Mining method for stope between large-volume backfill bodies

Abstract

Disclosed is a mining method for a stope between large-volume backfill bodies. First, a stope is isolated from large-volume backfill bodies by artificial solid barriers; and then, the stope is divided into a plurality of mining sections along the height direction, the mining sections sequentially undergo stoping from bottom to top, and each mining section is backfilled immediately after stoping is completed. Solid isolation walls are constructed on both sides of a stope to be mined along the height direction, the isolation walls are located between large-volume backfill bodies and an ore body to be mined, the entire construction process of the isolation walls is carried out within said stope, and after the isolation walls are formed, both rock drilling and blasting operations use isolation walls as barriers during the stoping of said stope, so that continuous disturbance to said stope is avoided, blasting-induced impact is isolated, and the movement and deformation of backfill bodies are restricted, thereby fundamentally solving the problem of instability and collapse of backfill bodies during the mining of stopes adjacent to large-volume backfill bodies. In addition, no loss of ore resources due to ore walls occurs in stopes.

Description

A method for mining a stope between large-volume backfill bodies Technical Field

[0001] This invention belongs to the field of mining and relates to a method for mining a stope between large-volume backfill bodies. Background Technology

[0002] Backfilling is a crucial measure to limit rock mass movement and deformation and eliminate mine ground pressure hazards. Backfill bodies, due to their low strength and poor stability, are easily damaged and unstable by mining disturbances. Continuous blasting operations near large-volume backfill bodies can easily trigger their collapse, causing them to infiltrate the mining area. This not only poses a serious threat to personnel and equipment but also encroaches on the working space, forcing mining to be interrupted or even halted, resulting in a permanent loss of substantial mineral resources.

[0003] In mining adjacent large-volume backfill bodies, reserving a protective wall to safeguard the backfill is a common technical measure. However, because the protective wall is formed by stripping from the ore body, it is difficult to create a relatively regular protective wall during the mining process. Even slight deviations in drilling or blasting can result in the loss of the protective wall, leading to the collapse of the backfill. On the other hand, from a resource recovery perspective, the ore wall itself is part of the ore body, a valuable non-renewable resource. Reserving a protective wall means that the resource cannot be developed, resulting in resource loss. Summary of the Invention

[0004] The purpose of this invention is to provide a mining method for large-volume backfill sites that can maintain the stability of the backfill and avoid loss of mineral resources.

[0005] The mining method for large-volume backfill bodies provided by this invention first isolates the mining area from the large-volume backfill body using artificial entities, then divides the mining area into several mining sections along the height direction, and mines each mining section sequentially from bottom to top. After the mining of each mining section is completed, backfilling is carried out.

[0006] When implementing the above method, the steps for artificially isolating the mining area from the large-volume backfill body are as follows:

[0007] Step 1: Symmetrically excavate several horizontal tunnels along the height direction at the junction of the mining area and the backfill body on both sides;

[0008] Step 2: Connect the two side access tunnels separately, with the connection width being less than the width of the access tunnel;

[0009] Step 3: Pour a reinforced concrete wall within the through width to create a man-made structure.

[0010] When implementing the above method, in step one, the spacing between the measure roadways is 10-15m, and both ends are connected to the external transport roadway of the ore body. The first measure roadway is located at the lowest point of the mining area.

[0011] When implementing the above method, in step two, the breakthrough width shall not exceed 1 / 2 of the width of the alleyway.

[0012] When implementing the above method, in step two, when the tunnel is connected, construction should proceed from bottom to top.

[0013] When implementing the above method, in step three, after the adjacent upper and lower tunnels are connected, a steel mesh is placed in the connected section from top to bottom. The joints of the steel mesh are interlocked. After the steel mesh is placed, high-strength concrete grout is poured.

[0014] When the above method is implemented, the height of the steel mesh frame is 2-3m and the width is 1-3m.

[0015] When implementing the above method, the corresponding height of the measure roadways on both sides are connected to form cutting roadways, and the ore body in the mining area is divided into ore sections by cutting roadways.

[0016] When the above method is implemented, during the mining of each section, blast holes are constructed from the cutting level above to blast and extract ore. The blast pile is then removed by a remotely controlled shovel and loader to form a goaf.

[0017] When implementing the above method, the highest mining section is mined and then backfilled. When backfilling other mining sections, the cutting level roadway above it is retained as the ore drop area of ​​the previous mining section.

[0018] This invention constructs solid isolation walls on both sides of the mining area along its height. These walls are located between the large-volume backfill and the ore body to be mined. The entire construction process of the isolation walls takes place within the mining area. After the isolation walls are formed, during the mining process, drilling and blasting operations are protected by the walls, preventing continuous disturbance to the mining area, isolating blasting impacts, and limiting the movement and deformation of the backfill. This fundamentally solves the problem of instability and collapse of backfill when mining large-volume backfill adjacent to mining areas. Furthermore, there is no loss of ore resources due to the absence of mining walls. Attached Figure Description

[0019] Figure 1 is a schematic diagram of the layout of the measures roadway in a mining area according to one embodiment of the present invention.

[0020] Figure 1a is a schematic diagram of AA in Figure 1.

[0021] Figures 2a-2d are schematic diagrams of the forming process of artificial isolation walls.

[0022] Figure 2e is a schematic diagram of the formed artificial isolation wall.

[0023] Figure 3 is a schematic diagram of dividing the mining area into mining sections by connecting the access roadways on both sides of the mining area to form a cutting roadway.

[0024] Figures 4a-4c are schematic diagrams of the mining process in the ore section.

[0025] The numbers in the diagram are as follows: 1-Mining area to be mined; 2-Large volume filling body; 3-Measure roadway; 4-External ore transport roadway; 5-First section injection shaft; 6-First section isolation wall; 7-Integral isolation wall; 8-Cutting horizontal roadway; 9-Blast hole. Detailed Implementation

[0026] The mining method for a large-volume backfill body provided by this invention is as follows: first, the mining area is isolated from the large-volume backfill body by artificial entities; then, the mining area is divided into several mining sections along the height direction; each mining section is mined sequentially from bottom to top; and backfilling is carried out after each mining section is mined.

[0027] In this embodiment, a reinforced concrete partition wall is used as the physical partition.

[0028] In this embodiment, the specific process of isolating the mining site 1 from the large-volume filling body 2 using artificial entities is as follows:

[0029] As shown in Figure 1, first determine the measure roadway 3 at the lowest and highest points of the mining area 1 to be mined, and then divide the mining area height into equal intervals of 10-15m to determine the number of intermediate measure roadways.

[0030] As shown in Figure 1a, the construction of the measure roadway 3 begins from the external ore transport roadway 4 and extends to the transport roadway on the other side of the ore body. That is, both ends of the measure roadway 3 are connected to the external ore transport roadway 4.

[0031] The width × height of the alleyway is (5m × 3m) - (6m × 5m).

[0032] Equipment selected for through-hole construction: well drilling rig.

[0033] Determine the breakthrough width: half the width of the tunnel.

[0034] As shown in Figures 2a-2d, during construction, a section is connected and then isolated to ensure that the exposed sidewalls of the filling material are supported in a timely manner.

[0035] The specific construction process for forming the isolation wall is as follows:

[0036] (1) The riser enters the second measure roadway 3 from the external transport roadway 4 of the ore body and drills downward at the specified width (changed to excavate from bottom to top at the specified width). When the first measure roadway is completed, the first section of injection well 5 is formed, and its depth is the sum of the height of the measure roadway and the distance between the measure roadways.

[0037] (2) The well drilling rig enters the external transport tunnel 4 of the ore body.

[0038] (3) Insert the steel mesh frame into the first section of the injection well, and at the same time, make the upper, lower and left and right splicing joints of each steel mesh frame interlock to form a whole; in order to facilitate the production and installation, the height of the steel mesh frame is 2-3m and the width is 1-3m.

[0039] (4) Install a blocking baffle on the outside of the corresponding steel mesh in the lowest measure alley;

[0040] (5) Pour concrete grout from top to bottom, and after curing, form the first section of the isolation wall 6;

[0041] (7) Repeat the above process until the highest section of the isolation wall is connected and the last section of the isolation wall is poured. The height of the last section of the isolation wall is the sum of the distance between the isolation walls and the height of the two isolation walls, and the height of the other sections of the isolation wall is the sum of the height of the isolation walls and the height of one isolation wall. That is, the last section of the isolation wall needs to be filled to the top, and the other sections of the isolation wall are filled to the bottom surface of the corresponding isolation wall at the top of the connected section.

[0042] After the integral isolation wall 7 is formed on both sides of the mining area, the width of each measure lane 3 will be half of the original width, as shown in Figure 2e.

[0043] After the overall isolation wall is maintained, the construction equipment enters the measures roadway from the external transport roadway 4 of the mine, and constructs the measures roadway 3 from both sides at the same height to form the cutting horizontal roadway 8, dividing the mining area height into four mining sections as shown in Figure 3.

[0044] The ore body is mined from bottom to top, and the specific process is as follows:

[0045] As shown in Figure 4a, during the mining of the first section, blast holes 9 are constructed downwards from the cutting level above the section to blast and excavate ore. The cutting level below the section serves as the ore excavation space. A remote-controlled loader removes the blasted material to form a goaf.

[0046] As shown in Figure 4b, during filling, the cutting level above the mining section is reserved as the ore dumping space for the second mining section.

[0047] The mining and backfilling of the second and third mining sections are the same as those of the first mining section.

[0048] During the mining of the fourth section, since it is the last section of the stope, there are cutting level tunnels above and below it, as shown in Figure 4c. Therefore, the cutting level tunnels above also need to be filled during backfilling, meaning that this section requires roof backfilling.

[0049] In summary, this embodiment first involves symmetrically distributing auxiliary roadways on both sides of the stope's height. These roadways are then connected vertically to form a grouting shaft. A steel mesh is then fabricated and lowered into the grouting shaft, followed by the injection of grout to solidify and form a high-strength grouting wall section. Finally, a reinforced concrete integral isolation wall is formed. Next, the remaining half of the auxiliary roadway is used to excavate a cutting level roadway, dividing the ore body into independent sections. Simultaneously, the cutting level roadway serves as the drilling and blasting space for the ore section, and blasting is carried out on the section. After mining, the ore is backfilled to the bottom of the cutting level roadway, reserving space for future blasting of the next ore section.

[0050] In summary, the present invention has the following advantages:

[0051] By constructing solid isolation walls on both sides of the mining area along its height, with the walls positioned between the large-volume backfill and the ore body, the entire construction process of the isolation walls takes place within the mining area. After the isolation walls are formed, they act as a barrier during drilling and blasting operations in the mining area. This not only prevents continuous disturbance to the mining area and isolates it from blasting impacts, but also restricts the movement and deformation of the backfill, fundamentally solving the problem of instability and collapse of backfill when mining large-volume backfill adjacent to other mining areas.

[0052] A "multi-purpose roadway" model was created for mining the mining area. First, the mining area was divided into several mining sections by constructing a cutting roadway using the raised shaft. Mining was carried out on a section-by-section basis. Second, a half-width roadway was used to access the mining area to shovel and transport blasted ore, and the roadway became the ore extraction channel. Finally, a half-width raised shaft roadway was used to install filling pipelines to fill the goaf.

[0053] The "one roadway, multiple uses" method significantly reduces the amount of preparatory work and improves the efficiency of ore body mining. This method enables segmented mining and filling; before mining, the ore body provides lateral support for the high-strength grouting wall, and after mining, the filling material provides lateral support, effectively ensuring the stability of the high-strength grouting wall. More importantly, the construction of the high-strength grouting wall isolates the ore section from blasting impacts, allowing for the placement of blast holes at the boundaries of each section without the need for retaining walls. This enables the complete recovery of resources in the mining area, truly achieving lossless mining.

Claims

1. A method for mining a stope between large-volume backfill bodies, characterized in that, The method first establishes an artificial isolation between the mining area and the large-volume backfill body, then divides the mining area into several mining sections along the height direction, and mines each mining section sequentially from bottom to top. After the mining of each mining section is completed, backfilling is carried out.

2. The mining method for a stope between large-volume backfill bodies as described in claim 1, characterized in that, The steps for artificially isolating the stope from the large-volume backfill body are as follows: Step 1: Symmetrically excavate several horizontal tunnels along the height direction at the junction of the mining area and the backfill body on both sides; Step 2: Connect the two side access tunnels separately, with the connection width being less than the width of the access tunnel; Step 3: Pour a reinforced concrete wall within the through width to create a man-made structure.

3. The mining method for a stope between large-volume backfill bodies as described in claim 2, characterized in that, In step one, the spacing between the measure roadways is 10-15m, and both ends are connected to the external transport roadways of the ore body. The first measure roadway is located at the lowest point of the mining area.

4. The mining method for a stope between large-volume backfill bodies as described in claim 2, characterized in that, In step two, the width of the tunnel should not exceed 1 / 2 of the width of the tunnel.

5. The mining method for a stope between large-volume backfill bodies as described in claim 2, characterized in that, In step two, when the tunnel is completed, construction proceeds from bottom to top.

6. The mining method for a stope between large-volume backfill bodies as described in claim 5, characterized in that, In step three, after the adjacent tunnels are connected, a steel mesh is placed in the connected section from top to bottom. The joints of the steel mesh are interlocked. After the steel mesh is placed, high-strength concrete grout is poured.

7. The mining method for a stope between large-volume backfill bodies as described in claim 6, characterized in that, The steel mesh frame has a height of 2-3m and a width of 1-3m.

8. The mining method for a stope between large-volume backfill bodies as described in claim 1, characterized in that, The corresponding height of the two sides of the roadway is connected to form a cutting level roadway, and the ore body in the mining area is divided into mining sections by the cutting level roadway.

9. The mining method for a stope between large-volume backfill bodies as described in claim 1, characterized in that, During the mining of each section, blast holes are constructed from the cutting level above to blast and extract ore. A remotely controlled loader then removes the blast pile, forming a goaf.

10. The mining method for a stope between large-volume backfill bodies as described in claim 1, characterized in that, When the highest mining section is mined out, it is then backfilled. When backfilling other mining sections, the cutting level roadway above it is retained as the ore drop area of ​​the previous mining section.

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