Hard rock vein hanging wall shaft security pillar delineation and ore quantity release mining method

Abstract

The invention provides a hard rock vein hanging wall shaft security pillar delineating and mine quantity releasing mining method, and belongs to the field of mine mining. According to the method, firstly, a rock stratum movement angle is determined through empirical formula calculation in combination with numerical simulation analysis, and a section cone security pillar is delineating with the center of a shaft as a datum line according to the rock stratum movement angle; rock movement control isolation areas are respectively arranged above and below the rock movement control isolation areas; an ore body is divided into a plurality of functional areas, aiming at the different areas, mining methods such as shallow hole shrinkage subsequent filling, upward horizontal layered filling and sublevel rock drilling stage open stoping subsequent filling are adopted for safe and efficient stoping, and damping pressure relief and presplitting supporting are conducted on the top of an enhanced mining area on the lower portion of a security pillar; in the whole recovery process, the shaft and the adjacent rock mass are monitored in real time, and under the premise that the safety of the shaft is guaranteed, the pressure covering ore is released and recovered to the maximum extent.

Description

Technical Field

[0001] This invention relates to the field of mining technology, specifically to a method for delineating and releasing ore reserves in the upper shaft of a hard rock vein. Background Technology

[0002] As a crucial component of the mining system, the shaft serves as the "throat" connecting the surface and underground production levels, and its stability and safety directly impact the normal operation of the entire mine. In mines mining steeply dipping, hard, thin veins, due to historical reasons or factors such as well-developed joints and fissures in the footwall rock and poor stability, the shaft is often located in the hanging wall rock, where the ore body has better stability. However, the hanging wall rock is more susceptible to mining-induced disturbances after the ore body is mined, leading to large-scale rock strata movement and deformation, which poses a serious threat to the structural safety of the shaft. Therefore, a certain range of safety pillars must be reserved in the preliminary design of the ore body mining to prevent rock strata movement induced by underground mining from damaging the shaft.

[0003] Currently, the conventional methods for establishing safety pillars are mainly divided into empirical analogy, theoretical analysis, and numerical analysis. While empirical formulas are highly practical and operable, their accuracy depends on the similarity of the analogy object. If the selected analogy mine differs significantly from the actual mine in key factors, it may lead to unreasonable placement of shaft safety pillars. Theoretical formulas often neglect geological structures (faults, joints), rock mass heterogeneity, and hydrological influences, resulting in calculations that may deviate from actual rock mass strength by 20% to 40%. Numerical simulation can more objectively and directly reflect the stress and displacement changes in the rock mass induced by mining activities. It can not only conduct stability assessments for safety pillars of specific sizes but also compare multiple schemes to optimize pillar size, making it a widely used method.

[0004] However, none of the three conventional methods mentioned above can effectively solve the problem of the safety pillars of the hanging wall shaft of steeply dipping thin to medium-thick hard rock veins covering a large amount of ore resources in the deep area of ​​the ore body. This can easily lead to a situation where there is no ore to mine, which seriously restricts the sustainable development and economic benefits of the mine.

[0005] In view of this, it is necessary to design a method for delineating safety pillars and releasing ore reserves in the hanging wall of hard rock veins to solve the above problems. Summary of the Invention

[0006] In view of the technical problems existing in the background art, this application provides a method for delineating and releasing ore reserves in the upper shaft of hard rock veins, aiming to solve the technical problems of existing technologies where the method of delineating ore reserves is unscientific, resulting in a large amount of ore being covered and unable to be recovered, and the lack of safe and efficient mining technology.

[0007] This application provides a method for delineating safety pillars in the hanging wall of a hard rock vein and releasing ore reserves during mining, including the following steps: S1. Calculate the moving angles of the hanging wall strata, footwall strata, and strike strata of the ore body using empirical formulas. Construct a three-dimensional numerical model of the mine using numerical simulation software, analyze the deformation of the shaft throughout its entire life cycle, and determine the final moving angles of the strata. S2. Using the centerline of the shaft as a reference, and taking the sum of the shaft radius and the width of the protection zone as the radius, and the rock strata movement angle as the slope angle of the safety pillar, delineate the cross-sectional cone safety pillar to the bottom of the shaft, and extend upwards for 2-3 middle sections at the bottom of the shaft to form a rock movement control isolation zone in the upper part of the shaft, and extend downwards for 100-150m to form a rock movement control isolation zone in the bottom part of the shaft; S3. Divide the ore body into several areas, including the rock movement control isolation zone in the upper part of the shaft, the rock movement control isolation zone in the bottom part of the shaft, the ore release zone of the upper safety pillar, the enhanced mining zone below the safety pillar, and the normal mining zone below the safety pillar. S4. The ore body in the upper safety pillar release zone is recovered by using the shallow hole retention and subsequent backfilling mining method; S5. Excavate a vibration-damping and pressure-relief roadway at the top of the reinforced mining area below the safety pillar, and arrange and support vibration-damping and pressure-relief pre-splitting holes; use the upward horizontal layered backfilling mining method to mine the reinforced mining area below the safety pillar, and provide support after each layer is mined. S6. The normal mining area below the safety pillar shall be mined using either shallow hole retention followed by backfilling mining or segmented rock drilling stage open area followed by backfilling mining, depending on the thickness of the ore body. S7. Throughout the entire mining process, the wellbore and adjacent rock mass are monitored in real time.

[0008] As a further improvement to this application, in step S1, the empirical formula is: γ = 55° + 1.5f; When f 上盘 ≥f 下盘 At that time, β = 55° + 1.5f; When f 上盘 <f 下盘 When, β=55°+1.5f-(0.30+0.01f)a; δ=(γ+β) / 2; Where f is the rock hardness coefficient; α is the dip angle of the ore body; γ is the angle of movement of the footwall strata; β is the angle of movement of the hanging wall strata; δ is the angle of movement of the strike strata; when f<5, α≤60°; when f≥5, α≤65°.

[0009] As a further improvement to this application, in step S1, the deformation parameters of the wellbore satisfy: inclination |i| < 3 mm / m, curvature |k| < 0.2 × 10⁻⁶. -3 / m, horizontal deformation |ε|<2mm / m; the area with a surface subsidence greater than 10mm is the surface subsidence movement zone, and the distance between the well shaft and the surface subsidence movement zone is not less than 20m.

[0010] As a further improvement of this application, in step S2, the width of the protective zone is 20m; the extension height of the rock movement control isolation zone in the upper part of the wellbore is 100~120m.

[0011] As a further improvement of this application, in step S5, the cross-sectional dimensions of the shock-absorbing and pressure-relieving roadway are 3.0m × 3.0m, and the length is the length of the safety pillar of the rock movement control isolation zone at the bottom of the shaft along the strike of the ore body. The roadway roof and adjacent hanging wall sidewalls are supported by anchor bolts with a length of 1.5~1.8m, a hole spacing of 1.4~1.5m, and a row spacing of 1.5~2.0m. The diameter of the shock-absorbing and pressure-relieving pre-splitting holes is greater than 70mm, the hole depth is 10.0~15.0m, the blast hole spacing is 3.0~4.0m, and a non-coupled charging structure is adopted.

[0012] As a further improvement of this application, the enhanced mining area below the security pillar includes two intermediate sections, the height of which is 40-50m, the length of which is 40-50m, the width of which is the thickness of the ore body, the layer height is 3-5m, the maximum control height of the top is 4.5m, no bottom pillar is left, and the thickness of the top pillar is 3-4m.

[0013] As a further improvement to this application, after the first layer of the two intermediate sections is mined, shock-absorbing and pressure-relieving pre-splitting holes are set at a distance of 1 to 1.5m from the bottom plate on the adjacent upper and lower sidewalls. The hole diameter is greater than 70mm. The hole depth on the upper sidewall is 10.0 to 15.0m and the hole spacing is 3.0 to 4.0m. The hole depth on the lower sidewall is 9.0 to 10.0m and the hole spacing is 3.0 to 8.0m. A non-coupled charging structure is adopted.

[0014] As a further improvement to this application, after each layer of the upper middle section of the reinforced mining area under the safety pillar is mined, the hanging wall area of ​​the stope is supported by long anchor cables with a length of 10-15m, a hole spacing of 3.0-4.0m, and a row spacing of 3.0-3.2m; after each layer of the lower middle section of the reinforced mining area under the safety pillar is mined, the hanging wall area of ​​the stope is supported by anchor bolts and double reinforcing bars with a hole spacing of 3.0-4.0m and a row spacing of 3.0-3.2m.

[0015] As a further improvement to this application, the mining sequence of the reinforced mining area under the security pillar is to first mine the central stope, and then mine from the central stope outwards to both sides one by one.

[0016] As a further improvement of this application, in step S6, when the ore body thickness is less than 4m, shallow hole retention followed by backfilling mining method is used for mining; when the ore body thickness is 4~10m, segmented rock drilling stage open space followed by backfilling mining method is used for mining, with the ore blocks arranged along the ore body strike; when the ore body thickness is greater than 10m, segmented rock drilling stage open space followed by backfilling mining method is used for mining, with the ore blocks arranged perpendicular to the ore body strike, and mining is carried out in two steps: stope and pillar.

[0017] The beneficial effects of this application are as follows: This application provides a method for delineating and releasing ore reserves in the hanging wall of a hard rock vein. The method first determines the rock strata movement angle by calculating using empirical formulas and combining numerical simulation analysis. Based on this, a cone-shaped safety pillar is delineated with the shaft center as the reference, and rock movement control isolation zones are set above and below it. The ore body is divided into multiple functional areas, and for different areas, mining methods such as shallow-hole ore retention followed by backfilling, upward horizontal layered backfilling, and staged drilling followed by backfilling are used for safe and efficient mining. Shock absorption, pressure relief, and pre-splitting support are implemented at the top of the reinforced mining area below the safety pillar. Throughout the mining process, the shaft and adjacent rock mass are monitored in real time to ensure that the overburdened ore reserves are released and recovered to the maximum extent possible while ensuring shaft safety.

[0018] This application applies to the delineation and release of ore reserves for safety pillars in the hanging wall of steeply dipping thin to medium-thick hard rock veins. By combining empirical formulas with numerical simulations, safety pillars are scientifically delineated, significantly improving delineation accuracy and preventing excessive ore coverage. Through the establishment of upper and lower rock movement control isolation zones and differentiated mining strategies, the safe and efficient recovery of ore reserves covered within the safety pillars is achieved, greatly enhancing resource utilization. The use of comprehensive technologies such as vibration damping and pressure relief, pre-splitting support, and layered backfilling effectively controls disturbances to the shaft and surrounding rock during mining, ensuring the structural safety of the shaft throughout its entire lifecycle. Simultaneously, the application of a real-time monitoring system provides dynamic safety assurance for the mining process, achieving synergistic optimization of safety and economic benefits, and providing important technical reference for the efficient development of resources in similar mines.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0021] Figure 1 A front view of the ore body partitioning for the method of delineating and releasing ore volume mining of the upper wall shaft safety pillar of a hard rock vein according to an embodiment of this application; Figure 2 A side view of the ore body partitioning for the method of delineating and releasing ore volume mining of the upper shaft safety pillar of a hard rock vein according to an embodiment of this application; Figure 3 This is a schematic diagram of the shock-absorbing and pressure-relieving roadway in the embodiments of this application; Figure 4 This is a front view of the upper middle section of the reinforced mining area below the security pillar in this embodiment of the application; Figure 5 This is a side view of the upper middle section of the reinforced mining area below the security pillar in this embodiment of the application; Figure 6 This is a top view of the upper middle section of the reinforced mining area below the security pillar in the embodiments of this application; Figure 7 This is a front view of the lower middle section of the reinforced mining area below the security pillar in this embodiment of the application; Figure 8 This is a side view of the lower middle section of the reinforced mining area below the security pillar in this embodiment of the application; Figure 9 This is a top view of the lower middle section of the reinforced mining area below the security pillar in the embodiments of this application; Explanation of reference numerals in the attached diagram: 1. Main shaft; 2. Ore body; 3. Ore release zone of the upper safety pillar; 4. Rock movement control isolation zone in the upper part of the shaft; 5. Rock movement control isolation zone in the bottom part of the shaft; 6. Vibration damping and pressure relief roadway; 7. Enhanced mining zone below the safety pillar; 701. Upper middle section; 702. Lower middle section; 8. Normal mining zone below the safety pillar; 9. Surrounding rock; 10. Anchor bolt; 11. Vibration damping and pressure relief pre-splitting hole; 12. Crushed stone filter layer; 13. Geotextile; 14. Filling body; 15. Long anchor cable; 16. Pedestrian filter well; 17. Passageway; 18. Stope connecting roadway; 19. Collapsed ore; 20. Double reinforcing bar. Detailed Implementation

[0022] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0026] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, 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. Therefore, they should not be construed as limitations on the embodiments of this application.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0028] In existing technologies, conventional methods for establishing safety pillars mainly fall into three categories: empirical analogy, theoretical analysis, and numerical analysis. While each method has its advantages, they all share a common limitation: they generally treat safety pillars as permanent and immovable safety barriers. This traditional design approach leads to a situation where, in the mining of steeply dipping thin to medium-thick hard rock veins, safety pillars cover a large amount of mineral resources as the depth increases, resulting in significant resource waste and economic losses. Furthermore, the continuous accumulation of covered ore can easily lead to the depletion of recoverable resources in the later stages of the mine and difficulties in production continuity, severely restricting the sustainable development and economic benefits of the mine.

[0029] To fully utilize proven ore resources, ensure safe underground production and surface stability, and provide crucial technical support and guarantees for the sustainable development of mines, this application proposes a method for delineating and releasing ore reserves in the hanging wall of steeply dipping thin to medium-thick hard rock veins, addressing the technical challenges of shaft safety pillar mining. This method delineates safety pillars, further refining their delineation range. It aims to fully exploit and efficiently utilize proven ore resources while ensuring safe underground operations and maintaining shaft stability. Furthermore, it includes a method for releasing ore reserves from shaft safety pillars, reducing disturbance from blasting and high stress accumulation, ensuring safe recovery of released ore reserves and the safety and stability of the shaft.

[0030] Please refer to Figures 1 to 2 This application provides a method for delineating safety pillars in the hanging wall of a hard rock vein and releasing ore for mining, including the following steps: S1. Calculate the moving angles of the hanging wall strata, footwall strata, and strike strata of ore body 2 using empirical formulas. Construct a three-dimensional numerical model of the mine using numerical simulation software, analyze the deformation of the shaft throughout its entire life cycle, and determine the final moving angles of the strata. S2. Using the centerline of the shaft as a reference, and taking the sum of the shaft radius and the width of the protection zone as the radius, and the rock stratum movement angle as the slope angle of the safety pillar, delineate the cross-sectional cone safety pillar to the bottom of the shaft, and extend upwards for 2-3 middle sections at the bottom of the shaft to form the rock movement control isolation zone 4 in the upper part of the shaft, and extend downwards for 100-150m to form the rock movement control isolation zone 5 in the bottom part of the shaft; S3. Divide the ore body 2 into several areas, including the rock movement control isolation zone 4 in the upper part of the shaft, the rock movement control isolation zone 5 in the bottom part of the shaft, the ore release zone 3 in the upper safety pillar, the enhanced mining zone 7 in the lower part of the safety pillar, and the normal mining zone 8 in the lower part of the safety pillar. S4. The ore body of the upper safety pillar release zone 3 is recovered by using the shallow hole retention and subsequent backfilling mining method; S5. Excavate a vibration damping and pressure relief roadway 6 at the top of the reinforced mining area 7 under the safety pillar, and arrange and support vibration damping and pressure relief pre-splitting holes 11; adopt the upward horizontal layered filling mining method to mine the reinforced mining area 7 under the safety pillar, and provide support after each layer is mined. S6. The normal mining area 8 below the safety pillar is mined by shallow hole retention followed by backfilling mining method or segmented rock drilling stage open area followed by backfilling mining method, depending on the thickness of the ore body 2. S7. Throughout the entire mining process, the wellbore and adjacent rock mass are monitored in real time.

[0031] This application uses a combination of empirical formulas and numerical simulations to accurately determine the rock strata movement angle, scientifically delineate the shaft safety pillar, and set up upper and lower rock movement control isolation zones to achieve full life-cycle protection of the shaft. At the same time, the ore body 2 is divided into multiple functional areas, and differentiated mining methods are used for step-by-step mining. Specifically, the upper ore release area adopts the shallow hole retention and subsequent backfilling method, the lower enhanced mining area implements shock absorption and pressure relief and layered backfilling mining, and the normal mining area flexibly selects appropriate mining technology according to the thickness of ore body 2. Real-time monitoring ensures that the mining process is safe and controllable, thereby achieving safe and efficient release and recovery of the ore covered inside the safety pillar while ensuring the stability of the shaft structure.

[0032] Furthermore, in some embodiments, in step S1, the empirical formula is: γ = 55° + 1.5f; When f 上盘 ≥f 下盘 At that time, β = 55° + 1.5f; When f 上盘 <f 下盘 When, β=55°+1.5f-(0.30+0.01f)a; δ=(γ+β) / 2; Where f is the rock hardness coefficient; α is the dip angle of the ore body; γ is the angle of movement of the footwall strata; β is the angle of movement of the hanging wall strata; δ is the angle of movement of the strike strata; when f < 5, α ≤ 60°; when f ≥ 5, α ≤ 65°. The deformation parameters of the shaft satisfy: inclination |i| < 3 mm / m, curvature |k| < 0.2 × 10⁻⁶. -3 / m, horizontal deformation |ε|<2mm / m; the area with a surface subsidence greater than 10mm is the surface subsidence movement zone, and the distance between the well shaft and the surface subsidence movement zone shall not be less than 20m.

[0033] In the technical solution of this application embodiment, empirical formulas are used to calculate the movement angles of the hanging wall, footwall, and flank strata of ore body 2. Multiple sets of strata movement angle schemes are set, and a three-dimensional numerical simulation calculation model of the mine is constructed using numerical simulation software. The deformation of the shaft during the entire mining life cycle is analyzed under the safety pillar scheme defined by different strata movement angles. By setting displacement monitoring points on the shaft wall, the inclination, curvature, and horizontal deformation index of the shaft wall during mining are calculated, and it is determined whether they exceed the allowable deformation values ​​for Class I buildings and structures in the "Design Code for Nonferrous Metal Mining". At the same time, in conjunction with the "Code for Coal Pillar Retention and Coal Mining of Buildings, Water Bodies, Railways and Main Shafts", areas with surface subsidence greater than 10 mm are defined as surface subsidence movement zones, thereby determining the three-dimensional spatial subsidence movement zone of steeply dipping hard rock thin veins. It is determined whether the distance between the hanging wall shaft and the three-dimensional spatial subsidence movement zone meets the protection zone width required for Class I buildings and structures. Finally, the strata movement angles of the hanging wall and footwall of the steeply dipping hard rock thin vein are comprehensively optimized.

[0034] Furthermore, in some embodiments, in step S2, the width of the protective zone is 20m; the extension height of the rock movement control isolation zone 4 in the upper part of the wellbore is 100~120m.

[0035] In the technical solution of this application embodiment, the shaft safety pillar is delineated according to the preferred rock stratum movement angle in step S1. The delineation method is as follows: with the center line of the shaft at the surface elevation as the center, with the radius as the sum of "shaft radius + the width of the protection zone required by Class I buildings and structures (20m)", and with the preferred rock stratum movement angle as the slope angle of the safety pillar, a cross-section cone safety pillar is set up to delineate the shaft bottom first. Then, from the shaft bottom, 2-3 middle sections (vertical distance 100-120m) of the safety pillar range are extended horizontally to the location of the safety pillar by the empirical formula method, forming the rock movement control isolation zone 4 in the upper area of ​​the shaft. At the same time, from the cross-section of the safety pillar at the horizontal elevation at the bottom of the shaft, a certain distance is extended vertically downward to form the cylindrical shaft bottom area rock movement control isolation zone 5. The extension distance is controlled at 100-150m. Specific parameters can also be set up in multiple schemes first, and analyzed and determined by numerical analysis method according to the method of step S1.

[0036] Furthermore, in some embodiments, in step S5, the cross-sectional dimensions of the shock-absorbing and pressure-relieving roadway 6 are 3.0m × 3.0m, and its length is the length of the safety pillar of the rock movement control isolation zone 5 at the bottom of the shaft along the strike of the ore body 2. The roadway roof and adjacent hanging wall sidewalls are supported by anchor bolts 10, with a length of 1.5~1.8m, a hole spacing of 1.4~1.5m, and a row spacing of 1.5~2.0m. The diameter of the shock-absorbing and pressure-relieving pre-splitting holes 11 is greater than 70mm, the hole depth is 10.0~15.0m, the hole spacing is 3.0~4.0m, and a non-coupled charging structure is adopted.

[0037] In the technical solution of this application embodiment, before the mining of the reinforced mining area 7 below the safety pillar, a shock-absorbing and pressure-relieving roadway 6 with a cross-section of 3.0m × 3.0m needs to be excavated on its top, such as... Figure 3 As shown, the roadway length is the length of the safety pillar 5 in the rock movement control isolation zone at the bottom of the shaft along the strike of ore body 2. The roadway roof and adjacent hanging wall sidewalls are supported by anchor bolts 10, with a length of 1.5~1.8m, a hole spacing of 1.4~1.5m, and a row spacing of 1.5~2.0m. At the same time, a row of blasting energy-absorbing and shock-absorbing pre-splitting holes 11 are drilled at a distance of 1~1.5m from the bottom plate adjacent to the hanging wall and hanging wall sidewalls. The hole diameter is greater than 70mm, the hole depth is 10.0~15.0m, and the hole spacing is 3.0~4.0m. A decoupled charging structure is used. Before backfilling the roadway, the holes of the pre-splitting holes must be sealed with cement mortar. At the same time, a 20cm thick layer of crushed stone is laid at the bottom, followed by a layer of geotextile 13, and finally backfilling is carried out. The strength of the backfill 14 is above 2MPa to ensure effective support and stress isolation for the goaf. By pre-excavating a shock-absorbing and pressure-relieving roadway 6 at the top of the enhanced mining area and implementing anchor bolt support 10 and pre-splitting blasting, the stress transmission path was actively cut off, effectively absorbing and weakening the blasting vibration and stress concentration generated by subsequent mining operations, and significantly reducing the disturbance to the upper shaft and surrounding rock 9. At the same time, the sealing of the shock-absorbing and pressure-relieving pre-splitting holes 11, the laying of the crushed stone filter layer 12 and geotextile 13 before roadway filling ensured the integrity, strength and water-proof performance of the filling body 14, forming a stable artificial roof and an effective rock stratum control barrier. This not only provided a safe and reliable working environment for the lower enhanced mining, but also further controlled the movement of the rock strata through the supporting effect of the filling body 14, achieving the dual goals of safely and efficiently releasing the overburdened ore and ensuring the long-term stability of the shaft.

[0038] Please refer to Figures 4 to 9 Furthermore, in some embodiments, the reinforced mining area 7 below the security pillar includes two intermediate sections, the height of which is 40-50m, the length of which is 40-50m, the width of which is the thickness of the ore body 2, the layer height is 3-5m, the maximum control height of the top is 4.5m, no bottom pillar is left, and the thickness of the top pillar is 3-4m.

[0039] In the technical solution of this application embodiment, the reinforced mining area 7 below the safety pillar is vertically divided into two independent intermediate sections for mining. The height of each intermediate section is designed to be 40-50m to ensure reasonable mining intensity and strata control capability. The length of the stope along the strike of the ore body 2 is 40-50m, and the width is consistent with the thickness of the ore body 2 to achieve full-face mining. The mining adopts the upward horizontal layered filling method, with the layer height controlled at 3-5m. The maximum control height during operation does not exceed 4.5m to ensure the safety of the mining face. To maximize the resource recovery rate, this area is designed without bottom pillars; at the same time, to protect the upper filling body 14 and the isolation layer, a top pillar with a thickness of 3-4m is left between the two intermediate sections as a safety barrier when mining the next intermediate section. Personnel and equipment enter the stope through the pedestrian filter wells 16 on both sides of the stope and the stope connecting road 18. The collapsed ore 19 is scraped by electric scrapers to the ore pass 17 and then transported out by electric locomotive.

[0040] Furthermore, in some embodiments, after the first layer of the two intermediate sections is mined, shock-absorbing and pressure-relieving pre-splitting holes 11 are set at a distance of 1 to 1.5m from the bottom plate on the adjacent upper and lower sidewalls. The hole diameter is greater than 70mm, the hole depth on the upper sidewall is 10.0 to 15.0m and the hole spacing is 3.0 to 4.0m, and the hole depth on the lower sidewall is 9.0 to 10.0m and the hole spacing is 3.0 to 8.0m. A non-coupled charging structure is adopted.

[0041] In the technical solution of this application embodiment, in order to accurately control the blasting damage range of the surrounding rock 9 in the stope and protect the stability of the hanging wall and footwall, after the mining of the first layer of the two middle sections of the reinforced mining area 7 under the safety pillar, a row of blasting energy-absorbing, shock-absorbing and pressure-relieving pre-splitting holes 11 need to be drilled at a distance of 1~1.5m from the bottom plate near the sidewall of the hanging wall and footwall to carry out pre-splitting blasting. All pre-splitting holes are blasted using a decoupled charge structure to form a through pre-splitting surface, thereby effectively isolating the disturbance of the final boundary by the subsequent mining blasting.

[0042] Furthermore, in some embodiments, after each layer of the upper middle section 701 of the reinforced mining area 7 under the safety pillar is mined, the hanging wall area of ​​the stope is supported by long anchor cables 15, with an anchor cable length of 10-15m, a hole spacing of 3.0-4.0m, and a row spacing of 3.0-3.2m; after each layer of the lower middle section 702 of the reinforced mining area 7 under the safety pillar is mined, the hanging wall area of ​​the stope is supported by anchor bolts 10 and double reinforcing bars 20, with a hole spacing of 3.0-4.0m and a row spacing of 3.0-3.2m.

[0043] In the technical solution of this application embodiment, to adapt to the stress characteristics and deformation risks of the hanging wall 9 after mining in different intermediate sections of the stope, a regional and differentiated active support strategy is adopted in the reinforced mining area 7 below the safety pillar. For the upper intermediate section 701, where stress is concentrated and the impact range is wider, long anchor cables 15 are immediately implemented in the hanging wall area after each layer of mining to achieve active suspension and reinforcement of the deep unstable rock strata; while for the lower intermediate section 702, where the stress is relatively small and the rock mass integrity is better, anchor bolts 10 and double reinforcing bars 20 are used for joint support in the hanging wall area after each layer of mining. Through the anchoring effect of the anchor bolts 10 and the overall connection effect of the double reinforcing bars 20, an effective surface reinforcement zone is formed. This regional and intensity-differentiated support design can accurately match the control requirements of the surrounding rock 9 in different areas, and optimize the support cost and efficiency while ensuring safety.

[0044] Furthermore, in some embodiments, the mining sequence of the reinforced mining area 7 below the security pillar is to first mine the central stope, and then mine from the central stope outwards to both sides one by one.

[0045] In the technical solution of this application embodiment, the mining operation first proceeds from the central mining area, and then, starting from this central mining area, mining is carried out symmetrically and sequentially on both sides. By first forming a central free face, a channel for releasing and transferring stress generated during the subsequent mining of the mining areas on both sides is provided, thereby avoiding the formation of high stress concentration zones at the boundaries or key locations, effectively reducing disturbance to the hanging wall 9 and adjacent shafts, and ensuring the safety and controllability of the entire enhanced mining process.

[0046] Furthermore, in some embodiments, in step S6, when the thickness of ore body 2 is less than 4m, shallow hole retention followed by backfilling mining method is used for mining; when the thickness of ore body 2 is 4~10m, segmented rock drilling stage open space followed by backfilling mining method is used for mining, with the ore blocks arranged along the strike of ore body 2; when the thickness of ore body 2 is greater than 10m, segmented rock drilling stage open space followed by backfilling mining method is used for mining, with the ore blocks arranged perpendicular to the strike of ore body 2, and mining is carried out in two steps: stope and pillar.

[0047] In the technical solution of this application embodiment, for the normal mining area 8 below the safety pillar, differentiated mining methods and structural parameters are adopted according to the different thicknesses of the ore body 2 to achieve safe and efficient mining. Specifically, when the thickness of the ore body 2 is <4m, shallow-hole stoping followed by backfilling mining method is used for mining, with a stope length of 40~60m, a stope width equal to the thickness of the ore body 2, and a stope height of 40~50m. A 6m wide inter-pillar and a 5m thick top pillar are left between the stopes. To improve resource recovery rate, no bottom pillar is left under this condition. When 4m ≤ ore body 2 thickness ≤ 10m, segmented drilling stage open-stope followed by backfilling mining method is used for mining, with the ore blocks arranged along the strike and a division height of 1. 5m, with a 5m thick top pillar and an 8m wide interstitial pillar; when the thickness of ore body 2 is >10m, the segmented rock drilling stage open-pit subsequent backfilling mining method is also adopted for mining, but the block layout and mining process are adjusted. The blocks are arranged perpendicular to the strike of ore body 2, and are divided into stopes and pillars. Two-step mining is adopted during mining, first mining the stopes and then mining the pillars. The stope length is the thickness of ore body 2, the span of the stopes and pillars is 15m, the division height is 15m, and the thickness of the top pillar is 5m.

[0048] Throughout the entire process of releasing ore from the safety pillar, it is necessary to monitor the stress and displacement of the main shaft 1 wall or adjacent ore in real time, analyze and process the monitoring data regularly, calculate the deformation index of the main shaft 1 wall based on the monitoring data, and determine whether the deformation of the shaft wall during production meets the requirements of the "Design Code for Nonferrous Metal Mining".

[0049] The method for delineating safety pillars and releasing ore reserves in the hanging wall of hard rock veins provided in this application has the following advantages compared with conventional methods: 1. Reduce the amount of ore covered by safety pillars: Compared with conventional safety pillar delineation methods, the amount of ore covered in the main shaft area of ​​the hanging wall is reduced by 40% to 50%, while the release rate of ore covered in the deep area is close to 100%; 2. Significantly reduced disturbance and high stress accumulation during blasting mining: The ore release area is rationally divided and mined using low-disturbance mining methods. At the same time, vibration-damping and stress-relieving roadways and intermediate vibration-damping and stress-relieving holes are arranged, resulting in a stress reduction of 40% to 50% and a vibration reduction of 35% to 40%. 3. Improve the stability and safety of the shaft: The anchor bolts or grouting long anchor cables used for reinforcement of the roof and sidewalls of the pressure relief roadway and the hanging wall of each layer of mining area have significantly controlled the rock movement in the shaft safety pillar area, thus improving the stability and safety of the shaft. 4. Promote the improvement of enterprise economic benefits and stable development: The significant release of the ore covered by the mine, along with the supporting measures for rock movement, blasting vibration, ground pressure control, and zoned mining, has extended the service life of the mine and promoted the healthy and stable development of mining enterprises.

[0050] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for delineating safety pillars and releasing ore reserves in a hanging wall shaft of a hard rock vein, characterized in that, Includes the following steps: S1. Calculate the moving angles of the hanging wall strata, footwall strata, and strike strata of the ore body using empirical formulas. Construct a three-dimensional numerical model of the mine using numerical simulation software, analyze the deformation of the shaft throughout its entire life cycle, and determine the final moving angles of the strata. S2. Using the centerline of the shaft as a reference, and taking the sum of the shaft radius and the width of the protection zone as the radius, and the rock strata movement angle as the slope angle of the safety pillar, delineate the cross-sectional cone safety pillar to the bottom of the shaft, and extend upwards for 2-3 middle sections at the bottom of the shaft to form a rock movement control isolation zone in the upper part of the shaft, and extend downwards for 100-150m to form a rock movement control isolation zone in the bottom part of the shaft; S3. Divide the ore body into several areas, including the rock movement control isolation zone in the upper part of the shaft, the rock movement control isolation zone in the bottom part of the shaft, the ore release zone of the upper safety pillar, the enhanced mining zone below the safety pillar, and the normal mining zone below the safety pillar. S4. The ore body in the upper safety pillar release zone is recovered by using the shallow hole retention and subsequent backfilling mining method; S5. Excavate a vibration-damping and pressure-relief roadway at the top of the reinforced mining area below the safety pillar, and arrange and support vibration-damping and pressure-relief pre-splitting holes; use the upward horizontal layered backfilling mining method to mine the reinforced mining area below the safety pillar, and provide support after each layer is mined. S6. The normal mining area below the safety pillar shall be mined using either shallow hole retention followed by backfilling mining or segmented rock drilling stage open area followed by backfilling mining, depending on the thickness of the ore body. S7. Throughout the entire mining process, the wellbore and adjacent rock mass are monitored in real time.

2. The method for delineating and releasing ore reserves using a hanging wall shaft safety pillar in hard rock veins according to claim 1, characterized in that, In step S1, the empirical formula is: γ = 55° + 1.5f; When f 上盘 ≥f 下盘 At that time, β = 55° + 1.5f; When f 上盘 <f 下盘 When, β=55°+1.5f-(0.30+0.01f)a; δ=(γ+β) / 2; Where f is the rock hardness coefficient; α is the dip angle of the ore body; γ is the angle of movement of the footwall strata; β is the angle of movement of the hanging wall strata; δ is the angle of movement of the strike strata; when f<5, α≤60°; when f≥5, α≤65°.

3. The method for delineating and releasing ore reserves using a safety pillar in a hanging wall of a hard rock vein according to claim 1, characterized in that... In step S1, the deformation parameters of the wellbore satisfy: inclination |i| < 3 mm / m, curvature |k| < 0.2 × 10⁻⁶. -3 / m, horizontal deformation |ε|<2mm / m; the area with a surface subsidence greater than 10mm is the surface subsidence movement zone, and the distance between the well shaft and the surface subsidence movement zone is not less than 20m.

4. The method for delineating and releasing ore reserves using a hanging wall shaft safety pillar in hard rock veins according to claim 1, characterized in that, In step S2, the width of the protective zone is 20m; the extension height of the rock movement control isolation zone in the upper part of the wellbore is 100~120m.

5. The method for delineating safety pillars and releasing ore reserves in hard rock veins according to claim 1, characterized in that, In step S5, the cross-sectional dimensions of the shock-absorbing and pressure-relieving roadway are 3.0m × 3.0m, and the length is the length of the safety pillar of the rock movement control isolation zone at the bottom of the shaft along the strike of the ore body. The roadway roof and adjacent hanging wall sidewalls are supported by anchor bolts with a length of 1.5~1.8m, a hole spacing of 1.4~1.5m, and a row spacing of 1.5~2.0m. The diameter of the shock-absorbing and pressure-relieving pre-splitting holes is greater than 70mm, the hole depth is 10.0~15.0m, the hole spacing is 3.0~4.0m, and a decoupled charging structure is adopted.

6. The method for delineating and releasing ore reserves using a safety pillar in a hanging wall of a hard rock vein according to claim 5, characterized in that... The reinforced mining area below the security pillar includes two intermediate sections. The height of each intermediate section is 40-50m, the length of the stope is 40-50m, the width of the stope is equal to the thickness of the ore body, the layer height is 3-5m, the maximum control height of the roof is 4.5m, no bottom pillar is left, and the thickness of the top pillar is 3-4m.

7. The method for delineating safety pillars and releasing ore reserves in hard rock veins according to claim 6, characterized in that, After the first layer of the two intermediate sections is mined, shock-absorbing and pressure-relieving pre-splitting holes are set at a distance of 1 to 1.5m from the bottom plate on the adjacent upper and lower sidewalls. The hole diameter is greater than 70mm. The hole depth on the upper sidewall is 10.0 to 15.0m and the hole spacing is 3.0 to 4.0m. The hole depth on the lower sidewall is 9.0 to 10.0m and the hole spacing is 3.0 to 8.0m. A decoupled charging structure is adopted.

8. The method for delineating safety pillars and releasing ore reserves in a hard rock vein according to claim 7, characterized in that, After each layer of the upper middle section of the reinforced mining area under the safety pillar is mined, the hanging wall area of ​​the stope is supported by long anchor cables with a length of 10-15m, a hole spacing of 3.0-4.0m, and a row spacing of 3.0-3.2m. After each layer of the lower middle section of the reinforced mining area under the safety pillar is mined, the hanging wall area of ​​the stope is supported by anchor bolts and double reinforcing bars with a hole spacing of 3.0-4.0m and a row spacing of 3.0-3.2m.

9. The method for delineating safety pillars and releasing ore reserves in hard rock veins according to claim 5, characterized in that, The mining sequence of the reinforced mining area below the security pillar is to first mine the central stope, and then mine from the central stope outwards to both sides one by one.

10. The method for delineating and releasing ore reserves using a hanging wall shaft safety pillar in hard rock veins according to claim 1, characterized in that, In step S6, when the ore body thickness is less than 4m, shallow hole retention followed by backfilling mining method is used for mining; when the ore body thickness is 4~10m, segmented rock drilling stage open space followed by backfilling mining method is used for mining, with the ore blocks arranged along the ore body strike; when the ore body thickness is greater than 10m, segmented rock drilling stage open space followed by backfilling mining method is used for mining, with the ore blocks arranged perpendicular to the ore body strike, and mining is carried out in two steps: stopes and pillars.

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