Three-in-one drilling fluidized filling green mining method in fully mechanized working face

Abstract

The application discloses a three-in-one drilling fluidized filling green mining method for a fully-mechanized coal mining face, and comprises the following steps: arranging a ground filling pump station on the ground and arranging a filling chamber underground, the ground filling system is responsible for the filling work of a separation layer area and transports filling materials to the filling chamber underground, and the underground filling system needs to fill the fissure zone and the caving zone. First, the key conditions of the separation layer grouting filling mining, such as the layer of the separation layer grouting, the arrangement of the separation layer drilling, the separation layer grouting quantity and the like, are determined according to the time of the separation layer, the separation layer space, the development condition of the separation layer and other factors. For the fissure zone and the caving zone, the height of the caving zone and the filling quantity parameters need to be determined. Finally, the filling system is designed, and the cooperation relationship of the underground filling system in time and space is mainly considered. The three-in-one filling can support the overburden rock, protect the safety of the underground workers and protect the ground buildings from being damaged.

Description

TECHNICAL FIELD

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

[0002] In recent years, as the main energy source for the rapid economic development of China, coal mining has a huge scale, which leads some mines to enter the decline period in advance, and the remaining coal is mostly "three-under" resources that cannot be mined by conventional methods, which seriously affects the sustainable development of the mining area. In order to solve the problems caused by mining, China began to introduce and use the reduced subsidence mining method, but the ordinary reduced subsidence mining method cannot effectively solve the problem of protecting ground buildings. For example, the traditional strip mining method will leave a large number of coal pillars in the underground, causing a large waste of resources, and this mining method has been eliminated by China's coal mines; some filling mining methods, such as separation layer grouting filling mining and caving area grouting filling mining, have limited subsidence effect and cannot meet the mining demand of non-migration of surface buildings. Therefore, a single reduced subsidence mining method cannot meet the requirement of maximum surface subsidence.

[0003] Chinese invention patent: publication number "CN117868973A", named "a goaf distributed filling method", discloses a goaf distributed filling method, which includes completing the coal seam mining operation and underground support body construction operation of the first mining section along the mining direction in the fully mechanized working face; completing the coal seam mining operation of the first mining section connected with the first mining section; completing the coal seam mining operation and underground support body construction operation of the second mining section connected with the first goaf; completing the coal seam mining operation of the second mining section connected with the second mining section; and so on, until completing the underground support body construction operation of all mining sections and the coal seam mining operation of all mining sections in the fully mechanized working face, to obtain multiple underground support bodies and goafs; and implementing the ground grouting filling operation of the goaf through the grouting drilling. This technical solution combines the underground support body filling and the ground grouting filling, realizes the step-by-step filling of the goaf, and effectively avoids the problems of long filling time and low coal mining efficiency caused by the one-time whole filling in the underground. However, this technical solution does not consider the influence of the filling mining method on the ground subsidence, and cannot meet the requirement of reduced subsidence.

[0004] Chinese invention patent: publication number "CN116575917A", name "a combined process of back mining-filling-storage carbon integration", discloses a combined process of back mining-filling-storage carbon integration, which determines the working face cycle step distance through the mine pressure measurement data of the fully mechanized working face, sets a filling tent cloth behind the hydraulic support when the fully mechanized working face recovery interval reaches the filling interval, and pumps the filling paste to the filling area along the support beam; after the paste fills the filling area, supercritical carbon dioxide is injected into the filling paste; and the supercritical carbon dioxide and the filling paste are fully reacted and solidified. The technical scheme realizes the synchronous operation of working face filling mining and carbon dioxide sequestration, fully utilizes the waste space after coal mining, realizes the maximum utilization of the abandoned goaf, forms a new combined mining process, meets the green mining target, and has important practical significance. However, the technical scheme does not consider the influence of the filling mining method on ground subsidence, and cannot meet the requirement of reducing subsidence. SUMMARY

[0005] In order to solve the problem that the single subsidence mining method in the prior art cannot meet the maximum ground subsidence requirement, the present application provides a three-in-one drilling fluidized filling green mining method for fully mechanized working face, which fills the goaf, fracture zone and caving zone (three-in-one) with fluidized filling material, so as to greatly reduce ground subsidence and protect ground buildings from being damaged.

[0006] The present application is realized by the following technical scheme: comprising the following steps:

[0007] S1, judging whether there is a key layer according to the overburden of the main coal seam;

[0008] S2, analyzing the migration law of the overburden of the main coal seam during mining to obtain the grouting and filling horizon, the arrangement of the grouting and filling borehole, the grouting amount of the separation zone, and the grouting amount of the fracture zone and the caving zone;

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

[0010] S4, excavating the development roadway and the preparation roadway of the filling working face, first excavating the return air upgate, the track upgate and the transportation upgate, then excavating the track gate of the filling working face, the track gate of the next working face and the transportation gate of the filling working face, so that the track gate of the filling working face and the track gate of the next working face are connected with the track upgate respectively, the transportation gate of the filling working face is connected with the transportation upgate, and the track gate of the next working face and the transportation gate of the filling working face are provided with a communication roadway, and finally laying the filling pipeline;

[0011] S5, establishing a filling chamber in the transportation upgate near the transportation gate of the filling working face;

[0012] S6, setting a separation zone filling pump station at a position between the strike and the inclination of the filling working face on the ground, and setting an underground filling pump station at the accessory of the industrial square auxiliary shaft;

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

[0014] S8, the filling working face is mined according to the conventional process; the separation zone filling pump station delivers the filling material to the separation zone filling area through the separation zone filling pipeline, and the filling of the separation zone is started when the filling working face advances to the predetermined position; the filling chamber delivers the super-high water material to the fissure zone filling area and the caving zone filling area through the fissure zone filling pipeline and the caving zone filling pipeline respectively to carry out filling;

[0015] S9, repeating step S8 until the coal seam mining of the entire mining area is completed.

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

[0017] S11, directly determining the first stratum from the coal seam being mined, determining the horizon of the hard stratum in the overburden from deep to shallow, and deriving a formula for judging the horizon of the key stratum according to the principle of the composite beam:

[0018]

[0019] wherein h i , γ i , E i are the thickness, the unit weight and the elastic modulus of the i-th stratum, the calculation starts from the first stratum above the coal seam, and when the above inequality is satisfied, the m+1-th stratum is a hard stratum;

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

[0021] wherein h k is the thickness of the k-th hard stratum, m; σ k is the tensile strength of the k-th hard stratum, MPa; q k is the load borne by the k-th hard stratum, MPa, and the calculation formula of q k is as follows:

[0022]

[0023] wherein m k is the number of soft strata controlled by the hard stratum; h k,j , γ k,j , E k,jThe values ​​are the thickness, unit weight, and elastic modulus of the j-th rock layer in the soft rock group controlled by the k-th hard rock layer, respectively, in m and MN / m. 3 GPa;

[0024] S13, determine if a critical layer exists;

[0025] Starting from the deepest layer of hard rock, calculate the fracture distance l of each hard rock layer. k <l k+1 Whether it is true or not, if l appears k >l k+1 Then, the load borne by the (k+1)th hard rock layer is added to the kth hard rock layer, and the fracture distance of the kth hard rock layer is recalculated. If the recalculated fracture distance of the kth hard rock layer is less than the fracture distance of the (k+1)th hard rock layer, then l is taken. k =l k+1 Continuing the comparison, if the fracture distance of the k-th hard rock layer is less than the fracture distance of all the hard layers above it, then the k-th hard rock layer is a key layer and can be filled by delamination grouting; otherwise, there is no key layer and delamination grouting cannot be carried out.

[0026] As a further preferred embodiment, step S2 includes the following steps:

[0027] S21. Based on the timing of delamination, the space of delamination, and the development of delamination, determine the layer position for delamination grouting, the arrangement of delamination boreholes, and the amount of delamination grouting.

[0028] The separation grouting layer is located below the (sub)critical layer above the height of the water-conducting fracture zone of the mined coal seam plus the thickness of the isolation layer, with a burial depth of not less than 0.3 times the mining depth;

[0029] The spacing l of the filling boreholes in the separation zone: The mining face is simulated by numerical simulation software or similar simulation tests. As the coal seam advances, the state of the key layer is observed. When the key layer fractures, the distance the filling face advances is the spacing l of the surface separation grouting boreholes.

[0030] Step 22, according to the formula Obtain the height H of the collapse zone k Where M is the coal seam thickness, and H is the height of the caving zone. k The filling volume of the fracture zone and the collapse zone was obtained.

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

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

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

[0034] According to the development of the separation layer, the separation layer area in the filling area is provided with the separation layer area filling drill hole, and the interval l of the separation layer area filling drill hole is obtained by the step S21; the drill hole of the fracture zone is drilled into the upper part of the filling area by the next working face track roadway, and the drill hole depth is obtained according to the height H of the caving zone in the step S22 k ; the drill hole of the caving zone is drilled into the caving zone from the bottom of the next working face track roadway, the drill hole angle is horizontal, and is located below the drill hole of the fracture zone.

[0035] As a further preferred, the angle of the drill hole of the fracture zone is 3°-5°, and the interval is 300-500mm.

[0036] As a further preferred, the interval of the drill hole of the caving zone is less than twice the effective diffusion radius of the super-high water material.

[0037] As a further preferred, the filling mode of the fracture zone and the caving zone in the step S8 is filling as mining; and the filling mode of the separation layer area is timed and fixed point filling.

[0038] As a further preferred, the fracture zone and the caving zone are filled first, and then the separation layer area is filled in the step S8.

[0039] Compared with the prior art, the beneficial effects of the present application are:

[0040] 1. The present application combines the idea of filling mining, and fills the separation layer area, the fracture zone, the caving zone and the goaf generated in the mining process of the mine, so that the ground subsidence can be reduced to the maximum extent, thereby reducing the surface subsidence and building damage, reducing the occurrence of secondary disasters, and protecting the surface water and soil and building facilities.

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

[0042] 3. The trinity filling designed in the present application can support the overburden rock, protect the safety of underground workers, and protect the ground buildings from being damaged. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 The working face roadway layout in the present application.

[0044] Figure 2 The A-A sectional view in the present application. Figure 1

[0045] Figure 3 The B-B sectional view in the present application. Figure 1 ​Cross-sectional view of the middle section (BB).

[0046] The image shows:

[0047] 1. Return air uphill; 2. Track uphill; 3. Transport uphill; 4. Track level roadway for filling working face; 4'. Track level roadway for next working face; 5. Transport level roadway for filling working face; 6. Filling working face; 7. High water filling material; 8. High water A material filling pipeline; 9. High water B material filling pipeline; 10. Filling chamber; 11. Connecting roadway; 12. Fissure zone filling pipeline; 13. Collapse zone filling pipeline; 14. Separation zone filling borehole; 15. Separation zone filling; 16. Separation zone filling pump station; 17. Separation zone filling pipeline; 18. Surface structure; 19. Collapse zone filling area; 20. Fissure zone filling area. Detailed Implementation

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

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

[0050] like Figure 1 The diagram shown is a layout of the roadway for the three-in-one filling working face. Figure 2 and Figure 3 They are respectively Figure 1 AA and BB cross-sectional views. The filling working face 6 separates the filling area from the working area. The filling area includes the delamination 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, transport uphill 3, filling chamber 10, ultra-high water A material filling pipeline 8 and ultra-high water B material filling pipeline 9, connecting roadway 11, fracture zone filling pipeline 12 and caving zone filling pipeline 13 in sequence, and finally fills the caving zone filling area 19 and fracture zone filling area 20. The preferred filling material for downhole filling is ultra-high water material, which is a mixture of ultra-high water material A and ultra-high water material B. Ultra-high water material A and ultra-high water material B enter the connecting roadway 11 from ultra-high water material A filling pipeline 8 and ultra-high water material B filling pipeline 9, respectively. The two ultra-high water materials are mixed in the connecting roadway 11, and then filled into 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, respectively. The ultra-high water material solidifies in the filling area.

[0052] The off-layer area filling process is as follows: the filling material is filled into the off-layer area filling area 15 from the off-layer area filling pump station 16 through the off-layer area filling pipeline 17. The filling material used for off-layer area filling is preferably a slurry prepared by taking fly ash, sand and gangue powder as main solid materials, and generally prepared according to a water-cement ratio of 2:1.

[0053] The application provides a three-in-one drilling fluidized filling green mining method for a fully-mechanized working face, and comprises the following steps:

[0054] Step 1: firstly, whether a key layer exists is determined according to the overburden situation of a main coal seam, which is a necessary prerequisite for off-layer grouting filling;

[0055] The key layer discrimination method comprises the following three steps:

[0056] Step 11: the immediate overburden of the coal seam is determined as the first layer of rock, and the layer position of the hard rock layer in the overburden is determined from the deep to the shallow. The hard rock layer here is not the hard rock layer in the general sense, but refers to the rock layer whose deflection is less than that of the lower rock layer in deformation, and which is not broken synchronously with the lower rock layer. Assuming that the first layer of rock is a hard rock layer, the layers above the first layer of rock deform coordinately with the first layer of rock, and the m+1 layer of rock does not deform coordinately with the first layer of rock, then the m+1 layer of rock is the second layer of hard rock. According to the principle of the composite beam, the formula for judging the layer position of the key layer can be deduced:

[0057]

[0058] Wherein: h i , γ i , E i are the thickness, unit weight and elastic modulus of the i layer of rock respectively. The calculation starts from the first layer of rock above the coal seam, and when the above inequality is satisfied, the m+1 layer of rock is a hard rock layer.

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

[0060]

[0061] Wherein: h k is the thickness of the k layer of hard rock, m; σ k is the tensile strength of the k layer of hard rock, MPa; q k is the load borne by the k layer of hard rock, MPa. The calculation formula of q k 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 , respectively, the thickness, the unit weight, and the elastic modulus of the jth rock layer in the group of soft rock layers controlled by the kth hard rock layer, with units of m, MN / m 3 , and GPa, respectively.

[0064] Step 13: Determine the key layer according to the following judgment flow.

[0065] First, if the kth hard rock layer is a key layer, its breaking distance should be less than the breaking distance of all the upper hard rock layers, i.e., l k < l k+1 (k = 1, 2, …, n); if the breaking distance of the kth hard rock layer l k is greater than the breaking distance of the k+1th hard rock layer above it, the load borne by the k+1th hard rock layer is added to the kth hard rock layer, and the breaking distance of the kth hard rock layer is recalculated. If the recalculated breaking distance of the kth hard rock layer is less than the breaking distance of the k+1th hard rock layer, then l k = l k+1 ; starting from the hard rock layer with the maximum burial depth, calculate l k < l k+1 (k = 1, 2, …, n) to determine whether it is true, if l k > l k+1 , the breaking distance of the kth hard rock layer is recalculated.

[0066] If the breaking distance of the kth hard rock layer is less than the breaking distance of all the upper hard rock layers, the kth hard rock layer is a key layer, and off-layer grouting and filling can be performed; otherwise, there is no key layer, and off-layer grouting and filling cannot be performed.

[0067] Step 2: Analyze the migration law of the overburden rock of the coal seam during mining to determine the grouting and filling layer position, the arrangement of the grouting and filling boreholes, the off-layer grouting amount, and the grouting amount of the fracture zone and the caving zone, and prepare for subsequent construction:

[0068] Step 21: First, determine the off-layer grouting layer position, the arrangement of the off-layer boreholes, and the off-layer grouting amount based on the timing, space, and development of the off-layer, which are the key conditions for implementing off-layer grouting and filling mining.

[0069] Determine the grouting and filling layer position: The off-layer grouting layer position of the overburden rock should be below the off-layer of the (sub) key layer above the height of the water-conducting fracture zone of the mined coal seam + the thickness of the isolation layer, with a burial depth not less than 0.3 times the mining depth.

[0070] Determination of the interval of the off-bed zone filling drilling hole 14: through numerical simulation software or similar simulation test and other methods to simulate the mining working face, with the advance of the coal seam, the state of the key stratum is observed. After the key stratum is broken, a hinged structure is formed, one end is the unbroken key stratum, and the other end acts on the caving rock mass on the goaf side. If off-bed grouting is not performed, the key stratum will periodically collapse with the advance of the working face, and the overburden gradually bends and subsides, until ground fissures and subsidence are formed on the ground. At this time, it is the off-bed grouting opportunity, and the working face advance distance is the interval of the ground off-bed grouting drilling hole.

[0071] Step 22, for fissure zone and caving zone filling, the filling amount parameter needs to be determined according to the caving zone height, which is calculated by the following formula:

[0072]

[0073] Wherein: H k Caving zone height, unit: m;

[0074] M - coal seam thickness, unit: m.

[0075] After the caving zone height is obtained, the fissure zone and caving zone filling amount can be calculated.

[0076] Step 3, select filling materials for off-bed zone, fissure zone and caving zone respectively.

[0077] Selecting appropriate filling materials, due to the off-bed zone, fissure zone and caving zone, there are more filling positions, resulting in a larger filling amount, so it is recommended to use two or more filling materials; the mine can flexibly select the filling material according to its by-products, which can be water sand, paste, gangue, and ultra-high water material. Different filling materials select appropriate filling system, which is prior art, and this patent will not be described here; in this example, the fissure zone and caving zone are filled with ultra-high water material, and the off-bed zone is filled with slurry made of fly ash, sand and gangue powder as the main solid material, usually with a water-cement ratio of 2:1.

[0078] Step 4, excavate the development roadway and preparation roadway of the filling working face 6, first excavate the return air upraise 1, the track upraise 2, the transportation upraise 3, then excavate the filling working face track roadway 4, the next working face track roadway 4', and the filling working face transportation roadway 5, so that the filling working face track roadway 4 and the next working face track roadway 4' are connected with the track upraise 2 respectively, the filling working face transportation roadway 5 is connected with the transportation upraise 3, and the next working face track roadway 4' and the filling working face transportation roadway 5 are connected with the communication roadway 11, and finally the ultra-high water A material filling pipeline 8, the ultra-high water B material filling pipeline 9, the fissure zone filling pipeline 12 and the caving zone filling pipeline 13 are laid.

[0079] For example,Figure 1 The roadway layout is shown. The preferential driving is the return air raise 1, the track raise 2, the transportation raise 3, and then the driving of the track roadway 4 of the filling working face, the track roadway 4' of the next working face and the transportation roadway 5 of the filling working face, and the connection of the track roadway 4 of the filling working face with the track raise 2 and the connection of the transportation roadway 5 of the filling working face with the transportation raise 3; the trinity filling working face adopts double roadway driving, and a communication roadway 11 is set every 50 m between the track roadway 4' of the next working face and the transportation roadway 5 of the filling working face, facilitating the laying of the super-high water A material filling pipeline 8, the super-high water B material filling pipeline 9, the fissure zone filling pipeline 12 and the caving zone filling pipeline 13.

[0080] Step 5, establishing the filling chamber 10.

[0081] The position of the filling chamber should be in the transportation raise 3 and close to the position where the transportation roadway 5 of the filling working face intersects; the filling chamber 10 is used to store the equipment required for the working face filling, store the filling materials and facilitate the pumping of the filling materials to the working face filling position; the filling chamber 10 controls the filling work of the fissure zone and the caving zone underground;

[0082] Step 6, arranging the separation zone filling pump station 16, which is arranged on the ground at the intermediate position of the strike and the trend of the filling working face 6.

[0083] The ground pump station is arranged, and since two kinds of filling materials are used, two kinds of filling pump stations are established, i.e. the separation zone filling pump station 16 and the underground filling pump station; the position of the separation zone filling pump station 16 should be at the intermediate position of the strike and the trend of the filling working face on the ground, as shown in Figure 1 、 2 The underground filling pump station should be located near the auxiliary shaft of the industrial square, which is a shaft in the mine used for lifting and lowering personnel, materials, waste rock and other auxiliary operations, so as to reduce the material conveying pipeline. The key equipment of the ground pump station includes raw material storage facilities, batching system, mixing equipment, pumping system and control system, and the main function of the separation zone filling pump station 16 is to transport the filling materials to the filling chamber 10 and fill the separation zone filling area 15 through the separation zone filling pipeline 17.

[0084] Step 7, drilling according to the drilling point position.

[0085] According to the previously determined development of the separation layer, the separation layer area filling drill hole 14 should be arranged in the separation layer area filling area 15 in the filling area, which is the position behind the corresponding filling working face 6 on the ground and where the separation layer appears during the mining process, and the interval l of the separation layer area filling drill hole 14 is determined by step 21; the drill hole of the fracture zone should be drilled into the upper part of the filling area by the next working face track roadway 4', the drill hole angle is best at 3°-5°, the interval is 300-500 mm, and the drill hole depth is determined according to the height H of the caving zone calculated in step 22 k The determination is made; the drill hole of the caving zone should be drilled into the caving zone from the bottom of the next working face track roadway 4', the drill hole angle is close to horizontal and is located below the drill hole of the fracture zone. The interval of the caving zone drill hole is determined according to the diffusion radius of the filling material, and the interval of the caving zone drill hole 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 the conventional process; the separation layer area filling pump station 16 delivers the filling material to the separation layer area filling area 15 through the separation layer area filling pipeline 17, and starts to fill the separation layer area when the filling working face 6 advances to the predetermined position; the filling chamber 10 delivers 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 respectively for filling.

[0087] The filling method of the fracture zone and the caving zone is to fill as mining; the filling method of the separation layer area is to fill at a fixed time and a fixed point, which needs to be calculated in advance when the filling working face 6 advances to where the separation layer area develops completely, and the time of the ground and the underground working face is particularly noted. 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 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 upward.

[0088] Step 9, repeat step 8 until the coal seam mining in the entire mining area is completed.

[0089] The filling system of the present example is a prior art known to those skilled in the art, and will not be described in detail here; the super-high water filling material of the present embodiment is a prior art known to those skilled in the art, and will not be described in detail here; the filling pump, the delivery pipeline, the filling support and the like of the present example use prior products or structures known to those skilled in the art, and the connection mode between them also uses a connection mode known to those skilled in the art, which will not be described in detail here.

[0090] The present example is filled according to the order of formation of the filling area. First, the back falling zone of the mining working face is filled with the super-high water filling material prepared by the filling chamber 10; then the fissure zone above the falling zone is filled through the filling borehole; finally, the ground filling pump station delivers the filling material to the separation layer area through the separation layer filling borehole. The completion of filling of each separation layer borehole marks the end of a cycle. The above process is repeated until the entire mining area is mined.

[0091] In addition to the above embodiments, the present application can have other implementation manners, and any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope of the present application.

Claims

1. A three-in-one drilling fluidized bed backfilling green mining method for fully mechanized mining faces, characterized in that: It includes the following steps: S1. Determine whether there is a key stratum based on the overlying strata of the main coal seam; S11. The first stratum is directly identified from the mined coal seam. The positions of the hard strata in the overlying strata are determined sequentially from deep to shallow. Based on the composite beam principle, a formula for determining the position of the key strata can be derived: ； Where: h i , E i Let be the thickness, unit weight and elastic modulus of the i-th rock layer, respectively. Starting from the 1st 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 formula The fracture distance l of each hard rock layer is obtained k , Where: h k Let be the thickness of the k-th layer of hard rock, in meters. q represents the tensile strength of the k-th layer of hard rock, in MPa; k The load q borne by the k-th layer of hard rock is expressed in MPa. k The calculation formula is as follows: ； Where m k The number of soft rock layers controlled by hard rock layers; h k,j , E k,j The values ​​are the thickness, unit weight, and elastic modulus of the j-th rock layer in the soft rock group controlled by the k-th hard rock layer, respectively, in m and MN / m. 3 , GPa; S13, determine if a critical layer exists; Starting from the deepest layer of hard rock, calculate the fracture distance l of each hard rock layer. k <l k+1 Whether it is true or not, if l appears k >l k+1 Then, the load borne by the (k+1)th hard rock layer is added to the kth hard rock layer, and the fracture distance of the kth hard rock layer is recalculated. If the recalculated fracture distance of the kth hard rock layer is less than the fracture distance of the (k+1)th hard rock layer, then l is taken. k =l k+1 The comparison continues. If the fracture distance of the k-th hard rock layer is less than the fracture distance of all the hard layers above it, then the k-th hard rock layer is the key layer and delamination grouting is performed; otherwise, there is no key layer and delamination grouting cannot be performed. S2. The migration pattern of the overlying strata of the main coal seam during the mining process is analyzed to obtain the grouting filling layer position, the arrangement of grouting filling boreholes, the grouting volume in the separation zone, and the grouting volume in the fracture zone and caving zone. S21. Based on the timing of delamination, the space of delamination, and the development of delamination, determine the layer position for delamination grouting, the arrangement of delamination boreholes, and the amount of delamination grouting. The separation grouting layer is located below the key layer above the height of the water-conducting fracture zone of the mining coal seam plus the thickness of the isolation layer, with a burial depth of not less than 0.3 times the mining depth; The spacing l of the filling boreholes (14) in the separation zone: The mining face is simulated by numerical simulation software. As the coal seam advances, the state of the key layer is observed. When the key layer fractures, the distance the filling face (6) advances is the spacing l of the ground separation grouting boreholes. Step 22, according to the formula Obtain the height H of the collapse zone k Where M is the coal seam thickness, and H is the height of the caving zone. k The filling volume of the fracture zone and the caving zone was obtained; S3. Select filling materials for filling the delamination zone, fracture zone and caving zone respectively; S4. Excavate the development roadway and preparation roadway of the filling working face (6). First, excavate the return air uphill (1), track uphill (2), and transport uphill (3). Then, excavate the track level roadway (4) of the filling working face, the track level roadway (4') of the next working face, and the transport level roadway (5) of the filling working face. Connect the track level roadway (4) of the filling working face and the track level roadway (4') of the next working face to the track uphill (2) respectively. Connect the transport level roadway (5) of the filling working face to the transport uphill (3). Establish a connecting roadway (11) between the track level roadway (4') of the next working face and the transport level roadway (5) of the filling working face. Finally, lay the filling pipeline. S5. Construct a filling chamber (10) in the transportation uphill (3) near the transportation level (5) of the filling working face; S6. Set up a delamination zone filling pump station (16) at the middle position of the strike and dip of the filling working face (6) on the ground, and set up an underground filling pump station near the auxiliary shaft of the industrial square. S7. Drill holes according to the drilling points; S8. The backfilling face (6) is mined according to the conventional procedure; the backfilling pump station (16) in the separation zone transports the backfilling material to the backfilling area (15) through the backfilling pipeline (17), and starts backfilling the separation zone when the backfilling face (6) advances to the predetermined position; the backfilling chamber (10) transports ultra-high water material to the fracture zone backfilling area (20) and the caving zone backfilling area (19) respectively through the fracture zone backfilling pipeline (12) and the caving zone backfilling pipeline (13) for backfilling; S9. Repeat step S8 until the coal seam mining of the entire mining area is completed.

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

1. The filling material for the fracture zone and the collapse zone is an ultra-high water content material.

3. The green mining method for three-in-one drilling fluidized bed filling in a fully mechanized mining face according to claim 2, characterized in that: The ultra-high water content material is composed of ultra-high water content A material and ultra-high water content B material.

4. The three-in-one drilling fluidized bed filling green mining method for fully mechanized mining faces according to claim 3, characterized in that: Step S7 includes the following steps: Based on the delamination development, delamination zone filling boreholes (14) are set in the delamination zone filling area (15) of the filling area. The spacing l of the delamination zone filling boreholes (14) is obtained from step S21. The boreholes in the fracture zone are driven into the upper part of the filling area by the track level roadway (4') of the next working face. The borehole depth is based on the height H of the caving zone in step S22. k The borehole for the caving zone is drilled into the caving zone from the bottom of the track level roadway (4') of the next working face. The borehole is horizontal and located below the borehole in the fracture zone.

5. The green mining method for three-in-one drilling fluidized bed filling in a fully mechanized mining face according to claim 4, characterized in that: The boreholes in the fracture zone have an elevation angle of 3° to 5° and a spacing of 300 to 500 mm.

6. The green mining method for three-in-one drilling fluidized bed filling in a fully mechanized mining face according to claim 4, characterized in that: The spacing between the boreholes in the caving zone is less than twice the effective diffusion radius of the ultra-high water material.

7. A three-in-one drilling fluidized bed filling green mining method for fully mechanized mining faces according to any one of claims 1 to 6, characterized in that: In step S8, the fracture zone and caving zone are first filled with filling material as it is mined; then the separation zone is filled with filling material at fixed times and locations.

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