A caving mining method for improving the caving size and increasing the recovery

Abstract

The application discloses a caving mining method for improving caving granularity and improving recovery rate, and comprises the following steps: S1, developing a transportation roadway and a communication channel, and excavating a rock drilling roadway, and constructing a transportation roadway and a mining roadway to excavate a draw roadway; S2, constructing a first upward deep hole according to a stope boundary, and constructing a second upward deep hole along a roadway strike; S3, loading an energy-gathering charge into the first upward deep hole, and the strip-shaped cut of the energy-gathering charge extends towards the extension direction of the roadway, and the arc-shaped cut extends towards the to-be-mined ore body; S4, initiating the first upward deep hole before mining the ore body; S5, initiating the second upward deep hole to expand the primary fissure of the ore body; and S6, forming a mining level by a post-drawing process, and mining after blasting. The energy-gathering charge is used to make the explosion stress field wave directional release and cut the ore body, and the ore body is disassociated with the surrounding ore body, so that the ore recovery rate is improved. The explosion stress wave and the blast gas are used to improve the development degree of the internal fissure field of the ore body, enhance the caving property of the rock mass, and reduce the large block rate on site.

Description

Technical Field

[0001] This invention relates to the field of metal mining technology, and in particular to a caving mining method that improves caving block size and increases recovery rate. Background Technology

[0002] Natural caving, as a mining method for mining large, low-grade, deep-buried deposits, has limitations in its further promotion and application due to its stringent mining conditions, poor controllability of ore caving speed, stress concentration at the bottom structure, and high proportion of large blocks.

[0003] Existing caving mining methods for metal ores primarily rely on controlling the spatial and temporal sequence of ore extraction to achieve ore recovery. During production, the caving capability of the ore body results in a high proportion of large ore blocks, which can clog the ore outlet, cause stress concentration at the bottom structure, and increase safety risks. Poor caving capability is also a major cause of overhanging roof problems, which severely reduce ore recovery rates and, in cases of large-scale overhanging, significantly impact on-site production safety. These problems encountered in caving mining of metal ores urgently need to be addressed.

[0004] In view of this, improvements should be made to the existing technology. Summary of the Invention

[0005] The main objective of this invention is to provide a caving mining method that improves caving block size and increases recovery rate. A shaped charge is inserted into the blast holes according to a predetermined layout. During detonation, the shaped charge uses the directional release of the explosive stress field wave to cut the ore body, effectively decoupling the ore body from the surrounding ore body, thereby increasing the ore recovery rate and effectively solving the problem of overhanging roof. Furthermore, through large-diameter upward-deep holes in the bottom-drainage roadway, the combined action of the explosive stress wave and the generated gas enhances the development of the fracture field within the ore body, increasing the rock mass's cavingability and reducing the proportion of large blocks at the site.

[0006] According to one aspect of the present invention, a caving mining method for improving caving block size and increasing recovery rate is proposed, comprising the following steps: S1. Before the mining body is recovered, a transport roadway and a connecting waterway are developed in the lower footing of the top of the mining area and a rock drilling roadway is excavated. A transport roadway and an ore extraction roadway are constructed in the lower footing of the mining area and a bottom-pulling roadway is excavated. The bottom-pulling roadway is used as a compensation space for ore falling. S2. Construct the first upward deep hole on one side of the footwall of the ore body according to the boundary of the mining area, and construct the second large-diameter upward deep hole at a predetermined distance along the direction of the roadway on the roof of the bottom roadway. S3. A shaped charge is installed in the first upward deep hole. The shaped charge includes a strip cut and an arc cut. The strip cut faces the direction of the roadway extension and the arc cut faces the ore body to be mined. S4. The first upward deep hole is detonated in front of the ore body. The arc-shaped cut releases energy to separate the ore body to be mined. The strip-shaped cut forms a linear jet that forms explosive cracks along the boundary of the ore body to be mined. S5, detonate the second upward deep hole to expand the original fractures in the ore body; S6. The bottom-pulling process is adopted. The ore extraction level is formed by blasting through medium-deep holes. The upper medium-deep holes in the bottom-pulling roadway form an empty area. Part of the collapsed ore body is arranged for extraction, and the remaining ore is left in the mining area. After the mining is completed, the ore in the mining area is released evenly at one time.

[0007] According to one embodiment of the present invention, in step S1, the bottom tunnel is arranged in a herringbone shape.

[0008] According to one embodiment of the present invention, in step S2, the arrangement angle of the first upward deep hole is the same as the dip angle of the ore body, the hole spacing is 1.0~1.8m, the hole diameter is 50~70mm, and the hole depth is 20~30m.

[0009] According to one embodiment of the present invention, in step S2, the diameter of the second upward deep hole is 80~120mm, the hole depth is 20~40m, and the charge length is 25~30m.

[0010] According to one embodiment of the present invention, in step S3, the width of the arc-shaped slit is 1~3cm, and the width of the strip-shaped slit is 1~2cm.

[0011] According to one embodiment of the present invention, the energy-concentrating drug pack includes multiple tubes, and the sidewalls of the tubes are provided with circumferential arc-shaped slits and axial strip-shaped slits, with the arc-shaped slits and strip-shaped slits spaced apart.

[0012] According to one embodiment of the present invention, the pipe body is made of PVC material.

[0013] According to one embodiment of the present invention, the detonation method of the first upward deep hole is reverse detonation at the bottom of the hole, and the holes are detonated in stages using millisecond delay detonators with a delay time of 12~16ms.

[0014] According to one embodiment of the present invention, the detonation method of the second upward deep hole is reverse detonation at the bottom of the hole, and the holes are detonated in stages using millisecond delay detonators.

[0015] According to one embodiment of the present invention, in step S6, the total amount of ore remaining in the mining area is controlled to be 30% to 50% of the total volume of the collapsed ore body.

[0016] In a caving mining method according to an embodiment of the present invention, which improves the caving block size and increases the recovery rate, a shaped charge is inserted into the blast hole according to a predetermined layout. During detonation, the shaped charge is used to release the explosive stress field wave in a directional manner, cutting the ore body and fully decoupling the ore body to be mined from the surrounding ore body, thereby increasing the ore recovery rate and effectively solving the problem of overhanging roof. In addition, through a large-diameter upward deep hole in the bottom haulage roadway, the explosive stress wave and the explosive gas work together to enhance the development of the fracture field inside the ore body to be mined, improve the rock mass cavingability, and reduce the proportion of large blocks on site. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some implementation examples of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a stopway for a caving mining method that improves caving block size and increases recovery rate according to an exemplary embodiment of the present invention is shown; Figure 2 A schematic diagram of the bottom roadway and blast holes of a caving mining method for improving caving block size and increasing recovery rate according to an exemplary embodiment of the present invention is shown; Figure 3 A schematic diagram of an upward deep hole is shown in a caving mining method for improving caving block size and increasing recovery rate according to an exemplary embodiment of the present invention; Figure 4 A schematic diagram of a shaped charge for a caving mining method that improves caving block size and increases recovery rate according to an exemplary embodiment of the present invention is shown; Figure 5 A schematic diagram of a large-diameter deep hole is shown in a caving mining method for improving caving block size and increasing recovery rate according to an exemplary embodiment of the present invention. Detailed Implementation

[0019] The following detailed description of the embodiments is intended to exemplify the principles of the present invention, but should not be construed as limiting the scope of the invention. The present invention can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0020] These embodiments are provided to make this disclosure thorough and complete, and to fully express the scope of the invention to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0021] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] It should also be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device.

[0023] All terms used in this invention have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0024] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0025] like Figures 1 to 5 As shown, the present invention provides a caving mining method for improving caving block size and increasing recovery rate, which includes the following steps: S1. Before the mining body is recovered, a transport roadway and a connecting waterway are developed in the lower footing of the top of the mining area and a rock drilling roadway is excavated. At the same time, a transport roadway and an ore extraction roadway are constructed in the lower footing of the mining area and a bottom-pulling roadway is excavated. The bottom-pulling roadway is used as a compensation space for ore falling. S2. Construct the first upward deep hole on the side of the ore body near the footwall according to the boundary of the mining area, and construct the second large-diameter upward deep hole along the direction of the roadway on the roof of the bottom roadway at a predetermined distance. S3. A shaped charge is installed in the first upward deep hole. The shaped charge includes a strip cut and an arc cut. The strip cut faces the direction of the rock drilling tunnel and the arc cut faces the ore body to be mined. S4. The first upward deep hole is detonated in front of the ore body. The arc-shaped cut releases energy to separate the ore body to be mined. The strip-shaped cut forms a linear jet that forms explosive cracks along the boundary of the ore body to be mined. S5, detonate the second upward deep hole to expand the original fractures in the ore body; S6. The bottom-pulling process is adopted. The ore extraction level is formed by blasting medium-deep holes at the bottom-pulling level. The upward medium-deep holes in the bottom-pulling roadway are blasted to form an empty area. Part of the collapsed ore body is arranged for extraction, and the remaining ore is left in the mining area. After the mining is completed, the ore in the mining area is released evenly at one time.

[0026] In the caving mining method for improving caving block size and increasing recovery rate according to an embodiment of the present invention, shaped charge charges are loaded into the blast holes according to a predetermined layout. During detonation, the shaped charge charges are used to directionally release the explosive stress field wave, cutting the ore body and fully decoupling the ore body to be mined from the surrounding ore body, thereby increasing the ore recovery rate and effectively solving the problem of overhanging roof. In addition, through large-diameter upward deep holes in the bottom-drilling roadway, the combined action of the explosive stress wave and the explosive gas enhances the development of the fracture field inside the ore body to be mined, increases the rock mass cavingability, and reduces the proportion of large blocks on site.

[0027] In some specific embodiments, in step S1, the bottom-pulling roadway is arranged in a fishbone shape, which promotes the directional flow of ore under gravity, reduces dead corners, forms a stable mechanical funnel, reduces the risk of blockage, and thus ensures effective ore recovery; the fishbone structure realizes multi-level stress release, reduces the overall support pressure of the roadway, and ensures the stability of the bottom-pulling level.

[0028] Based on the above embodiments, in step S2, the arrangement angle of the first upward deep hole is the same as the dip angle of the ore body, the hole spacing is 1.0~1.8m, the hole diameter is 50~70mm, and the hole depth is 20~30m.

[0029] In some specific embodiments, in step S2, the diameter of the second upward deep hole is 80~120mm, the hole depth is 20~40m, and the charge length is 25~30m.

[0030] Based on the above embodiments, in step S3, the width of the arc-shaped slit is 1~3cm, and the width of the strip-shaped slit is 1~2cm.

[0031] like Figure 2As shown, based on the above embodiments, the diameter of the medium-deep hole is 40~70mm and the depth is 5~15m.

[0032] In some specific embodiments, the shaped charge includes multiple tubes, with circumferential arc-shaped slits and axial strip-shaped slits arranged alternately on the sidewalls of the tubes. The shaped charge effectively separates the ore body from the surrounding ore body, forming a smooth slip surface, facilitating subsequent ore body caving and recovery, and improving the recovery rate.

[0033] Based on the above embodiments, the pipe body is made of PVC material.

[0034] In some specific embodiments, the detonation method of the first upward deep hole is reverse detonation at the bottom of the hole, and the holes are detonated in stages using millisecond delay detonators with a delay time of 12~16ms.

[0035] Based on the above embodiments, the second upward deep hole is detonated in reverse at the bottom of the hole, and the holes are blasted in stages using millisecond delay detonators, which further expands the internal fractures of the ore body to be mined, improves the development of the internal fracture field, improves the ore body's collapseability, and reduces the rate of large ore body collapses.

[0036] In some specific embodiments, in step S4, the special structure of the shaped charge is used to guide the directional release of the explosive stress wave. Energy is released at the arc-shaped cut to the top of the ore body to be mined, severing the connection with the upper ore body. The strip cut is used to form a linear jet, which forms explosive cracks along the boundary of the ore body to be mined, thereby achieving the purpose of cutting the ore body and forming a smooth sliding surface.

[0037] In some specific embodiments, in step S4, the large-diameter second upward deep hole in the blasting bottom roadway, through the action of the explosion stress wave and the explosive gas, further expands the original fractures in the ore body, improves the degree of fracture development inside the ore body to be mined, thereby improving the ore body's collapseability and reducing the rate of large blocks on site.

[0038] Based on the above embodiments, in step S6, forming a void of a certain height is to ensure the realization and continuous progress of ore body collapse.

[0039] Based on the above embodiments, in step S6, the total amount of ore remaining in the mining area is controlled to be 30% to 50% of the total volume of the collapsed ore body.

[0040] The present application will be further described below through specific embodiments.

[0041] Example 1 like Figure 1As shown, before the mining body is recovered, construction is carried out on the lower footing of the top of the mining area. The transportation level, intake and return air level, and ore extraction level in the mining area serve the entire mining area. The bottom level is used for medium-deep hole blasting to create a large area of ​​voids, providing compensation space for ore falling.

[0042] like Figure 3 As shown, upward deep holes are constructed along the boundary of the ore body to be mined in the footwall at the bottom of the mining area, and shaped charge charges are loaded for blasting pre-splitting.

[0043] like Figure 4 As shown, a single shaped charge structure is prepared. The shaped charge structure is divided into two types. The first type includes a tube body with circumferential arc-shaped slits and axial strip-shaped slits on its sidewalls, the arc-shaped slits and the strip-shaped slits being spaced apart. The second type includes a tube body with strip-shaped slits on its sidewalls. The tube body of the shaped charge structure is made of PVC material.

[0044] Before ore recovery, the shaped charge structure is detonated first. The arc-shaped cut of the shaped charge in the blast hole guides the explosive stress wave to release energy from the arc-shaped cut to the side of the ore body to be collapsed, thus breaking the rock and forming a circumferential cut to avoid the phenomenon of overhang. The strip cut of the shaped charge guides the explosive stress wave to release energy from the strip cut to form a jet, which causes explosive cracks to form on the ore body. This jet cuts the ore body along the roadway and forms a smooth slip surface for ore recovery.

[0045] The borehole diameter is 50~70mm, the borehole depth is 20~30m, the borehole spacing is 1.0m~1.2m, the borehole inclination angle is close to the inclination angle of the ore body, and the borehole delay time is set to 12~16ms.

[0046] like Figure 5 As shown, before the bottoming operation, the upward deep holes in the bottoming roadway are blasted. During the blasting process, under the combined action of the blast energy and the blast gas, the fractures in the ore body further expand, improve the development of the fracture field inside the ore body, increase the rock collapseability, improve the ore recovery rate, and at the same time solve the problem of high ore block rate.

[0047] In step S6, the bottom-pulling process is adopted. The ore extraction level is formed by blasting through medium-deep holes at the extraction level. Then, blasting is carried out in the bottom-pulling level roadway to form a certain height void, which ensures the realization and continuous ore body collapse. Part of the ore body that collapses each time is arranged for extraction, and the rest of the ore is left in the mining area. After the mining is completed, the ore in the mining area is released evenly at once.

[0048] Through steps S1 to S6, deep holes are used on the boundary of the ore body to be mined. The explosive stress wave is guided to release and cut the ore body in a predetermined direction through energy-concentrated cutting, which fully decouples it from the surrounding ore body. While forming a smooth slip surface, the "suspended roof" problem in the ore falling is solved at the same time, and the ore recovery rate is greatly improved. By using deep hole blasting to induce fracturing, during the detonation process, under the combined action of explosive energy and explosive gas, the fractures in the ore body are further developed and expanded. The degree of development of the fracture field inside the ore body is increased, the rock collapseability is improved, and the problem of high ore block ratio is effectively solved.

[0049] In this application, a novel blasting method called "TCL" is proposed to address the problems existing in natural caving mining. "T" stands for Tunneling, which refers to a fishbone-shaped bottom-runway layout that enhances the overall support capacity of the runway while ensuring effective ore recovery. "C" stands for Cut, which refers to the use of shaped charge structures in upward deep holes to cut the ore body in a predetermined direction. "L" stands for Loose, which refers to deep hole detonation in the bottom-runway, which further develops the fractures in the ore body, improves the cavingability of the ore body, and increases the ore recovery rate.

[0050] The above are exemplary embodiments disclosed in this invention. The order of the disclosed embodiments is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. However, it should be noted that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of this invention (including the claims) is limited to these examples. Various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular.

[0051] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of the different aspects of the invention as described above exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A caving mining method for improving caving block size and increasing recovery rate, characterized in that, Includes the following steps: S1. Before mining the ore body, develop transportation roadways and connecting waterways in the lower footing of the top of the mining area and excavate rock drilling roadways. Construct transportation roadways and ore extraction roadways in the lower footing of the mining area and excavate bottom-pulling roadways. Use the bottom-pulling roadways as ore compensation space. S2. Construct the first upward deep hole on one side of the footwall of the ore body according to the boundary of the mining area, and construct the second large-diameter upward deep hole at a predetermined distance along the direction of the roadway on the roof of the bottom roadway. S3. A shaped charge is inserted into the first upward deep hole. The shaped charge includes a strip cut and an arc cut. The strip cut faces the direction of the roadway extension, and the arc cut faces the ore body to be mined. S4. The first upward deep hole is detonated in front of the ore body. The arc-shaped cut releases energy to separate the ore body to be mined. The strip-shaped cut forms a linear jet that forms explosive cracks along the boundary of the ore body to be mined. S5. Detonate the second upward deep hole to expand the original fractures in the ore body; S6. The bottom-pulling process is adopted. The ore extraction level is formed by blasting through medium-deep holes. The upper medium-deep holes in the bottom-pulling roadway form an empty area. Part of the collapsed ore body is arranged for extraction, and the remaining ore is left in the mining area. After the mining is completed, the ore in the mining area is released evenly at one time.

2. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, In step S1, the bottom tunnel is arranged in a herringbone shape.

3. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, In step S2, the arrangement angle of the first upward deep hole is the same as the dip angle of the ore body, the row spacing of the first upward deep hole is 1.0~1.8m, the hole diameter is 50~70mm, and the hole depth is 20~30m.

4. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, In step S2, the diameter of the second upward deep hole is 80~120mm, the hole depth is 20~40m, and the charge length is 25~30m.

5. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, In step S3, the width of the arc-shaped slit is 1~3cm, and the width of the strip-shaped slit is 1~2cm.

6. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, The energy-concentrating drug pack includes a tube body, on the side wall of which are provided an arc-shaped slit extending circumferentially and a strip-shaped slit extending axially, the arc-shaped slit and the strip-shaped slit being spaced apart axially.

7. The caving mining method for improving caving block size and increasing recovery rate according to claim 6, characterized in that, The pipe body is made of PVC.

8. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, The first upward deep hole is detonated by reverse detonation at the bottom of the hole, and the holes are detonated in stages using millisecond delay detonators with a delay time of 12~16ms.

9. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, The second upward deep hole is detonated by reverse detonation at the bottom of the hole, and the holes are detonated in stages using millisecond delay detonators.

10. The caving mining method for improving caving block size and increasing recovery rate according to claim 1, characterized in that, In step S6, the total amount of ore remaining in the mining area is controlled to be 30% to 50% of the total volume of the collapsed ore body.

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