12 and the caving zone filling pipeline 13. The ultra-high water material solidifies in the filling area.

[0052] The filling process of the separation zone is as follows: the filling material is filled from the separation zone filling pump station 16 to the separation zone filling area 15 through the separation zone filling pipeline 17. The filling material used for the separation zone filling is preferably a slurry with fly ash, sand, and gangue powder as the main solid materials, usually made at a water-cement ratio of 2:1.

[0053] The present invention provides a three-in-one drilling fluidized filling green mining method for a fully mechanized mining face, comprising the following steps:

[0054] Step 1: First, determine whether there is a key layer based on the overlying rock layer of the main coal mining seam, which is a necessary prerequisite for grouting and filling of the separation layer;

[0055] The key layer identification method is divided into the following three steps:

[0056] Step 11, directly determine the first rock layer from the mined coal seam, and determine the position of the hard rock layer in the overlying rock layer from deep to shallow. The hard rock layer here is not a hard rock layer in the general sense. It refers to those rock layers that have a smaller deflection than the lower rock layer during deformation and are not broken synchronously with the lower rock layer. Assuming that the first rock layer is a hard rock layer, and the rock layers above it to the mth layer deform in coordination with it, while the m+1th rock layer does not deform in coordination with it, then the m+1th rock layer is the second hard rock layer. According to the composite beam principle, the formula for determining the position of the key layer can be derived:

[0057]

[0058] Where: h i , γ i 、E i are the thickness, bulk density and elastic modulus of the i-th rock layer respectively. Starting from the first rock layer above the coal seam, when the above inequality is satisfied, the m+1-th rock layer is a hard rock layer;

[0059] Step 12: Calculate the breaking distance of each hard rock layer according to the formula. The breaking distance of the hard rock layer is calculated using the fixed-end beam model. The breaking distance of the kth hard rock layer is l k It can be calculated by the following formula:

[0060]

[0061] Where: h k is the thickness of the kth hard rock layer, m; σ k is the tensile strength of the kth layer of hard rock, MPa; q k is the load borne by the kth layer of hard rock, MPa. k The calculation formula is as follows:

[0062]

[0063] m k The number of soft rock layers controlled by hard rock layers; h k,j , γ k,j 、E k,j are the thickness, bulk density, and elastic modulus of the jth rock layer in the soft rock layer group controlled by the kth hard rock layer, in units of m and MN / m respectively. 3 , GPa;

[0064] Step 13, determine the key layer according to the following determination process.

[0065] First, if the kth hard rock layer is the key layer, then its breaking distance should be smaller than the breaking distance of all the hard rock layers above, that is, l k <l k+1 (k=1,2,…,n); if the breaking distance of the kth hard rock layer is l k If the recalculated breaking distance of the kth hard rock layer is smaller than the breaking distance of the k+1th hard rock layer, then take l k = l k+1 ; Calculate from the deepest hard rock layer l k <l k+1 (k=1,2,…,n) is true, if l k > k+1 , then recalculate the breaking distance of the kth hard rock layer.

[0066] If the breaking distance of the kth hard rock layer is smaller than the breaking distance of all the hard layers above it, then the kth hard rock layer is the key layer and can be filled by grouting; otherwise, there is no key layer and grouting cannot be performed.

[0067] Step 2: Analyze the migration law of the overlying rock strata during the mining process, determine the grouting filling layer, the layout of the grouting filling boreholes, the grouting amount in the separation zone, and the grouting amount in the fracture zone and the caving zone, in preparation for subsequent construction:

[0068] Step 21. First, it is necessary to determine the stratum position for grouting, the arrangement of stratum drilling holes, and the amount of grouting according to the timing of stratum delamination, stratum delamination space, and stratum delamination development. These are the key conditions for implementing stratum delamination grouting filling mining.

[0069] Determine the grouting filling layer position: the grouting layer position of the overburden stratum should be in the stratum below the (sub) key layer above the height of the water-conducting fracture zone of the mined coal seam + the thickness of the isolation layer, and the burial depth should be no less than 0.3 times the mining depth.

[0070] Determine the spacing l of the filling boreholes 14 in the delamination zone: simulate the mined working face by numerical simulation software or similar simulation tests, and observe the state of the key layer as the coal seam advances. After the key layer is fractured, an articulated structure is formed, with one end being the unfractured key layer and the other end acting on the collapsed rock mass on the side of the goaf. If delamination filling is not performed, the key layer will collapse periodically as the working face advances, and the overburden will gradually bend and sink until ground fissures and subsidence are formed on the surface. At this time, it is time for delamination grouting, and the distance the working face advances is the spacing l of the ground delamination grouting boreholes.

[0071] Step 22: For filling of the fracture zone and the caving zone, the filling amount parameter needs to be determined according to the height of the caving zone. The height of the caving zone is calculated by the following formula:

[0072]

[0073] Where: H k ——Height of the caving zone, in m;

[0074] M——coal seam thickness, in m.

[0075] After obtaining the height of the caving zone, the filling volume of the fracture zone and the caving zone can be calculated.

[0076] Step 3: Select filling materials for filling the delamination zone, fracture zone and caving zone respectively.

[0077] Select appropriate filling materials. Since there are delamination zones, fissure zones and caving zones in the filling positions, and there are many filling positions, resulting in a large filling volume, it is recommended to use two or more filling materials; the mine can flexibly select filling materials according to its by-products, and can select water-sand, paste, gangue, and ultra-high water materials. The appropriate filling system for different filling materials is the prior art here and will not be repeated in this patent; in this example, the fissure zone and the caving zone are filled with ultra-high water materials, and the delamination zone is filled with slurry made of fly ash, sand, and gangue powder as the main solid materials, usually at a water-cement ratio of 2:1.

[0078] Step 4, excavate the development tunnels and preparation tunnels of the filling working face 6, first excavate the return air uphill 1, the track uphill 2, and the transport uphill 3, then excavate the filling working face track tunnel 4, the next working face track tunnel 4' and the filling working face transport tunnel 5, so that the filling working face track tunnel 4 and the next working face track tunnel 4' are respectively connected to the track uphill 2, and the filling working face transport tunnel 5 is connected to the transport uphill 3, and a connecting tunnel 11 is set between the next working face track tunnel 4' and the filling working face transport tunnel 5, and finally lay the super-high water A material filling pipeline 8, super-high water B material filling pipeline 9, fracture zone filling pipeline 12 and caving zone filling pipeline 13.

[0079] like Figure 1 As shown in the tunnel layout diagram. Priority is given to excavating the return air uphill 1, track uphill 2, and transport uphill 3, followed by excavating the filling working face track tunnel 4, the next working face track tunnel 4', and the filling working face transport tunnel 5, and connecting the filling working face track tunnel 4 with the track uphill 2, and the filling working face transport tunnel 5 with the transport uphill 3; the three-in-one filling working face adopts double tunnel excavation, and a connecting tunnel 11 is set up every 50m between the next working face track tunnel 4' and the filling working face transport tunnel 5, which is convenient for laying the super-high water A material filling pipeline 8, super-high water B material filling pipeline 9, fracture zone filling pipeline 12, and caving zone filling pipeline 13.

[0080] Step 5: Establish a filling chamber 10.

[0081] The filling chamber should be located in the transport uphill 3 and close to the intersection of the transport level tunnel 5 of the filling working face; the function of the filling chamber 10 is to store the equipment required for the filling of the working face, store the filling materials and facilitate the pumping of the filling materials to the filling position of the working face; the filling chamber 10 controls the filling work of the underground fracture zone and the caving zone;

[0082] Step 6: Arrange the separation zone filling pump station 16. The separation zone filling pump station 16 is arranged on the ground and is located in the middle of the direction and inclination of the filling working face 6.

[0083] Arrange the surface pump station. Since two kinds of filling materials are used, in order to avoid the materials from mixing with each other, two filling pump stations are established, namely the separation filling pump station 16 and the underground filling pump station; the separation filling pump station 16 should be located in the middle of the direction and inclination of the filling working face on the ground, such as Figure 1 , 2 As shown, the underground filling pump station should be located near the auxiliary shaft of the industrial square. The auxiliary shaft is a shaft used for lifting and lowering personnel, materials, waste rock and other auxiliary operations in the mine. Therefore, it can play a role in reducing the material transportation pipeline. The key equipment of the ground pump station includes raw material storage facilities, batching system, mixing equipment, pumping system and control system. The main function of the separation layer filling pump station 16 is to transport filling materials to the filling chamber 10 and fill the separation layer filling area 15 through the separation layer filling pipeline 17.

[0084] Step 7: Drill holes according to the drilling points.

[0085] According to the previously determined development of the separation layer, the separation layer filling borehole 14 should be arranged in the separation layer filling area 15 in the filling area. The separation layer filling area 15 is the position behind the corresponding filling working face 6 on the ground and where the separation layer appears during the mining process. The spacing l of the separation layer filling borehole 14 is determined by step 21; the boreholes in the fracture zone should be driven from the track level lane 4' of the next working face into the upper part of the filling area. The best drilling angle is 3° to 5°, the spacing is 300 to 500 mm, and the drilling depth is based on the caving zone height H calculated in step 22. k The drilling holes in the caving zone should be driven into the caving zone from the bottom of the track lane 4' of the next working face, with the drilling angle close to the horizontal and located below the drilling holes in the fissure zone. The spacing of the drilling holes in the caving zone is determined according to the diffusion radius of the filling material, and the spacing of the drilling holes in the caving zone is less than twice the effective diffusion radius of the super-high water material.

[0086] Step 8, the filling working face 6 is mined according to conventional procedures; the abscission zone filling pump station 16 transports the filling material to the abscission zone filling area 15 through the abscission zone filling pipeline 17, and the abscission zone filling is started when the filling working face 6 is advanced to the predetermined position; the filling chamber 10 transports super-high water material to the fracture zone filling area 20 and the caving zone filling area 19 through the fracture zone filling pipeline 12 and the caving zone filling pipeline 13 for filling.

[0087] The filling method of the fracture zone and the caving zone is to fill as the coal is mined; the filling method of the separation zone is to fill at a fixed time and at a fixed point. It is necessary to calculate in advance where the separation zone will be fully developed when the filling working face 6 is advanced, and pay special attention to the time of the ground and underground working faces. The filling of the fracture zone and the caving zone is located behind the filling working face 6, and the distance from the filling position to the filling working face 6 is adjusted according to the different coal seam occurrence conditions. For example, the distance from the filling position to the filling working face 6 can be shortened when the coal seam is mined in an upward direction.

[0088] Step 9: Repeat step 8 until the coal seam recovery in the entire mining area is completed.

[0089] The filling system of this example is an existing technology well known to those skilled in the art, and will not be described in detail here; the ultra-high water filling material of this embodiment is an existing material well known to those skilled in the art, and will not be described in detail here; the filling pump, conveying pipeline, filling bracket, etc. of this example adopt existing products or structures well known to those skilled in the art, and the connection method between them also adopts the connection method well known to those skilled in the art, and will not be described in detail here.

[0090] In this example, filling is performed according to the order in which the filling areas are formed. First, the caving zone behind the mining face is filled with the super-high water filling material prepared in the filling chamber 10; then, the fracture zone above the caving zone is filled through the filling borehole; finally, the ground filling pump station transports the filling material to the separation zone through the separation filling borehole. The completion of filling of each separation borehole marks the end of a cycle. Repeat the above process until the mining of the entire mining area is completed.

[0091] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A three-in-one drilling fluidized filling green mining method for a fully mechanized mining face, characterized in that: The following steps are included: S1. Determine whether there is a key layer based on the overlying rock layer of the main coal seam; S2. Analyze the migration law of the overlying strata of the main coal seam during the mining process to obtain the grouting filling layer position, the layout of the grouting filling boreholes, the grouting amount in the separation zone, and the grouting amount in the fracture zone and the caving zone; S3, respectively selecting filling materials for filling the delamination zone, the fracture zone and the caving zone; S4, excavating the development tunnel and preparation tunnel of the filling working face (6), first excavating the return air uphill (1), the track uphill (2), and the transport uphill (3), then excavating the filling working face track tunnel (4), the next working face track tunnel (4') and the filling working face transport tunnel (5), so that the filling working face track tunnel (4) and the next working face track tunnel (4') are respectively connected to the track uphill (2), so that the filling working face transport tunnel (5) is connected to the transport uphill (3), and a connecting tunnel (11) is set between the next working face track tunnel (4') and the filling working face transport tunnel (5), and finally the filling pipeline is laid; S5, establishing a filling chamber (10) at a position close to the filling working face transport tunnel (5) during the uphill transport (3); S6, setting a separation zone filling pump station (16) on the ground at a position between the strike and inclination of the filling working face (6), and setting an underground filling pump station near the auxiliary shaft of the industrial square; S7, drilling according to the drilling point; S8, the filling working face (6) is mined according to conventional procedures; the abscission zone filling pump station (16) transports the filling material to the abscission zone filling area (15) through the abscission zone filling pipeline (17), and the abscission zone filling begins when the filling working face (6) is advanced to a predetermined position; the filling chamber (10) transports the super-high water material to the fracture zone filling area (20) and the caving zone filling area (19) through the fracture zone filling pipeline (12) and the caving zone filling pipeline (13) for filling; S9. Repeat step S8 until the coal seam recovery in the entire mining area is completed.

2. According to claim 1, a three-in-one drilling fluidized filling green mining method for a fully mechanized mining face is characterized by: The step S1 comprises the following steps: S11. The first rock layer is directly determined from the mined coal seam, and the position of the hard rock layer in the overlying rock layer is determined from the deep to the shallow. According to the composite beam principle, the formula for determining the position of the key layer can be derived: Where: h i , γ i 、E i are the thickness, bulk density and elastic modulus of the i-th rock layer, respectively. The calculation starts from the first rock layer above the coal seam. When the above inequality is satisfied, the m+1-th rock layer is a hard rock layer. S12, according to the formula Get the fracture distance l of each hard rock layer k , Where: h k is the thickness of the kth hard rock layer, m; σ k is the tensile strength of the kth layer of hard rock, MPa; q k is the load borne by the kth layer of hard rock, MPa, q k The calculation formula is as follows: Where m k The number of soft rock layers controlled by hard rock layers; h k,j , γ k,j 、E k,j are the thickness, bulk density, and elastic modulus of the jth rock layer in the soft rock layer group controlled by the kth hard rock layer, in units of m and MN / m respectively. 3 , GPa; S13, determining whether there is a key layer; Calculate the breaking distance l of each hard rock layer starting from the hard rock layer with the largest burial depth k <l k+1 (k=1,2,…,n) is true, if l k > k+1 , then add the load borne by the k+1th hard rock layer to the kth hard rock layer, and recalculate the breaking distance of the kth hard rock layer. If the recalculated breaking distance of the kth hard rock layer is smaller than the breaking distance of the k+1th hard rock layer, then take l k = l k+1 , continue to compare, if the breaking distance of the kth hard rock layer is smaller than the breaking distance of all the hard layers above it, then the kth hard rock layer is the key layer and can be filled by delamination grouting; otherwise, there is no key layer and delamination grouting cannot be performed.

3. A three-in-one drilling fluidized filling green mining method for a fully mechanized mining face according to claim 2, characterized in that: The step S2 comprises the following steps: S21. According to the timing of the occurrence of the delamination, the delamination space, and the delamination development, the layer position for delamination grouting, the arrangement of the delamination drilling holes, and the delamination grouting amount are obtained. The layer for grouting of separation layer is the separation layer below the (sub) key layer above the height of the water-conducting fracture zone of the mining coal seam + the thickness of the isolation layer, and the burial depth is not less than 0.3 times the mining depth; Spacing l of filling boreholes (14) in the separation zone: The mining working face is simulated by numerical simulation software or similar simulation test methods, and the state of the key layer is observed as the coal seam advances; when the key layer breaks, the distance that the filling working face (6) advances is the spacing l of the ground separation grouting boreholes; Step 22: According to the formula Get the height H of the fall zone k , where M is the thickness of the coal seam, according to the height of the caving zone H k Obtain the filling volume of the fracture zone and the caving zone.

4. A three-in-one drilling fluidized filling green mining method for fully mechanized mining face according to claim 3, characterized in that: In step S3, the filling material of the delamination zone is a slurry made of fly ash, sand and gangue powder as main solid materials at a water-cement ratio of 2:1, and the filling material of the fracture zone and the caving zone is a super-high water material.

5. A three-in-one drilling fluidized filling green mining method for fully mechanized mining face according to claim 4, characterized in that: The ultra-high water material is formed by mixing ultra-high water A material and ultra-high water B material.

6. A three-in-one drilling fluidized filling green mining method for fully mechanized mining face according to claim 4, characterized in that: The step S7 comprises the following steps: According to the development of the separation layer, the separation layer filling borehole (14) is set in the separation layer filling area (15) in the filling area, and the spacing l of the separation layer filling borehole (14) is obtained by step S21; the borehole of the fracture zone is driven into the upper part of the filling area from the next working face track lane (4'), and the depth of the borehole is determined according to the height H of the caving zone in step S22. k The drill hole of the caving zone is driven into the caving zone from the bottom of the track lane (4') of the next working face, and the drill hole elevation angle is horizontal and located below the drill hole of the fracture zone.

7. A three-in-one drilling fluidized filling green mining method for fully mechanized mining face according to claim 6, characterized in that: The elevation angle of the drill holes in the fracture zone is 3° to 5°, and the spacing is 300 to 500 mm.

8. The green mining method of three-in-one drilling fluidized filling in fully mechanized mining face according to claim 6 is characterized by: The spacing between the boreholes in the caving zone is less than twice the effective diffusion radius of the ultra-high water material.

9. A three-in-one drilling fluidized filling green mining method for a fully mechanized mining face according to any one of claims 1 to 8, characterized in that: In the step S8, the filling method of the fracture zone and the caving zone is to fill as the mining progresses; the filling method of the separation zone is to fill at a fixed time and at a fixed point.

10. A three-in-one drilling fluidized filling green mining method for fully mechanized mining face according to any one of claim 9, characterized in that: In the step S8, the fracture zone and the caving zone are filled first, and then the separation zone is filled.

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