A method for arranging mining projects in confined space with ultra-high-panel pillars

Abstract

The present application belongs to the field of mining, and in particular relates to a method for arranging a confined space mining project for ultra-high panel pillars, comprising the following steps: S1. Mining area division; S2. Backfill retaining wall construction and backfilling operations; S3. Ramp construction; S4. New mining level and tunnel layout; S5. Mining tunnel support design; S6. Bottom tunnel support design. By optimizing the mining area layout, shortening the ore transportation distance, and improving the transportation and mining efficiency, the mining cost and complexity are reduced, and the mining production efficiency and economic benefits are improved. This method comprehensively considers the panel layout, production capacity and cost optimization, and provides an efficient and economic solution for confined space pillar mining.

Description

Technical Field

[0001] The present application relates to the field of mining technology, and in particular to a method for arranging a mining project for confined space in an ultra-high panel area. Background Art

[0002] Due to their height and narrow width, the panel pillars have only one access tunnel at the bottom. Furthermore, the fillings on both sides of the panel pillars are relatively weak and tall, and the space for mining and preparation, especially the layout of the bottom structure, is limited. Therefore, it is necessary to flexibly select the appropriate bottom structure based on the mining technical conditions and surrounding environmental conditions for each panel pillar. Based on the experience of staged (sub-stage) open-stop and subsequent backfill mining methods both domestically and internationally, three bottom structures can be used: trench bottom structure, flat bottom structure, and funnel bottom structure. The bottom structure of the trench is safer because the shovel loader loads ore in a dedicated tunnel, but its ore discharge eyebrow is easily damaged by the impact of the ore flow, and residual losses will be caused between the end of the access road in the mining area and the two loading access roads; the flat bottom structure is relatively simple, and the mining and cutting workload is small, but there are risks such as the shovel loader being hit or buried during operation; the funnel bottom structure is similar to the trench bottom structure in terms of ore discharge method, but it uses intermittent ore-receiving funnels instead of a fully opened trench. Compared with the trench, the funnel causes less damage to the bottom structure, but its ore-receiving conditions are worse than those of the trench, and the mining accuracy workload is large.

[0003] Because most of the panel pillars are flanked by equal-height backfill, space for bottom structural engineering is severely limited. Given the presence of panel-connected tunnels in the center of the pillar, rationally arranging the bottom ore-discharging system presents a significant challenge. The bottom structure of the block is a critical component of the mining method, and its design directly impacts production capacity, labor productivity, ore loss and dilution, and the safety of ore-discharging operations. The bottom structure design should ensure that it meets ore-drawing requirements, provides excellent stability, guarantees ore-discharging quality, minimizes engineering effort, and strives for a simple structure and ease of construction.

[0004] Currently, the panel stope is high, difficult to construct, and limited in space. Furthermore, there is only one horizontal tunnel between the panel pillars, which cannot meet the requirements for mining thick ore bodies and is not suitable for distributed mining and ore extraction equipment. Summary of the Invention

[0005] The embodiment of the present application provides a method for arranging a mining project for confined spaces in ultra-high-pan pillar areas. Through scientific mining area division, filling wall construction, tunnel layout and support design, it effectively solves the safety and economic problems of high-pan pillar mining.

[0006] To achieve the above objectives, the present application provides a method for arranging a confined space mining project for an ultra-high panel pillar. The mining and backfilling operations have been completed in the stopes on both sides of the panel pillar. An original mining tunnel is provided at the bottom middle of the panel pillar along the direction of the panel pillar. The method for arranging a confined space mining project for an ultra-high panel pillar comprises the following steps:

[0007] S1. Mining Area Division: Divide the panel pillars into several mining areas based on the distribution characteristics and vertical changes of the ore body. Leave permanent pillars between adjacent mining areas, and divide each mining area into multiple continuous panel stopes;

[0008] S2. Backfill Retaining Wall Construction and Backfilling Operations: Prior to mining in a pan stope within a particular mining area, backfill retaining walls are constructed at both ends of the original mining tunnel between the mining area and the bottom of the permanent ore pillar located to its left. The original mining tunnel between the mining area and the bottom of the permanent ore pillar located to its left is backfilled with full tailings cementation.

[0009] S3 ramp construction: construction of the ramp in the permanent pillar, the ramp starts from the original mining tunnel at the bottom of the mining area on the left side of the permanent pillar, and extends to the upper right in the permanent pillar;

[0010] S4. New Mining Level and Roadway Arrangement: At the right end of the ramp, a bottom lane and an exit lane are constructed along the direction of the panel pillar toward the mining area level. These serve as new mining levels for panel stopes within the mining area. A certain width is provided between the exit lane and the backfill on one side of the panel pillar. The bottom lane is arranged close to the backfill on the other side of the panel pillar. Within each panel stope, an exit access is constructed between the bottom lane and the exit lane.

[0011] S5. Mine exit tunnel support: The mine exit tunnel uses a steel arch frame, and the side of the mine exit tunnel close to the backfill is sprayed with concrete to ensure the stability of the tunnel;

[0012] S6. Ladi tunnel support: The Ladi tunnel adopts shotcrete mesh support, and the angle of the ore cutting trench does not exceed the natural repose angle of the ore.

[0013] Optionally, in step S1, the length of the permanent pillar is L1, L1=(L n +L n+1 ) / 3, where L n is the length of the mining area on the left side of the permanent pillar, L n+1 It is the length of the mining area on the right side of the permanent pillar.

[0014] Optionally, in step S2, the 28d compressive strength of the filling body in the original mining tunnel is not less than 3.0 MPa.

[0015] Optionally, in step S3, the slope of the ramp is 10% to 15%, the height difference between the two ends of the ramp is H, H=(10% to 15%)L1, and the length of the ramp is L2. L1 is the length of the permanent pillar.

[0016] Optionally, in step S4, there is an oblique angle α between the mine exit route and the mine exit tunnel, and α is designed according to the turning ability of the scraper and the tunnel space.

[0017] Optionally, in step S5, the mining tunnel is supported by a 25U steel arch frame, the spacing between adjacent 25U steel arch frames is 0.8 meters, and is equipped with a Φ22 threaded anchor rod with a length of 1.5 meters. The base width of the 25U steel arch frame is 2 meters, and C25 concrete with a thickness of 15 cm is sprayed on the side of the mining tunnel close to the filling body.

[0018] Optionally, in step S6, the specifications of the anchor rods are Φ20mm×2200mm, the spacing is 1.2m×1.2m, and the specifications of the anchor cables are Φ21.8mm×7300mm.

[0019] The beneficial effects of the method for arranging a mining project in a confined space in an ultra-high panel area provided by this application are:

[0020] By adopting a phased, open-stop, and backfill mining method, the underground panel pillars were divided into mining areas for optimized layout. By constructing backfill retaining walls and filling the original exit tunnel at the bottom of the mining area, a new exit tunnel and bottom tunnel were constructed at a certain height above the original exit tunnel. Based on the original exit tunnel, a dual-tunnel mining layout was designed, addressing the previously limited space at the bottom of the panel pillars. The permanent pillars and backfill retaining walls ensured the stability of the upper construction and tunnels, avoiding the risk of instability in traditional stopes within the pillar-restricted area. The optimized layout of the new exit levels and ramps improved mining efficiency, shortened ore hauling distances, increased transportation and ore extraction efficiency, and reduced mining costs and complexity. Steel arch support technology enhanced the safety of the exit tunnels in the ultra-high stopes and avoided the risk of rock collapse. Furthermore, the continuous mining of multiple panel stopes not only reduced the cost and preparation time of panel pillar mining but also effectively reduced the complexity and overall cost of backfilling the voids, further improving mining production efficiency and economic benefits. This method comprehensively considers panel layout, production capacity, and cost optimization, providing an efficient and economical solution for pillar mining in confined spaces. While ensuring safety, it reduces construction difficulty and improves mine recovery and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] in:

[0023] Figure 1 This is a flow chart of a method for arranging a mining project in a confined space in an ultra-high panel area, as shown in one embodiment of the present application;

[0024] Figure 2 This is a diagram illustrating the division of panel pillars in a method for arranging ultra-high panel pillars in a confined space mining project according to an embodiment of the present application;

[0025] Figure 3 It is a longitudinal projection diagram of a mining project in a method for arranging a mining project in a confined space in an ultra-high panel pillar area, as shown in one embodiment of the present application;

[0026] Figure 4 This is a diagram showing the bottom structure of a panel pillar in a method for arranging a super-high panel pillar confined space mining project according to an embodiment of the present application;

[0027] Figure 5 It is a schematic diagram of an upward inclined ramp in a method for arranging an ultra-high panel pillar confined space mining project shown in one embodiment of the present application.

[0028] Description of reference numerals:

[0029] 1. Pan area pillars; 101. Mining area; 2. Backfill retaining wall; 3. Inclined ramp; 4. Chute; 5. Pan area stope; 6. Backfill; 7. Mine exit tunnel; 8. Bottom tunnel; 9. Mine exit approach; 10. Cutting trough; 11. Cutting skylight; 12. Permanent pillars; 13. Blast holes; 14. Stope trench; 15. Bottom pillar; 16. Concrete; 17. Original mine exit tunnel; 18. Roof. DETAILED DESCRIPTION

[0030] To facilitate understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many other forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0031] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the terms "length," "width," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended only to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting this application. In the description of this application, "plurality" means two or more, unless otherwise expressly and specifically defined.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0034] As mentioned in the background, currently, the height of the panel stope is high, construction is difficult, and space is limited. Furthermore, there is only one horizontal connecting lane before the panel pillar, which cannot meet the requirements of thick ore bodies and is not suitable for distributed mining and ore extraction equipment.

[0035] The present invention is different from other one-step mining or two-step mining double-tunnel layout methods. When there are filling bodies on both sides of the ore pillars in the pan area and the bottom space is limited, the original ore-exporting tunnel is filled and then a new horizontal tunnel is designed. While ensuring safety, it reduces the construction difficulty and improves the mine recovery rate and economic benefits.

[0036] The embodiment of the present application provides a method for arranging mining projects in a confined space in an ultra-high-pit area, which is particularly suitable for areas with high stope heights, high construction difficulty, and limited mining project arrangements. Figure 1-Figure 5 As shown, the mining and filling operations have been completed on both sides of the panel pillar 1. The original mining tunnel 17 is set at the middle position of the bottom of the panel pillar 1 along the direction of the panel pillar 1. The layout method of the confined space mining project of the super-high panel pillar includes the following steps:

[0037] S1. Mining area division: Divide the panel pillar 1 into several mining areas 101 according to the ore body distribution characteristics and vertical changes of the ore body. Figure 4It is shown that the mining area 101 is divided into three continuous pan-area stopes 5, and permanent pillars 12 are left between adjacent mining areas 101, dividing each mining area 101 into multiple continuous pan-area stopes 5; the permanent pillars 12 serve as structural supports, which can effectively withstand the surrounding rock pressure, reduce the mutual influence between stopes, and prevent large-scale collapse.

[0038] The length of the permanent pillar 12 is L1, L1 = (L n +L n+1 ) / 3, where L n is the length of the mining area 101 on the left side of the permanent pillar 12, L n+1 is the length of the mining area 101 on the right side of the permanent pillar 12, and the length of the mining area 101 is L n =75m, L n+1 =75m, then the length L1 of the permanent pillar 12 left between the two mining areas 101 = (75+75)×1 / 3 = 50m.

[0039] S2. Construction of filling retaining wall and filling operation: before mining the disk stope 5 in a certain mining area 101, a filling retaining wall 2 is built at both ends of the original mining tunnel 17 at the bottom of the mining area 101 and the permanent ore pillar 12 located on its left side, and the original mining tunnel 17 at the bottom of the mining area 101 and the permanent ore pillar 12 located on its left side is filled with full tailings cementation; in order to ensure the safety and stability of the bottom tunnel 8 and the mining tunnel 7 constructed in the upper part of the subsequent step S4, the 28d compressive strength of the filling body in the original mining tunnel 17 is not less than 3.0MPa.

[0040] S3 ramp construction: construction of the permanent pillar 12 in the ramp 3, the ramp 3 starts from the permanent pillar 12 on the left side of the mining area 101 at the bottom of the original mining tunnel 17, and the permanent pillar 12 extends to the upper right; it should be noted that, as Figure 4 As shown, a cutting groove 10 and a chute 4 communicating with the original mining tunnel 17 are also provided at the bottom of the mining area 101 on the left.

[0041] Specifically, the slope of the ramp 3 is 10% to 15%, the height difference between the two ends of the ramp 3 is H, H = (10% to 15%) L1, and the length of the ramp 3 is L2. When H is 6 meters and L1 is 50 meters, the length of ramp 3 can be calculated by the above formula:

[0042] S4. New mining level and roadway layout: At the right end of the ramp 3, a bottom laneway 8 and an exit laneway 7 are constructed along the direction of the panel pillar 1 toward the mining area 101 level. These serve as new mining levels for the panel stope 5 within the mining area 101. Due to the high height of the panel pillar 1 and the low strength of the backfill 6, and the fact that the exit laneway 7 is a permanent reserved laneway, a certain width (d = 18 × 20% = 3.6m) is provided between the exit laneway 7 and the backfill 6 on one side of the panel pillar 1 to prevent collapse; the bottom laneway Road 8 is a temporary tunnel. The bottom tunnel 8 is arranged close to the filling body 6 on the other side of the panel pillar 1. In each panel mining field 5, a mining access road 9 is constructed between the bottom tunnel 8 and the mining tunnel 7. By optimizing the layout of the mining access road 9, multiple panel mining fields 5 can share the same mining tunnel 7, avoiding the duplication of work and waste of resources caused by setting up a separate mining channel for each panel mining field 5, thereby reducing the cost of engineering construction. At the same time, it simplifies the mining process, improves the efficiency of the mining operation, and saves time and human resources.

[0043] Furthermore, the bottom tunnel 8 in each panel stope 5 is also provided with a cutting shaft 11. There is an oblique angle α between the mining access road 9 and the mining tunnel 7. α is designed based on the turning capability of the scraper and the tunnel space. Preferably, the oblique angle α between the mining access road 9 and the mining tunnel 7 is 45°.

[0044] S5. Mine roadway support: The mine roadway 7 uses a steel arch frame, the mine roadway 7 is sprayed with concrete 16 on one side of the backfill body 6 to ensure the stability of the roadway;

[0045] Specifically, the mining tunnel 7 is supported by 25U steel arch frames, the spacing between adjacent 25U steel arch frames is 0.8 meters, and it is equipped with Φ22 threaded anchor rods with a length of 1.5 meters. The base width of the 25U steel arch frames is 2 meters. The mining tunnel 7 is sprayed with 15 cm thick C25 concrete on the side close to the filling body 6 to ensure stability and strength.

[0046] S6. Bottom tunnel support: The bottom tunnel 8 is supported by a shotcrete mesh. The anchor rod specification is Φ20mm×2200mm, the spacing is 1.2m×1.2m, the anchor cable specification is Φ21.8mm×7300mm, and the angle of the ore cut does not exceed the natural repose angle β of the ore. Preferably, β=45°.

[0047] Furthermore, after step S6, step S7 is further included. Blast hole arrangement: There are two rock drilling horizontal panel area joint tunnels on the upper part of the original mining joint tunnel of the panel area pillar 1, which can be used as rock drilling tunnels, and downward fan-shaped blast holes 13 are constructed, with a hole bottom distance d m =2.7m, retaining walls on both sides of panel stope 5 are reserved l =18×10%=1.8m.

[0048] In the embodiments of the present application, the method for arranging a confined space mining project for ultra-high-panel pillars utilizes a phased open-pit, then backfill mining method to divide the underground panel pillar 1 into a mining area 101 for optimized layout. By constructing a backfill retaining wall 2 and filling the original mining tunnel 17 at the bottom of mining area 101, a new mining tunnel 7 and bottom tunnel 8 are constructed at a certain height above the original mining tunnel 17. Based on the original mining tunnel 17, a dual-tunnel mining layout is designed, solving the problem of limited space at the bottom of the panel pillar 1.

[0049] The design of the permanent pillars 12 in step S1 and the backfill retaining wall 2 in step S2 ensures the stability of upper construction and roadways, avoiding the risk of instability in traditional stopes within the pillar-restricted area. The optimized layout of the new mining levels and ramps 3 in steps S3 and S4 improves mining efficiency, shortens ore transportation distances, improves transportation and mining efficiency, and reduces mining costs and complexity. The steel arch support technology in step S5 improves the safety of the ultra-high stope mining roadway 7 and avoids the risk of rock collapse. Furthermore, the continuous mining of multiple panel stopes 5 not only saves the cost and preparation time of panel pillar 1 mining, but also effectively reduces the complexity and overall cost of backfilling the voids, further improving mining production efficiency and economic benefits.

[0050] This method comprehensively considers panel layout, production capacity, and cost optimization, providing an efficient and economical solution for pillar mining in confined spaces. While ensuring safety, it reduces construction difficulty and improves mine recovery and economic benefits.

[0051] In summary, this invention provides a method for mining and arranging ultra-high-panel pillars in confined spaces. By optimizing the layout of mining area 101, shortening ore transportation distances, and improving transportation and ore extraction efficiency, this method reduces mining costs and complexity, thereby enhancing mining production efficiency and economic benefits. This method comprehensively considers panel layout, production capacity, and cost optimization, providing an efficient and economic solution for mining pillars in confined spaces.

[0052] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for arranging a mining project in a confined space of an ultra-high ore pillar, wherein the mining and backfilling operations have been completed in the stopes on both sides of the ore pillar, and an original ore-exit tunnel is provided at the bottom middle position of the ore pillar along the direction of the ore pillar, characterized in that: The method for arranging a mining project in a confined space in an ultra-high panel area includes the following steps: S1. Mining Area Division: Divide the panel pillars into several mining areas based on the distribution characteristics and vertical changes of the ore body. Leave permanent pillars between adjacent mining areas, and divide each mining area into multiple continuous panel stopes; S2. Backfill Retaining Wall Construction and Backfilling Operations: Prior to mining in a pan stope within a particular mining area, backfill retaining walls are constructed at both ends of the original mining tunnel between the mining area and the bottom of the permanent ore pillar located to its left. The original mining tunnel between the mining area and the bottom of the permanent ore pillar located to its left is backfilled with full tailings cementation. S3 ramp construction: construction of the ramp in the permanent pillar, the ramp starts from the original mining tunnel at the bottom of the mining area on the left side of the permanent pillar, and extends to the upper right in the permanent pillar; S4. New Mining Level and Roadway Arrangement: At the right end of the ramp, a bottom lane and an exit lane are constructed along the direction of the panel pillar toward the mining area level. These serve as new mining levels for panel stopes within the mining area. A certain width is provided between the exit lane and the backfill on one side of the panel pillar. The bottom lane is arranged close to the backfill on the other side of the panel pillar. Within each panel stope, an exit access is constructed between the bottom lane and the exit lane. S5. Mine exit tunnel support: The mine exit tunnel uses a steel arch frame, and the side of the mine exit tunnel close to the backfill is sprayed with concrete to ensure the stability of the tunnel; S6. Bottom tunnel support: The bottom tunnel adopts shotcrete support, and the angle of the ore cut does not exceed the natural angle of repose of the ore; In step S3, the slope of the ramp is 10% to 15%, the height difference between the two ends of the ramp is H, H = (10% to 15%) L1, and the length of the ramp is L2. ; L1 is the length of the permanent pillar.

2. The method for arranging a mining project in a confined space in an ultra-high panel area according to claim 1 is characterized in that: In step S1, the length of the permanent pillar is L1, L1=(L n +L n+1 ) / 3, where L n is the length of the mining area on the left side of the permanent pillar, L n+1 It is the length of the mining area on the right side of the permanent pillar.

3. The method for arranging a mining project in a confined space in an ultra-high panel area according to claim 1 is characterized in that: In step S2, the 28d compressive strength of the filling body in the original mining tunnel is not less than 3.0 MPa.

4. The method for arranging a mining project in a confined space in an ultra-high panel area according to claim 1 is characterized in that: In step S4, there is an oblique angle α between the mine exit route and the mine exit tunnel, and α is designed according to the turning ability of the scraper and the tunnel space.

5. The method for arranging a mining project in a confined space in an ultra-high panel area according to claim 1 is characterized in that: In step S5, the mining tunnel is supported by a 25U steel arch frame, the spacing between adjacent 25U steel arch frames is 0.8 meters, and is equipped with a Φ22 threaded anchor rod with a length of 1.5 meters. The base width of the 25U steel arch frame is 2 meters, and C25 concrete with a thickness of 15 cm is sprayed on the side of the mining tunnel close to the filling body.

6. The method for arranging a mining project in a confined space in an ultra-high panel area according to claim 1 is characterized in that: In step S6, the specifications of the anchor rods are Φ20mm×2200mm, the spacing is 1.2m×1.2m, and the specifications of the anchor cables are Φ21.8mm×7300mm.

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