Collaborative method for mining, discharging and filling process flow of nearly-upright extra-thick coal seam

Abstract

A mining, releasing and filling process flow collaboration method for a nearly-upright super-thick coal seam belongs to the technical field of coal mining and comprises the following steps: dividing the nearly-upright super-thick coal seam into a plurality of sections, respectively establishing a low-level mining and releasing system at the bottom of each section, and respectively establishing a high-level filling system at the horizontal position of the top interface of each section; comprising a coal mining period and a filling period, after the low-position mining and caving system is established, coal mining and caving are carried out through a coal mining machine and a support in the coal mining period, in the machine following and support moving process, a novel support synchronously lays a separation net on a goaf, and after a filling step pitch is pushed forwards, the novel support unfolds slurry blocking cloth; then filling slurry is injected into the goaf through a high-position filling process roadway, a filling chamber and a filling hole in sequence, the stability of nearly upright surrounding rock is maintained, and it is ensured that the mining depth is safely extended; the method effectively solves the problems of difficulty in prevention and control of surrounding rock instability, difficulty in control of cutting type subsidence and low recovery rate of coal resources in the existing horizontal section fully mechanized caving mining method of the steeply inclined nearly-upright extra-thick coal seam.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mining, and specifically refers to a method for coordinating the mining, draining and filling processes of a nearly vertical and extra-thick coal seam. Background Art

[0002] Coal is my country's primary energy source. Currently, coal is mined using the horizontal, staged, fully mechanized caving method. Bottom coal is mechanized to cut and release top coal, creating a large, overhanging void. This creates a loss of support for the nearly vertical surrounding rock, and with increasing mining depth, poses a significant risk of sudden rock instability, leading to disasters. This presents challenges in preventing and controlling large-scale surrounding rock instability, controlling surface graben-like subsidence, and ensuring coal resource recovery rates. Shifting mining methods to ensure the safe extraction of high-quality coal resources is urgently needed. Backfill mining offers a reliable solution to these problems, but requires addressing the significant challenge of efficiently coordinating the mining and backfilling processes. Summary of the Invention

[0003] In order to overcome some of the problems mentioned in the above background, the present invention provides a method for coordinating the mining, draining and filling processes of a nearly vertical and extra-thick coal seam to at least partially solve the above problems.

[0004] According to the technical solution of the present invention, a method for coordinating the mining, caving and filling processes of a nearly vertical and extra-thick coal seam is provided, comprising the following steps:

[0005] Divide the nearly vertical extra-thick coal seam into multiple horizontal segments, establish low-level mining and caving systems at the bottom of each horizontal segment, and establish high-level filling systems at the horizontal positions of the top surfaces of each horizontal segment;

[0006] The method includes a coal mining period and a filling period. After the low-level mining and caving system is established, during the coal mining period, coal mining and caving work are carried out on the horizontal segment by a coal shearer and a top coal caving and filling mining hydraulic support. During the process of the coal shearer moving forward, a top coal caving and filling mining mesh slurry blocking support is used to lay an isolation net in the goaf. After the next filling step is reached and the coal shearer stops working, the top coal caving and filling mining mesh slurry blocking support is unfolded with a slurry blocking cloth. Then, during the filling period, a detection device is used to perform three-dimensional detection of the goaf to obtain the spatial contour, volume and amount of coal residue of the goaf. According to the information obtained, slurry preparation is carried out and slurry is injected into the goaf through the high-level filling process lane, the filling chamber and the filling detection hole in sequence during the filling period.

[0007] The low-level mining and caving system includes a coal mining machine and a caving mesh slurry retaining support. The coal mining machine and the caving mesh slurry retaining support are used to mine and caving coal in the horizontal segment. The caving mesh slurry retaining support is used to lay an isolation net on the floor of the goaf formed after caving coal in the horizontal segment. During the filling process of the goaf, the slurry retaining isolation cloth is deployed to ensure that the slurry does not leak during the filling process and affect the coal mining machine.

[0008] The high-position filling system includes a high-position filling process tunnel, a filling chamber, a filling detection hole and a slurrying system. The filling chambers are evenly distributed in the high-position filling process tunnel. The filling detection holes connect the filling chambers and the goaf. The slurrying system is connected to the filling chambers through the high-position filling process tunnel. The slurrying system is used to prepare filling slurry and transport the slurry to the filling chamber through the high-position filling process tunnel and then fill it into the goaf.

[0009] Furthermore, the horizontal segment height is 20-40m, the mining height of the coal mining machine is 2.5-4m, and the mining and filling step distance is (3-8): 1, that is, the filling step distance is to mine 3 to 8 pieces of coal, and the coal placing step distance is usually to place the top coal once after mining 2-3 pieces of bottom coal, that is, to fill the goaf once after mining 3-8 pieces of coal, so as to realize the coordination of mining, placing and filling processes.

[0010] Furthermore, the low-level mining and caving system is configured to perform bottom coal cutting, top coal caving and mesh laying cycles on the horizontal sections in sequence through the coal mining machine during the coal mining period, and to deploy the slurry blocking cloth through the mesh laying slurry blocking bracket after the coal mining period is completed.

[0011] Furthermore, the high-position filling system is deployed before the corresponding horizontal segmented coal mining. The high-position filling system is configured to first use the detection device to perform three-dimensional detection of the goaf through the filling detection hole during the filling period. After receiving the detection information of the detection device, the slurry system injects the filling slurry into the goaf in sequence through the high-position filling process lane, the filling chamber and the filling detection hole. After the grouting is completed, the filling detection hole is sealed and the slurry in the goaf is left to solidify.

[0012] Furthermore, before mining, the low-level mining and caving system detects the slurry filled in the previous filling period to ensure that the slurry filled in the previous filling period has been completely solidified, and implements filling body stability control through displacement monitoring optical fiber.

[0013] Furthermore, the steps of establishing a low-level mining and discharge system include excavating a cutting eye, a transport tunnel, a return air tunnel, a connecting tunnel, an auxiliary transport tunnel, a transport chute and a return air chute at the bottom of the current horizontal segment; wherein the transport chute connects the transport tunnel with the current horizontal segment, the return air chute connects the auxiliary transport tunnel and the return air tunnel with the current horizontal segment, the transport chute and the return air chute are connected through a connecting tunnel and a protective coal pillar is reserved, and the cutting eye is located at the boundary of the protective coal pillar.

[0014] Furthermore, adjacent horizontal segments adopt a staggered filling process so that the filling body between segments forms a staggered block structure, and the width of the goaf is 10 to 20 meters.

[0015] Furthermore, the mesh-laying and slurry-blocking support for top coal caving and backfilling mining comprises a top coal caving hydraulic support body, an automatic mesh-laying device and an isolation and slurry-blocking device;

[0016] The top coal caving hydraulic support is composed of an inverted four-link support body, a split shield beam mechanism, and a coal caving mechanism;

[0017] The inverted four-bar support body includes a load-bearing beam, an inverted four-bar linkage, two groups of hydraulic columns, and a base. The inverted four-bar linkage is hinged to the load-bearing beam, and the hinge angle is designed to be 15°-45°. The two groups of hydraulic columns include two front columns and two rear columns, which are respectively hinged to the load-bearing beam and the base.

[0018] Furthermore, the split shield beam mechanism includes a shield beam, a shield beam lifting column, a shield beam lifting cylinder, and a shield beam swing cylinder. The shield beam lifting column is hinged to the shield beam, and the shield beam lifting cylinder and shield beam swing cylinder are hinged to the shield beam and the base respectively.

[0019] The coal placing mechanism comprises a plug-in plate and a plug-in plate telescopic oil cylinder. The plug-in plate is inserted at the rear of the shield beam and can be extended and retracted by the plug-in plate telescopic oil cylinder.

[0020] Furthermore, it also includes a filling device, which is fixed in the filling chamber and includes a retractable pipe for transporting filling slurry to the goaf; the filling pipe is provided with a flow sensor, a high-definition camera, a pressure sensor and an explosion-proof monitor, the flow sensor is used to monitor the slurry flow in real time to regulate the slurry concentration and diffusion, the high-definition camera monitors the grouting status in real time and collects filling status images; the pressure sensor is used to monitor the pressure of the retractable pipe, and the explosion-proof monitor is used to integrate the control of flow and pressure parameters.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention divides the nearly vertical extra-thick coal seam into multiple horizontal segments, and then establishes a low-level mining and caving system and a high-level filling system respectively. The coal seam in the horizontal segment is cyclically implemented with the coordinated work of a coal mining machine, a mesh-laying slurry retaining support, a detection device and a grouting system, thereby realizing the coordinated operation of coal mining and filling, effectively reducing stress concentration and energy accumulation in the goaf, and improving the stability of the surrounding rock and the resource recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the horizontal sub-level fully-mechanized caving and filling mining system of this embodiment;

[0024] Figure 2 This is a flow chart of the mining and filling process of a nearly vertical extra-thick coal seam of this embodiment;

[0025] Figure 3 This is a schematic diagram of the block assembly filling of this embodiment;

[0026] Figure 4This is a functional schematic diagram of the top coal caving filling mesh slurry retaining structure of this embodiment;

[0027] Figure 5 Schematic diagram of the installation position of the distributed optical fiber displacement sensor of this embodiment;

[0028] Figure 6 This is a chart of the regular operation cycle of mining, discharging and charging in this embodiment;

[0029] Figure 7 This is a time sequence table for a complete process cycle in this embodiment.

[0030] In the figure, 1. Main inclined shaft; 2. Auxiliary shaft; 3. Transport stone gate; 4. Track main tunnel; 5. Coal chute; 6. Transport tunnel; 7. Connecting tunnel; 8. Return air tunnel; 9. Grouting material conveying tunnel; 10. Air shaft; 12. High-level filling process tunnel; 13. Slurry making system; 14. Block filling body; 15. High-level filling system; 16. Low-level mining and placing system; 17. Block bonding interface; 18. Segmented horizontal interface.

[0031] 101-bearing beam, 102-front column, 103-reverse four-bar linkage, 104-shielding beam lifting cylinder, 105-shielding beam lifting column, 106-shielding beam, 107-shielding beam swing cylinder, 108-slurry blocking cloth, 109-insert plate telescopic cylinder, 110-insert plate, 111-rear scraper conveyor, 112-fixed latch, 113-rotating shaft, 115-rear column, 116-base. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection.

[0033] like Figure 1-Figure 7 As shown, the distribution of the main inclined shaft 1, auxiliary shaft 2, transport stone gate 3, track main tunnel 4, coal chute 5, transport tunnel 6, connecting tunnel 7, return air tunnel 8, grouting material conveying tunnel 9, air shaft 10, high-level filling process tunnel 12, pulping system 13, block-type filling body 14, high-level filling system 15, low-level mining and setting system 16 and block bonding interface 17 in the embodiment of the present invention is disclosed, wherein Figure 6 This is a chart of a regular operation cycle of mining, discharging and charging according to an embodiment of the present invention. Figure 7 This is a time sequence table for a complete process cycle according to an embodiment of the present invention.

[0034] A specific embodiment of the present invention provides a method for coordinating the mining, caving and filling processes of a near-vertical and extra-thick coal seam, including the following steps:

[0035] The nearly vertical extra-thick coal seam is divided into multiple horizontal segments, a low-level mining and caving system 16 is established at the bottom of the horizontal segment, and a high-level filling system 15 is established at the horizontal position of the top surface of the horizontal segment;

[0036] The method includes a coal mining period and a filling period. After the low-level mining and caving system 16 is established, during the coal mining period, a coal shearer is used to mine and caving coal in the horizontal section. During the advance of the coal shearer, a mesh-laying slurry blocking support is used to lay an isolation mesh in the goaf. After the coal shearer stops working, the mesh-laying slurry blocking support unfolds a slurry blocking cloth 108. Then, during the filling period, a detection device is used to perform three-dimensional detection of the goaf to obtain the spatial contour, volume, and amount of coal residue in the goaf. Based on the information obtained, slurry is prepared and slurry is injected into the goaf in sequence during the filling period through the high-level filling process tunnel 12, the filling chamber, and the filling detection hole.

[0037] The low-level mining and caving system 16 includes a coal mining machine, a front scraper conveyor, a rear scraper conveyor, and a mesh slurry blocking support for top coal caving and filling. The mesh slurry blocking support is arranged on the coal mining machine. The coal mining machine is used to mine and caving coal in the horizontal segment. The mesh slurry blocking support is used to lay an isolation net on the floor of the goaf formed after the horizontal segment caving. The slurry blocking isolation cloth is deployed during the filling process of the goaf to ensure that the slurry does not leak during the filling process and affect the coal mining machine.

[0038] The high-position filling system 15 includes a high-position filling process tunnel 12, a filling chamber, a filling detection hole and a slurrying system 13. The filling chambers are evenly distributed in the high-position filling process tunnel 12. The filling detection holes connect the filling chambers and the goaf. The slurrying system 13 is connected to the filling chambers through the high-position filling process tunnel 12. The slurrying system 13 is used to prepare filling slurry and transport the slurry to the filling chamber through the high-position filling process tunnel 12 and then fill it into the goaf.

[0039] In a further implementation of this embodiment, the horizontal segment height is 20-40m, the mining height of the coal mining machine is 2.5-4m, and the mining and filling step distance is (3-8):1, that is, the filling step distance is to mine 3-8 bottom coals, and fill once after completing the top coal placement. The mining and placing step distance can be (1-2):1, that is, to mine 1-2 bottom coals and place the top coal once, so as to realize the coordination of mining, placing and filling processes.

[0040] In a further implementation of this embodiment, the low-level mining and caving system 16 is configured to perform bottom coal cutting, top coal caving and mesh laying cycles on the horizontal sections in sequence through the coal mining machine during the coal mining period, and after the coal mining period is completed, the mesh caving slurry blocking support is used to deploy the slurry blocking cloth 108 by caving the top coal for filling and mining.

[0041] In a further implementation of this embodiment, the high-position filling system 15 is deployed before the corresponding horizontal segmented coal mining. The high-position filling system 15 is configured to first use the detection device to perform three-dimensional detection of the goaf through the filling detection hole during the filling period. After receiving the detection information of the detection device, the slurry making system 13 injects the filling slurry into the goaf in sequence through the high-position filling process tunnel 12, the filling chamber and the filling detection hole. After the grouting is completed, the filling detection hole is sealed and the slurry in the goaf is left to solidify.

[0042] In a further implementation of this embodiment, the low-level mining and discharge system 16 detects the slurry filled in the previous filling period before mining to ensure that the slurry filled in the previous filling period has been solidified, and implements filling body stability control through displacement monitoring optical fiber.

[0043] In a further implementation of this embodiment, the step of establishing a low-level mining and discharge system 16 includes excavating a cutting eye, a transport tunnel 6, a return air tunnel 8, a connecting tunnel 7, an auxiliary transport tunnel, a transport chute and a return air chute at the bottom of the current horizontal segment; wherein the transport chute connects the transport tunnel 6 with the current horizontal segment, the return air chute connects the auxiliary transport tunnel and the return air tunnel 8 with the current horizontal segment, the transport chute and the return air chute are connected through the connecting tunnel 7 and a protective coal pillar is reserved, and the cutting eye is located at the boundary of the protective coal pillar.

[0044] In a further implementation of this embodiment, adjacent horizontal segments are filled with a staggered filling process so that the filling body between the segments forms a staggered block structure, and the width of the blocks is 3 to 8 meters.

[0045] In a further implementation of this embodiment, the mesh-laying and slurry-blocking support includes a top coal caving hydraulic support body, an automatic mesh-laying device and an isolation and slurry-blocking device.

[0046] The top coal caving hydraulic support consists of a reverse four-bar linkage support body, a split shield beam mechanism, and a coal caving mechanism. The reverse four-bar linkage support body includes a load-bearing beam 101, a reverse four-bar linkage mechanism 103, two sets of hydraulic columns, and a base 116. The reverse four-bar linkage mechanism 103 is hinged to the load-bearing beam 101, with an articulation angle designed to be 15°-45°. The two sets of hydraulic columns, two front columns 102 and two rear columns 115, are hinged to the load-bearing beam 101 and the base 116, respectively. The split shield beam mechanism consists of a shield beam 106, shield beam lifting columns 105, shield beam lifting cylinders 104, and shield beam swing cylinders 107. The shield beam lifting columns 105 are hinged to the shield beam 106, and two shield beam lifting cylinders 104 and two shield beam swing cylinders 107 are hinged to the shield beam 106 and the base 116, respectively. The split shield beam mechanism is removable and adjustable, allowing the shield beam 106 and telescopic beam to be adjusted to suit varying mining conditions. The coal caving mechanism includes a splice 110 and a splice telescopic cylinder 109. The splice 110 is inserted into the shield beam 106 from behind and can be extended or retracted to a specific length by the splice telescopic cylinder 109.

[0047] In a further implementation of this embodiment, the inverted four-bar linkage 103 controls the lifting and lowering of the height of the top coal caving hydraulic support. During the lifting process, the top coal caving hydraulic support has a certain offset in the horizontal direction, which causes interference between the load-bearing beam 101 and the shielding beam 106. The shielding beam lifting cylinder 104 should dynamically adjust the height of the shielding beam lifting column 105 according to the height H of the top coal caving hydraulic support to ensure that the top of the shielding beam 106 always maintains a safety gap of Δh = 50 mm or more with the load-bearing beam 101 to avoid interference.

[0048] The automatic mesh laying device consists of an isolation net, fixed pins 112, a rotating shaft 113, and an electric drive. The isolation net is made of graphene-coated polyester fiber and is wrapped around the rotating shaft 113. The rotating shaft 113 is fixed to the bottom of the top coal caving hydraulic support shield beam 106 by fixed pins 112. The isolation net can be deployed by rotating the electric drive.

[0049] The isolation slurry barrier device consists of a slurry barrier cloth 108, a fixing pin 112, a rotating shaft 113, and an electric drive device. The anti-leakage efficiency of slurry barriers 108 made of three different materials was tested under a pressure of 0.5 MPa and a duration of 2 hours. The results are shown in Table 1.

[0050] Table 1

[0051]

[0052] The test results show that graphene-coated polyester fiber slurry barrier cloth has the best anti-leakage performance, with a leakage rate of only 2.5% of that of ordinary nylon cloth, fully meeting the requirements of high-pressure filling conditions.

[0053] The preferred slurry barrier 108 adopts a five-layer composite structure, ① outer layer: graphene-coated polyester fiber (thickness 0.2mm); ② compression layer: aramid fiber woven mesh (thickness 0.5mm); ③ isolation layer: microporous PTFE membrane (thickness 0.1mm); ④ reinforcement layer: stainless steel wire mesh (thickness 0.3mm); ⑤ inner layer: wear-resistant polyurethane coating (thickness 0.4mm), total thickness 1.5mm, surface density 1800g / m 2 , blasting strength ≥1.2MPa.

[0054] The slurry retaining cloth 108 is laid flat on the shielding beam 106, and one end is wrapped around the rotating shaft 113. The rotating shaft 113 is fixed to the bottom of the shielding beam 106 of the top coal hydraulic support through the fixing pin 112. The isolation net can be rotated to unfold or retracted by an electric drive device. The electric drive device is arranged at the end of the plug plate 110, the middle of the shielding beam 106 and the rotating shaft 113, and can adjust the laying position, length and tension of the slurry retaining cloth 108.

[0055] Each device cooperates with others to execute the process actions, completing the process of coal placement, mesh laying, slurry blocking, etc. in the horizontal sub-level fully-mechanized caving and filling mining technology, and plays a role in controlling the stability of the filling body. The specific steps are as follows:

[0056] In the first step, the frame is moved after the coal mining process is completed, and the net laying process and the frame moving process are carried out simultaneously. When the hydraulic support for placing the top coal is moved forward, the rotating shaft 113 is rotated by the electric drive device, so that the isolation net is automatically unfolded and laid on the upper surface of the lower section coal seam. The isolation net is flattened during the subsequent process of pulling the rear scraper conveyor 111, and the full coverage of the upper surface of the lower section coal seam is completed as the working face advances.

[0057] The second step, coal caving, is performed after the coal mining and frame shifting processes. The top coal caving hydraulic support's shield beam swing cylinder 107 and the flapper extension and retraction cylinder 109 coordinate to rotate the shield beam 106 and retract the flapper 110. The top coal then falls out and is transported out of the working face via the rear scraper conveyor 111. Once the top coal is completely caving, the shield beam swing cylinder 107 and the flapper extension and retraction cylinder 109 coordinate to extend the shield beam 106 and extend the flapper 110. The conveyor's push-pull cylinder retracts the rear scraper conveyor 111. Coal caving is completed across the entire working face by caving the hydraulic supports individually or in groups.

[0058] The third step is to make the length greater than the sum of the length of the shielding beam 106 and the maximum extension length of the plug plate 110. By controlling the stroke of the shielding beam swing cylinder 107 and the plug plate telescopic cylinder 109, the slurry blocking cloth 108 is fixed at the bottom end of the plug plate 110. The electric drive device adjusts the tension of the slurry blocking cloth 108 according to the shape of the goaf, ranging from 50 to 200 N / m, and a tension sensor is set to monitor the force on the slurry blocking cloth 108 in real time.

[0059] The slurry blocking cloth 108 completely covers and fits the shield beam 106 tightly, and the shield beam lifting cylinder 104 controls the shield beam 106 to rise and block, ensuring that the slurry can be prevented from flowing into the support and the working surface.

[0060] The fourth step is to execute the filling grouting process, after which coal mining is carried out to start the next process cycle.

[0061] In a further implementation of this embodiment, it also includes a filling device, which is fixed in the filling chamber and includes a retractable pipe for transporting filling slurry to the goaf; the filling pipe is provided with a flow sensor, a high-definition camera, a pressure sensor and an explosion-proof monitor, the flow sensor is used to monitor the slurry flow in real time to regulate the slurry concentration and diffusion, the high-definition camera monitors the grouting status in real time and collects filling status images; the pressure sensor is used to monitor the pressure of the retractable pipe, and the explosion-proof monitor is used to integrate the control of flow and pressure parameters.

[0062] It should be noted that: after the low-level mining and caving system implements coal mining work during the coal mining period, it performs space detection and hole-by-hole filling technology in the filling chamber, and the top coal filling mining and mesh slurry blocking support are used to perform the slurry blocking technology. Combined with the stable control of the filling body, the overall process of nearly vertical and extra-thick coal seam mining and filling, which includes the "mining, caving, exploration, filling and control" technology, is formed. Through the organic coordination of low-level coal cutting, coal caving, mesh slurry blocking, high-level exploration and filling, fiber optic sensor laying and staggered filling technology, an integrated three-dimensional time-space connection and coordination method is formed to achieve the coordination of filling and mining of steeply inclined and extra-thick coal seams.

[0063] Under the support of the new type of mesh-laying slurry-blocking support, the bottom coal is mechanized cut by the coal mining machine, and the machine mining height is about 3m. The top coal is released by the coal-releasing mechanism of the new type of support. The coal-releasing step distance is comprehensively calculated based on parameters such as the segment height, bottom coal cutting footage, top coal hardness, and the stress degree of the filling weakened surrounding rock. The coal-releasing step distance ranges from 1:2 to 1:3, that is, the maximum coal-releasing step distance is to mine 3 cuts of bottom coal and release top coal once, realizing the coordination of mining and releasing processes.

[0064] The implementation of the high-position filling system 15 is as follows: first, a detection filling borehole is drilled in the filling chamber, and the detection robot is controlled to probe into the space after coal placement to perform spatial shape and volume detection, and the filling quantity parameters required for each filling position are transmitted to the feedback control system to complete the detection process. Then, the injection filling equipment, i.e., the filling device, is probed into the filling borehole, and the probe length, angle, and filling flow are adjusted. The filling status is monitored in real time and fed back to the core filling parameter dynamic feedback control system to adjust the parameters. The system passes the parameters to the pulping system 13 to control the material parameters to achieve differentiated performance control of the filling material, and realize intelligent and precise filling of the comprehensive caving space. After the filling is completed, the sealing process is implemented, and the detection process and the filling process are organically coordinated to achieve coordination of the high-position exploration and filling processes.

[0065] The method for coordinating the differentiated performance control of the filling body and the precise filling process relies on a detection and characterization robot, a probe injection filling equipment and a core filling parameter dynamic feedback control system. First, the detection and characterization robot obtains the shape and volume of the subsequent space, i.e., the goaf, and transmits the required filling quantity parameters of each filling position to the feedback control system. Then, the system transmits the parameters to the pulping system 13 to control the material parameters to achieve differentiated performance control of the filling material. Finally, the probe injection filling equipment controls the probe length, angle, and filling flow, and monitors the filling status in real time to feed back the adjustment parameters to the core filling parameter dynamic feedback control system, thereby jointly achieving the differentiated performance control of the filling body and the precise filling process.

[0066] Specifically, the backfill material parameter control is determined according to the following steps: First, the amount of quick-setting agent used in the backfill material is optimized and controlled based on the slurry-blocking effect of the horizontal segmented working face to prevent the backfill slurry from flowing into the front working face and the two tunnels. Then, based on the stability of the backfill body after initial setting and the monitoring parameters of the surrounding rock prevention and control effect, the backfill material strength, water seepage rate and other parameters are optimized to achieve the stability control of the backfill body and surrounding rock. After that, based on the volume and morphological characteristics of the top filling space, the expansion characteristic parameters of the backfill material are controlled to achieve the backfill material connecting to the top and achieving the high filling rate requirement. In addition, the strength of the backfill material needs to be adjusted accordingly with the deepening of the segment to meet the surrounding rock control requirements at different mining depths.

[0067] The method of coordinating the deployment of distributed fiber grating sensors with the staggered filling process of blocks is realized by coordinating with the exploration and filling process and regulating the parameters of the two-segment mining, placement, and filling. First, the deployment of distributed fiber grating sensors is used to monitor the displacement and deformation parameters of the filling body, which is completed during the exploration and filling process. Specifically, the deployment is carried out through the detection and filling borehole before the top filling space is filled. After the deployment is completed, the top filling space is filled with the quick-setting high-expansion filling material. The staggered filling process of blocks is completed when the mining and filling process is implemented in the next segment after the horizontal segment is extended downward. Specifically, the filling step is controlled to achieve the misalignment of the filling step boundary of the current step with the filling step boundary of the same position of the previous segment, so that the two block-type filling bodies formed after the current filling step and the next filling step of multiple horizontal segments jointly support the previous segment block, thereby achieving the effect of misalignment control of the stability of the block filling body. By monitoring the data of the distributed fiber Bragg grating sensors deployed in the previous section, the filling step distance and filling material strength are dynamically adjusted to meet the needs of filling body stability and surrounding rock stability control, thereby achieving coordination between the deployment of distributed fiber Bragg grating sensors and the staggered filling process of blocks.

[0068] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A collaborative method for mining, draining and filling processes in a nearly vertical and extra-thick coal seam, characterized in that: The following steps are involved: Divide the nearly vertical extra-thick coal seam into multiple horizontal segments, establish low-level mining and caving systems at the bottom of each horizontal segment, and establish high-level filling systems at the horizontal positions of the top interfaces of each horizontal segment; The method includes a coal mining period and a filling period. After the low-level mining and caving system is established, during the coal mining period, coal mining and caving work are carried out on the horizontal section by a coal shearer and a top coal caving filling mining mesh slurry retaining support. During the process of the coal shearer moving forward, the top coal caving filling mining mesh slurry retaining support lays an isolation net on the goaf. After a filling step is advanced and the coal shearer stops working, the top coal caving filling mining mesh slurry retaining support unfolds the slurry retaining cloth. Then, during the filling period, a detection device is used to perform three-dimensional detection of the goaf to obtain the spatial contour shape, volume and amount of residual coal of the goaf. According to the information obtained, slurry preparation is carried out and the slurry is injected into the goaf through the high-level filling process tunnel, the filling chamber and the filling detection hole in sequence during the filling period. The low-level mining and caving system includes a coal mining machine, a front scraper conveyor, a rear scraper conveyor, and a mesh slurry retaining support for top coal caving and filling. The coal mining machine is used to mine coal in horizontal sections. The mesh slurry retaining support for top coal caving is used to caving coal in horizontal sections and to lay an isolation net on the floor of the goaf formed after caving. During the filling process of the goaf, the slurry retaining isolation cloth is deployed to ensure that the slurry does not leak during the filling process and affect the working face. The high-position filling system includes a high-position filling process tunnel, a filling chamber, a filling detection hole and a slurrying system. The filling chambers are evenly distributed in the high-position filling process tunnel. The filling detection holes connect the filling chambers and the goaf. The slurrying system is connected to the filling chambers through the high-position filling process tunnel. The slurrying system is used to prepare filling slurry and transport the slurry to the filling chamber through the high-position filling process tunnel and then fill it into the goaf.

2. The collaborative method for mining, draining and filling processes of a near-vertical and extra-thick coal seam according to claim 1 is characterized in that: The horizontal segment height is 20-40m, the mining height of the coal mining machine is 2.5-4m, and the mining and filling step distance is (3-8):

1.

3. The collaborative method for mining, draining and filling processes of a near-vertical and extra-thick coal seam according to claim 1 is characterized in that: The low-level mining and caving system is configured to perform bottom coal cutting, top coal caving and mesh laying cycles on horizontal sections in sequence through a coal mining machine during the coal mining period, and to deploy a slurry blocking cloth through a mesh-laying slurry blocking bracket after the coal mining period is completed.

4. The method for coordinating the mining, draining and filling process of a nearly vertical and extra-thick coal seam according to claim 1 is characterized in that: The high-position filling system is deployed before the corresponding horizontal segmented coal mining. The high-position filling system is configured to first use the detection device to perform three-dimensional detection of the goaf through the filling detection hole during the filling period. After receiving the detection information of the detection device, the slurry system injects the filling slurry into the goaf in sequence through the high-position filling process lane, the filling chamber and the filling detection hole. After the grouting is completed, the filling detection hole is sealed and the slurry in the goaf is left to solidify.

5. The collaborative method for mining, draining and filling processes of a near-vertical and extra-thick coal seam according to claim 1 is characterized in that: Before mining, the low-level mining and caving system detects the slurry filled in the previous filling period to ensure that the slurry filled in the previous filling period has been completely solidified, and implements filling body stability control through displacement monitoring optical fiber.

6. The method for coordinating the mining, draining and filling process of a nearly vertical and extra-thick coal seam according to claim 1 is characterized in that: The steps of establishing the low-level mining and placing system include excavating a cutting hole, a transport tunnel, a return air tunnel, a connecting tunnel, an auxiliary transport tunnel, a transport chute and a return air chute at the bottom of the current horizontal segment; The transport chute connects the transport tunnel with the current horizontal section, the return air chute connects the auxiliary transport tunnel and the return air tunnel with the current horizontal section, the transport chute and the return air chute are connected through a connecting tunnel and a protective coal pillar is reserved, and the cutting eye is located at the boundary of the protective coal pillar.

7. The method for coordinating the mining, draining and filling process of a nearly vertical and extra-thick coal seam according to claim 1 is characterized in that: Adjacent horizontal segments adopt a staggered filling process, so that the filling body between segments forms a staggered block structure with a block width of 3 to 8m.

8. The method for coordinating the mining, draining and filling process of a nearly vertical and extra-thick coal seam according to claim 1 is characterized in that: The mesh-laying and slurry-blocking support for top coal caving and filling mining comprises a top coal caving hydraulic support, an automatic mesh-laying device and an isolation and slurry-blocking device; The top coal caving hydraulic support is composed of an inverted four-link support body, a split shield beam mechanism, and a coal caving mechanism; The inverted four-bar support body includes a load-bearing beam, an inverted four-bar linkage, two groups of hydraulic columns, and a base. The inverted four-bar linkage is hinged to the load-bearing beam, and the hinge angle is designed to be 15°-45°. The two groups of hydraulic columns include two front columns and two rear columns, which are respectively hinged to the load-bearing beam and the base.

9. The collaborative method for mining, draining and filling processes of a near-vertical and extra-thick coal seam according to claim 8 is characterized in that: The split shield beam mechanism includes a shield beam, a shield beam lifting column, a shield beam lifting cylinder, and a shield beam swing cylinder. The shield beam lifting column is hinged to the shield beam, and the shield beam lifting cylinder and shield beam swing cylinder are hinged to the shield beam and the base respectively. The coal placing mechanism comprises a plug-in plate and a plug-in plate telescopic oil cylinder. The plug-in plate is inserted at the rear of the shield beam and can be extended and retracted by the plug-in plate telescopic oil cylinder.

10. The method for coordinating the mining, draining and filling process of a nearly vertical and extra-thick coal seam according to claim 1 is characterized in that: It also includes a filling device, which is fixed in the filling chamber and includes a retractable pipe for transporting filling slurry to the goaf; the filling pipe is provided with a flow sensor, a high-definition camera, a pressure sensor and an explosion-proof monitor, the flow sensor is used to monitor the slurry flow in real time to regulate the slurry concentration and diffusion, the high-definition camera monitors the grouting status in real time and collects filling status images; the pressure sensor is used to monitor the pressure of the retractable pipe, and the explosion-proof monitor is used to integrate the control of flow and pressure parameters.

Images