Method for mining space partition filling and cooperative control of strata movement

Abstract

The application discloses a kind of mining space partition filling collaborative control strata movement methods, comprising: setting paste filling area and grouting filling area, coal cutting operation is carried out by coal mining machine, and is supported in mining space using hydraulic support, paste slurry filling is carried out behind the hydraulic support in paste filling area, and paste filling body is formed after paste slurry solidification;After several rounds of coal cutting and paste slurry filling, coal cutting operation is carried out by coal mining machine, and paste slurry filling is carried out in paste filling area and grouting filling area close to the position of coal cutting operation, to form retaining wall, and grouting slurry is filled between retaining wall and formed paste filling body to form grouting filling body;The forming process of paste filling body and grouting filling body is repeated until the whole mining space stoping operation is completed, to realize mining space partition filling collaborative control strata movement.

Description

Technical Field

[0001] This invention belongs to the field of coal mine backfilling technology, and particularly relates to a method for coordinating and controlling rock strata movement through mining-induced spatial partitioning backfilling. Background Technology

[0002] In coal mining, coal pillars are typically left unmined under buildings, railways, and water bodies. This not only results in a large backlog of coal resources but also prevents the mine from being mined efficiently, especially in deep-buried areas with multiple coal seams, where the amount of coal trapped is staggering. Failure to promptly recover this portion of coal not only wastes significant energy resources but also impacts mine profitability and reduces its service life.

[0003] To achieve safe mining of coal under the "three-under" pressure (underground, underground, and coal seams) and build green mines, backfilling mining technology should be adopted according to local conditions to reduce the hazards of coal mining subsidence, while simultaneously disposing of coal gangue and eliminating mine solid waste such as gangue piles. Backfilling mining prevents surface subsidence from the source, achieving coal resource acquisition with minimal ecological disturbance. Paste backfilling and grouting backfilling technologies are the main backfilling mining technologies. However, because they require the complete filling of paste or slurry into the mining space, the bag hanging time, filling time, and paste / slurry solidification time are excessively long, affecting coal mining operations and thus reducing coal recovery efficiency. Therefore, how to reduce the backfilling process time while ensuring backfilling effectiveness has become a crucial issue faced by most backfilling mining mines. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method for coordinating the control of rock strata movement through zoned filling of mining space. This method solves the problem that existing paste filling and grouting filling technologies require complete filling of the mining space, resulting in excessively long bag hanging time, filling time, and paste and grout solidification time. At the same time, it ensures the effectiveness of filling mining in controlling surface subsidence, thus resolving the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides a method for coordinated control of rock strata movement through mining-induced spatial zoning and filling, comprising:

[0006] The mining space is divided into a paste filling area and a grouting filling area. Coal cutting is carried out by a coal mining machine, and hydraulic supports are used for support in the mining space. Paste slurry is filled behind the hydraulic supports in the paste filling area. After the paste slurry solidifies, a paste filling body is formed.

[0007] After several rounds of coal cutting and paste slurry filling, coal cutting is carried out by a coal mining machine. Paste slurry is filled in the paste filling area and grouting filling area near the coal cutting operation to form a retaining wall. Grouting slurry is then filled between the retaining wall and the formed paste filling body to form a grouting filling body.

[0008] The process of forming paste-filled and grout-filled bodies is repeated until all working face mining and mining space filling operations are completed, so as to achieve coordinated control of rock strata movement through zoned filling of mining space.

[0009] Optionally, the paste filling zone and the grouting filling zone are set according to the geological conditions of the mining space and the size of the working face, wherein the two sides of the mining space of the working face are fixed as paste filling zones, and the interval area between every two sections of the paste filling zone is a grouting filling zone.

[0010] Optionally, the number of rounds for coal cutting and paste filling is set according to the single-round advance and pressure step distance in the working face, wherein the number of rounds is the largest integer less than the ratio of pressure step distance to single-round advance.

[0011] Optionally, the specific formation process of the paste filler includes:

[0012] Coal cutting operations are carried out using a coal mining machine, and the paste filling area in the mining space is supported by hydraulic supports. Filling bags are suspended in the space formed by the top beam, rear baffle, side partition plates and previous paste filling body behind the hydraulic supports.

[0013] The filling bag is filled with paste slurry, and the filling paste slurry is allowed to solidify to form a paste filling body, so that the next round of coal cutting operation and paste slurry filling can be carried out.

[0014] Optionally, the specific formation process of the grouting filling body includes:

[0015] Coal cutting operations are carried out by a coal mining machine. At the same time, filling bags are hung near the coal cutting operations in the paste filling area and grouting filling area. Grouting filling pipes are pre-installed in the middle of the filling bags in the grouting filling area, and paste slurry is filled into the filling bags. After the paste slurry solidifies, the solidified paste slurry in the grouting filling area forms a retaining wall.

[0016] In the grouting filling zone, a filling void is formed between the top slab, bottom slab, retaining wall, the paste filling bodies on both sides, and the end wall of the mining space or the paste filling body of the previous grouting filling zone. Grouting slurry is injected into the filling void through the grouting filling pipe. After the grouting slurry solidifies, the grouting filling body is formed.

[0017] Optionally, when the coal seam being mined in the working face of the mining space is not under buildings, water bodies, or under coal pressure from railways and highways, the grouting and filling process is not performed; only the formation process of the paste filling body is performed.

[0018] Optionally, the process also includes the preparation of paste slurry and grouting slurry, wherein paste slurry and grouting slurry are prepared from mine solid waste materials at the surface filling station.

[0019] Optionally, the mine solid waste materials include coal gangue and fly ash.

[0020] On the other hand, the present invention also provides a mining-driven spatial partitioning and filling collaborative control system for rock strata movement, used to perform the above-described method.

[0021] Compared with the prior art, the present invention has the following advantages and technical effects:

[0022] Due to the adoption of the above technical solution, this invention adopts paste-grouting co-filling technology, which alternately arranges paste filling areas and grouting filling areas in the mining space along the working face dip. The main process is divided into paste filling stage and grouting filling stage. The paste filling stage is similar to the back-support filling mining process, only requiring the filling bags to be hung in the paste filling area and the paste material to be filled. After solidification, the next round of coal mining operation is carried out. The grouting filling stage is connected after multiple rounds of coal mining-paste filling process. A layer of paste is filled behind the support in the grouting filling area as a retaining wall. The grout is transported to the cuboid void through the pre-embedded grouting pipe. After the grout solidifies, it works in conjunction with the paste filling bodies on both sides to control the movement of the rock strata. This mining method integrates paste filling and grouting filling technologies, and innovatively proposes a zoned paste-grouting co-filling technology for mining spaces. By filling part of the mining space with paste, the process time of bag hanging, filling and solidification can be significantly reduced, improving filling mining efficiency and reducing investment costs. After multiple rounds of paste filling, the remaining mining space is filled with grouting, which works in conjunction with the paste filling to control the roof, reducing the impact of the filling process on the efficiency of coal mining operations. It also disposes of a large amount of coal gangue, fly ash and other mine solid waste materials. Furthermore, when the surface control requirements are low, grouting filling can be omitted, reducing the complexity of the process and achieving safe, efficient and green mining of coal resources. Attached Figure Description

[0023] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1 This is a flowchart of the mining space partitioning paste-grouting co-filling technology according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the filling process behind the hydraulic support according to an embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the filling body and rock strata structure according to an embodiment of the present invention;

[0027] Figure 4 This is a displacement cloud diagram of the top plate of the working surface under no-fill conditions according to an embodiment of the present invention;

[0028] Figure 5This is a displacement cloud diagram of the top plate of the working surface under the paste partitioning filling according to an embodiment of the present invention;

[0029] Figure 6 This is a displacement cloud diagram of the top plate of the working surface under the paste-slurry partition filling method according to an embodiment of the present invention.

[0030] Figure 7 This is a displacement cloud diagram of the top plate of the working surface under all paste filling in this embodiment of the invention;

[0031] Figure 8 This is a line graph showing the displacement of the top plate of the working face in an embodiment of the present invention.

[0032] Among them, 1. Paste filling area; 2. Grouting filling area; 3. Coal mining machine; 4. Hydraulic support for paste filling area (blue area); 5. Paste filling bag for paste filling area; 6. Paste filling pipe; 7. Paste filling body; 8. Hydraulic support for grouting filling area (green area); 9. Grouting filling pipe; 10. Retaining wall; 11. End wall; 12. Grout filling body; 13. Grouting filling bag for grouting filling area. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0035] This invention relates to a method for coordinating and controlling rock strata movement through zoned filling in mining space, belonging to the field of coal mine filling mining technology. This method innovatively integrates a zoned paste-grouting coordinating filling technology, in which paste-filling zones and grouting zones are alternately arranged along the dip in the mining space of the working face. After zoned filling and solidification, a paste-grout combination is formed, which coordinating and controlling rock strata movement. The process of paste filling area is similar to that of paste filling behind the support frame, including the coal mining-paste filling process. During the coal mining process, the filling bag is installed behind the filling support frame of the paste filling area. After the coal is cut, paste is transported to the filling bag through the filling pipeline behind the support frame. After solidification, the next round of coal mining-filling cycle is carried out. The grouting filling area operation is connected after the multi-round paste filling stage, including the multi-round coal mining-paste filling + grouting filling process. After the multi-round coal mining operation, paste is filled behind the support frame as a retaining wall. Grout is transported to the grouting filling area through the pre-embedded grouting pipeline. After solidification, it works in conjunction with the paste filling area to control the movement of the rock strata. This method leverages the advantages of paste filling and grouting filling while avoiding their drawbacks. It mitigates the impact of low strength in grouting filling, reduces the bag-filling-solidification time, improves filling mining efficiency, and lowers investment costs. It also disposes of large quantities of mine solid waste materials such as coal gangue and fly ash. Furthermore, when surface control requirements are low, grouting filling can be omitted, reducing process complexity and enabling safe, efficient, and green mining of coal resources.

[0036] The above technical solution is described in detail below:

[0037] This invention provides a method for coordinating and controlling rock strata movement through zoned filling in mining space, belonging to the field of coal mine filling mining technology. This method innovatively integrates a zoned paste-grouting coordinating filling technology, comprising two stages: paste filling and grouting filling. In the mining space of the working face, paste filling zone 1 and grouting filling zone 2 are alternately arranged along the dip. After zoned filling and solidification, a paste-grout combination is formed, which coordinating and controlling rock strata movement. The specific steps are as follows:

[0038] ① At the surface backfilling station, paste and slurry backfill materials are prepared using mining solid waste materials such as coal gangue and fly ash;

[0039] ② Paste filling stage: This includes the coal mining-paste filling process. The purpose is to first fill part of the mining space, and then solidify it to support the roof strata. Compared with filling the entire mining space, this reduces the filling time. At the same time, it achieves the effect of controlling the movement of the roof strata and surface subsidence, and disposes of mine solid waste such as coal gangue.

[0040] a. Coal cutting operation is carried out using coal mining machine 3. At the same time, filling bags 5 for the paste filling area are suspended in the space formed by the hydraulic support 4 rear top beam, rear baffle, side partitions and the previous filling body in the paste filling area of ​​the mining space.

[0041] b. After inspecting the filling equipment and preparing for filling, inform the filling station of the required amount of slurry, and pump the paste material to the working face through the filling pump, and then transport it to the filling bag 5 in the paste filling area through the paste filling pipe 6;

[0042] c. After the paste slurry solidifies, it forms paste filling body 7, completing one round of paste filling stage and preparing for the next round of coal mining-paste filling process.

[0043] ③ Grouting and filling stage: This includes the coal mining-paste filling-grouting and filling process. The purpose is to complete the filling operation of the grouting and filling area of ​​the mining space in one go after multiple rounds of coal mining-paste filling process. After solidification, it works together with the paste filling body to support the roof rock strata. For mines with high requirements for surface deformation control, it makes up for the shortcomings of insufficient support effect of paste filling area alone, realizes the coordinated control of rock strata movement by paste and grout, reduces the time consumption of filling process, and disposes of mine solid waste such as coal gangue.

[0044] a. After multiple rounds of coal mining-grout filling processes, while a new round of coal mining is being carried out, grout filling bags 5 are suspended in grout filling area 1 and grouting filling area 2.

[0045] b. A grouting pipe 9 is pre-arranged in the middle of the grouting filling bag 13 in the grouting filling area to deliver paste into the grouting filling bag 13. After solidification, the paste filling body of the grouting filling area 2 forms a retaining wall 10.

[0046] c. In the grouting and filling zone 2, a rectangular filling void is formed by the top and bottom plates, the plaster retaining wall 10 behind the support, the plaster filling bodies 7 on both sides, and the end wall 11 of the mining space. Grout is injected into the rectangular void through the grouting and filling pipe 9. After the grout solidifies, it forms a grout filling body 12, which, together with the plaster filling bodies 7 on both sides, controls the movement of the rock strata and completes one round of grouting and filling stage.

[0047] ④ Repeat steps ② to ③ until the entire backfilling working face mining operation is completed, so as to realize the coordinated control of rock strata movement by zonal backfilling in the mining space.

[0048] As some embodiments, the grouting and filling stage can be omitted when the coal seam being mined in the working face of the mining space is not under coal pressure from "three areas" (under buildings, under water bodies, and under railways and highways), thereby improving the efficiency of filling and mining while reducing costs.

[0049] As some embodiments, the dimensions of the paste filling area 1 and the grouting filling area 2 are designed according to geological conditions and working face dimensions. The mining space is divided along the working face dip into n+1 paste filling areas 1 with a width of l1 and n grouting filling areas 2 with a width of l2. The areas on both sides of the working face are fixed as paste filling areas 1. The design method for the dimensions of paste filling areas 1 and grouting filling areas 2 is as follows:

[0050] Because the zonal filling process requires that both sides of the working face must be filled with filling material, directly designing the widths of paste filling zone 1 and grouting filling zone 2 for different working face conditions is quite complex. Therefore, the width of the filling zone is indirectly determined by designing the filling zone width ratio, the number of filling units (a pair of paste filling zone 1 and grouting filling zone 2 constitute one unit), and the working face width. Specific parameters for each factor are shown in Table 1, and the parameters in Table 1 can be freely paired with each other.

[0051] Table 1

[0052]

[0053] As some embodiments, in step 3, the number of rounds in the multi-round coal mining-paste filling process is determined based on the single-round advance and pressure step distance of the working face. The number of rounds p, the single-round advance b, and the pressure step distance q satisfy p≤[q / b] ([x] is a Gaussian function, [x] represents the integer part of the real number x, that is, [x] represents the largest integer not exceeding the real number x).

[0054] The above technical solution is described in detail with reference to the accompanying drawings and relevant data:

[0055] The backfilling area of ​​a certain coal mine is located in the entire coal-bearing area under the old city, covering an area of ​​approximately 8.45 km². 2 The main coal seam being mined is No. 2-2 coal seam, with a surface elevation of 31.03m, an average coal thickness of 3.0m, and a coal seam volume of 36.64 million tons. The coal seam is located in the central part of the Shanxi Formation. The average distance to the bottom of the upper K4 marker layer is 52.02m, and the average distance to the top of the lower K3 marker layer is 49.10m. The stratum is stable and is the main coal seam being mined within the mining area. Drilling revealed a pseudo-thickness of 0–7.68m, averaging 2.95m. The elevation of the coal seam floor ranges from -927.72m to -276.25m, with the floor elevation in the first mining area approximately -470m. The coal seam exhibits a single-layer structure. Double-layer structures are only observed in a few boreholes and are scattered.

[0056] Implementation steps:

[0057] In the first mining area of ​​a certain coal mine, the width of the first mining backfilling face is 140m. The mining space zoning backfilling method is used for mining. The width ratio of the backfilling area is set to 5:5, and the number of backfilling units is set to 3. Therefore, it can be calculated that the width of paste backfilling area 1 and grouting backfilling area 2 is 20m.

[0058] like Figure 1 As shown, the first step is the coal mining-paste filling process: A coal mining machine 3 is used for coal cutting. Simultaneously, a paste filling bag 5 is suspended behind the hydraulic support 4 in the paste filling area of ​​the mining space. After inspecting the filling equipment and preparing for filling, the paste material is pumped to the working face via a filling pump and then transported through the paste filling pipe 6 to the paste filling bag 5 in the paste filling area. Figure 2As shown, after solidification, the next round of coal mining-paste filling process is carried out. Figure 2 In the process, the top plate is supported by a hydraulic support 4 for the paste filling area, and a corresponding paste filling bag 5 is installed. Paste filling material 7 is filled into the paste filling bag 5 through a paste filling pipe 6. Figure 2 The same structure is also applicable to the grouting filling method. Replace the hydraulic support 8 of the grouting filling area with the hydraulic support 4 of the paste filling area, replace the paste filling bag 5 of the grouting filling area with the filling bag 13 of the grouting filling area, and replace the paste filling body 7 with the paste filling body 12. Then, through the hydraulic support 8 of the grouting filling area, use the grouting filling pipe 9 to fill the grout filling bag 13 with the paste filling body 12 to complete the grouting filling method.

[0059] Because there are buildings on the surface of the backfilling face, it belongs to the "three-under" coal mining, and therefore a grouting backfilling stage is carried out. Based on the mining data of the adjacent working face, the initial pressure step distance of this backfilling face is determined to be 25m, and the single-round advance is 2.4m. It is calculated that the number of rounds p is 10 rounds. Therefore, after 10 rounds of coal mining-paste backfilling process, one round of coal mining-paste backfilling-grouting backfilling process is carried out. After the coal is cut by the coal mining machine 3, backfilling bags are suspended in the paste backfilling area 1 and the grouting backfilling area 2, and paste is transported into them. After solidification, grout is transported into the grouting backfilling void through the pre-arranged grouting backfilling pipe 9. After the grout solidifies, it forms a grout backfilling body 12, which, together with the paste backfilling bodies 7 on both sides, controls the movement of the rock strata. Figure 3 As shown.

[0060] Numerical simulations were used to study the roof deformation characteristics after no filling, paste-partial filling, paste-slurry-partial filling, and full paste filling. Survey lines were laid out along the width of the working face at a height of 5m above the roof. Curves for different filling schemes were plotted based on the maximum deformation of the roof in the middle of the working face. The results are as follows: Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 As shown in the figure. Analysis shows that without filling, the roof collapses directly, with a maximum deformation of 2960 mm. After using paste-based sectional filling, the deformation of the roof is significantly reduced, with the maximum deformation concentrated in the empty area, reaching 720 mm. After using paste-slurry sectional filling, the deformation of the roof is further reduced, with the maximum deformation located in the middle of the working face, decreasing to 538 mm. This is not significantly different from the maximum deformation of 473 mm achieved with all paste filling, indicating good control of roof deformation. This effectively prevents ground subsidence and ensures the stability of surface structures.

[0061] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for coordinated control of rock strata movement through spatial zoning and filling during mining, characterized in that, include: The mining space is divided into a paste filling area and a grouting filling area. Coal cutting is carried out by a coal mining machine, and hydraulic supports are used for support in the mining space. Paste slurry is filled behind the hydraulic supports in the paste filling area. After the paste slurry solidifies, a paste filling body is formed. After several rounds of coal cutting and paste slurry filling, coal cutting is carried out by a coal mining machine. Paste slurry is filled in the paste filling area and grouting filling area near the coal cutting operation to form a retaining wall. Grouting slurry is then filled between the retaining wall and the formed paste filling body to form a grouting filling body. The process of forming paste-filled and grout-filled bodies is repeated until all working face mining and mining space filling operations are completed, so as to achieve coordinated control of rock strata movement through zoned filling of mining space.

2. The method according to claim 1, characterized in that, The paste filling zone and the grouting filling zone are set up according to the geological conditions of the mining space and the size of the working face. The two sides of the mining space of the working face are fixed as paste filling zones, and the interval area between every two sections of the paste filling zone is the grouting filling zone.

3. The method according to claim 1, characterized in that, The number of rounds for coal cutting and paste filling is set according to the single-round advance and pressure step distance in the working face, wherein the number of rounds is the largest integer less than the ratio of pressure step distance to single-round advance.

4. The method according to claim 1, characterized in that, The specific formation process of the paste-filled body includes: Coal cutting operations are carried out using a coal mining machine, and the paste filling area in the mining space is supported by hydraulic supports. Filling bags are suspended in the space formed by the top beam, rear baffle, side partition plates and previous paste filling body behind the hydraulic supports. The filling bag is filled with paste slurry, and the filling paste slurry is allowed to solidify to form a paste filling body, so that the next round of coal cutting operation and paste slurry filling can be carried out.

5. The method according to claim 1, characterized in that, The specific formation process of the grouting filling body includes: Coal cutting operations are carried out by a coal mining machine. At the same time, filling bags are hung near the coal cutting operations in the paste filling area and grouting filling area. Grouting filling pipes are pre-installed in the middle of the filling bags in the grouting filling area, and paste slurry is filled into the filling bags. After the paste slurry solidifies, the solidified paste slurry in the grouting filling area forms a retaining wall. In the grouting filling zone, a filling void is formed between the top slab, bottom slab, retaining wall, the paste filling bodies on both sides, and the end wall of the mining space or the paste filling body of the previous grouting filling zone. Grouting slurry is injected into the filling void through the grouting filling pipe. After the grouting slurry solidifies, the grouting filling body is formed.

6. The method according to claim 1, characterized in that, When the coal seam being mined in the working face of the mining area is not under buildings, water bodies, railways, or highways, the grouting and filling process is not carried out; only the formation process of the paste filling body is performed.

7. The method according to claim 1, characterized in that, It also includes the preparation process of paste slurry and grouting slurry, in which paste slurry and grouting slurry are prepared from mine solid waste materials at the surface filling station.

8. The method according to claim 7, characterized in that, The solid waste materials from the mine include coal gangue and fly ash.

9. A system for coordinated control of rock strata movement through spatial zoning and filling during mining, characterized in that, Used to perform the method described in any one of claims 1-8.

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