Staggered mining method under pre-support condition and use of method

Abstract

A staggered mining method under a pre-support condition and a use of the method, relating to the field of mining methods. In the staggered mining method, directional pre-support and high-strength grouting of a caved material are first performed by means of strike drifts, so that the caved material forms a cemented combination body, and thus a certain self-stabilizing capability is provided for the caved material, creating a safe environment for the recovery of an ore body next to the caved material. Moreover, middle sections of the ore body are divided into upper stoping units and lower stoping units, the mining order of the upper stoping units and the lower stoping units are defined, the upper stoping units and the lower stoping units perform stoping in rhombic stope structures and backfilling, and a stable inverted triangle-like structure is first formed, so that a diagonal bracing effect is provided for the caved material from the hanging wall, thereby improving the safety of stoping by the lower stoping units. Compared with a mining method in the prior art in which ore pillars need to be reserved, the mining method has a high ore recovery rate, does not cause a waste of ore resources, and solves the problems of difficulty in recovery, poor safety, and low recovery rate of ore bodies next to caved materials of existing mines.

Description

Cross-cut mining method under pre-support conditions and its application Technical Field

[0001] This invention relates to the field of mining methods, specifically to an alternating mining method under pre-support conditions and its application. Background Technology

[0002] As the mining industry continues to develop, many mines face historical problems. Due to disorderly mining practices, lack of long-term planning and design, absence of targeted problem-solving, and the prevailing mentality of mining only where the mineral resources are richest, while considering surrounding ore bodies later, indiscriminate underground mining has disrupted the overall stress environment. Under dynamic disturbances, the mined-out voids are prone to large-scale collapses. Under strong disturbances, even the previously reserved pillars cannot withstand the immense pressure and break, easily causing significant underground ground pressure activity. This also creates numerous areas of collapse underground, posing enormous difficulties for the mining of surrounding ore bodies. Furthermore, it has resulted in extremely complex underground mining conditions in most old mines, leading to incalculable resource losses and a tremendous waste of mineral resources.

[0003] Currently, most mines leave pillars of a certain width as protective pillars when mining ore bodies next to bulk materials, but this method results in ore loss. Existing technology discloses an improved method for mining thick, fractured top and bottom pillars under bulk materials. This method divides the remaining pillars vertically into several blocks, leaving intervening pillars and arched top pillars between the blocks to control the roof of the access road. The top and bottom pillars are mined using an access road method, with the access road being mined one by one in a retreating manner. The mined access road is then backfilled with cemented backfill material, serving as a roof pillar for the next access road, jointly supporting the roof with the ore body on the other side of the access road. Although this method re-mines the remaining pillars, it still cannot completely remove them, and it increases the mining process and costs, reducing mining profitability.

[0004] Some existing mines use full grouting to fill large areas of collapsed loose material with low-strength, low-concentration backfill. However, due to a lack of understanding of the area and condition of the collapse, the backfill can easily flow erratically after entering the mine, resulting in large-scale grout leakage in some areas. This poses a significant risk to mine safety. Furthermore, the collapsed area has not formed an effective cemented aggregate, which still threatens the safety of mining the normal ore body around the collapsed loose material. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides a staggered mining method under pre-support conditions and its application, aiming to solve the technical problems of difficult mining, poor safety and low recovery rate of ore bodies next to collapsed loose bodies in existing mines.

[0006] In a first aspect, this application provides a staggered mining method under pre-supported conditions, comprising the following steps:

[0007] S1. Divide the ore body to be mined into several intermediate sections in the vertical direction, and divide it into several sub-sections along the ore body strike. The intermediate sections are mined step by step in the sub-sections. The intermediate sections are further divided into several smaller sub-sections in the vertical direction. The mining preparation project is arranged, including the external roadways of the intermediate sections and the external roadways of the smaller sub-sections.

[0008] S2. The cross-vein roadways of each section are excavated from the middle section external vein roadway and the small section external vein roadway into the ore body until the near point of exposure of the collapsed bulk material is reached. Then, several vein-along roadways are excavated along the strike of the ore body at a certain distance from the collapsed bulk material. The entire cross-section of the vein-along roadways is supported, and high-strength grouting anchor cables are used to support the vein-along roadways in the direction of the collapsed bulk material. Grout is injected into the collapsed bulk material using high-strength grouting anchor cables.

[0009] S3. Within any partition, a first drilling roadway is excavated along the ore body strike at the center of the middle section. The first drilling roadway is perpendicular to and connected to the cross-cut roadway. The middle section is divided into an upper mining unit and a lower mining unit by the first drilling roadway. The upper mining unit has a quasi-inverted triangle structure, and the lower mining unit has a quasi-equilateral triangle structure. The upper and lower mining units are mined using a diamond-shaped stope structure with alternating upper and lower sections. High-strength backfilling can be carried out after the mining of any diamond-shaped stope structure is completed to form a diamond-shaped support space.

[0010] S4. During mining, the upper mining unit is mined first. After the upper mining unit is fully mined and filled, a diagonal bracing structure resembling an inverted triangle is formed in the upper part of the middle section. Then, the lower mining unit is mined and filled. After the mining and filling are completed, a support structure resembling an equilateral triangle is formed, which, together with the diagonal bracing structure resembling an inverted triangle, forms a complete combination. At this point, the mining of the ore body in this middle section is completed. The same method is then used to mine the next middle section until the mining of the entire ore body to be mined is completed.

[0011] Preferably, in step S4, when the upper and lower mining units are mining, they are mining in an alternating manner from bottom to top, taking the diamond-shaped stope structure as the unit. In step S3, before the upper and lower mining units begin mining in the diamond-shaped stope structure, they first excavate drilling roadways and ore-receiving roadways along the ore body strike. The drilling roadways and ore-receiving roadways are both perpendicular to and connected to the cross-cut roadways. The ore-receiving roadway is located at the bottom of the diamond-shaped stope structure, and the drilling roadway is located at the edge of the diamond-shaped stope structure near the collapsed bulk.

[0012] Preferably, during the mining of the diamond-shaped stope structure, blasting fan-shaped holes are drilled from the wall of the drilling roadway into the ore body surrounding the drilling roadway. During blasting, the receiving roadway at the bottom of the diamond-shaped stope structure receives the ore and then extracts it through the cross-vein roadway to the sub-section or mid-section cross-vein roadway. During the filling of the diamond-shaped stope structure, a filling retaining wall is installed in the drilling roadway so that the blasted drilling roadway can continue to be used as a receiving roadway for the mining of adjacent diamond-shaped stopes distributed in an alternating pattern above.

[0013] Preferably, the number of the sub-segments is even, and the first drilling roadway is located between two adjacent sub-segments. The first drilling roadway can be used as the drilling roadway for the first mining diamond-shaped stope structure in the upper mining unit. The diamond-shaped stope structure consists of upper and lower triangular mining areas located in two adjacent sub-segments, and the mining height of the diamond-shaped stope structure is the height of the two sub-segments. Both the drilling roadway and the ore-receiving roadway are located between two adjacent sub-segments.

[0014] Preferably, if a complete rhombus stope structure cannot be formed when mining at the upper boundary of the upper mining unit or the lower boundary of the lower mining unit, a triangular stope structure is used for mining, or the stope is retained until the next middle section forms a rhombus stope structure before mining.

[0015] For the remaining ore body at the upper and lower boundaries of the middle section, it can be handled flexibly. When mining with a triangular stope structure, only the bottom roadway of the triangular stope structure is excavated and used as a rock drilling roadway and ore receiving roadway. That is, the roadway is used to drill upward fan-shaped holes for blasting and to blast out ore.

[0016] Preferably, in step S2, when supporting the entire cross-section of the roadway along the vein, high-strength I-beams are used for dense support.

[0017] Full-section support along the ore body roadway helps maintain the stability of the collapsed loose material next to the ore body and avoids the problem of collapse during blasting mining.

[0018] Secondly, this application provides an application of a staggered mining method under pre-support conditions, which is suitable for the mining of ore bodies adjacent to caving boulders. This method provides a new approach to the mining of ore bodies adjacent to caving boulders, improves the safety of ore body mining, and does not cause waste of ore resources. Beneficial effects:

[0019] (1) In the technical solution of this application, the caving mass is first pre-supported and grouted in a directional manner along the vein roadway, so that the caving mass forms a cemented composite, giving it a certain self-stabilizing ability, creating a safe environment for the mining of the ore body next to the caving mass, and the grouting fluid will not flow randomly, avoiding the problem of large-scale grout leakage. At the same time, by dividing the middle section of the ore body into upper and lower mining units, and limiting the mining sequence and mining and filling with a diamond-shaped stope structure, a stable inverted triangular structure is first formed, which provides a diagonal support for the caving mass in the hanging wall, improving the safety of the mining of the lower mining unit; and after the mining and filling of the lower mining unit, a quasi-equilateral triangular support structure is formed, which, together with the diagonal support of the inverted triangular structure, forms a complete support composite, providing a safe space for the mining of the next middle section. Compared with the existing mining methods that reserve pillars, the mining method proposed in this application has a high recovery rate and does not cause ore loss. It solves the problems of difficult recovery, poor safety and low recovery rate of ore bodies next to collapsed loose bodies in existing mines.

[0020] (2) In the mining method of this application, the upper mining unit and the lower mining unit are staggered from bottom to top with the diamond-shaped mining structure as the unit. After blasting, a diamond-shaped space is formed, that is, an upper and lower triangular structure, which can maintain relative stability to a certain extent; and after filling, a diamond-shaped support body is formed, which avoids damage to the overall stability of the ore body and is conducive to the safe mining of the subsequent mining area.

[0021] (3) Unlike the traditional arrangement of upward or downward blasting fan holes, the blasting fan holes in this application face the front of the roadway and are distributed in all directions. The blasting effect is more stable and the damage to the rock drilling roadway is less. The rock drilling roadway is only used as the roadway for drilling blasting fan holes. It can be used directly or after simple repair as the receiving roadway of the next diamond-shaped mining structure, which reduces the amount of engineering work and shortens the mining time.

[0022] 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

[0023] 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.

[0024] Figure 1 is a schematic diagram of the ore body recovery structure in the I-I direction in a staggered mining method under pre-support conditions according to an embodiment of this application;

[0025] Figure 2 is a schematic diagram of the ore body recovery structure in the II-II direction in a staggered mining method under pre-support conditions according to an embodiment of this application;

[0026] Figure 3 is a schematic diagram of the ore body mining structure in the III-III direction in a staggered mining method under pre-support conditions according to an embodiment of this application;

[0027] Figure 4 is a schematic diagram of the structure during the mining of stope #2 in a staggered mining method under pre-support conditions according to an embodiment of this application;

[0028] Figure 5 is a schematic diagram of the structure during the mining of stope #3 in a staggered mining method under pre-support conditions according to an embodiment of this application.

[0029] Figure 6 is a schematic diagram of the structure during the mining of stope #4 in a staggered mining method under pre-support conditions according to an embodiment of this application;

[0030] Figure 7 is a schematic diagram of the structure during the mining of stope ⑤# in a staggered mining method under pre-support conditions according to an embodiment of this application;

[0031] Figure 8 is a structural diagram of the back mining of stope ⑥ in a staggered mining method under pre-support conditions according to an embodiment of this application;

[0032] Figure 9 is a schematic diagram of the structure during the mining of stope #7 in a staggered mining method under pre-support conditions according to an embodiment of this application.

[0033] Explanation of reference numerals in the attached drawings: 100, middle section; 110, middle section external roadway; 120, small segment external roadway; 130, through-vein roadway; 140, along-vein roadway; 141, high-strength grouting anchor cable; 150, first drilling roadway; 160, rhomboid stope structure; 161, drilling roadway; 162, receiving roadway; 163, blasting fan-shaped hole; 164, blasting upward fan-shaped hole; 200, caving debris; 300, filling material. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" and "several" mean two or more, unless otherwise explicitly defined.

[0037] 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.

[0038] 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," etc., indicating the orientation or positional relationship, are 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 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. Therefore, they should not be construed as limitations on the embodiments of this application. 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.

[0039] For ease of explanation, the following embodiments use an example of an interleaved mining method under pre-support conditions and its application.

[0040] Referring to Figures 1 to 3, in a first aspect, embodiments of this application provide a staggered mining method under pre-support conditions, comprising the following steps:

[0041] S1. Divide the ore body to be mined into several intermediate sections 100 in the height direction and into several sub-sections along the ore body strike. Mining of the intermediate sections 100 is carried out step by step in the sub-sections. The intermediate sections 100 are further divided into several small sub-sections in the height direction. The mining preparation engineering is arranged, including the intermediate section external roadway 110 and the small sub-section external roadway 120.

[0042] S2. The cross-vein roadways 130 of each section are excavated from the middle section external vein roadway 110 and the small section external vein roadway 120 into the ore body until the near point of the exposed caving mass 200 is reached. Then, several vein-side roadways 140 are excavated along the ore body at a certain distance from the caving mass 200. The entire cross section of the vein-side roadway 140 is supported. At the same time, high-strength grouting anchor cables 141 are used to support the vein-side roadway 140 towards the caving mass 200, and grout is injected into the caving mass 200 using the high-strength grouting anchor cables 141.

[0043] S3. Within any zone, the first drilling roadway 150 is excavated along the ore body strike at the center of the middle section 100. The first drilling roadway 150 is set perpendicular to and connected to the cross-vein roadway 130. The middle section 100 is divided into an upper mining unit and a lower mining unit by the first drilling roadway 150. The upper mining unit has a quasi-inverted triangle structure, and the lower mining unit has a quasi-equilateral triangle structure. The upper mining unit and the lower mining unit are mined using a diamond-shaped stope structure 160 with alternating upper and lower distribution. After the mining of any diamond-shaped stope structure 160 is completed, high-intensity backfilling can be carried out to form a diamond-shaped support space.

[0044] S4. During mining, the upper mining unit is mined first. After the upper mining unit is fully mined and backfilled, a diagonal bracing structure resembling an inverted triangle is formed in the upper part of the middle section 100. Then, the lower mining unit is mined and backfilled. After the mining and backfilling are completed, a support structure resembling an equilateral triangle is formed, which, together with the diagonal bracing structure resembling an inverted triangle, forms a complete combination. At this point, the mining of the ore body in the middle section 100 is completed. The same method is then used to mine the next middle section until the mining of the entire ore body to be mined is completed.

[0045] This mining method first involves directional pre-support grouting of the caving mass 200 along the vein roadway 140, forming a cemented aggregate that provides self-stabilizing capabilities. This creates a safe environment for the mining of the ore body adjacent to the caving mass 200, and prevents the grout from flowing erratically, thus avoiding large-scale grout leakage. Simultaneously, by dividing the ore body into upper and lower mining units within the middle section 100, and defining the mining sequence, a diamond-shaped stope structure 160 is used for mining and backfilling, forming a stable inverted triangular structure. This provides a bracing effect for the upper caving mass 200, improving the safety of the lower mining unit. Compared to existing technologies that use pillar-reserved mining methods, this method offers higher recovery rates, avoids ore loss, and solves the problems of difficult mining, poor safety, and low recovery rates associated with ore bodies adjacent to caving masses in existing mines.

[0046] Furthermore, in some embodiments, during step S4, the upper and lower mining units mine in a staggered manner from bottom to top, using the rhombus stope structure 160 as the unit. In step S3, before the upper and lower mining units mine using the rhombus stope structure 160, the drilling roadway 161 and the ore receiving roadway 162 are excavated along the ore body strike. Both the drilling roadway 161 and the ore receiving roadway 162 are perpendicular to and connected to the cross-cutting roadway 130. The ore receiving roadway 162 is located at the bottom of the rhombus stope structure 160, and the drilling roadway 161 is located at the edge of the rhombus stope structure 160 near the collapsed mass 200.

[0047] In the technical solution of this embodiment, the upper and lower mining units are staggered from bottom to top in a diamond-shaped stope structure of 160. After blasting, a diamond-shaped space is formed, that is, an upper and lower triangular structure, which can maintain relative stability to a certain extent. After filling, a diamond-shaped support body is formed, which avoids damage to the overall stability of the ore body and is conducive to the safe mining of subsequent stops.

[0048] Furthermore, in some embodiments, during the mining of the rhombus stope structure 160, construction proceeds from the inner wall of the drilling roadway 161 towards the ore body surrounding the drilling roadway 161; during blasting, the receiving roadway 162 located at the bottom of the rhombus stope structure 160 receives ore and exits through the cross-vein roadway 130 to the sub-section external roadway 120 or the intermediate external roadway 110. During the filling of the rhombus stope structure 160, a filling retaining wall is constructed for the drilling roadway 161 so that the blasted drilling roadway 161 can continue to be used as the receiving roadway 162 for the mining of adjacent rhombus stopes 160 distributed in an alternating pattern above.

[0049] In this embodiment, unlike the traditional arrangement of upward or downward blasting fan-shaped holes, the blasting fan-shaped holes 163 face the front of the drilling roadway 161 and are distributed in all directions. The blasting effect is more stable and the damage to the drilling roadway 161 is less. The drilling roadway 161 is only used as the roadway for drilling the blasting fan-shaped holes 163. It can be used directly or after simple repair as the receiving roadway 162 of the next diamond-shaped stope structure 160, which reduces the amount of engineering work and shortens the mining time.

[0050] Furthermore, in some embodiments, the number of small segments is even. The first drilling roadway 150 is located between two adjacent small segments. The first drilling roadway 150 can be used as the drilling roadway 161 of the first mining diamond stope structure 160 in the upper mining unit. The vein roadway 140 can be used as the drilling roadway 161 of the diamond stope structure 160 near the caving mass 200. The diamond stope structure 160 is composed of upper and lower triangular mining areas located in two adjacent small segments. The mining height of the diamond stope structure 160 is the height of the two small segments. The drilling roadway 161 and the ore receiving roadway 162 are both located between two adjacent small segments.

[0051] Furthermore, in some embodiments, if a complete rhombus stope structure 160 cannot be formed when mining at the upper boundary of the upper mining unit or the lower boundary of the lower mining unit, a triangular stope structure is used for mining, or the mining is carried out after the next middle section forms a rhombus stope structure 160.

[0052] In the technical solution of this embodiment, the remaining ore body at the upper and lower boundaries of the middle section 100 can be flexibly handled. When mining with a triangular stope structure, only the bottom roadway of the triangular stope structure is excavated and used as the rock drilling roadway 161 and the ore receiving roadway 162. That is, the roadway is used to drill upward fan-shaped holes 164 and blast out ore.

[0053] Furthermore, in some embodiments, in step S2, when supporting the entire cross-section of the roadway 140 along the vein, high-strength I-beams are used for dense support.

[0054] In the technical solution of this embodiment, full-section support is provided for the vein roadway 140, which helps to maintain the stability of the collapsed loose material 200 next to the ore body and avoids the problem of collapse during blasting mining.

[0055] Secondly, this application provides an application of a staggered mining method under pre-support conditions. The staggered mining method under pre-support conditions is suitable for the mining of ore bodies next to the 200-meter-long caving mass. This method provides a new approach to the mining of ore bodies next to the caving mass, improves the safety of ore body mining, and does not cause waste of ore resources.

[0056] Specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0057] Example 1

[0058] Please refer to Figures 3 to 9. This embodiment provides a staggered mining method under pre-support conditions, including the following steps:

[0059] S1. Divide the ore body to be mined into several intermediate sections 100 in the height direction and into several sub-sections along the ore body strike. Mining of the intermediate sections 100 is carried out step by step in the sub-sections. The intermediate sections 100 are further divided into several small sub-sections in the height direction. The mining preparation engineering is arranged, including the intermediate section external roadway 110 and the small sub-section external roadway 120.

[0060] S2. The cross-vein roadways 130 of each section are excavated from the middle section external vein roadway 110 and the small section external vein roadway 120 into the ore body until the near point of the exposed caving mass 200 is reached. Then, several vein-side roadways 140 are excavated along the ore body at a certain distance from the caving mass 200. The entire cross section of the vein-side roadway 140 is supported. At the same time, high-strength grouting anchor cables 141 are used to support the vein-side roadway 140 towards the caving mass 200, and grout is injected into the caving mass 200 using the high-strength grouting anchor cables 141.

[0061] S3. Within any zone, the first drilling roadway 150 is excavated along the ore body strike at the center of the middle section 100. The first drilling roadway 150 is set perpendicular to and connected to the cross-vein roadway 130. The middle section 100 is divided into an upper mining unit and a lower mining unit by the first drilling roadway 150. The upper mining unit has a quasi-inverted triangle structure, and the lower mining unit has a quasi-equilateral triangle structure. The upper mining unit and the lower mining unit are mined using a diamond-shaped stope structure 160 with alternating upper and lower distribution. After the mining of any diamond-shaped stope structure 160 is completed, a high-strength backfill body 300 can be used to fill the hole, forming a diamond-shaped support space.

[0062] S4. During mining, the upper mining unit is mined first (as shown in Figures 3 to 6). The specific mining sequence for the rhombus-shaped stope structure 160 is: ①#-②#-③#-④#. After all the upper mining units are mined and filled, a diagonal bracing structure resembling an inverted triangle is formed in the upper part of the middle section 100. Then, the lower mining unit is mined and filled (as shown in Figures 7 to 9). The specific mining sequence for the rhombus-shaped stope structure 160 is: ⑤#-⑥#-⑦#. After the mining and filling are completed, a support structure resembling an equilateral triangle is formed, which, together with the diagonal bracing structure resembling an inverted triangle, forms a complete combination. At this point, the mining of the ore body in the middle section 100 is completed. The same method is then used to mine the next middle section until the mining of the entire ore body to be mined is completed.

[0063] It should be noted that in this embodiment, the first drilling roadway 150 can be used as the drilling roadway 161 of the first diamond-shaped stope structure 160 in the upper mining unit, and the vein roadway 140 can be used as the drilling roadway 161 of the diamond-shaped stope structure 160 near the caving mass 200. The remaining ore body at the upper boundary of the middle section 100 is mined in a triangular stope structure (e.g., stope ④#). Only the roadway at the bottom of the triangular stope structure is excavated as the drilling roadway 161 and the ore receiving roadway 162. That is, the roadway is used to drill upwards and blast upwards to create fan-shaped holes 164, and then blast to extract ore. Stopes ⑧# and ⑨# at the lower boundary are considered for mining in the lower middle section. That is, mining is carried out when a diamond-shaped stope structure 160 is formed in the next middle section. In addition, although the drilling roadways 161 and ore-receiving roadways 162 of each rhomboid stope structure 160 in Figures 3 to 9 have been drawn in the figures, the drilling roadways 161 and ore-receiving roadways 162 should not be formed in advance during the actual mining process of the ore body. This is to avoid destroying the pre-formed drilling roadways 161 and ore-receiving roadways 162 during the mining of other rhomboid stope structures 160, which would increase the amount of work.

[0064] 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 staggered mining method under pre-support conditions, characterized in that, Includes the following steps: S1. Divide the ore body to be mined into several intermediate sections in the vertical direction, and divide it into several sub-sections along the ore body strike. The intermediate sections are mined step by step in the sub-sections. The intermediate sections are further divided into several smaller sub-sections in the vertical direction. The mining preparation project is arranged, including the external roadways of the intermediate sections and the external roadways of the smaller sub-sections. S2. The cross-vein roadways of each section are excavated from the middle section external vein roadway and the small section external vein roadway into the ore body until the near point of exposure of the collapsed bulk material is reached. Then, several vein-along roadways are excavated along the strike of the ore body at a certain distance from the collapsed bulk material. The entire cross-section of the vein-along roadways is supported, and high-strength grouting anchor cables are used to support the vein-along roadways in the direction of the collapsed bulk material. Grout is injected into the collapsed bulk material using high-strength grouting anchor cables. S3. Within any partition, a first drilling roadway is excavated along the ore body strike at the center of the middle section. The first drilling roadway is perpendicular to and connected to the cross-cut roadway. The middle section is divided into an upper mining unit and a lower mining unit by the first drilling roadway. The upper mining unit has a quasi-inverted triangle structure, and the lower mining unit has a quasi-equilateral triangle structure. The upper and lower mining units are mined using a diamond-shaped stope structure with alternating upper and lower sections. High-strength backfilling can be carried out after the mining of any diamond-shaped stope structure is completed to form a diamond-shaped support space. S4. During mining, the upper mining unit is mined first. After the upper mining unit is fully mined and filled, a diagonal bracing structure resembling an inverted triangle is formed in the upper part of the middle section. Then, the lower mining unit is mined and filled. After the mining and filling are completed, a support structure resembling an equilateral triangle is formed, which, together with the diagonal bracing structure resembling an inverted triangle, forms a complete combination. At this point, the mining of the ore body in this middle section is completed. The same method is then used to mine the next middle section until the mining of the entire ore body to be mined is completed. In step S4, when the upper mining unit and the lower mining unit are mining, they are mining in an alternating manner from bottom to top, taking the diamond-shaped mining structure as the unit. In step S3, before the upper and lower mining units carry out mining in the diamond-shaped stope structure, they first excavate drilling roadways and ore-receiving roadways along the ore body strike. The drilling roadways and ore-receiving roadways are both set perpendicular to and connected to the cross-vein roadway. The ore-receiving roadway is located at the bottom of the diamond-shaped stope structure, and the drilling roadway is located at the edge of the diamond-shaped stope structure near the collapsed bulk.

2. The staggered mining method under pre-support conditions according to claim 1, characterized in that, During the mining of the diamond-shaped stope structure, blasting fan-shaped holes are constructed from the wall of the drilling roadway to the ore body in front of the drilling roadway. During blasting, the ore receiving roadway located at the bottom of the diamond-shaped stope structure receives the ore and then exits the ore through the cross-vein roadway to the small segment outside the vein roadway or the middle segment outside the vein roadway.

3. The staggered mining method under pre-support conditions according to claim 2, characterized in that, When filling the diamond-shaped stope structure, a filling retaining wall is set for the drilling roadway so that the drilling roadway after blasting can continue to be used as the receiving roadway for mining adjacent diamond-shaped stopes distributed in an upper staggered manner.

4. The staggered mining method under pre-support conditions according to claim 2, characterized in that, The number of the sub-segments is even. The first drilling roadway is located between two adjacent sub-segments. The first drilling roadway can be used as the drilling roadway for the first mining diamond-shaped stope structure in the upper mining unit.

5. The staggered mining method under pre-support conditions according to claim 4, characterized in that, The diamond-shaped stope structure consists of upper and lower triangular mining areas located in two adjacent sub-segments. The mining height of the diamond-shaped stope structure is the height of the two sub-segments. The drilling roadway and the ore receiving roadway are both located between two adjacent sub-segments.

6. The staggered mining method under pre-support conditions according to claim 1, characterized in that, If a complete rhombus stope structure cannot be formed when mining at the upper boundary of the upper mining unit or the lower boundary of the lower mining unit, then mining will be carried out using a triangular stope structure, or the stope will be retained until the next middle section forms a rhombus stope structure before mining.

7. The staggered mining method under pre-support conditions according to claim 1, characterized in that, In step S2, when supporting the entire cross-section of the roadway along the vein, high-strength I-beams are used for dense support.

8. The application of a staggered mining method under pre-support conditions according to any one of claims 1-7, characterized in that, The staggered mining method under pre-support conditions is applicable to the mining of ore bodies adjacent to collapsed loose bodies.

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