Deep thick and large ore body stress regulation and mechanical layered stoping method

Abstract

The invention belongs to the technical field of mining, and discloses a deep thick and large ore body stress regulation and mechanical layered stoping method. Through cooperative implementation of a hanging wall surrounding rock stress regulation raise, surrounding rock presplitting weakening, mechanical cutting stoping and goaf filling, a stress regulation and mechanical layered stoping integrated mode suitable for a deep high-stress thick and large ore body is constructed. The method can improve the stress state of the surrounding rock in the to-be-mined area, adjust the stress transfer path, promote ordered transfer and redistribution of stress, and realize layered continuous stoping. Furthermore, by controlling the form and the propelling direction of the mining frontal surface in the propelling process of the middle-section stope, an approximately elliptical or ellipsoidal envelope is formed, and the long and short axis relation of the mining frontal surface is restrained by combining the equal stress axial ratio, so that the stress distribution uniformity of the surrounding rock can be effectively improved, and the local stress concentration degree of the boundary is reduced; and a more stable stress environment is created for continuous stoping.

Description

Technical Field

[0001] This invention relates to the field of mining technology, and in particular to a method for stress control and mechanized layered mining of deep, thick ore bodies. Background Technology

[0002] With the increasing depletion of shallow mineral resources, metal mining is continuously extending to deeper areas. The mining of deep, thick ore bodies faces complex geomechanical problems such as high ground stress, a high tendency for rockbursts, and rheological deformation of the surrounding rock. While conventional layered mining can alleviate localized stress concentration to some extent through layer-by-layer extraction, the complex process of stress transmission, transfer, and redistribution between layers means residual stress can easily accumulate in localized areas, potentially triggering roof instability, spalling, and rockbursts. Existing stress control measures for deep ore bodies mainly include drilling, hydraulic fracturing, pre-cutting, and local pre-splitting. While these measures can improve the local stress state to some extent, they generally suffer from limited control range, insufficient sustainability, and poor integration with subsequent mechanized mining operations. They often require separate construction outside of normal mining operations, affecting continuous operation efficiency and extending the mining cycle, thus hindering the large-scale continuous mining of deep, thick ore bodies. Therefore, there is an urgent need to propose a method that combines stress control with mechanized stratified mining in deep, thick ore bodies. This method involves deploying several stress control risers and combining them with mechanized rock breaking to pre-fracture and weaken the surrounding rock, thereby improving the stress state and stress transmission path of the surrounding rock in the mining area. This creates favorable conditions for subsequent mechanized stratified mining, thereby improving the stability and continuous operation capability of the mining area. Summary of the Invention

[0003] (a) The technical problems to be solved; In the high-stress environment of deep, thick metallic ore bodies, traditional mining methods suffer from the following problems: First, insufficient ability to regulate surrounding rock stress. Existing methods have limited effectiveness in releasing and transferring localized high stress, and residual stress tends to concentrate around the stope, increasing the risk of rockbursts, roof instability, and spalling. Simultaneously, the mining boundary morphology lacks optimized constraints on the original rock stress field, easily leading to uneven boundary stress distribution and excessively high local stress peaks. Second, difficulty in coordinating stress regulation with continuous mining. Existing stress regulation processes require independent construction and are difficult to integrate closely with mechanized layered mining, resulting in frequent operational interruptions, prolonged stope preparation and advancement cycles, and hindering continuous operation efficiency.

[0004] In view of the above-mentioned shortcomings, this invention provides a method for stress control and mechanized layered mining of deep, thick ore bodies. This method involves mining several stress control risers within the ore body, using mechanized rock-breaking equipment to pre-fracture and weaken adjacent surrounding rocks, forming a stress control zone along the ore body's extension direction. Based on this, mechanized layered continuous mining is carried out on the ore body. During the advancement of the same intermediate stope, the mining front is controlled to form an approximately elliptical or ellipsoidal envelope, with the major axis of the ellipse arranged along the direction of the maximum principal stress in the original rock. The ratio of the major and minor axes of the ellipse is equal to or close to the ratio of the corresponding principal stress magnitudes, i.e., the isostress axis ratio, to reduce stress concentration at the mining boundary and achieve uniform stress distribution. Simultaneously, combined with continuous ore and rock transport and goaf filling, continuous stress control and surrounding rock stability control are achieved during the mining process, balancing stope safety, mechanized continuous operation efficiency, and mining stability under deep, high-stress, hard rock conditions.

[0005] (II) Technical Solution To address the challenges of effectively controlling stress concentration in deep, thick ore bodies under high ground stress conditions, the high risk of rock bursts and surrounding rock instability, and the difficulty in coordinating stress control procedures with mechanized layered mining, this invention proposes a method for stress control and mechanized layered mining in deep, thick ore bodies. This method involves arranging several stress-regulating risers within the ore body and using machinery to pre-fracture and weaken the surrounding rock, thereby altering the stress boundary conditions and stress transmission paths of the surrounding rock in the mining area and forming a stress-regulating zone continuously distributed along the ore body's extension direction. Based on this, mechanized rock-breaking equipment is used for layered continuous mining of the ore body. During the advancement of the intermediate stope, the morphology and direction of the mining front are controlled to ensure that the mining boundary adapts to the principal stress distribution characteristics of the original rock, thereby reducing local stress concentration at the boundary and promoting orderly stress transfer and uniform stress distribution. The mining front extends in an approximately elliptical or ellipsoidal shape in planar or spatial dimensions, with its major axis direction basically consistent with the direction of the maximum principal stress in the original rock, and the ratio of its major and minor axes determined according to the magnitude of the principal stress in the original rock. Simultaneously, combined with continuous ore and rock transport and goaf filling, this method achieves continuous stress regulation, surrounding rock stability control, and continuous mechanized mining during the mining of deep, thick ore bodies.

[0006] The technical solution of this invention is as follows: A method for stress regulation and mechanized layered mining of deep, thick ore bodies, with the specific steps as follows: Step 1: Based on the ore body occurrence state, the direction of the principal stress of the original rock, and the stability of the surrounding rock, the ore body to be mined is divided into mid-section, panel, and layered mining units. Several stress-regulating wells are arranged on one side of the hanging wall of the ore body. The stress-regulating wells extend vertically or inclined. Their number, spacing, cross-sectional size, extension length, and arrangement direction are determined according to the stress distribution characteristics of the original rock, the structural characteristics of the hanging wall, and the subsequent mining advance direction, so as to form a stress-regulating well group covering the corresponding hanging wall area of ​​the subsequent layered mining area. At the same time, the advance direction and mining boundary of each layered mining unit are determined to create conditions for the pre-fracture and weakening of the hanging wall and mechanized layered mining.

[0007] Step 2: After the stress control wells are arranged, pre-fracture and weakening are carried out on the adjacent hanging wall surrounding rock along each stress control well. The mechanized rock breaking equipment forms interconnected or continuously extended fracture weakening zones, so that a continuously distributed stress control zone is formed on one side of the hanging wall surrounding rock of the ore body. The range, depth, extension direction and relationship of the stress control zone and the adjacent weakening zones are determined according to the distribution characteristics of the original rock principal stress, the structural characteristics of the hanging wall surrounding rock and the subsequent layered mining range, and are used to improve the stress state of the surrounding rock in the mining area and adjust the stress transmission path.

[0008] Step 3: Deploy mechanized rock-breaking equipment within the ore body of the stress regulation zone formed in Step 2; excavate production risers or form mining channels from bottom to top to provide working space and ore extraction channels for subsequent layered continuous mining; Step 4: The mechanized rock-breaking equipment advances continuously along the designed path, and the cutting disc rotates and cuts the ore body to form blocky ore and rock. After the cut ore and rock fall into the rock-breaking machine's collection mechanism, it is transferred by the onboard conveying device to the mining channel, ore pass, or subsequent transportation system, realizing a mechanized mining process that connects continuous cutting, continuous collection, and continuous transfer. Step 5: During continuous mining, the area in front of and adjacent to the boundary of the mechanized rock-breaking equipment is within the stress control zone formed in Step 2. As the ore and rock are extracted, the goaf gradually forms behind, and the self-stabilizing capacity of the local surrounding rock may decrease. Depending on the stability of the surrounding rock, support measures should be taken for weak points if necessary. Step 6: After the mechanical cutting and mining advances to the designed length and height or reaches the control boundary of the section, the formed goaf is filled. After filling, a filling body is formed to achieve spatial closure of the goaf, provide continuous support for the roof and sidewalls, and promote the orderly redistribution of stress in the surrounding rock of the mining area to the filling body, the surrounding rock and the unmined area, thereby reducing the risk of goaf instability, roof collapse and local stress reconcentration, and maintaining the stability of the surrounding rock in the subsequent layered mining process.

[0009] Step 7: Control the elliptical or ellipsoidal mining front; during the advance, the mining front should be arranged with the major axis of the mining area along the direction of the maximum principal stress. First, start mining in the middle and then mine back towards both ends to make the mining front form an approximately elliptical envelope; the ratio of the major axis to the minor axis should be equal to the ratio of the magnitudes of the two corresponding principal stresses. Step 8: After a work unit completes mining and backfilling closure, the mechanized rock breaking equipment and supporting system are moved to the adjacent work unit or the next layer, and steps 3 to 7 are repeated.

[0010] The stress control wells extend vertically or inclined, and their number, spacing, cross-sectional dimensions, extension length, and arrangement direction are determined based on the stress distribution characteristics of the original rock, the structural characteristics of the hanging wall, and the subsequent mining direction.

[0011] The range, depth, extension direction, and relationship of the stress regulation zone with adjacent weakened zones are determined based on the distribution characteristics of the principal stress of the original rock, the structural characteristics of the hanging wall, and the subsequent layered mining range. It is used to improve the stress state of the surrounding rock in the mining area and adjust the stress transmission path.

[0012] The mechanized rock-breaking equipment is equipped with a cutting disc and a roller cutter 13 at the front end, which are used to continuously cut and break rocks under hard rock conditions.

[0013] Step S3 involves applying electromagnetic pulse pre-fracture weakening to the working face where the rock or ore body contacts the cutterhead before cutting, in order to induce the expansion of micro-fractures and reduce the cutting load.

[0014] During the ore extraction process in step S4, the ore transport path and transfer method are adjusted according to the stratified advancement status and working space conditions.

[0015] The support measures include anchor bolts, anchor cables, wire mesh, and shotcrete.

[0016] During the advancement process of step S8, the advancement sequence, advancement step distance, and mining front control parameters of the work unit are adjusted based on the stress and deformation monitoring results to ensure the safety and controllability of continuous mining.

[0017] Overall, this invention constructs an integrated stress control and mechanized layered mining model suitable for deep, high-stress, thick ore bodies by synergistically implementing a hanging wall stress control riser, pre-fracture weakening of the surrounding rock, mechanized cutting and mining, and goaf backfilling. This method can improve the stress state of the surrounding rock in the mining area, adjust the stress transmission path, promote the orderly transfer and redistribution of stress, and achieve continuous layered mining. Furthermore, by controlling the shape and direction of the mining front during the advancement of the intermediate stope to form an approximately elliptical or ellipsoidal envelope, and by constraining the major and minor axes of the mining front with equal stress axis ratios, the uniformity of stress distribution in the surrounding rock can be effectively improved, the degree of local stress concentration at the boundary can be reduced, and a more stable stress environment can be created for continuous mining.

[0018] Compared with the prior art, the present invention has the following advantages and improvements: 1) Reduce blasting disturbance and achieve mechanized rock breaking and mining: This method does not require explosive blasting. It uses mechanical cutting of mining hard rock breakers to break and mine the ore body. Optionally, it can be combined with electromagnetic pulse pre-fracture weakening to induce the expansion of micro-fractures in the working face and improve rock breaking efficiency, thereby reducing the risk of blasting disturbance and improving the controllability of surrounding rock disturbance.

[0019] 2) Improve continuous operation efficiency: Employ remote-controlled or automated mechanical cutting methods to organize mining operations, and connect with continuous material collection and roadway transportation systems to achieve a stable and continuous ore extraction process. The transportation system can be belt conveyor, scraper conveyor, or other continuous transportation methods, with belt conveyor being the preferred implementation method. This avoids the interrupted rhythm caused by the alternation of blasting, ventilation, support, and ore extraction in traditional layered blasting mining, thereby improving advancement efficiency and production organization stability.

[0020] 3) Achieving stress regulation of surrounding rock and uniformity of stress at mining boundaries: This method involves arranging several stress regulation risers in the hanging wall of the ore body and pre-fracture and weakening adjacent surrounding rock to form a continuously distributed stress regulation zone. This improves the stress state of the surrounding rock in the mining area and adjusts the stress transmission path, reducing the risks of rock bursts, roof instability, and spalling. At the same time, during the advancement of the same intermediate stope, the shape and direction of the mining front are controlled so that the mining front forms an approximately elliptical or ellipsoidal envelope. Its major axis is arranged along the direction of the maximum principal stress in the original rock, and the ratio of the major and minor axes matches the magnitude of the principal stress, thereby weakening the local stress concentration at the mining boundary and improving the uniformity of stress distribution in the surrounding rock.

[0021] 4) Enhance the stability of the mining area and improve the mining effect: This method, through the coordinated implementation of stress regulation, mechanized layered mining and goaf filling and closure, can maintain the stability of the surrounding rock in the mining area and control the deformation and expansion of the goaf during continuous mining; at the same time, it is conducive to improving the safe mining capacity, continuous operation capacity and resource recovery effect of deep and thick ore bodies.

[0022] In summary, this invention addresses the challenges of high ground stress and complex geological conditions in deep, thick ore bodies. It constructs an integrated continuous mining method that coordinates stress regulation, mechanized layered mining, and goaf filling and closure. By constructing a stress regulation zone in the hanging wall and controlling the mining front morphology, it can improve continuous mining efficiency and resource recovery while ensuring the stability of the mining area. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating an embodiment of the present invention; Figure 2A longitudinal cross-sectional schematic diagram of a method for stress control and mechanized layered mining of deep, thick ore bodies provided in an embodiment of the present invention. Figure 3 for Figure 2 AA cross-section view; Figure 4 for Figure 2 BB cross-section; Figure 5 A three-dimensional schematic diagram of a method for stress regulation and mechanized layered mining of deep, thick ore bodies according to an embodiment of the present invention; Figure 6 This is a schematic diagram of a mining hard rock breaker and an electromagnetic pulse transmitting device in one embodiment of the present invention; Figure 7 This is a schematic diagram of the cutterhead of a mining hard rock crusher according to an embodiment of the present invention; Figure 8 This is a schematic diagram of elliptical mining front control and equal stress axis ratio based on the direction of maximum principal stress in one embodiment of the present invention.

[0024] In the diagram: 1-Stress control riser; 2-Production riser; 3-Ore body; 4-Main shaft; 5-Mining access road; 6-Pre-fractured weakened zone; 7-Ore to be mined; 8-Electromagnetic pulse; 9-Loose ore; 10-Mining hard rock breaker lifting platform; 11-Mining area; 12-Transport roadway; 13-Roll cutterhead; 14-Electromagnetic pulse transmitter; 15-Telescopic cutting head; 16-Belt conveyor; 17-Cut head; 18-Intermediate ore body; 19-Mining area layout; 20-Intermediate transport roadway. Detailed Implementation

[0025] To better explain and facilitate understanding of the present invention, it is described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described below are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other; for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0026] like Figures 1 to 8 As shown, this embodiment provides a method for stress control and mechanized layered mining of deep, thick ore bodies. Figure 1 As shown, the overall process includes stress control of the hanging wall, mechanized layered mining, continuous ore extraction, and goaf backfilling. First, the main shaft 4, intermediate transport roadway 20, and mining access road 5 are developed to reach the ore body. For example... Figure 2 , Figure 5As shown, several stress-regulating risers 1 are arranged on one side of the hanging wall of ore body 3, and pre-fracture and weakening are carried out along each stress-regulating riser 1 on the adjacent hanging wall surrounding rock, thereby forming a pre-fracture and weakening zone 6. This creates a continuously distributed stress-regulating zone in the hanging wall surrounding rock, improving the stress state of the surrounding rock in the mining area and adjusting the stress transmission path. Subsequently, under the control of the stress-regulating zone, a mining hard rock breaker is arranged in the ore to be mined 7 of the corresponding layered mining unit to form a mining channel from bottom to top, and the ore body is continuously cut and mined. The cut ore and rock are aggregated and then enter the roadway transportation system. The roadway transportation system can adopt continuous transportation methods such as belt conveyor or scraper conveyor, with belt conveyor being the preferred implementation. When the mining advances to the designed length, height, or predetermined section boundary, the goaf is filled and closed to achieve spatial closure of the goaf, restoration of surrounding rock support, and stress redistribution. Furthermore, in order to reduce stress concentration at the mining boundary and improve the uniformity of stress distribution in the surrounding rock, this invention controls the shape and direction of the mining front during the advancement of the same intermediate stope 11, so that it forms an approximately elliptical or ellipsoidal envelope, and its major axis is arranged along the direction of the maximum principal stress of the original rock; at the same time, the ratio of the major and minor axes of the front is determined according to the relationship of the principal stresses, so that it is equal to or close to the ratio of the corresponding principal stresses, thereby improving the safety and stability of continuous mining of deep, thick ore bodies.

[0027] This embodiment provides a method for stress control and mechanized layered mining of deep, thick ore bodies, which specifically includes the following steps: First, the development project was implemented, forming the main connecting ramp, 12 transport tunnels, a ventilation system, and related auxiliary infrastructure. Then, as... Figure 5 As shown, multiple vertical or slightly inclined stress control risers 1 are arranged along the strike of the ore body and in the hanging wall region, and utilize methods such as... Figure 6 The mining hard rock breaker shown applies pre-fracture weakening to the adjacent hanging wall surrounding rock along each stress control riser 1, forming a continuously extending fracture weakening zone along the strike, dip, or height direction. For example... Figure 3 As shown, the fracture weakening zones around each stress control well 1 are interconnected or continuously distributed, thus forming a continuous stress control zone on the side of the hanging wall of the ore body. This improves the stress state of the surrounding rock of the ore to be mined 7 and adjusts the stress transmission path, creating favorable conditions for subsequent mechanized layered mining.

[0028] Optionally, the mining hard rock breaker can be equipped with an electromagnetic pulse pre-splitting device 14 to pre-splitting and weaken the working face with electromagnetic pulse 8 before grooving or mechanical cutting, so as to induce the expansion of micro-cracks and improve rock breaking efficiency.

[0029] like Figure 7As shown, the front end of the mining hard rock crusher is equipped with two cutting discs and several electromagnetic pulse emitting units; the cutting discs 17 are preferably arranged in a concentric circle manner, and several roller cutters 13 are provided on the cutting discs 17 for rotating and cutting the working face.

[0030] like Figure 4 As shown, under the control of the stress regulation zone formed in step 2, it is preferable to first use a mining hard rock breaker to excavate the production well 2 from bottom to top starting from the lifting platform 10 of the mining hard rock breaker. The production well 2 has a rectangular cross-section. Subsequently, continuous mining is carried out from bottom to top along the production well 2: first, the working face is pre-fractured and weakened by an electromagnetic pulse pre-fracture device, which expands the micro-fractures inside the rock mass and reduces the local strength, making it loose ore 9; then, the roller cutter 13 of the cutterhead system is in contact with the working face and rotates to cut and complete the mechanical crushing and ore extraction. The shape of the working cross-section can be adjusted according to the stope layout 19.

[0031] Furthermore, electromagnetic pulse pre-splitting can induce fracture propagation in the near-field of the working face, release some strain energy and reduce the degree of local stress concentration, thereby improving the stress conditions of mechanical cutting and improving the stability of the surrounding rock and mining safety during continuous mining.

[0032] Optionally, the output power, action time, and action frequency of the electromagnetic pulse pre-splitting device can be selected or adjusted according to the rock-breaking effect.

[0033] The mining hard rock crusher used in this invention includes a crusher body, a cutting disc system, an electromagnetic pulse pre-splitting device, and a control system. The crusher body provides structural support and propulsion. The cutting disc system is located at the front and sides of the crusher body for mechanical cutting and rock breaking. The telescopic cutting discs 15 on both sides are adjustable to accommodate different cross-sectional requirements. The electromagnetic pulse transmitter 14 is positioned near the working face of the cutting disc and is used for electromagnetic pulse pre-splitting and weakening of the ore. The control system includes an electromagnetic pulse parameter adjustment module and a data processing module, used to set and regulate the operating parameters of the electromagnetic pulse transmitter 14 and monitor its operating status.

[0034] During rock breaking operations, the electromagnetic pulse 8 pre-splitting action induces the propagation of micro-fractures on the working face. Subsequently, the roller cutter 13 on the cutting disc rotates and cuts against the working face to achieve mechanical rock breaking. The rock breaker's main axis applies a normal thrust to the working face, causing the roller cutter 13 to cut into the ore and form fragments. With the assistance of the weakened pre-splitting effect of the electromagnetic pulse 8, the cutting load can be reduced and the crushing efficiency can be improved. The cutting process is continuous, and the mining hard rock rock breaker cuts and mines along the side wall working face of the production raise 2 from bottom to top.

[0035] Furthermore, as the working face ore and rock mass are continuously cut, broken and mined, the stress state of the surrounding rock in the vicinity of stope 11 is gradually adjusted. Stress transfer and redistribution occur between the stress control zone of the hanging wall, the surrounding rock of the goaf, and the unmined area. This helps to reduce the local stress concentration near the working face and at the mining boundary, creating favorable conditions for the stability control of the surrounding rock and safe mining during continuous mining.

[0036] After the cutterhead of the mining hard rock crusher rotates and cuts, the ore and rock are broken into small fragments. During the layered mining process, the ore body undergoes electromagnetic pulse 8 pre-splitting (optional), mechanical cutting and rock breaking, continuous material collection and continuous transportation, etc., to form a continuous mining process and improve the mechanized continuous mining capability of deep and thick ore bodies.

[0037] Optionally, the cutting parameters can be adjusted according to the strength of the ore body and the cutting load, such as the extension and retraction of the cutter head 13, the cutter head attitude angle, and the feed speed, to ensure the stability of the cutting process. Optionally, the size of the production riser 2 or the working section can be selected according to the project requirements, with a rectangular section being the preferred form; the section size can be adapted by adjusting the arrangement position and extension and retraction of the cutter head 13 (or drill bit).

[0038] To improve the overall stability of weak parts of the layered roof, support measures such as hanging metal mesh and shotcrete can be adopted according to the surrounding rock conditions to suppress the loosening of the surrounding rock and prevent loose rocks from falling.

[0039] The collection and transportation of crushed ore can be carried out continuously: the front shovel of the rock crusher collects the crushed rock and transfers it to the belt conveyor at the rear of the equipment. The belt conveyor 16 transports the ore from the inside of the stope 11 to the transport roadway 12 or ore pass, achieving continuous ore output. Optionally, the belt conveyor is installed at the rear of the mining hard rock crusher to receive the ore slag discharged by the shovel and transport the ore to the surface or a designated location.

[0040] After the excavation and mining of one layer is completed, the mining hard rock breaker is moved to the next layer via the inclined ramp of stope 11 or the access road of stope 11, ready to start a new excavation and mining task. Optionally, the advancement method of the next layer can be upward or downward; under the condition that the ore body and roof have good stability, upward layering is preferred to improve the safety of operation.

[0041] Optionally, depending on the stability of the ore body and whether the surface allows for subsidence, it may be decided whether to backfill the goaf. As a layered backfilling scheme: after the mining hard rock breaker completes a layer of continuous tunneling and mining, a backfilling retaining wall can be built at the 11th access road of the layered stope, and the goaf can be backfilled with backfilling slurry.

[0042] like Figure 2As shown, layered tunneling and equipment relocation can be carried out cyclically: after completing the tunneling and mining of one layer, the operation of the mining hard rock breaker is stopped, and the equipment is moved to the next layer along the inclined ramp. After positioning, the operation of steps 3 to 6 is repeated to achieve continuous layered advancement.

[0043] like Figure 8 As shown, to reduce stress concentration at the mining boundary, the advancing direction of the same middle section of the ore body 18 is arranged with the major axis of the stope 11 along the direction of the maximum principal stress in the original rock. Preferably, mining is first carried out in a "one-line" pattern along the strike in the middle of the ore body, and then mining is carried out towards both ends, so that the mining front forms an approximately elliptical envelope. The ratio of the major axis to the minor axis of the ellipse is equal to the ratio of the magnitudes of the two corresponding principal stresses (equal stress axis ratio), and the major axis of the ellipse is consistent with the direction of the maximum principal stress, so as to achieve uniform stress distribution in the surrounding rock. Preferably, the mining hard rock breaker is moved along the advance path of the stope 11 to the upper layer to carry out upward mining, and the mining direction can be from the hanging wall of the ore body towards the transport roadway 12.

[0044] This invention addresses the problems of high blasting disturbance, high risk, and insufficient continuous operation capacity in deep, thick metal ore bodies under high ground stress and high hardness conditions. It proposes a continuous mining method combining stress control and mechanized layered mining. This method involves arranging several stress control risers 1 in the hanging wall of the ore body and implementing pre-fracture weakening of the surrounding rock to form a continuous stress control zone, thereby improving the stress state and stress transmission path of the surrounding rock in the mining area. Based on this, a mining hard rock breaker is deployed for continuous cutting and mining, optionally combined with electromagnetic pulse 8 pre-fracture weakening to reduce cutting load and improve rock-breaking efficiency. The crushed ore is transported off-site via a continuous collection and transportation system, and the goaf is filled and closed after advancing to the control boundary. Furthermore, by controlling the morphology and advancement direction of the mining front in the intermediate stope 11, and determining the ratio of the major and minor axes based on the equal stress axis ratio, the stress concentration at the mining boundary can be effectively reduced, improving the safety and controllability of mining.

Claims

1. A method for stress regulation and mechanized layered mining of deep, thick ore bodies, characterized in that, The specific steps are as follows: Step 1: Based on the ore body occurrence state, the direction of the principal stress of the original rock and the stability of the surrounding rock, the ore body to be mined is divided into middle section, panel area and layered mining units; several stress control risers are arranged on the side of the hanging wall of the ore body to form a stress control riser group covering the corresponding hanging wall area of ​​the subsequent layered mining area; at the same time, the advancing direction and mining boundary of each layered mining unit are determined. Step 2: After the stress control wells are arranged, pre-fracture and weakening are carried out on the adjacent hanging wall surrounding rock along each stress control well. The mechanized rock breaking equipment forms interconnected or continuously extended fracture weakening zones, so that a continuously distributed stress control zone is formed on one side of the hanging wall surrounding rock of the ore body. Step 3: Deploy mechanized rock-breaking equipment within the ore body; excavate production risers or form mining tunnels from bottom to top to provide working space and ore extraction channels for subsequent layered continuous mining; Step 4: The mechanized rock-breaking equipment advances continuously along the designed path, and the cutting disc rotates and cuts the ore body to form blocky ore and rock. After the cut ore and rock fall into the rock-breaking machine's collection mechanism, it is transferred by the onboard conveying device to the mining channel, ore pass, or subsequent transportation system, realizing a mechanized mining process that connects continuous cutting, continuous collection, and continuous transfer. Step 5: During continuous mining, the area in front of the mechanized rock-breaking equipment and the adjacent boundary area are within the stress regulation zone formed in Step 2. As the ore is extracted, the goaf gradually forms behind it; depending on the stability of the surrounding rock, support measures should be taken for weak points when necessary. Step 6: After the mechanical cutting and mining advances to the designed length and height or reaches the control boundary of the section, the formed goaf is filled. After filling, a filling body is formed to achieve spatial closure of the goaf, provide continuous support for the roof and sidewalls, and promote the orderly redistribution of stress in the surrounding rock of the mining area to the filling body, the surrounding rock and the unmined area. Step 7: Control the elliptical or ellipsoidal mining front; during the advance, the mining front should be arranged with the major axis of the mining area along the direction of the maximum principal stress. First, start mining in the middle and then mine back towards both ends to make the mining front form an approximately elliptical envelope; the ratio of the major axis to the minor axis should be equal to the ratio of the magnitudes of the two corresponding principal stresses. Step 8: After a work unit completes mining and backfilling closure, the mechanized rock breaking equipment and supporting system are moved to the adjacent work unit or the next layer, and steps 3 to 7 are repeated.

2. The method for stress regulation and mechanized layered mining of deep, thick ore bodies according to claim 1, characterized in that, The stress control wells extend vertically or inclined, and their number, spacing, cross-sectional dimensions, extension length, and arrangement direction are determined based on the stress distribution characteristics of the original rock, the structural characteristics of the hanging wall, and the subsequent mining direction.

3. The method for stress regulation and mechanized layered mining of deep, thick ore bodies according to claim 1, characterized in that, The range, depth, extension direction, and relationship of the stress regulation zone with adjacent weakened zones are determined based on the distribution characteristics of the principal stress of the original rock, the structural characteristics of the hanging wall, and the subsequent layered mining range. It is used to improve the stress state of the surrounding rock in the mining area and adjust the stress transmission path.

4. The method for stress regulation and mechanized layered mining of deep, thick ore bodies according to claim 1, characterized in that, The mechanized rock-breaking equipment is equipped with a cutting disc and a roller cutter at the front end, which is used to continuously cut and break rocks under hard rock conditions.

5. The method for stress regulation and mechanized layered mining of deep, thick ore bodies according to claim 1, characterized in that, Step S3 involves applying electromagnetic pulse pre-fracture weakening to the working face where the rock or ore body contacts the cutterhead before cutting, in order to induce the expansion of micro-fractures and reduce the cutting load.

6. The method for stress regulation and mechanized layered mining of deep, thick ore bodies according to claim 1, characterized in that, During the ore extraction process in step S4, the ore transport path and transfer method are adjusted according to the stratified advancement status and working space conditions.

7. The method for stress regulation and mechanized layered mining of deep, thick ore bodies according to claim 1, characterized in that, The support measures include anchor bolts, anchor cables, wire mesh, and shotcrete.

8. The method for stress regulation and mechanized layered mining of deep, thick ore bodies according to claim 1, characterized in that, During the advancement process of step S8, the advancement sequence, advancement step distance, and mining front control parameters of the work unit are adjusted based on the stress and deformation monitoring results to ensure the safety and controllability of continuous mining.

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