Steeply inclined coal seam group drilling-fracturing-migration-transportation-filling collaborative mining process

Abstract

The present application relates to coal seam mining technical field, disclose a steep coal seam group drill-crack-move-transportation-filling collaborative mining process, first in the underground coal seam arrangement transportation roadway and complete ventilation, power supply configuration, at the same time, establish operation platform on the ground;Through the reverse drilling machine construction guide hole, reverse reaming form open cut, as the free surface of directional fracturing;Along the coal seam strike in turn interval arrangement borehole, and from bottom to top sectional implementation directional fracturing, form coal;Then through the underground hydraulic support and scraper conveyor collaborative work to the coal continuous transportation;With the mining advance, interval distance set coal pillar, and to the goaf filling, to maintain the stability of roof and floor strata.The present application through each process in the spatial position, operation sequence and function on the mutual cooperation, form the ground well linkage collaborative mining process system, significantly improve the safety, continuity and resource recovery rate of steep coal seam group mining, have good engineering application value.

Description

Technical Field

[0001] This invention relates to the field of coal seam mining technology, and in particular to a coordinated mining process for steeply inclined coal seams involving drilling, fracturing, moving, transporting, and filling. Background Technology

[0002] my country possesses abundant high-quality, scarce coking coal in its steeply dipping coal seams, characterized by strong coking properties, low sulfur, and low ash content. In terms of total resources, these coals are plentiful and widely distributed, primarily concentrated in western and southern my country, possessing enormous development potential and long-term supply capacity. However, due to the generally greater than 45° dip angles, reaching over 80° in some areas, and the relatively thin seam thickness (mostly between 0.8 and 1.5 meters), their unique geological conditions result in extremely difficult development, posing a series of severe challenges to the safe, efficient, and green development of coal resources.

[0003] Due to factors such as complex geological structures, narrow working spaces, and poor roof and floor stability, the safe and efficient mining of steeply inclined coal seams has always been a century-old challenge for the coal industry. Currently, for steeply inclined, very thick, and extra-thick coal seams, the main technologies used are horizontal segmented fully mechanized longwall mining and pseudo-inclined fully mechanized mining. Traditional blasting and manual segmented mining methods have low levels of mechanization, harsh working environments, high labor intensity, high safety risks, and are difficult to achieve continuous production. In steeply inclined thin and medium-thick coal seams, the applicability of the above methods is significantly reduced due to the dual constraints of coal seam thickness and dip angle, and they generally suffer from problems such as limited construction space, difficulty in controlling surrounding rock, harsh working environments, and low mining efficiency. Especially for steeply inclined thin coal seams, due to the thin seam thickness and limited working space, conventional fully mechanized mining, longwall mining, and segmented mining processes designed for medium-thick or thick coal seams are difficult to deploy complete sets of mining equipment. Support and transportation equipment also struggle to achieve effective coordination within thin coal seams. Furthermore, mechanical cutting operations easily cause excessive disturbance to the surrounding rock, severe coal-rock mixing, and a large amount of marginal coal, resulting in low resource recovery rates, large deformation of the surrounding rock, and high safety risks. In conclusion, existing mining technologies and equipment primarily designed for medium-thick and thick coal seams are difficult to directly apply to steeply inclined coal seam groups.

[0004] To address this, a collaborative mining process of drilling-fracture-movement-transportation-filling is proposed for steeply inclined coal seams. Summary of the Invention

[0005] The specific problem this invention aims to solve is how to achieve safe and efficient mining of steeply inclined coal seams. Addressing the challenges of large dip angles, limited coal seam space, poor surrounding rock stability, and the limited adaptability of traditional mining techniques, this invention proposes a systematic closed-loop mining process centered on multi-process spatiotemporal coordination and underground well operation linkage, aiming to achieve safe, efficient, and green mining of steeply inclined coal seams.

[0006] To address the aforementioned problems, this invention employs a coordinated drilling-fracture-transfer-transportation-filling mining process for steeply inclined coal seams. The entire process comprises two parts: surface and underground. The surface part primarily utilizes mechanical equipment for drilling, fracturing, and filling operations; the underground part arranges self-propelled hydraulic supports and a coal transport system within the roadways for transportation. This invention does not combine isolated operational steps, but rather represents a systematic and holistic design centered around the mining process of steeply inclined coal seams. Each step is interconnected, requiring coordinated operation during mining. Specific parameters mentioned herein, such as roadway dimensions, borehole diameter, reverse-pull-out cut size, working face dimensions, and coal pillar width, need to be specifically designed based on the actual geological conditions of the coal seam.

[0007] First, a transport roadway is constructed within the underground coal seam, and self-propelled supports and scraper conveyors are arranged within it to provide space for coal flow transportation and surface operations. Then, a guide hole is drilled downwards along the coal seam's dip using a riser drilling rig. After the guide hole connects to the roadway, a reverse-pull cutterhead is installed. The hole is enlarged through reverse-pull operations to form an opening, serving as a free face for ejecting the fractured coal mass. Next, fracturing operations are carried out progressively along the coal seam's strike. A directional drilling rig drills fracturing boreholes into the coal seam, and fracturing pipes are placed inside the boreholes. From bottom to top, segmented and directional fracturing is used to eject the broken coal mass towards the opening, achieving segmented fracturing along the coal seam's strike. The amount of coal falling onto the scraper conveyor is controlled by the coal drop outlet at the top of the self-propelled support, and the scraper conveyor transports the coal to the surface, achieving continuous coal flow transportation. Finally, to prevent roof and floor subsidence, a coal pillar of a certain width is left after the first working face is mined, before the next working face mining cycle. Solid waste is then used to backfill the goaf on the surface, forming a stable backfill body to ensure the stability of the rock strata. The entire process is implemented according to the above steps. Each operation link is interdependent and cyclically promoted in terms of spatial location, operation sequence and function, forming a drilling-fracture-movement-transportation-filling well linkage and collaborative mining process suitable for steeply inclined coal seam groups.

[0008] In the overall process flow, the drilling stage involves two aspects: reverse-pull opening of the cut-out and drilling fracturing. The reverse-pull drilling operation creates the cut-out, forming a free face to provide the necessary space for subsequent fracturing and coal dropping. The fracturing process is based on the drilling stage. Directional fracturing tubes are placed into the borehole, and segmented directional fracturing is carried out from bottom to top. Under impact, the broken coal body is thrown into the cut-out and lands above the self-moving support. The support shifting and transportation processes move continuously as the working face advances. The hydraulic support maintains the stability of the roof and, by controlling the opening of the self-moving support, allows coal to fall onto the scraper conveyor, achieving continuous coal transportation under support conditions. The backfilling process is carried out after the working face is mined out. Special solid waste materials are used to backfill the goaf. This is done to maintain the stability of the roof and floor strata, reduce surface deformation, and isolate the lower-level coal body from air, preventing spontaneous combustion and providing a foundation for the next level of mining. The above-mentioned processes form a closed loop in terms of time sequence, spatial location, and function. No single process can be separated from the overall process to complete the safe and efficient mining of steeply inclined coal seams independently.

[0009] Under steeply inclined coal seam conditions, due to the large dip angle and limited space, conventional coal mining faces and supporting mining equipment are difficult to arrange along the coal seam, and the surrounding rock stability is poor. If isolated drilling, fracturing, support, or backfilling operations are used, continuous advancement cannot be achieved while ensuring safety. Therefore, this invention does not improve a single operation, but rather, based on the aforementioned objective engineering constraints, it holistically designs the spatial structure and operational sequence of each process—drilling, fracturing, moving, transporting, and backfilling—so that each process mutually restricts and supports each other.

[0010] If conventional sequential or isolated mining processes are used in steeply inclined coal seam groups, the following problems are likely to occur: lack of stable free surfaces for fracturing leads to uncontrolled fracture propagation; mismatch between support and transportation timing causes localized unsupported roofs or coal pile-ups; and failure to form effective support in the goaf in a timely manner leads to increased deformation of the surrounding rock, thereby forcing operation to stop or even causing safety accidents. The drilling-fracturing-moving-transporting-filling coordinated mining process of this invention allows each process to proceed cyclically based on the formation of stable boundary conditions, avoiding the aforementioned engineering failure problems.

[0011] Based on the above overall concept, this invention provides a coordinated mining process for steeply inclined coal seams involving drilling, fracturing, moving, transporting, and filling, including... (a) Construction of surface drilling groups: On the surface of the steeply inclined coal seam mining area, several groups of surface vertical wells or directional wells are arranged along the coal seam strike to form a drilling group network that runs through the surface to the bottom of the coal seam group. (II) Construction of underground roadway system: A centralized transport roadway is arranged in the bottom rock of the coal seam group, and a segmented transport roadway is arranged in each coal seam. The roadway is connected to the centralized transport roadway through the connecting roadway to form a fully enclosed underground transport system. (III): Drilling-Fracturing-Transfer-Refilling Coordinated Operation: Using the surface well as a channel, directional fracturing is carried out on the coal seam from bottom to top; the pre-fractured coal body slides along the dip angle of the coal seam under gravity to the segmented transport roadway; the coal that has slid and converged to the segmented transport roadway is precisely controlled by setting adjustable-angle hydraulic gates or flow control valves at the entrance of the segmented transport roadway to balance the load of the scraper conveyor. Finally, it is transferred to the centralized transport roadway by large crushing and transfer equipment, and continuously transported to the surface washing and beneficiation system by underground belt conveyor; the solid waste generated by the surface washing and beneficiation system or the gangue from underground tunneling is crushed and processed, and then pumped back into the mined-out area through a dedicated filling pipeline.

[0012] (iv) The continuous cycle operation line adopts the “staggered parallel operation” method: that is, within the same mining area, there is at least one working face in the drilling stage, one working face in the fracturing mining and transportation stage, and one working face in the filling stage, and each process does not interfere with each other in time and space, so as to achieve parallel mining and filling.

[0013] Specifically, it includes the following steps: Step 1: Mining Preparation; Mining preparation involves: On the surface of the steeply dipping coal seam mining area, arranging several sets of vertical or directional wells along the coal seam strike to form a drilling network connecting the surface to the coal seam floor; arranging centralized haulage roadways in the coal seam floor rock, and segmented haulage roadways in each coal seam, connected to the centralized haulage roadway via connecting roadways to form a fully enclosed underground haulage system; installing mining equipment at both the underground mining location and the surface mining area; The underground system layout begins in the stable area of ​​the coal seam floor, where a tunneling machine is used to excavate along the designed strike to form haulage roadways. These haulage roadways are used for personnel and equipment passage, coal ore removal, and the centralized arrangement of ventilation, power supply, and drainage systems. During the excavation of the haulage roadways, necessary support is provided according to the surrounding rock conditions to ensure roadway stability. After the haulage roadway is excavated, the ventilation system, power supply system, drainage system, and coal transport system are installed and commissioned sequentially within the roadway. Then, self-propelled supports and scraper conveyors are assembled at the underground coal mining location. A belt conveyor is installed at the tail end of the scraper conveyor, and its head is connected to the pre-reserved transfer interface in the haulage roadway to form a continuous coal transport system. All underground equipment undergoes a no-load test run after installation to ensure normal system operation. For the surface site layout, the corresponding surface area of ​​the mining area is first leveled and reinforced to form a stable working platform. The following surface equipment is then installed and positioned sequentially: a raise boring machine and a directional drilling machine; an electro-blasting control system for rock-breaking energy control; and a cement silo and filling pump. After all equipment is installed, its fixing, positioning verification, and safety protection settings are completed.

[0014] Step Two: Drilling. A pullback drilling rig is used on a surface working platform to construct a pilot hole along a predetermined axis. After the pilot hole connects to the transport roadway, the reverse-pull cutterhead is replaced to perform reverse reaming, forming an opening through the coal seam thickness, serving as a stable free surface for directional fracturing. After completing mining preparation and system layout, the pullback drilling rig is installed on the surface working platform. The position and direction of the drilling axis are determined based on the coal seam's dip angle, thickness, and the target mining section. In the initial stage, the drill bit is installed on the pullback drilling rig, and the pilot hole is constructed along the predetermined axis using rotary drilling. The pilot hole is used to determine the center position and extension direction of the opening, and provides a guiding channel for subsequent reverse reaming operations. Once the pilot hole connects to the roadway, drilling is stopped, the drill bit is disassembled, and the reverse-pull cutterhead is replaced. After the reverse-pull cutterhead is connected and fixed to the drill pipe, the pullback drilling rig is started to perform reverse reaming operations along the pilot hole, gradually enlarging the hole diameter to form an opening with the designed diameter and height inside the coal seam. The cutting hole penetrates the thickness of the coal seam, and its spatial location and geometry are designed based on the single advance step distance and fracturing range, serving as a stable free surface for subsequent directional fracturing of the coal. The cutting hole not only provides free space for coal fracturing but also defines the direction of fracturing energy release and the fracture propagation boundary. The arrangement, orientation, and fracturing sequence of the fracturing holes are all based on the cutting hole as a spatial reference, and the advance step distance of the self-moving support and scraper conveyor is also matched to the length of the single fracturing unit corresponding to the cutting hole.

[0015] Step 3, fracturing: A directional drilling rig is used to drill fracturing holes along the dip of the coal seam. Fracturing tubes are arranged within these holes, and directional fracturing is carried out in stages from bottom to top, causing the coal body to fracture quantitatively, directionally, and controllably in a predetermined direction, forming fracturing coal drop. Several fracturing holes are drilled along the dip of the coal seam on one side of the cut-out. The orientation, depth, and spacing of the fracturing holes are designed based on the coal seam structure characteristics, coal body integrity, and single-stage advance distance, ensuring that the single fracturing range forms a controlled fracturing unit. Isolating coal pillars are set between adjacent fracturing areas to achieve zoned fracturing and staged advancement.

[0016] After the fracturing borehole is constructed, a fracturing tube is installed inside. A closed reaction chamber is formed inside the fracturing tube, filled with liquid carbon dioxide, in which combustible metal powder is dispersed in suspension. An electro-explosion ignition unit, including a metal wire, is installed inside the fracturing tube to achieve constant-pressure directional release. After the fracturing tube is placed in the fracturing borehole, the borehole is sealed. Before fracturing operations, underground personnel are evacuated from the fracturing area. After confirming that no personnel remain in the work area and that ventilation and monitoring parameters meet safety requirements, ground personnel remotely issue a detonation command through the detonation control system. The metal wire undergoes an electro-explosion, generating a transient shock wave that creates initial fractures in the coal seam. Subsequently, the suspended metal powder deflagrates and heats the liquid carbon dioxide, causing it to undergo phase change expansion. When the pressure inside the reaction chamber reaches the threshold set by the constant-pressure directional release unit, the high-pressure gas is released directionally and, under the induction of the open-cut free surface, pushes the fractures to expand along a preset direction, causing quantitative, directional, and controllable fracturing of the coal seam, resulting in fracturing coal drop.

[0017] The above-mentioned fracturing process is carried out in a segmented sequence from bottom to top. After each segment of fracturing is completed, the coal falling situation and the stability of the surrounding rock are confirmed. Once the conditions are met, the coal transportation step begins.

[0018] Step four: Moving the self-moving supports; During and after the fracturing operation, the self-moving supports on one side of the fracturing area move in stages along the mining advance direction. The advancing step distance of the self-moving supports matches the length of the fracturing unit and the length of the filling section. During and after the fracturing and coal breaking operation, self-moving supports are arranged along the coal seam dip on one side of the fracturing area. The self-moving supports provide continuous protection for the working area during fracturing and coal transportation to prevent coal body instability or surrounding rock spalling. After completing one round of fracturing and coal transportation operations, the self-moving supports move forward in stages according to the predetermined advancing step distance, so that the support range moves forward synchronously, providing a safe working space for the next round of fracturing hole construction and fracturing operations.

[0019] Step 5: Transporting the fractured coal seam. Under the continuous protection of the self-moving support, the fractured coal seam is fed into the scraper conveyor. The scraper conveyor and belt conveyor continuously transport the fractured coal seam out of the mining area. Under the protection of the self-moving support, the fractured coal seam formed by fracturing is allowed to fall naturally or be guided into the scraper conveyor. The scraper conveyor is arranged along the dip of the coal seam, and its advancing direction is consistent with the advancing direction of the self-moving support. It continuously transports the coal seam to the tail end and transfers it to the belt conveyor. The belt conveyor transports the coal seam to the external transport system in the transport roadway, realizing continuous external transport of the coal seam.

[0020] During the initial setup phase, the self-propelled support and scraper conveyor are arranged side-by-side along one side of the working face, positioning the scraper conveyor below the natural falling area of ​​the fractured coal. The centerline of the scraper conveyor chute remains stable with the projected position of the front beam of the self-propelled support, ensuring that the coal body formed after fracturing can directly enter the conveying system within the support shielding range, avoiding coal pile-up and secondary coal cleaning operations under unsupported conditions.

[0021] During the coordinated advancement of the conveyors, the following parameters need to be controlled synchronously: the support advancement speed should be controlled at ≤0.2m / min to avoid disturbance to the top plate caused by rapid advancement; the scraper conveyor 5 should be briefly paused before advancement, and restarted after advancement is completed and the support is confirmed to be in place; the pressure change of the support cylinder should be monitored in real time during advancement to prevent instability or slippage; after advancement is completed, the connection status of the scraper conveyor chute should be checked to ensure chain tension and smooth operation.

[0022] After the self-propelled support and scraper conveyor advance and move out, a goaf gradually forms behind them. The advance step distance is set to be consistent with the length of the fracturing unit, making the spatial shape of the goaf regular and continuous, which facilitates subsequent zonal and layered filling by filling pumps. By controlling the synchronous advancement of the self-propelled support and scraper conveyor, the formation rhythm of the goaf is matched with the filling rhythm of the filling body, avoiding the formation of large-span unsupported roof areas, thereby providing stable rear conditions for the next round of fracturing and advancing operations.

[0023] The coordinated propulsion of the self-moving support and scraper conveyor not only undertakes the functions of support and transportation, but also connects the two key processes of fracturing and filling. Its propulsion parameters directly determine the length of the fracturing unit, the spatial morphology of the goaf, and the filling sequence, thus having a decisive impact on the continuity and safety of the entire drilling-fracturing-moving-transporting-filling cycle.

[0024] Step 6: Filling the goaf; As the self-propelled support and scraper conveyor advance and move out, a goaf is gradually formed behind them. Filling material is transported into the goaf generated by the work in steps 3 to 5, and compacted and consolidated to form a filling body.

[0025] In the first cycle, a cement silo and filling pump are set up in the surface working area to form a filling system. In subsequent cycles, when the haulage roadway becomes the new working face, a cement silo and filling pump are set up in the haulage roadway to form a filling system. The cement silo is used to store cementing materials, and the filling pump is used to transport the filling material to the goaf. Coal gangue, exposed overburden, or other solid waste is mixed with cementing materials and water to form filling material, which is then transported to the goaf by the filling pump. After compaction and consolidation, it forms a filling body to support the surrounding rock and control the deformation of the goaf.

[0026] Through the aforementioned filling parameters and timing control, the filling body provides continuous support to the goaf after its formation, stabilizing the redistribution of surrounding rock stress and thus providing a clear rear stability boundary for the next round of fracturing operations. Under these conditions, the subsequent arrangement of fracturing holes and the range of fracturing energy loading can be precisely controlled based on the boundary of the formed filling body, preventing the disorderly expansion of fractures into the goaf and improving the controllability and safety of fracturing coal breaking.

[0027] In the overall mining process of this invention, the goaf filling and the self-moving support advance form a strict time-series linkage relationship. The support advance forms the goaf, and the filling operation quickly follows to form the filling body. The filling body stabilizes the surrounding rock in the reverse direction and constrains the subsequent fracture boundary.

[0028] Through the above-mentioned linkage control, the drilling-fracture-movement-transportation-filling processes form a closed loop and coordinate, ensuring the continuity and overall stability of the mining process under steeply inclined coal seam conditions.

[0029] Step 7: Cyclic Advancement and Layered Continuous Mining; Steps 2 to 6 constitute a complete drilling-fracture-transfer-transport-filling mining cycle. The cyclic steps are repeated. The continuous cyclic operation line adopts the "staggered parallel operation" method, that is, within the same mining area, different working faces are respectively in the drilling, fracturing mining, transfer, and filling stages. Each process does not interfere with each other in time and space, and the line of sight mining and filling are carried out in parallel. After each cycle is completed, the self-moving support, scraper conveyor and belt conveyor advance one step distance synchronously. After the goaf is formed, it is stably supported by the filling body to achieve continuous advancement. After the first layer is mined, the formed transport roadway is retained as the working channel for the lower coal seam. The mining equipment is rearranged, and the lower coal seam is continuously mined according to the same drilling-fracture-transfer-transport-filling process. Layered and continuous mining of steeply inclined coal seam groups is carried out.

[0030] Steps four and five are performed together.

[0031] Preferably, step one includes Step 1.1: In the stable area of ​​the coal seam floor, a tunneling machine is used to excavate to form a transport roadway. A ventilation system, power supply system, drainage system and coal flow transport system are installed in the transport roadway and debugged. A self-moving support and scraper conveyor are assembled at the underground coal mining position. The tail end of the scraper conveyor is connected to a belt conveyor to form a continuous coal transport system. Step 1.2: Level and reinforce the corresponding mining area on the ground to form a working platform, and install ground equipment, including a raise boring machine, a directional drilling machine, an electro-blasting control system for rock breaking energy control, a cement silo, and a filling pump.

[0032] Preferably, the directional fracturing in step three includes arranging a fracturing tube inside the fracturing hole, forming a closed reaction chamber inside the fracturing tube, filling the reaction chamber with liquid carbon dioxide, and dispersing combustible metal powder in a suspended state in the liquid carbon dioxide, setting an electric explosion activation unit inside the fracturing tube; setting a constant pressure energy release unit inside the fracturing tube; sealing the fracturing tube after its installation; and, after confirming safety, remotely controlling the electric explosion activation unit through the detonation control system by ground personnel, pushing the fracture to expand along a preset direction under the induction effect of the free surface of the cut hole, causing quantitative, directional, and controllable fracturing of the coal body, forming fracturing coal drop.

[0033] Preferably, the scraper conveyor and the self-moving support are mechanically linked by a pushing device. The arrangement direction and advancing step distance of the scraper conveyor are consistent with those of the self-moving support, and the center line of the scraper conveyor chute is set to correspond to the projection of the front beam of the self-moving support.

[0034] Preferably, in step six, the filling operation begins within 2 hours after the formation of the goaf, and the filling height of the filling body is not less than 0.9 times the coal seam mining height. The filling operation is carried out in a zoned and layered manner, with each layer having a filling thickness of 0.5m to 0.7m. The pumping pressure of the filling pump 18 is 2 to 6MPa. After the filling body is formed, the natural consolidation time is not less than 24 hours. After reaching the initial stable state, the next cycle of mining operation is carried out.

[0035] Preferably, the filling material in step six includes solid aggregate and cementing material. The solid aggregate is one or two of coal gangue and open-pit stripped rock and soil. The particle size of the solid aggregate is not greater than 50 mm. The mass of the cementing material is 8% of the mass of the solid aggregate. The water-cement ratio of the cementing material is 0.6. The volume concentration of the cementing material slurry is not less than 70%.

[0036] Preferably, in step one, anchor bolts, anchor cables and metal mesh are used to support the transport roadway according to the surrounding rock conditions. After the equipment in the transport roadway is installed, it is run under no-load test. After the equipment in the surface mining area is arranged, it is fixed, positioned and checked and protected for safety.

[0037] Preferably, in step four, the advancing speed of the self-moving support is no more than 0.2 m / min. The scraper conveyor is stopped before advancing, and the scraper conveyor is restarted after the advancement is completed and the support is confirmed to be in place.

[0038] The present invention discloses the following technical effects: This invention uses a reverse drilling rig to create an open hole as a stable free surface, and combines it with directional drilling to induce fracturing, so that the coal body fractures in a preset direction and range, avoiding the problem of uncontrollable fracturing range in traditional blasting, and effectively reducing disturbance to slopes and surrounding rock.

[0039] By using borehole fracturing instead of large-scale explosive blasting, and with the addition of mobile shield and support devices that advance with mining operations, the safety risks to personnel and equipment under steeply inclined coal seams are significantly reduced, and the safety of operations under complex coal seam conditions is improved.

[0040] By controlling the range of coal body fracturing through directional and quantitative fracturing, the phenomenon of coal-rock mixing can be effectively reduced, the coal resource recovery rate can be improved, and the impact on the overburden can be avoided, preventing the overburden from collapsing and becoming unstable. This method is suitable for thin coal seams and coal seams with frequent thickness changes.

[0041] After the upper coal seam is mined, the existing transport roadway can be used directly as the working face for the lower coal seam, which facilitates the mining of the next coal seam and enables the continuous, cyclical, and continuous mining of multiple coal seams or layered coal bodies, significantly improving the mine's production continuity capacity and overall resource recovery rate.

[0042] This invention organically couples drilling, fracturing, support movement, coal flow transportation, and goaf filling. Through the mutual coordination of each process in terms of spatial location, operation sequence, and function, a drilling-fracturing-movement-carrying well linkage and collaborative mining process is formed, creating a continuous operation process. This overcomes the problem of low efficiency in the traditional intermittent mining and loading of steeply inclined coal seams and improves overall production efficiency. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the integrated drilling-fracture-movement-transportation-filling well collaborative mining process of the present invention; Figure 2 This is a schematic diagram of the self-moving support and scraper conveyor structure in the transport tunnel of the present invention; Figure 3 This is a schematic diagram of the hole-cutting construction state of the reverse drilling rig of the present invention; Figure 4 This is a cross-sectional view of the drilling operation state of the reverse drilling rig of the present invention; Figure 5 A schematic diagram of the construction process for directional drilling to induce coal flow through fractured holes; Figure 6 A schematic diagram illustrating the process of gradually removing the self-moving support and scraper conveyor in a cyclical manner; Figure 7 This is a schematic diagram illustrating the state of filling the goaf area according to the present invention; Among them, 1. Coal seam; 2. Surrounding rock; 3. Tunneling machine; 4. Self-propelled support; 5. Scraper conveyor; 6. Raised shaft drilling rig; 7. Reverse pull cutterhead; 8. Pilot hole; 9. Directional drilling rig; 10. Cutting hole; 11. Fracturing coal drop; 12. Isolation coal pillar; 13. Gangue; 14. Goaf; 15. Filling body; 16. Fracturing hole; 17. Cement silo; 18. Filling pump; 19. Belt conveyor; 20. Transport roadway; 21. Fracturing pipe; 22. Detonation control system. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] This implementation method focuses on steeply inclined thin coal seams. By constructing stable free surfaces within the coal seam and implementing directional, segmented, and controllable fracturing, combined with support, transportation, and backfilling, the safe and continuous recovery of the coal body is achieved.

[0048] In this embodiment, coal seam 1 has a dip angle of 70° and an average thickness of 1.2m. The surrounding rock 2 is a medium-stability interbedded sandstone and mudstone structure. The working face advances along the strike of coal seam 1. The specific process is as follows: I. Mining Preparation and System Layout First, the underground system layout was carried out. In the stable area of ​​the coal seam floor, tunneling machine 3 was used to excavate and form transport roadway 20. Transport roadway 20 has a cross-sectional width of 4.2m and a height of 3.5m, serving as a passageway for personnel and equipment, and also for the centralized arrangement of coal transport, ventilation, power supply, and drainage systems. After transport roadway 20 was completed, a combination of anchor bolts, anchor cables, and metal mesh support was implemented based on the surrounding rock conditions to ensure the long-term stability of the roadway.

[0049] After the construction of transport roadway 20 is completed, the ventilation system, power supply system, and drainage system are installed sequentially within the roadway, and a coal transfer interface is reserved. A belt conveyor 19 is installed within transport roadway 20 for continuous transfer with the subsequent scraper conveyor 5.

[0050] The self-propelled support 4 and scraper conveyor 5 are then transported into the transport tunnel 20 and assembled in place at the working face. The self-propelled support 4 has a single-frame width of 1.25m, a support height of 1.0–1.6m, and a rated working resistance of not less than 3000kN. The scraper conveyor 5 has a trough width of 630mm, a rated conveying capacity of not less than 300t / h, and its arrangement direction is consistent with the advancing direction of the self-propelled support 4. The tail end of the scraper conveyor 5 connects continuously with the belt conveyor 19 for transfer.

[0051] At the same time, the site was leveled and reinforced in the corresponding mining area on the ground to form a stable working platform for the installation of the raise boring machine 6, directional drilling machine 9, detonation control system 22, cement silo 17 and filling pump 18, and the equipment foundation was fixed and the positioning was checked.

[0052] II. Construction of the Raise-Drill Rig and Opening the Hole After the system layout is completed, the riser 6 is accurately positioned on the ground working platform, and the central axis of the opening hole 10 is determined according to the spatial location of the coal seam 1.

[0053] The raise boring machine 6 employs raise boring equipment with reverse reaming capability. Its rated drilling torque is no less than 120 kN·m, and its maximum thrust-pull force is no less than 2000 kN, meeting the requirements for through drilling and reverse reaming operations in steeply inclined coal seams. The drill pipe is a high-strength hollow drill pipe, with a single pipe length of 3.0 m and an outer diameter of [missing information]. A 168mm continuous drill string, connected by threads, is used to transmit drilling torque and axial thrust, and serves as a stable guiding structure for pilot hole 8 and the reaming stage. The drill bit is used to construct pilot hole 8, and its outer diameter is... 216mm, with a wear-resistant alloy structure, suitable for stable drilling in coal seams and interbedded rock conditions; the reverse-pull cutterhead 7 is used for reverse hole reaming, and its outer diameter is... The 1200mm cutterhead features evenly distributed cutting teeth for continuous cutting of the coal seam during reverse borehole reaming. The riser rig 6 is equipped with a monitoring and parameter display system to monitor drilling torque, feed rate, drilling pressure, and borehole deviation in real time, ensuring that the borehole axis accuracy meets the spatial requirements for subsequent fracturing.

[0054] On the ground working platform corresponding to the mining area, the central axis position of the opening 10 is determined based on the spatial location, dip angle, and thickness of coal seam 1. The hole position is accurately projected onto the ground working platform through measurement and layout, and the raise boring machine 6 is positioned.

[0055] After the drilling rig is in place, the rig base is leveled and fixed, ensuring the verticality error of the rig's vertical shaft is no greater than 1 / 1000 and the deviation between the rig center and the designed hole position is no greater than 20mm. After completing the positioning verification, a no-load test is performed on each system of the drilling rig to confirm that the transmission, hydraulic, and monitoring systems are operating normally.

[0056] After the drilling rig is positioned, the raise boring machine 6 installs the drill bit and begins drilling the pilot hole 8. The main function of the pilot hole 8 is to determine the spatial position and axial direction of the opening hole 10, and to provide a stable guiding channel for subsequent reverse reaming. During the drilling of the pilot hole 8, the drilling speed is controlled at 60-120 r / min, the axial drilling speed is controlled at 0.3-0.6 m / min, and the drilling pressure is adjusted in real time according to the coal body strength to keep the drilling process stable and continuous, avoiding hole deviation or hole wall collapse.

[0057] The pilot hole 8 is drilled along the predetermined axis and penetrates the thickness of coal seam 1. After entering the stable rock strata at the bottom, drilling continues for 0.5–1.0 m to improve the axial stability during subsequent reverse borehole enlargement. After drilling is completed, the pilot hole 8 is inspected and its inclination is measured. The inclination deviation is controlled within ≤1 / 200.

[0058] After completing the pilot hole 8, drilling operations are stopped, the drill bit is disassembled, and a reverse pull cutterhead 7 is installed at the lower end of the drill pipe. The reverse pull cutterhead 7 is fixed to the drill pipe via a flange or threaded connection. Rotation and fixing checks are performed to ensure reliable connection. Then, the raise boring machine 6 is started to perform reverse reaming operations. During reverse reaming, the reverse pull cutterhead 7 cuts the coal body from bottom to top along the axis of the pilot hole 8, gradually enlarging the hole diameter to form the open cutterhead 10. During reverse reaming, the reaming speed is controlled at 20–40 r / min, and the lifting speed is controlled at 0.1–0.3 m / min. Parameters are adjusted by real-time monitoring of drilling torque and vibration to prevent cutterhead jamming or local overcutting.

[0059] Once the reverse reaming reaches the designed height, stop the reaming operation and inspect the opening 10. The diameter of the opening 10 is controlled as follows: 1200mm±50mm, axis offset not greater than 50mm, hole wall continuous and intact, no obvious diameter reduction or hole collapse.

[0060] The loose coal and rock within a 2m radius of the cut hole 10 should be cleared, and if necessary, the unstable areas should be simply repaired to ensure the continuity and stability of the cut hole 10 as the free surface for fracturing.

[0061] After inspection and confirmation that the incision hole 10 meets the requirements for spatial size, stability and positional accuracy, it is put into use as the main control free surface for subsequent fracturing hole 16 arrangement and directional fracturing operation.

[0062] In the overall process of this invention, the cutting eye 10 not only provides free space for coal fracturing, but also defines the release direction of fracturing energy and the boundary of fracture expansion. The arrangement position, orientation, and fracturing sequence of the fracturing holes 16 are all based on the cutting eye 10 as a spatial reference, and the advancing step distance of the self-moving support 4 and the scraper conveyor 5 are also matched with the length of the single fracturing unit corresponding to the cutting eye 10.

[0063] Through the above equipment configuration, operation procedures and parameter control, the opening hole 10 constructed by the riser drilling rig can stably and reliably provide the necessary space conditions for subsequent drilling-fracking-moving-charging-filling coordinated mining, thereby ensuring the continuity and safety of the overall process.

[0064] III. Directional drilling and segmented controlled fracturing of coal seams Using the cut-out 10 as the free surface, a fracture-inducing hole 16 is drilled within coal seam 1 using a directional drilling rig 9. The diameter of fracture-inducing hole 16 is... The 75mm diameter holes have a depth of 18m, a spacing of 1.5m between holes, and a row spacing of 1.8m. The fracturing holes 16 are arranged in staggered rows along the strike of coal seam 1, so that the direction of fracture propagation is towards the incision hole 10. A 2.0m wide isolation coal pillar 12 is set between adjacent fracturing areas for zoned fracturing and step-by-step advancement.

[0065] After fracturing hole 16 is formed, the hole is cleaned, and fracturing tube 21 is inserted into it. The effective working length of a single section of fracturing tube 21 is 1.5m. Fracturing operations are carried out in sections from bottom to top, with each section being 3.0m long. Each section of fracturing tube 21 is filled with 1.2kg of liquid carbon dioxide, and the combustible metal powder is dispersed in a suspended state within the liquid carbon dioxide. The electro-explosion activation unit is connected by metal wires and equipped with a constant pressure energy release unit. After fracturing tube 21 is inserted, fracturing hole 16 is sealed, with a sealing length of 1.0m.

[0066] In the fracturing operation, the electro-explosive fracturing uses a low-voltage, high-current transient discharge electro-explosive method to excite the metal wire in the fracturing tube 21. The electro-explosive parameters and detonation conditions are determined as follows.

[0067] The metal wire is made of a metal material with stable conductivity. The metal wire has a diameter of 0.30 mm and a length of 120 mm. Both ends are connected to the electric explosion excitation unit in the fracturing tube 21 through wires, and form a complete circuit with the detonation control system 22.

[0068] The detonation control system 22 adopts a centralized electric detonation control device with an output voltage of 24–48V, an instantaneous discharge current of 3–6kA, and a single discharge duration of 50–200µs. At the moment of detonation, the current passes through the metal wire, causing it to melt and vaporize in a very short time, forming a high-temperature and high-pressure plasma, thereby generating a transient shock wave inside the fracturing tube 21.

[0069] The peak pressure of the transient shock wave is not less than 100 MPa, and the duration is controlled within the range of 0.1 to 1 ms. It is used to form an initial microfracture network in the coal body and to provide fracture initiation conditions for subsequent energy loading.

[0070] After electrical explosion, the suspended metal powder inside the fracturing tube 21 undergoes a rapid deflagration reaction, releasing heat and heating the liquid carbon dioxide, causing the liquid carbon dioxide to undergo phase change expansion. When the internal pressure of the fracturing tube 21 rises to the constant pressure energy release threshold of 20-30 MPa, the constant pressure energy release unit is activated, and the high-pressure gas is released in a preset direction.

[0071] Under the induction effect of the free surface formed by the cut hole 10, the high-pressure gas pushes the initial fracture to extend in the direction away from the stable zone of the surrounding rock 2 toward the cut hole 10, causing the coal body to undergo quantitative, directional and controllable fracturing under low impact conditions, and finally forming the fractured coal 11.

[0072] To ensure the safety and consistency of fracturing, each fracturing operation is controlled individually by the detonation control system 22. The detonation current, voltage and discharge time parameters are checked before detonation. After fracturing is completed, ventilation and dilution and environmental parameter testing are carried out at intervals of no less than 10 minutes. The next fracturing operation can only be carried out after confirming that there are no abnormalities.

[0073] IV. Coordinated Operation of Self-Moving Support Propulsion and Scraper Conveyor The self-moving support 4 is arranged along the strike of coal seam 1, and its arrangement direction is consistent with the working face advancing direction. The contact surface between the base of the self-moving support 4 and the bottom plate is equipped with an anti-slip structure, and controlled unloading, pushing and re-support are realized through a hydraulic system to adapt to the stress changes under the condition of steeply inclined coal seam 1.

[0074] During the directional fracturing operation at fracturing hole 16, the self-moving support 4 remains stationary, maintaining initial support force and working resistance to ensure the stability of the roof and coal wall in the fracturing area. The scraper conveyor 5 is in operation or ready to operate, ensuring that the fracturing coal 11 can fall into the conveying system in a timely manner.

[0075] V. Coal Falls Due to Transportation The scraper conveyor 5 is arranged along the strike of the coal seam 1, with its head located at the lower end of the mining area and its tail continuously transferred to the belt conveyor 19. The scraper conveyor 5 and the self-moving support 4 are mechanically linked by a pushing device, enabling the scraper conveyor 5 to advance synchronously with the self-moving support 4.

[0076] In the initial setup phase, the self-moving support 4 and the scraper conveyor 5 are arranged side by side along one side of the working face, so that the scraper conveyor 5 is located below the natural falling area of ​​the fractured coal 11. The center line of the scraper conveyor 5 chute and the projected position of the front beam of the self-moving support 4 remain stable, so that the coal body formed after fracturing can directly enter the conveying system within the support shielding range, avoiding coal pile-up and secondary coal cleaning operations under unsupported conditions.

[0077] After the fracturing coal 11 in a fracturing unit is transported out, the support-conveyor coordinated advancement stage begins. First, the supports are unloaded, and the self-moving supports 4 gradually reduce their support pressure, allowing the top beam to detach from the roof while maintaining a minimum safe support force to prevent sudden roof instability. Then, synchronous advancement begins. The pushing cylinders of the self-moving supports 4 are activated, causing the supports to move forward as a whole according to the designed step distance, with a single advancement step distance of 0.8 m. Simultaneously, the scraper conveyor 5 moves forward synchronously through the pushing mechanism connected to the supports, with the forward movement consistent with the support advancement. After advancement is complete, the self-moving supports 4 reload their support pressure, ensuring reliable contact between the top beam and the roof. The support height is adjusted according to the roof conditions to ensure continuous protection of the next fracturing unit's operating area.

[0078] During the coordinated advancement of the support and conveyor, the following parameters need to be controlled synchronously: the advancement speed of the support should be controlled at ≤0.2 m / min to avoid disturbance to the top plate caused by rapid advancement; the scraper conveyor 5 should be briefly paused before advancement and restarted after advancement is completed and the support is confirmed to be in place; the pressure change of the support cylinder should be monitored in real time during advancement to prevent instability or slippage; after advancement is completed, the chute connection status of the scraper conveyor 5 should be checked to ensure chain tension and smooth operation.

[0079] After the self-moving support 4 and scraper conveyor 5 advance and move out, the goaf 14 gradually forms behind them. The advance step distance is set to be consistent with the length of the fracturing unit, so that the spatial shape of the goaf 14 is regular and continuous, which facilitates subsequent zonal and layered filling by the filling pump 18. By controlling the synchronous advancement of the self-moving support 4 and scraper conveyor 5, the formation rhythm of the goaf 14 is matched with the filling rhythm of the filling body 15, avoiding the formation of large-span unfilled areas, thereby providing stable rear conditions for the next round of fracturing and advancing operations.

[0080] In the overall mining process of this invention, the coordinated advancement of the self-moving support 4 and the scraper conveyor 5 not only undertakes the functions of support and transportation, but also connects the two key processes of fracturing and filling. Its advancement parameters directly determine the length of the fracturing unit, the spatial morphology of the goaf, and the filling sequence, thus having a decisive impact on the continuity and safety of the entire drilling-fracturing-moving-transporting-filling cycle.

[0081] VI. Goaf backfilling The goaf 14 backfilling system is located on a ground working platform and consists of a cement silo 17, a backfilling pump 18, and conveying pipelines. The cement silo 17 stores the cementing material, and the backfilling pump 18 continuously conveys the backfill material to the goaf 14. The backfilling pump 18 is a plunger or screw pump suitable for conveying high-concentration solid slurry, with a rated pumping capacity of not less than 30 m³ / h. 3 / h, rated working pressure is 6MPa. The delivery pipeline uses wear-resistant steel pipe or composite pipe with a diameter of DN125, and check valves and pressure monitoring devices are installed at key nodes to prevent backflow and pipe blockage.

[0082] The filling body 15 is mainly composed of solid waste, including coal gangue 13, exposed stripped rock and soil, or a combination of the two.

[0083] To ensure that the backfill 15 has sufficient load-bearing capacity and early stability, the backfill material is configured according to the following parameters: maximum solid aggregate particle size ≤ 50 mm; cementitious material content accounts for 8% of the solid aggregate mass; water-cement ratio 0.6; slurry volume concentration ≥ 70%. After the backfill material is centrally mixed on the ground or underground, it is continuously pumped to the goaf 14 through the backfill pump 18 to ensure a balance between slurry fluidity and backfill density.

[0084] In the overall process of this invention, the formation time of the goaf 14 strictly corresponds to the advancing step distance of the self-moving support 4. After each fracturing unit is completed and the coal transportation operation is finished, the self-moving support 4 and the scraper conveyor 5 move forward by one advancing step distance of 0.8m, forming a goaf 14 with regular geometric boundaries behind it. After the self-moving support 4 has been advanced and re-supported in place, the goaf 14 backfilling operation is immediately started, so that the goaf 14 begins backfilling within 2 hours after its formation, avoiding the formation of a large-span unsupported roof area.

[0085] The backfilling operation is carried out in zones and layers, with each zone corresponding to one backfilling section along the direction of the working face advance. The length of the backfilling section is consistent with the advance step of the support, and the width covers the entire width of the goaf after the support is removed. A layered backfilling method is used during the backfilling process, with the thickness of each layer controlled between 0.5 and 0.7 meters. Continuous pumping allows the grout to spread and compact naturally within the goaf, reducing segregation and voids.

[0086] The filling height is controlled to be more than 0.9 times the mining height of coal seam 1, and the filling body 15 is gradually brought into contact with the roof by controlling the pumping volume to form a continuous support structure. For local irregular areas, the filling sequence is adjusted or the pump is briefly stopped for supplementary backfilling to ensure that the filling body 15 forms effective contact with the surrounding rock 2.

[0087] During the operation of filling pump 18, the pumping pressure is controlled within the range of 2 to 6 MPa. If abnormal pressure fluctuations occur, pumping should be stopped immediately and the pipeline and goaf filling status should be checked to avoid pipeline rupture due to overpressure or incomplete filling due to underpressure.

[0088] After filling is completed, the filling body 15 undergoes natural consolidation within the goaf 14. To ensure its stability during support advancement and subsequent fracturing operations, the initial consolidation time of the filling body 15 is controlled to be no less than 24 hours. After the filling body 15 reaches its initial stable state, the self-propelled support 4 continues to advance in front of it for the next cycle. At the same time, the filling body 15, as a stabilizing rear structure, constrains the deformation of the surrounding rock 2, thereby reducing the risk of roof pressure and floor bulging during support advancement.

[0089] Through the aforementioned filling parameters and timing control, the filling body 15 provides continuous support to the goaf 14 after its formation, causing the stress redistribution of the surrounding rock 2 to tend to stabilize, thereby providing a clear rear stability boundary for the next round of fracturing operations. Under this condition, the subsequent arrangement of fracturing holes 16 and the range of fracturing energy loading can be precisely controlled according to the boundary of the formed filling body 15, avoiding the disorderly expansion of fractures into the goaf, and improving the controllability and safety of fracturing coal breaking.

[0090] In the overall mining process of this invention, the filling of the goaf 14 and the advancement of the self-moving support 4 form a strict time-series linkage relationship. The advancement of the support forms the goaf, and the filling operation quickly follows to form the filling body 15. The filling body 15 stabilizes the surrounding rock in the reverse direction and constrains the subsequent fracture boundary.

[0091] Through the above-mentioned linkage control, the drilling-fracture-movement-transportation-filling processes form a closed loop and coordinate, ensuring the continuity and overall stability of the mining process under steeply inclined coal seam conditions.

[0092] VII. Cyclic Advancement and Layered Continuous Mining: The drilling-fracture-transfer-transport-filling process is implemented cyclically. After each cycle, the self-propelled support 4, scraper conveyor 5, and belt conveyor 19 advance synchronously by one step. Once the goaf 14 is formed, it is stably supported by the filling material, enabling continuous advancement. After the first coal seam is mined, the resulting transport roadway 20 is retained and used as the working face for the lower coal seam. Within this transport roadway, the riser 6, directional drilling rig 9, and related fracturing, transport, and filling equipment are rearranged. Following the same drilling-fracture-transfer-transport-filling process, the lower coal seam is continuously mined, thus achieving layered, continuous, and efficient mining of the steeply inclined coal seam group.

[0093] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0094] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A coordinated mining technology for steeply inclined coal seams, characterized by: Includes the following steps, Step 1, mining preparation work; On the surface of the steeply inclined coal seam group mining area, arrange several sets of surface vertical wells or directional wells along the strike of coal seam (1) to form a drilling network that runs through the surface to the bottom of the coal seam group; Arrange centralized transport roadways (20) in the rock of the bottom of the coal seam group, and arrange segmented transport roadways in each coal seam (1), which are connected to the centralized transport roadway through connecting roadways to form a fully enclosed underground transport system; Install mining equipment at the underground coal mining location and the surface mining area respectively; Step 2, drilling; using a reverse drilling rig (6) to construct a guide hole (8) on the ground working platform along the predetermined axis. After the guide hole (8) connects to the transport roadway (20), the reverse pull cutter head (7) is replaced to carry out reverse enlargement, forming an open cut (10) that penetrates the thickness of the coal seam (1) inside the coal seam (1), which serves as a stable free surface for directional fracturing; Step 3, fracturing; use a directional drilling rig (9) to drill fracturing holes (16) along the coal seam (1), arrange fracturing tubes (21) in the fracturing holes (16) and carry out directional fracturing in sections from bottom to top, so that the coal body is quantitatively, directionally and controllably fractured in a preset direction to form fracturing coal (11). Step 4, move the self-moving support (4); during and after the fracturing operation, the self-moving support (4) on one side of the fracturing area moves step by step along the mining advance direction, and the advance step distance of the self-moving support (4) matches the length of the fracturing unit and the length of the filling section; Step 5, transport the fractured coal (11); under the continuous cover of the self-moving support (4), the fractured coal (11) is brought into the scraper conveyor (5), and the fractured coal (11) is continuously transported out of the mining area by the scraper conveyor (5) and the belt conveyor (19). Step 6, filling the goaf (14); conveying filling material into the goaf (14) generated by the work in steps 3 to 5, and compacting and consolidating it to form a filling body (15). Step 7, cyclic advancement and layered continuous mining; Steps 2 to 6 constitute a complete drilling-fracture-transfer-transport-filling mining cycle, repeating the cycle steps, the continuous cycle operation line adopts the "staggered parallel operation" method, that is, in the same mining area, different working faces are respectively in the drilling, fracturing mining, transfer and filling stages, and each process does not interfere with each other in time and space, and the line of sight mining and filling is parallel; after each cycle is completed, the self-moving support (4), scraper conveyor (5) and belt conveyor (19) advance one step distance synchronously, and after the goaf (14) is formed, it is stably supported by the filling body (15) to achieve continuous advancement; after the first layer is completed, the formed transport roadway (20) is retained as the operation channel of the lower coal seam (1), the mining equipment is rearranged, and the lower coal seam (1) is continuously mined according to the same drilling-fracture-transfer-transport-filling process flow, and the layered and continuous mining of the steeply inclined coal seam (1) group is carried out.

2. The collaborative mining technology for steeply inclined coal seams using drilling-fracture-movement-transportation-filling as described in claim 1, characterized in that: Step one includes Step 1.1: In the stable area of ​​the bottom plate of the coal seam (1), a tunneling machine (3) is used to tunnel to form a transport roadway (20). A ventilation system, power supply system, drainage system and coal flow transport system are installed and debugged in the transport roadway (20). A self-moving support (4) and a scraper conveyor (5) are assembled at the underground coal mining position. The tail end of the scraper conveyor (5) is connected to a belt conveyor (19) to form a continuous coal transport system. Step 1.2: Level and reinforce the corresponding mining area on the ground to form a working platform, and install ground equipment, including a riser (6), a directional drilling rig (9), an electro-blasting control system for rock breaking energy control, a cement silo (17), and a filling pump (18).

3. The collaborative mining technology for steeply inclined coal seams using drilling-fracture-movement-transportation-filling as described in claim 1, characterized in that: The directional fracturing in step three includes arranging a fracturing tube (21) in the fracturing hole (16), forming a closed reaction chamber inside the fracturing tube (21), filling the reaction chamber with liquid carbon dioxide, and dispersing combustible metal powder in a suspended state in the liquid carbon dioxide, setting an electric explosion ignition unit in the fracturing tube (21); setting a constant pressure energy release unit in the fracturing tube (21), sealing the fracturing tube (21) after the installation is completed; after confirming safety, the ground personnel remotely control the electric explosion ignition unit through the detonation control system (22) to cause quantitative, directional, and controllable fracturing of the coal body, forming fracturing coal drop (11).

4. The collaborative mining technology for steeply inclined coal seams using drilling-fracture-movement-transportation-filling as described in claim 1, characterized in that: The scraper conveyor (5) and the self-moving support (4) are mechanically connected by a pushing device. The arrangement direction and pushing distance of the scraper conveyor (5) are consistent with those of the self-moving support (4). The center line of the chute of the scraper conveyor (5) is set to correspond to the projection of the front beam of the self-moving support (4).

5. The coordinated mining technology for steeply inclined coal seams using drilling-fracture-movement-transportation-filling as described in claim 1, characterized in that: In step six, the filling operation shall begin within 2 hours after the formation of the goaf (14), and the filling height of the filling body (15) shall not be less than 0.9 times the mining height of the coal seam (1). The filling operation shall be carried out in a zoned and layered manner, and the next cycle of mining operation shall be carried out after the initial stable state is reached.

6. The coordinated drilling-fracture-transfer-transportation-filling mining technology for steeply inclined coal seams according to claim 1, characterized in that: The filling material in step six includes solid aggregate and cementing material, wherein the solid aggregate is one or two of coal gangue (13) and open-pit stripped rock and soil.

7. The coordinated drilling-fracture-transfer-transportation-filling mining technology for steeply inclined coal seams according to claim 1, characterized in that: In step one, anchor bolts, anchor cables and metal mesh are used to support the transport roadway (20) according to the surrounding rock (2) conditions. After the equipment in the transport roadway (20) is installed, it is put into no-load test run. After the equipment in the ground mining area is arranged, it is fixed, positioned and checked and protected.

8. The coordinated drilling-fracture-transfer-transportation-filling mining technology for steeply inclined coal seams according to claim 1, characterized in that: In step four, the scraper conveyor (5) is stopped before the advance is completed, and the scraper conveyor (5) is restarted after confirming that the support is in place.

Images