Mud filtering and water control method for water inrush in goaf of inclined longwall mining working face

Abstract

The present invention relates to the technical field of coal mining, and provides a method for filtering mud and controlling water for water gushing from the goaf of a downward-inclined longwall mining working face, comprising constructing a filter mud barrier on the bottom plate of the goaf before the roof rock layer of the goaf collapses, wherein the filter mud barrier protrudes from the bottom plate of the goaf, and the two ends of the filter mud barrier extend to the coal ridges on both sides of the goaf along the inclined direction of the working face. With such an arrangement, the content of solids such as coal mud in the water gushing into the working space can be effectively reduced from the source through the blocking and filtering effect of the filter mud barrier on solids such as coal mud. Then, a drainage pump is set at a suitable location to discharge the water gushing from the working space, thereby solving the problem of water gushing from the old pond in the downward-inclined mining process in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mining, in particular to a mud filtering and water control method for water gushing from a goaf of a downward-sloping longwall mining working face. Background Art

[0002] During the mining process of an inclined longwall face, the roof rock strata in the goaf periodically collapse after coal seam extraction. This causes water to flow into the goaf from the roof aquifer, creating a flood. This flood carries with it coal slime and rock dust from the goaf, mixing to form slurry water, which then flows into the working area. This massive influx of slurry water into the working area can lead to slurry accumulation and significant water accumulation, especially in inclined longwall faces. This influx of slurry water can cause significant disruptions to both normal coal mining and the working environment.

[0003] With the increase in the intensity of coal mining, large water working faces have become more common. For water gushing from goafs, water pumps can be used to relieve the problem. However, since the water gushing from old ponds generally carries a large amount of coal slime and rock powder, the water inlet of the water pump is easily clogged and cannot function.

[0004] Therefore, how to solve the problem of water gushing from old ponds during the inclined mining process in the prior art has become an important technical problem to be solved by those skilled in the art. Summary of the Invention

[0005] The present invention provides a mud filtering and water control method for water gushing from a goaf of a downward-inclined longwall mining working face, which is used to solve the defect of water gushing from old ponds in the downward-inclined mining process in the prior art.

[0006] The present invention provides a mud filtering and water control method for water gushing from a goaf in a downward-sloping longwall mining working face, comprising:

[0007] Before the roof rock layer of the goaf collapses, a filter mud barrier is constructed on the bottom plate of the goaf. The filter mud barrier protrudes from the bottom plate of the goaf, and both ends of the filter mud barrier extend along the inclined direction of the working face to the coal seams on both sides of the goaf.

[0008] According to the present invention, a mud filtering and water control method for water gushing in the goaf of a downward-sloping longwall mining working face is provided. The mud filtering barriers are provided in multiple rows, and the multiple mud filtering barriers are spaced apart along the mining direction.

[0009] According to the present invention, a mud filter and water control method for water inrush in the goaf of a downward-sloping longwall mining working face is provided. The mud filter barrier comprises a bottom coal convex slope portion located in the mined area and a retaining wall portion located in the roadway, wherein the bottom coal convex slope portion and the retaining wall portion form an integrated structure.

[0010] The construction of a filter mud barrier on the floor of the goaf comprises:

[0011] During the coal mining process, the bottom coal convex slope portion is reserved on the bottom plate of the mined area;

[0012] The retaining wall portion is built on the bottom plate of the tunnel, the retaining wall portion corresponds to the bottom coal convex slope portion, the end of the retaining wall portion is connected to the end of the bottom coal convex slope portion and the side wall of the tunnel, and the height of the retaining wall portion is greater than or equal to the height of the bottom coal convex slope portion.

[0013] According to the present invention, a method for filtering mud and controlling water inrush in a goaf of a downward-sloping longwall mining working face, before reserving the bottom coal convex slope portion on the floor of the mined area, further comprises:

[0014] determining a preset width and a preset height of the bottom coal convex slope portion;

[0015] The preset spacing between two adjacent bottom coal convex slope portions and the preset number of the bottom coal convex slope portions are determined.

[0016] According to the present invention, a mud filtering and water control method for water inrush in the goaf of a downward-sloping longwall mining working face is provided, wherein the bottom coal convex slope portion is reserved on the floor of the mined area, comprising:

[0017] Coal mining equipment is controlled according to the preset width, the preset height, the preset spacing and the preset number.

[0018] According to the present invention, a method for filtering mud and controlling water inrush in a goaf of a downward-sloping longwall mining working face is provided, wherein the coal mining control equipment comprises:

[0019] Adjust the height of the cutting portion of the coal mining equipment.

[0020] According to a mud filtering and water control method for water inrush in a goaf of a downward-sloping longwall mining working face provided by the present invention, determining a preset width and a preset height of the bottom coal convex slope portion includes:

[0021] determining a preset width of the bottom coal convex slope portion;

[0022] determining an inclination angle of the bottom coal convex slope portion relative to the floor of the mined area according to a limit climbing angle of the coal mining equipment;

[0023] The preset height is determined according to the preset width and the inclination angle of the bottom coal convex slope portion relative to the floor of the mined area.

[0024] According to a mud filtering and water control method for water inrush in a goaf of a downward-sloping longwall mining working face provided by the present invention, determining a preset spacing between two adjacent bottom coal convex slope portions and a preset number of the bottom coal convex slope portions comprises:

[0025] Determining the preset amount by iterative calculation based on a calculation model for the final content of solid matter in the goaf water gushing out and a target content of solid matter in the goaf water gushing out;

[0026] The preset spacing is determined according to the preset number, the collapse step distance of the rock layer on the top of the goaf and the preset width.

[0027] According to a mud filtration and water control method for water inrush in the goaf of a downward-sloping longwall mining working face provided by the present invention, the calculation model is:

[0028]

[0029] Among them, q n is the final content of solid matter in the goaf water when n filter mud barriers are set, q0 is the initial content of solid matter in the goaf water, B is the roughness coefficient of the goaf floor, L is the collapse step distance of the goaf roof rock layer, the collapse step distance of the goaf roof rock layer is the distance between the initial end of the collapse section of the goaf roof rock layer and the working face, n is the number of filter mud barriers, E is the preset width of the bottom coal convex slope, α is the inclination angle of the goaf floor, V is the flow rate of the goaf water, a n-1 The final content of solid matter in the goaf water when (n-1) filter mud barriers are set, and C and A are both constants.

[0030] According to a mud filtering and water control method for water gushing in the goaf of a downward-sloping longwall mining working face provided by the present invention, the retaining wall portion is constructed on the bottom plate of the tunnel, comprising:

[0031] Sandbags or bricks are piled on the floor of the tunnel.

[0032] In the mud filtration and water control method for water gushing from the goaf of a downwardly inclined longwall mining working face provided by the present invention, a mud filtration barrier is constructed on the floor of the goaf before the roof rock layer of the goaf collapses. The mud filtration barrier protrudes from the floor of the goaf, and the ends of the mud filtration barrier extend along the inclination direction of the working face to the coal ribs on both sides of the goaf. After the roof rock layer of the goaf collapses, the water gushing from the goaf will pass through the mud filtration barrier as it flows into the working space. As the water gushing from the goaf passes through the mud filtration barrier, it can block and filter out solid matter such as coal slime in the water gushing from the goaf. The intercepted solid matter such as coal slime will gradually settle, thereby reducing the content of solid matter such as coal slime in the water gushing. After passing through the mud filtration barrier, the water gushing from the goaf can continue to seep out through the gaps in the collapsed rock blocks above the mud filtration barrier. With this arrangement, the mud filtration barrier's blocking and filtering effect on solid matter such as coal slime can effectively reduce the content of solid matter such as coal slime in the water gushing from the working space at its source. Then, a suitable location is selected to set up a drainage pump to drain the gushing water in the working space, thereby solving the problem of gushing water in the old pond during the inclined mining process in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 It is a side view of a filter mud barrier in a filter mud water control method for water inrush in a goaf of a downward-sloping longwall mining working face provided by the present invention;

[0035] Figure 2 It is a front view of the sludge filter barrier in the sludge filter water control method for water gushing from the goaf of the inclined longwall mining working face provided by the present invention.

[0036] Reference numerals:

[0037] 1. Filter mud barrier; 11. Bottom coal slope; 12. Retaining wall; 2. Coal mining equipment; 3. Working face; 4. Collapsed rock; E. Preset width; H. Preset height; N. Preset spacing. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0039] The following combination Figures 1 to 2 The present invention describes a mud filtering and water control method for water gushing from a goaf area of ​​a downward-sloping longwall mining working face.

[0040] The embodiment of the present invention provides a mud filtering and water control method for water gushing from a goaf of a downward-sloping longwall mining working face, comprising the following steps:

[0041] Before the roof rock of the goaf collapses, a filter mud barrier 1 is constructed on the floor of the goaf. The filter mud barrier 1 protrudes from the floor of the goaf, and both ends of the filter mud barrier 1 extend along the inclined direction of the working face 3 to the coal ribs on both sides of the goaf.

[0042] The inclination direction of the working face 3 is perpendicular to the mining direction and is along the transverse direction of the working face 3 .

[0043] Before the roof rock layer of the goaf collapses, the filter mud barrier 1 is constructed on the bottom plate of the goaf. After the roof rock layer of the goaf collapses, the water gushing from the goaf will pass through the filter mud barrier 1 when flowing into the working space.

[0044] When water gushing from the goaf passes through filter mud barrier 1, it blocks and removes solid matter, such as coal slime, from the water. The intercepted solid matter gradually settles, reducing the amount of solid matter in the water. After passing through filter mud barrier 1, the water continues to seep out through the gaps in the collapsed rock blocks 4 above the filter mud barrier 1.

[0045] This arrangement effectively reduces the content of solids such as coal slime in the water entering the working space by blocking and filtering out solids such as coal slime through the filter barrier 1. A drainage pump can then be installed at a suitable location to drain the water from the working space, thus resolving the problem of water gushing from old ponds during inclined mining in the prior art.

[0046] In the specific implementation process, multiple filter mud barriers 1 can be constructed on the bottom plate of the goaf, and the multiple filter mud barriers 1 are spaced apart along the mining direction, such as Figure 1 As shown, when the water gushing from the goaf flows toward the working space, it passes through multiple filter mud barriers 1 in sequence. Through the blocking and filtering effects of the multiple filter mud barriers 1, the content of solid matter such as coal slime in the water gushing can be effectively reduced.

[0047] In this embodiment, the goaf includes the mined area corresponding to the working face 3 and the roadways located on both sides of the mined area. The filter mud barrier 1 includes a bottom coal convex slope portion 11 and a retaining wall portion 12. The bottom coal convex slope portion 11 is located in the mined area, and the retaining wall portion 12 is located in the roadway. The bottom coal convex slope portion 11 and the retaining wall portion 12 form an integrated structure. Figure 2 .

[0048] The above-mentioned bottom coal convex slope portion 11 can be realized by reserving bottom coal during the coal mining process.

[0049] The retaining wall 12 needs to be additionally built at both ends of the bottom coal convex slope 11. Specifically, after the bottom coal convex slope 11 is formed, sandbags or bricks can be piled on the bottom plate of the tunnel to form the retaining wall 12 by piling up sandbags or bricks.

[0050] When constructing the retaining wall 12, it is necessary to make the retaining wall 12 correspond to the bottom coal convex slope 11, that is, the retaining wall 12 is only built at the end of the bottom coal convex slope 11. When constructing the retaining wall 12, it is necessary to make the height of the retaining wall 12 greater than or equal to the height of the bottom coal convex slope 11, and make the end of the retaining wall 12 connected to the end of the bottom coal convex slope 11 and the side wall of the roadway, so as to avoid as much as possible the formation of gaps between the retaining wall 12 and the bottom coal convex slope 11 and between the retaining wall 12 and the side wall of the roadway, thereby ensuring the filter mud barrier 1's blocking effect on solid matter such as coal slime.

[0051] In the embodiment of the present invention, before reserving the bottom coal convex slope portion 11 on the floor of the mined area, it is necessary to determine the parameters of the bottom coal convex slope portion 11, specifically, determining the preset width E and preset height H of the bottom coal convex slope portion 11, as well as determining the preset spacing N between two adjacent bottom coal convex slope portions 11 and the preset number of bottom coal convex slope portions 11.

[0052] The preset width E of the bottom coal convex slope 11 is the distance between the two ends of a single bottom coal convex slope 11 along the mining direction. The preset height H of the bottom coal convex slope 11 is the maximum distance between a single bottom coal convex slope 11 and the bottom plate of the mined area. The preset spacing N between two adjacent bottom coal convex slopes 11 is the distance between two adjacent bottom coal convex slopes 11. Figure 1 .

[0053] It should be noted that the greater the height of the bottom coal convex slope 11, the better the blocking effect of the bottom coal convex slope 11 on solid matter such as coal slime, but it will inevitably increase the reserved amount of bottom coal, resulting in increased coal loss during coal mining.

[0054] Furthermore, after reserving the bottom coal convex slope 11, the mining equipment 2 needs to pass through the bottom coal convex slope 11 during the mining process. Since the mining equipment 2 has a maximum climbing angle, the slope of the bottom coal convex slope 11 relative to the floor of the mined area needs to be smaller than the maximum climbing angle of the mining equipment 2 to ensure the normal movement of the mining equipment 2.

[0055] It should be noted that the coal mining equipment 2 includes conveyors, supports, and coal cutters, among other devices. Different devices have different climbing capabilities and each has a maximum climbing angle. The maximum climbing angle of the coal mining equipment 2 is the minimum of the maximum climbing angles of each device. In other words, in this embodiment, it is necessary to ensure that the device with the lowest climbing capability among the coal mining equipment 2 can pass through the bottom coal convex slope 11.

[0056] In summary, it is necessary to control the preset height H and preset width E of the bottom coal convex slope portion 11 within a certain value range.

[0057] Specifically, the preset width E of the bottom coal convex slope 11 may be determined first, and then the preset height H of the bottom coal convex slope 11 may be further determined based on the preset width E of the bottom coal convex slope 11 and the maximum climbing angle of the coal mining equipment 2 .

[0058] If the maximum climbing angle of the coal mining equipment 2 is β, which is regarded as the maximum allowable value of the inclination angle of the bottom coal convex slope 11 relative to the floor of the mined area, the preset width of the bottom coal convex slope 11 is E, and the preset height of the bottom coal convex slope 11 is H, then,

[0059] Therefore, the maximum value of the preset height H of the bottom coal convex slope 11 can be determined to be

[0060] In some embodiments, the preset width E of the bottom coal convex portion 11 is set within a range of 3-5 meters.

[0061] The target content of solid matter in the goaf water gushing out is determined based on the drainage capacity of the drainage pump and the requirements of the drainage pump for the content of solid matter such as coal slime contained in the gushing water. The determined target content of solid matter in the goaf water gushing out needs to be lower than the required value of the drainage pump for the content of solid matter such as coal slime contained in the gushing water.

[0062] After determining the target content of solid matter in the goaf water, the preset number of bottom coal convex slope portions 11 can be determined through iterative calculation based on the calculation model of the final content of solid matter in the goaf water and the target content of solid matter in the goaf water.

[0063] Then, the preset distance N between two adjacent bottom coal convex slope portions 11 can be determined by combining the preset number, the collapse step distance of the rock layer in the goaf roof, and the preset width E.

[0064] After determining the preset width E, preset height H, preset spacing N and preset number of the bottom coal convex slope 11, during the coal mining process, the coal mining equipment 2 can be controlled according to the preset width E, preset height H, preset spacing N and preset number of the bottom coal convex slope 11.

[0065] Specifically, the height of the cutting part of the coal mining equipment 2 can be adjusted at the corresponding position so that the cutting part of the coal mining equipment 2 can mine coal above the upper contour surface of the bottom coal convex slope 11 that needs to be reserved, thereby reserving and forming the corresponding bottom coal convex slope 11.

[0066] It should be noted that as goaf water flows into the working space, it is not only blocked and filtered by the filter mud barrier 1, but also naturally settles. When determining the final solid content of goaf water, it is necessary to comprehensively consider the natural settling rate of solids in the goaf water and the filtration rate of solids in the goaf water by the filter mud barrier 1.

[0067] Specifically, through a large number of experimental summaries, we learned that:

[0068] The natural precipitation rate of solid matter in the goaf water is in:

[0069] q z is the natural sedimentation rate of solid matter in the goaf water, B is the roughness coefficient of the goaf floor, l is the distance the goaf water flows, α is the inclination angle of the goaf floor, V is the flow rate of the goaf water, q0 is the initial content of solid matter in the goaf water, and C is a constant;

[0070] The removal rate of solid matter in the goaf water by filter mud barrier 1 is

[0071] Where: q l is the filtration rate of solid matter in goaf water by n filter mud barriers, n is the number of filter mud barriers, and A is a constant;

[0072] The final content of solid matter in the water gushing from the goaf when n filter mud barriers are set is q n The final content of solid matter in the goaf water when (n-1) filter mud barriers are set is q n-1 The relationship between them is:

[0073]

[0074] This relationship is the calculation model for the final solid matter content in the goaf water, where E is the preset width of the bottom coal convex slope 11, L is the collapse step distance of the goaf roof stratum, and the collapse step distance of the goaf roof stratum is the distance between the initial end of the collapse section of the goaf roof stratum and the working face 3. The goaf roof stratum collapses periodically and stepwise, and the end of the collapse section of each goaf roof stratum farthest from the working face 3 is the initial end.

[0075] Among the above parameters, B can be determined according to the roughness of the floor of the goaf, and the values ​​of α, V and q0 can be determined by measurement.

[0076] The inclination angle α of the floor of the goaf is consistent with the inclination angle of the floor of the tunnel. Two measuring points can be selected on the floor of the tunnel. The two measuring points are distributed along the mining direction. By measuring the height difference and horizontal distance between the two measuring points, the inclination angle α of the floor of the goaf can be determined.

[0077] For V and q0, they can be measured in the end triangle area of ​​the working surface.

[0078] The mud filtering and water control method for water gushing in the goaf of the inclined longwall mining working face in the embodiment of the present invention can block and filter out solid matter such as coal slime in the water gushing in the goaf, so that the gushing water without solid matter such as coal slime or with a low content of solid matter such as coal slime can seep out through the gap between the collapsed rock blocks 4 above the filtering mud barrier 1, thereby solving the problem of old pond water gushing in the process of inclined mining from the root, avoiding solid matter such as coal slime from entering the working space and production links, and ensuring the safe and efficient production of coal mine recovery work.

[0079] The mud filtering and water control method for water gushing in the goaf of the inclined longwall mining working face in the embodiment of the present invention realizes the arrangement of the mud filtering barrier 1 during the coal mining operation process, basically without adding additional processes and manpower input. It only requires reserving a small amount of bottom coal according to the design when cutting coal, which requires low investment, is economical and reasonable, and has strong operability.

[0080] Moreover, the mud filtering and water control method for water gushing in the goaf of the inclined longwall mining working face in the embodiment of the present invention can dynamically adjust the number and spacing of the mud filtering barriers 1 according to the total amount of water gushing in the goaf and the content of solid matter such as coal slime. It is easy to implement and has wide applicability.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A mud filtering and water control method for water inrush in goaf of inclined longwall mining working face, characterized in that: include: Before the roof rock layer of the goaf collapses, a filter mud barrier (1) is constructed on the bottom plate of the goaf, wherein the filter mud barrier (1) protrudes from the bottom plate of the goaf, and both ends of the filter mud barrier (1) extend along the inclined direction of the working face (3) to the coal ribs on both sides of the goaf; The filter mud barrier (1) comprises a bottom coal convex slope portion (11) located in the mined area and a retaining wall portion (12) located in the roadway, wherein the bottom coal convex slope portion (11) and the retaining wall portion (12) form an integrated structure; The construction of a filter mud barrier (1) on the floor of the goaf comprises: During the coal mining process, the bottom coal convex slope portion (11) is reserved on the bottom plate of the mined area; The retaining wall portion (12) is built on the bottom plate of the tunnel, the retaining wall portion (12) corresponds to the bottom coal convex slope portion (11), the end of the retaining wall portion (12) is connected to the end of the bottom coal convex slope portion (11) and the side wall of the tunnel, and the height of the retaining wall portion (12) is greater than or equal to the height of the bottom coal convex slope portion (11); Before reserving the bottom coal convex slope portion (11) on the bottom plate of the mined area, the method further comprises: Determining a preset width (E) and a preset height (H) of the bottom coal convex slope portion (11); Determining a preset spacing (N) between two adjacent bottom coal convex slope portions (11) and a preset number of the bottom coal convex slope portions (11); Determining the preset width (E) and the preset height (H) of the bottom coal convex slope portion (11) comprises: Determining a preset width (E) of the bottom coal convex slope portion (11); Determining the inclination angle of the bottom coal convex slope portion (11) relative to the bottom plate of the mined area according to the limit climbing angle of the coal mining equipment (2); Determining the preset height (H) according to the preset width (E) and the inclination angle of the bottom coal convex slope portion (11) relative to the floor of the mined area; Determining the preset spacing (N) between two adjacent bottom coal convex slope portions (11) and the preset number of the bottom coal convex slope portions (11) includes: Determining the preset amount by iterative calculation based on a calculation model for the final content of solid matter in the goaf water gushing out and a target content of solid matter in the goaf water gushing out; The preset spacing (N) is determined according to the preset number, the collapse step distance of the rock layer on the roof of the goaf and the preset width (E).

2. The method for filtering mud and controlling water inflow in goaf of inclined longwall mining working face according to claim 1, characterized in that: The filter mud barrier (1) is provided with a plurality of paths, and the plurality of filter mud barriers (1) are distributed at intervals along the mining direction.

3. The method for filtering mud and controlling water inflow in goaf of inclined longwall mining working face according to claim 1, characterized in that: The bottom coal convex slope portion (11) is reserved on the bottom plate of the mined area, comprising: Coal mining equipment (2) is controlled according to the preset width (E), the preset height (H), the preset spacing (N) and the preset number.

4. The method for filtering mud and controlling water inflow in goaf of inclined longwall mining working face according to claim 3, characterized in that: The coal mining control equipment (2) comprises: Adjust the height of the cutting part of the coal mining equipment (2).

5. The method for filtering mud and controlling water inflow in goaf of inclined longwall mining working face according to claim 1, characterized in that: The calculation model is: in, is the final content of solid matter in the goaf water when n filter mud barriers are set, is the initial content of solid matter in the goaf water, B is the roughness coefficient of the goaf floor, L is the collapse step distance of the goaf roof rock layer, the collapse step distance of the goaf roof rock layer is the distance between the initial end of the collapse section of the goaf roof rock layer and the working face, n is the number of filter mud barriers, E is the preset width of the bottom coal convex slope, α is the inclination angle of the goaf floor, V is the flow rate of the goaf water, The final content of solid matter in the goaf water when (n-1) filter mud barriers are set, and C and A are both constants.

6. The method for filtering mud and controlling water inflow in goaf of inclined longwall mining working face according to claim 1, characterized in that: The retaining wall portion (12) is constructed on the bottom plate of the tunnel, comprising: Sandbags or bricks are piled on the floor of the tunnel.

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