Open-pit coal mine slope coal pressing collaborative filling mining method and open-pit coal mine slope coal pressing collaborative filling mining system

Abstract

The mining method comprises the following steps that S10, geological conditions of slope coal pressing resources of the open pit coal mine are investigated and researched, mining parameters of a slope mining cave (1) are designed and numbered in sequence, and the mining parameters comprise the width, the length and the dip angle; s20, mining the multiple mining caves (1) according to preset parameters and a specified mining mode by using slope coal mining equipment, and arranging filling drill holes (6) at intervals in each overlying step (2) above the mining caves (1); s30, a waste gangue throwing and filling machine (4) is used for throwing and filling the waste gangue stripped from the overlying step (2) of the open pit coal mine into the mined mining chamber (1) to form a pile body (5), and a mining chamber inlet (17) is closed after the pile body (5) is completed; and S40, a paste filling material (7) is injected into the mining cave (1) through the filling drill hole (6) until the filling drill hole (6) is full, the drill hole is closed, and the next mining cave (1) of the mining slope is filled repeatedly.

Description

Technical Field

[0001] The invention relates to the technical field of side wall coal mining in open-pit coal mines, and in particular to a side wall coal collaborative filling mining method and system for open-pit coal mines. Background Art

[0002] In recent years, the number and output of open-pit coal mines have gradually increased. Due to the limitations of mining technology, the amount of coal pressure on the side walls is large and the mining difficulty is high. The waste rock stripped from open-pit mining is gradually discharged to the internal dump as the working face moves, resulting in the burial of coal resources on the side walls, causing a large amount of coal resources to be wasted. At present, the main technologies for recovering side wall resources are tunnel mining or underground mining. The tunnel mining method requires a large number of coal pillars to be left. Under the action of the blasting power of open-pit coal mines, the possibility of coal pillar instability is high and the safety is low. The side wall resources of underground mining are affected by the original cracks, the pressure of fire prevention and extinguishing in the goaf is high, and resource recovery is difficult.

[0003] The backfill mining method has always been the optimal solution for recovering compressed coal resources in coal mines. However, the solid backfill mining method has a low filling rate and is difficult to achieve filling and top connection. The paste backfill mining method requires the open-pit side wall waste rock to be stripped and crushed into a slurry state before it can be filled into the mining shaft. The gangue crushing process is complicated and the power consumption is high. Therefore, the present invention proposes a method for collaborative filling and mining of solid and paste compressed coal on the side walls of open-pit coal mines. The advantages are complementary, the filling and top connection rate is improved, the amount of crushing of paste filled gangue is reduced, and the side wall compressed coal resources are recovered as much as possible through interval mining shaft cyclic backfill mining. Summary of the invention

[0004] In response to the problems and needs raised above, this solution proposes a method and system for collaborative filling and mining of side coal in open-pit coal mines. By adopting the following technical features, it can achieve the above-mentioned technical objectives and bring about many other technical effects.

[0005] One object of the present invention is to provide a method for mining open-pit coal mines by slab-coal compaction and coordinated backfilling, comprising the following steps:

[0006] S10: Investigate the geological conditions of the sidewall coal resources in the open-pit coal mine, design the mining parameters of the sidewall mining tunnels, and number them in sequence, where the mining parameters include width, length and inclination;

[0007] S20: using the side coal mining equipment to mine multiple mining tunnels according to preset parameters and designated mining methods, and arranging filling drill holes at intervals on each overlying step above the mining tunnels;

[0008] S30: Use a gangue filling machine to throw and fill the abandoned gangue stripped from the overlying steps of the open-pit coal mine into the mined mining tunnel to form a pile, and close the entrance of the mining tunnel after the pile is completed;

[0009] S40: injecting the paste filling material into the mining tunnel through the filling borehole until it is full, closing the borehole, and repeating the filling process for the next side mining tunnel that has been mined.

[0010] In addition, the open-pit coal mine side wall pressure coal collaborative filling mining method according to the present invention can also have the following technical features:

[0011] In an example of the present invention, in step S10, the width of the mining tunnel is determined by the side coal mining equipment and the stability of the overlying step, and the width of the mining tunnel is maintained at 3m to 6m; the length of the mining tunnel is determined by the boundary range of the open-pit mine, and the length of the mining tunnel should not exceed 400m, and the inclination of the mining tunnel should be downward, with an angle of 0 to 10°.

[0012] In an example of the present invention, in step S20, the designated mining method of multiple mining tunnels is: after mining the previous mining tunnel in sequence, the next mining tunnel is mined at intervals of an integral multiple of the width of the mining tunnel.

[0013] In one example of the present invention, the calculation expression for mining the next mining tunnel at intervals equal to an integral multiple of the mining tunnel width is:

[0014]

[0015] Where: [N] is the multiple of the width of the mining tunnel, which is automatically rounded; Q is the width of the plastic zone of the coal pillar, d is the width of the mining tunnel, H is the height of the coal body, γ is the bulk density of the overlying rock mass, and k is the peak pressure coefficient, which is taken as 2.5. is the internal friction angle of coal body, and c is the cohesion of coal body.

[0016] In an example of the present invention, in step S20, filling boreholes are arranged at equal intervals at each overlying step (2) above the mining tunnel, and the distance between two adjacent filling boreholes is less than or equal to 150m.

[0017] In an example of the present invention, in step S30, the height of the pile is determined according to the ejection trajectory of the waste rock filler, so that the distance between the waste rock pile and the top plate completed by the waste rock filler is less than 0.8m.

[0018] In one example of the present invention, the ejection trajectory of the waste rock filling machine includes the maximum ejection distance S and the waste rock height h s , which is expressed as follows:

[0019]

[0020] Where: h is the height of the pile after the gangue filler is completed, c is the safety distance of the gangue filler, which is 1.5m, θ is the inclination angle of the gangue filler, which is generally 13-25°, v is the ejection speed, which is generally 2.5-10m / s, h pis the height of the waste rock dumping platform, and g is the acceleration due to gravity.

[0021] In an example of the present invention, in step S30, a retaining wall is used to close the entrance of the mining tunnel, and a ventilation hole connected to the outside is provided on the retaining wall.

[0022] In one example of the present invention, in step S40, whether the paste filling material is fully injected into the mining tunnel is comprehensively judged based on the grouting pressure and the slurry level observed through the ventilation holes on the retaining wall.

[0023] Another object of the present invention is to provide a mining system for the open-pit coal mine side wall pressure coal collaborative filling mining method as described above, comprising:

[0024] A mining parameter design unit is configured to investigate the geological conditions of the sidewall coal resources of the open-pit coal mine, design the mining parameters of the sidewall mining tunnel, and number them in sequence, wherein the mining parameters include width, length and inclination;

[0025] The mining unit is configured to complete mining of multiple mining shafts according to preset parameters and a specified mining method using sidewall mining equipment, and to arrange filling boreholes at intervals at each overlying step above the mining shafts;

[0026] The first mining tunnel filling unit is configured to use a gangue filling machine to throw and fill the abandoned gangue stripped from the overlying steps of the open-pit coal mine into the mined mining tunnel to form a pile, and to close the mining tunnel entrance after the pile is completed;

[0027] The second mining tunnel filling unit is configured to inject the paste filling material into the mining tunnel through the filling borehole until it is full, close the borehole, and repeat the filling of the next side mining tunnel that has been mined.

[0028] The beneficial effects of the present invention are as follows: the present invention mines the side wall coal resources of the open-pit coal mine by means of interval mining and cyclic filling, without leaving coal pillars in the middle, and has strong ability to withstand overburden loads and blasting dynamics, and has high safety. In addition, a large amount of side wall stripping waste rock is consumed by throwing away gangue solid filling, and the top connection rate is improved by paste filling slurry, which combines the advantages of solid filling mining and paste filling mining, reduces the amount of gangue crushing and processing, and improves the filling efficiency. It achieves a harmonious win-win situation between mine solid waste disposal and resource recovery, improves the overall stripping ratio of open-pit coal mines, and has high economic benefits.

[0029] The best embodiment for carrying out the present invention will be described in more detail below with reference to the accompanying drawings so that the features and advantages of the present invention can be easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention, wherein the drawings are only used to illustrate some embodiments of the present invention, but not to limit all embodiments of the present invention thereto.

[0031] Figure 1 It is a flow chart of a method for collaborative filling mining of sidewall coal in an open-pit coal mine according to an embodiment of the present invention;

[0032] Figure 2 A schematic cross-sectional diagram of coal-filling mining in an open-pit coal mine according to an embodiment of the present invention;

[0033] Figure 3 for Figure 1 A partial enlarged view of point I in the middle;

[0034] Figure 4 It is a schematic diagram of cyclic filling mining in the side wall coal compression interval mining of an open-pit coal mine according to an embodiment of the present invention.

[0035] List of reference numerals:

[0036] Mining tunnel 1;

[0037] Overlying step 2;

[0038] Belt conveyor 3;

[0039] Gangue filling machine 4;

[0040] Heap 5;

[0041] Filling the borehole 6;

[0042] Paste filling material 7;

[0043] Retaining wall 8;

[0044] 1# mining tunnel 9;

[0045] 2# mining tunnel 10;

[0046] 3# mining tunnel 11;

[0047] 4# mining tunnel 12;

[0048] 5# mining tunnel 13;

[0049] 6# mining tunnel 14;

[0050] 7# mining tunnel 15;

[0051] 8# mining tunnel 16;

[0052] Mining entrance 17;

[0053] Width of mining tunnel D. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the technical solution of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in conjunction with the drawings of specific embodiments of the present invention. The same figure marks in the drawings represent the same parts. It should be noted that the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second" and similar words used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "one" do not necessarily indicate a quantity limitation. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0056] According to the first aspect of the present invention, an open-pit coal mine side wall pressure coal collaborative filling mining method is as follows: Figures 1 to 4 As shown, the following steps are included:

[0057] S10: Investigate the geological conditions of the sidewall coal resources of the open-pit coal mine, design the mining parameters of the sidewall mining tunnel 1, and number them in sequence, where the mining parameters include width, length and inclination;

[0058] S20: using the side coal mining equipment to mine the multiple mining tunnels 1 according to the preset parameters and the specified mining method, and arranging the filling drill holes 6 at intervals at each overlying step 2 above the mining tunnels 1;

[0059] S30: Use the gangue filling machine 4 to strip the waste gangue from the overlying step 2 of the open-pit coal mine and throw it into the mined mining tunnel 1 to form a pile 5, and close the entrance of the mining tunnel 1 after the pile 5 is completed; for example, the belt conveyor 3 is connected to the gangue filling machine 4, which is used to transport the gangue transported by the belt conveyor 3 to the gangue filling machine 4, and throw it to form a pile 5; it should be noted that Figure 2 The direction of the arrow in the mining tunnel 1 is the moving direction of the waste rock filling machine 4.

[0060] S40: inject the paste filling material 7 into the mining tunnel 1 through the filling borehole 6 until it is full, close the borehole, and repeat the filling process for the next side mining tunnel 1 that has been mined.

[0061] This mining method mines the side wall coal resources of open-pit coal mines by filling and backfilling in intervals, without leaving coal pillars in the middle. It has strong ability to withstand overburden loads and blasting dynamics, and is highly safe. In addition, a large amount of side wall stripping waste rock is consumed by throwing gangue solid filling, and the top connection rate is improved by filling with paste. It combines the advantages of solid filling mining and paste filling mining, reduces the amount of gangue crushing and processing, and improves the filling efficiency. It achieves a harmonious win-win situation between mine solid waste disposal and resource recovery, improves the overall stripping ratio of open-pit coal mines, and has high economic benefits.

[0062] In one example of the present invention, Figure 2 As shown, in step S10, the width of the mining shaft 1 is determined by the side coal mining equipment and the stability of the overlying step 2, and the width of the mining shaft 1 is maintained at 3m to 6m; the length of the mining shaft 1 is determined by the boundary range of the open-pit mine, and the length of the mining shaft 1 should not exceed 400m, and the inclination of the mining shaft 1 should be downward, with an angle of 0 to 10°.

[0063] In one example of the present invention, Figure 4 As shown, in the step S20, the designated mining method of the multiple mining tunnels 1 is: after the previous mining tunnel 1 is mined in sequence, the next mining tunnel 1 is mined at intervals of an integral multiple of the width of the mining tunnel 1;

[0064] The spacing between the two mining shafts 1 for front and rear mining is an integral multiple of the width of the mining shaft 1 in order to prevent the influence of the unfilled top mining shaft 1; in this way, the stress concentration area can be avoided and the mining shaft can be mined within the elastic area, which is highly safe.

[0065] In one example of the present invention, the calculation expression for mining the next mining tunnel 1 at intervals equal to an integral multiple of the width of mining tunnel 1 is:

[0066]

[0067] Where: [N] is the multiple of the width of mining tunnel 1, which is automatically rounded; Q is the width of the plastic zone of the coal pillar, d is the width of mining tunnel 1, H is the height of the coal body, γ is the bulk density of the overlying rock mass, and k is the peak pressure coefficient, which is taken as 2.5. is the internal friction angle of coal body, and c is the cohesion of coal body.

[0068] In one example of the present invention, in step S20, filling boreholes 6 are arranged at equal intervals at each overlying step 2 above the mining tunnel 1, and the interval between two adjacent filling boreholes 6 is less than or equal to 150m;

[0069] The equal spacing of the filling boreholes 6 is determined by the flow properties of the paste filling material 7; the flow diffusion diameter of the paste filling material 7 is greater than or equal to the borehole spacing, ensuring that the slurry can completely cover the unconnected area above the mining tunnel 1 without leaving any gaps.

[0070] In one example of the present invention, Figure 3 As shown, in the step S30, the height of the pile 5 is determined according to the ejection trajectory of the waste rock filler 4, so that the distance between the waste rock pile 5 and the top plate after the waste rock filler 4 is completed is less than 0.8m.

[0071] Since it is impossible for the waste rock to connect to the top, considering the projection angle and safety of the waste rock filling body, a range of 0.8m at the top is reserved to ensure the smooth progress of the waste rock filling operation, and the subsequent paste filling slurry can seal this space.

[0072] In one example of the present invention, the ejection trajectory of the waste rock filling machine 4 includes the maximum ejection distance S and the waste rock height h s , which is expressed as follows:

[0073]

[0074] Where: h is the height of the pile 5 after the completion of the gangue filler 4, c is the safety distance of the gangue filler 4, which is 1.5m, θ is the projection angle of the gangue filler 4, which is generally 13-25°, v is the projection speed, which is generally 2.5-10m / s, h p is the height of the waste rock dumping platform, and g is the acceleration due to gravity.

[0075] In one example of the present invention, in step S30, the entrance of the mining tunnel 1 is closed by using a retaining wall 8, and a ventilation hole connected to the outside is provided on the retaining wall 8;

[0076] Ventilation holes are provided for ventilation and observation of the filling condition of the mining tunnel 1;

[0077] For example, the retaining wall 8 may be a cement wall;

[0078] It should be noted that there is no specific regulation on the material of the retaining wall 8 , as long as the mining tunnel 1 has a sealing effect.

[0079] In one example of the present invention, in the step S40, whether the paste filling material 7 is filled in the mining tunnel 1 is determined comprehensively based on the grouting pressure and the slurry level observed through the ventilation holes on the retaining wall 8;

[0080] Specifically, the drilling grouting pressure first increases, indicating that the voids in the mining tunnel are basically filled. Then, the distribution of the slurry is observed through the ventilation holes on the retaining wall to see whether it reaches the top, thereby determining the injection status of the paste filling material.

[0081] According to the second aspect of the present invention, a mining system of the open-pit coal mine side wall pressure coal collaborative filling mining method as described above comprises:

[0082] The mining parameter design unit is configured to investigate the geological conditions of the side wall coal resources of the open-pit coal mine, design the mining parameters of the side wall mining tunnel 1, and number them in sequence, wherein the mining parameters include width, length and inclination;

[0083] The mining unit is configured to complete mining of multiple mining shafts 1 according to preset parameters and a specified mining method using sidewall mining equipment, and to arrange filling boreholes 6 at intervals at each overlying step 2 above the mining shafts 1;

[0084] The first mining tunnel filling unit is configured to use a gangue filling machine 4 to strip the waste gangue from the overlying step 2 of the open-pit coal mine and projectile fill it into the mined mining tunnel 1 to form a pile 5, and to close the mining tunnel entrance 17 after the pile 5 is completed;

[0085] The second mining tunnel filling unit is configured to inject the paste filling material 7 into the mining tunnel 1 through the filling borehole 6 until it is full, close the borehole, and repeat the filling of the next side mining tunnel 1 that has been mined.

[0086] This mining method mines the side wall coal resources of open-pit coal mines by filling and backfilling in intervals, without leaving coal pillars in the middle. It has strong ability to withstand overburden loads and blasting dynamics, and is highly safe. In addition, a large amount of side wall stripping waste rock is consumed by throwing gangue solid filling, and the top connection rate is improved by filling with paste. It combines the advantages of solid filling mining and paste filling mining, reduces the amount of gangue crushing and processing, and improves the filling efficiency. It achieves a harmonious win-win situation between mine solid waste disposal and resource recovery, improves the overall stripping ratio of open-pit coal mines, and has high economic benefits.

[0087] Specific examples

[0088] The average thickness of the No. 11 coal seam on the southern side of an open-pit mine is 4.47m. The overlying rock strata are in the reverse direction and have good stability. The mining area is about 182,000m 2 , about 1.6km long from east to west and about 200m long from north to south. When the open-pit mining direction in this area changes from north to south to east to west, the eastern sidewall will be drained inward, causing permanent loss of coal resources covered by the southern sidewall, and it is urgent to mine it by sidewall coal mining method. The specific steps are as follows:

[0089] Step 1: According to the survey, the mining width of the existing complete set of intelligent and safe mining equipment for side coal is 3.3m, and the appropriate downward inclination angle is 0-7°. Combined with the mining experience of similar geological conditions in this mining area, when the width of side filling mining shaft 1 is 3.3m, the roof can remain stable without support. It is comprehensively determined that the width of mining shaft 1 is 3.3m and the length is 320m, and mining shaft 1 is numbered one by one in sequence as 1# mining shaft 9, 2# mining shaft 10, 3# mining shaft 11, ..., 8#. (This embodiment only shows 8 mining shafts, and the specific number of mining shafts is subject to actual conditions)

[0090] Step 2: Use side coal mining equipment to mine No. 1 mining shaft 9. After mining is completed, arrange a borehole every 100m on the overlying step 2, and arrange a total of 3 paste grouting boreholes. Calculate the result of the calculation expression for mining the next mining shaft according to the integer multiples of the interval mining shaft width D. The multiple of the interval mining shaft width D is 3 times, that is, after the mining of No. 1 mining shaft 9 is completed, No. 5 mining shaft 13 can be mined. The mining order is No. 1 mining shaft 9→No. 5 mining shaft 13→No. 2 mining shaft 10→No. 6 mining shaft 14→No. 3 mining shaft 11→No. 7 mining shaft 15→No. 4 mining shaft 12→No. 8 mining shaft 16.

[0091] Step 3: Use the belt conveyor 3 and the waste rock filling machine 4 to strip the waste rock from the overlying step 2 of the open-pit coal mine and fill it into the mined No. 1 mining shaft 9. The inclination angle of the waste rock filling machine 4 is 20°, the ejection speed is 8 m / s, and the ejection distance is 8 m. According to formula (2), the height of the pile 5 is 3.74 m, the distance from the top plate is 730 mm, and the filling rate is 83%, forming a waste rock filling pile 5. After the waste rock filling of No. 1 mining shaft 9 is completed, the retaining wall 8 is used to close the mining shaft entrance 17.

[0092] Step 4: The waste rock stripped from the side walls is crushed and processed to form a paste filling slurry, which is then transported to No. 1 mining tunnel 9 through the pre-arranged vertical borehole until it is full and the borehole is closed, completing the filling operation. According to the second, third, and fourth steps, mining and filling are carried out in a cycle until the resource recovery in the area is completed, and the filling operation lags behind the mining operation.

[0093] The paste filling slurry used in this embodiment has a mass concentration of 78%, gangue: cement: fly ash = 72: 8: 20, the gangue particle size is less than 10mm, and the 28d strength can reach 5MPa. By adopting this method and system, the open-pit mine consumes about 500,000 t / a of waste rock stripping from the sidewalls, of which the amount of crushed gangue required for paste filling materials is only 150,000 t / a, and the remaining consumed gangue can be directly transported and thrown into the mining tunnel, reducing the transportation pressure, crushing processing volume and power consumption of the internal and external dumping sites. At the same time, the paste filling slurry is used to improve the top connection rate of the mining tunnel, and the top connection rate can reach more than 90%. Combining the advantages of solid filling mining and paste filling mining, compared with the single filling mining method, the filling coal mining efficiency is higher, the annual output is 463,800 t / a, and the economic benefits are better.

[0094] The exemplary implementation scheme of the open-pit coal mine side wall coal compression and collaborative filling mining method and system proposed in the present invention is described in detail above with reference to the preferred embodiments. However, those skilled in the art will understand that, without departing from the concept of the present invention, various modifications and variations can be made to the above-mentioned specific embodiments, and various technical features and structures proposed in the present invention can be combined in various ways without exceeding the protection scope of the present invention. The protection scope of the present invention is determined by the attached claims.

Claims

1. A method for mining open-pit coal mines by using sidewall coal pressure and coordinated filling, characterized in that: The steps include: S10: Investigate the geological conditions of the sidewall coal resources of the open-pit coal mine, design the mining parameters of the sidewall mining tunnel (1), and number them in sequence, wherein the mining parameters include width, length and inclination; S20: using side coal mining equipment to mine the multiple mining tunnels (1) according to preset parameters and a designated mining method, and arranging filling holes (6) at intervals at each overlying step (2) above the mining tunnels (1); S30: using a gangue filling machine (4) to strip the waste gangue from the overlying step (2) of the open-pit coal mine and projectile fill it into the mined tunnel (1) to form a pile (5), and after the pile (5) is completed, the entrance (17) of the mining tunnel is closed; S40: injecting the paste filling material (7) into the mining tunnel (1) through the filling borehole (6) until it is full, closing the borehole, and repeating the process to fill the next side mining tunnel (1) that has been mined.

2. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 1 is characterized in that: In step S10, the width of the mining tunnel (1) is determined by the side coal mining equipment and the stability of the overlying step (2), and the width of the mining tunnel (1) is maintained at 3m to 6m; the length of the mining tunnel (1) is determined by the boundary range of the open-pit mine, and the length of the mining tunnel (1) should not exceed 400m. The inclination angle of the mining tunnel (1) should be downward, with an angle of 0 to 10°.

3. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 1 is characterized in that: In step S20, the designated mining method of the plurality of mining shafts (1) is: after the previous mining shaft (1) is mined in sequence, the next mining shaft (1) is mined at intervals equal to an integral multiple of the width (D) of the mining shaft.

4. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 3 is characterized in that: The calculation expression for mining the next mining tunnel (1) at an interval of an integer multiple of the mining tunnel width (D) is: Where: [N] is the multiple of the width of the mining tunnel (D), which is automatically rounded; Q is the width of the plastic zone of the coal pillar, d is the width of the mining tunnel (D), H is the height of the coal body, γ is the bulk density of the overlying rock mass, and k is the peak pressure coefficient, which is taken as 2.

5. is the internal friction angle of coal body, and c is the cohesion of coal body.

5. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 1 is characterized in that: In the step S20, filling boreholes (6) are arranged at equal intervals on each overlying step (2) above the mining tunnel (1), and the distance between two adjacent filling boreholes (6) is less than or equal to 150m.

6. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 1 is characterized in that: In the step S30, the height of the pile (5) is determined according to the projection trajectory of the waste rock filler (4), so that the distance between the waste rock pile (5) and the top plate completed by the waste rock filler (4) is less than 0.8m.

7. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 6 is characterized in that: The ejection trajectory of the waste rock filling machine (4) includes a maximum ejection distance S and a waste rock height h. s , which is expressed as follows: Where: h is the height of the pile (5) after the completion of the dumping and filling machine (4), c is the safety distance of the dumping and filling machine (4), which is 1.5m, θ is the dumping and filling machine (4) dumping inclination angle, which is generally 13-25°, v is the dumping speed, which is generally 2.5-10m / s, h p is the height of the waste rock dumping platform, and g is the acceleration due to gravity.

8. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 1 is characterized in that: In the step S30, a retaining wall (8) is used to close the mining entrance (17), and a ventilation hole communicating with the outside is provided on the retaining wall (8).

9. The open-pit coal mine side wall pressure coal collaborative filling mining method according to claim 8, characterized in that: In the step S40, whether the paste filling material (7) is filled in the mining tunnel (1) is determined comprehensively based on the grouting pressure and the slurry level observed through the ventilation holes on the retaining wall (8).

10. A mining system for the open-pit coal mine sidewall coal pressure coordinated filling mining method adopted in any one of claims 1 to 9, characterized in that: include: A mining parameter design unit is configured to investigate geological conditions of side wall coal resources in an open-pit coal mine, design mining parameters of side wall mining tunnels (1), and number them in sequence, wherein the mining parameters include width, length and inclination; A mining unit is configured to complete mining of multiple mining chambers (1) according to preset parameters and a specified mining method using sidewall mining equipment, and to arrange filling boreholes (6) at intervals at each overlying step (2) above the mining chambers (1); The first mining tunnel filling unit is configured to use a gangue filling machine (4) to strip the waste gangue from the overlying step (2) of the open-pit coal mine and projectile fill it into the mined mining tunnel (1) to form a pile (5), and to close the mining tunnel entrance (17) after the pile (5) is completed; The second mining tunnel filling unit is configured to inject the paste filling material (7) into the mining tunnel (1) through the filling borehole (6) until it is full, close the borehole, and repeat the filling of the next side mining tunnel (1) that has been mined.

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