Irregular residual ore recovery method

Abstract

The invention discloses an irregular residual ore recovery method. The method comprises the following steps that a ventilation loop with an emergency exit is arranged at the bottom of an ore body in the stope direction; a rock drilling chamber in the average thickness direction of the ore body is arranged on the footwall of the ore body through a ventilation loop and used for arranging a drilling machine; a cardinal number of blasting surfaces are arranged in the average thickness direction of the ore body, and the blasting surfaces are arranged on the two side edges and the middle position of the average thickness of the ore body correspondingly; drilling machine point positions corresponding to the blasting surfaces are arranged in the drilling chamber; fan-shaped bunchy blast hole rows are constructed on all the blasting surfaces through a drilling machine; cleaning blast holes; explosives are installed in the blast holes in a segmented mode; the same sections of all the blast hole rows are blasted at the same time; and after blasting ore removal, next-stage blasting and ore removal are carried out. A plurality of rows of fan-shaped beam-shaped blast holes are formed along the average thickness of an ore body, explosives are installed in the blast holes in a segmented mode according to the depth, the same segments of all the blast holes are blasted at a time, and cutting grooves or cutting courtyards do not need to be formed in the mining preparation project; blasting ore breaking is achieved through stress wave extrusion in the blasting process, so that the purpose of efficiently and safely recycling residual ore resources is achieved.

Description

Technical Field

[0001] This invention belongs to the field of residual ore recovery, specifically a method for recovering irregular residual ore. Background Technology

[0002] Currently, during the underground mining of metallic and non-metallic mineral deposits, due to various factors such as technology, equipment, transportation, and environmental protection requirements, a large amount of ore resources remain buried underground, leading to serious resource waste. As the main mineral resources are gradually mined, the underground stress environment of the mine also undergoes significant changes, impacting the stability of the surrounding rock. Residual ore in mines is mostly marginal and fine-grained vein ore, and the recovery of this residual ore resource has become a crucial research challenge in the mining industry.

[0003] Due to the significant variations in the occurrence of the ore body, residual ore resources are reserved as reserve resources during the mining of the main ore body. However, after the main ore body is mined out, factors such as mining conditions, ground pressure, surrounding rock conditions, backfilling, and roadway collapse render the residual ore resources unsuitable for mining. Furthermore, large-scale bottoming out of the ore body can lead to instability and collapse of the roof.

[0004] The remaining ore resources are of high grade, but the rock mass is of poor quality and the ore body is irregular in size. Based on economic calculations, large-scale mining and redevelopment projects are not feasible, and the only option is to utilize existing roadway engineering for mining. However, due to constraints such as the surrounding engineering geological conditions and the damage to the original shaft engineering caused by previous large-scale production, the remaining ore blocks do not meet the conditions for forming complete cutting grooves or cutting risers. Summary of the Invention

[0005] The purpose of this invention is to provide a method for efficiently and safely recovering irregular residual ore without the need for cutting grooves or cutting wells.

[0006] The method for recovering irregular residual ore provided by this invention includes the following steps:

[0007] (1) A ventilation circuit with a safe exit is arranged at the bottom of the ore body along the direction of the mining area;

[0008] (2) Drilling chambers are arranged in the footwall of the ore body along the average thickness of the ore body through ventilation circuits for the placement of drilling rigs;

[0009] (3) Set up a base number of blasting faces along the average thickness of the ore body, and set up blasting faces at the two sides and the middle position of the average thickness of the ore body respectively;

[0010] (4) Arrange drilling rig positions in the rock drilling chamber corresponding to the blasting face;

[0011] (5) Each blasting face is constructed with a fan-shaped cluster of blast holes by drilling rig;

[0012] (6) Cleaning of blast holes;

[0013] (7) Install explosives in sections of the blast holes;

[0014] (8) All sections of the same borehole row are detonated simultaneously;

[0015] (9) After the blasting is completed, the next blasting and ore extraction will be carried out.

[0016] When the above method is implemented, the ventilation circuit includes the lower plate external tunnel, the upper plate external tunnel, and the lower plate connecting tunnel, the drilling tunnel, and the upper plate connecting tunnel that are connected to each other in sequence. The lower plate external tunnel and the upper plate external tunnel serve as safety exits.

[0017] When implementing the above method, at the edge of the footwall boundary of the ore body, at the connection point between the footwall connecting roadway and the drilling roadway, drilling chambers are developed towards both sides of the ore body in a direction perpendicular to the drilling roadway.

[0018] When implementing the above method, the drilling rig should be at least 1.5m away from the bottom plate and at least 1.75m away from the wall of the rock drilling chamber.

[0019] When implementing the above method, the end of the borehole row should be 2-2.5m away from the boundary of the ore body.

[0020] When the above method is implemented, the intermediate blast hole row installs explosives from the rock drilling tunnel, while the other blast hole rows install explosives from the rock drilling chamber.

[0021] When implementing the above method, the blast hole is blasted twice, in the upper and lower sections. After the explosives in the upper and lower sections are installed, they are filled with sealing materials respectively.

[0022] When implementing the above method, determining the blasting length of the lower section of the borehole includes the following steps:

[0023] (1) Let the total blasting area of ​​the upper section of all blast holes be A, and the total blasting area of ​​the lower section be B. Based on the specifications and production requirements, there should be at least 12% compensation space after the blasted ore body in area A is loosened.

[0024] (2) Assume the cross-section of the intermediate blasting surface is regular;

[0025] (3) Let the volume of the ore body in area A be V1, the space for ore to fall in the drilling tunnel below the ore body in area A be V2, the length of the drilling tunnel corresponding to V2 be L2, the remaining length of the drilling tunnel be L1, the cross-sectional area of ​​the drilling tunnel be S, the height of the ore body be H1, the height of the blasted ore body in the lower section be H2, and the average thickness of the ore body be D. The following relationships should be ensured:

[0026] (4) Based on the volume relationship, the rock drilling tunnel sections L1 and L2 corresponding to the intermediate profile have the following relationship:

[0027] (5) Assuming the ore body varies uniformly across all sections, and the ore body size in the middle section is the average of the two symmetrical sections, the ratio of the length of the lower section of the borehole to the total length of the borehole can be approximated by the following relationship:

[0028] When the above method is implemented, after the first blasting is completed, the loader transports the ore through the rock drilling tunnel and connecting tunnel to the lower vein external tunnel for ore extraction. After the ore extraction is completed, a sufficiently large compensation space is formed for the second blasting.

[0029] This invention sets up multiple rows of fan-shaped bundles of blasting holes along the average thickness of the ore body, installs explosives in sections according to depth of the blasting holes, and detonates the same section of all blasting holes at once. In the mining preparation process, there is no need to form cutting grooves or cutting risers. The blasting process achieves the purpose of efficient and safe recovery of residual ore resources by squeezing the stress wave. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the main ore body and its residual ore profile according to an embodiment of the present invention.

[0031] Figure 2 This is an enlarged plan view of the preparation engineering for the residual ore in this embodiment.

[0032] Figure 3 This is a magnified schematic diagram of the preparation work and compensation space after the first blast.

[0033] Figure 4 This is a schematic diagram of the 3P section and the preparation engineering section.

[0034] Figure 5 This is an enlarged schematic diagram of the 1P section and the preparation engineering section.

[0035] Figure 6 This is an enlarged schematic diagram of the 2P section and the preparation engineering section.

[0036] Figure 7 This is an enlarged schematic diagram of the 4P section and the preparation engineering section.

[0037] Figure 8 This is an enlarged schematic diagram of the 5P section and the preparation engineering section.

[0038] Figure 9 An enlarged schematic diagram showing the installation of emulsion explosives and borehole plugs in the blast hole.

[0039] Figure 10 This is a simplified enlarged schematic diagram of the 3P profile of the ore body.

[0040] Detailed list of serial numbers in the diagram:

[0041] 1. Lower connecting roadway, 2. Drilling rig location, 3. Drilling roadway, 4. Drilling chamber, 5. Upper connecting roadway, 6. Lower external roadway, 7. Upper external roadway, 8. Blasting hole, 8-1 Upper section blasting hole, 8-2 Lower section blasting hole, 8-3 Upper section blasting hole plugging material, 8-4 Lower section blasting hole plugging material, A. Upper section one-time blasting range, B. Lower section one-time blasting range, C. Upper section one-time blasting ore body falling range in the drilling roadway, D. Ore body boundary plane projection range, E. Compensation space plane projection formed after the first blast. Detailed Implementation

[0042] like Figures 1-10 As shown, the irregular residual ore recovery method disclosed in this invention includes the following steps:

[0043] (1) A ventilation circuit with a safety exit is arranged at the bottom of the ore body along the length of the ore body mining direction.

[0044] The ventilation circuit includes the lower plate external tunnel 6, the upper plate external tunnel 7, and the lower plate connecting tunnel 1, the rock drilling tunnel 3, and the upper plate connecting tunnel 5 that are connected to each other in sequence.

[0045] During the construction of the ventilation circuit, the lower connecting roadway 1 is developed from the lower vein external roadway 6 towards the ore body. The length of the lower connecting roadway 1 is from the lower vein external roadway 6 to the vicinity of the lower edge of the ore body.

[0046] Starting from the lower connecting roadway 1, the drilling roadway 3 is developed into the ore body. The drilling roadway is located in the middle of the ore body. After penetrating the ore body, it is connected to the upper connecting roadway 7 through the development of the upper connecting roadway 5, forming a complete ventilation circuit and safety exit. That is, the ventilation circuit has two safety exits: the lower connecting roadway 6 and the upper connecting roadway 7.

[0047] (2) After the ventilation circuit is completed, at the connection point of the footwall connecting roadway 6 and the drilling roadway 3 at the edge of the footwall of the ore body, the drilling chamber 4 is developed towards both sides of the ore body in a direction perpendicular to the drilling roadway 3.

[0048] (3) According to the design, the ore body is divided into an odd number of sections along the thickness direction. The number of sections is determined according to the average thickness of the ore body, and the middle section is located at the center of the average thickness of the ore body.

[0049] (4) Drilling rig positions are set at the corresponding cross-sectional positions in the rock drilling chamber 4, with a distance of more than 1.5m from the bottom plate and more than 1.75m from the rock drilling chamber wall.

[0050] (5) For each section, fan-shaped bundle-shaped blast holes are constructed. Since the middle section corresponds to the position of the rock drilling tunnel, the blast holes are constructed from the rock drilling tunnel in the middle section, and the blast holes are constructed from the rock drilling chamber in other sections.

[0051] (6) After the blast holes of each section are completed, the blast holes are cleaned by high-speed air.

[0052] (7) Install emulsion explosives into each row of blast holes according to the design. First, install the upper section of the one-time blasting area in each blast hole, then install the sealing material, then install the emulsion explosives for the lower section of the one-time blasting area, and then install the sealing material again.

[0053] Before installing explosives, the lengths of the upper and lower sections of the borehole must be determined, as follows:

[0054] The first blast was performed in a single explosion to destroy the boreholes in area A in front of each bundle of boreholes. The second blast was performed in a single explosion to destroy the boreholes in area B behind each bundle of boreholes.

[0055] The blasting range in Area A should be calculated based on the ore-falling space in the roadway to ensure at least 12% compensation space after the ore body is loosened by blasting.

[0056] Assuming the intermediate profile of the ore body is regular, such as Figure 10 As shown, the volume of the ore body in area A is V1, the space for ore to fall into the drilling tunnel below the ore body in area A is V2, the length of the drilling tunnel corresponding to V2 is L2, the remaining length of the drilling tunnel is L1, the cross-sectional area of ​​the drilling tunnel is S, the height of the ore body is H1, the height of the ore body after the second single blast is H2, and the average thickness of the ore body is D. The following relationships should be maintained: (1)

[0057] (4) Let the total volume of the ore body be V, and the volumes of the ore bodies in each region have the following relationship: V-V3=V1+V2(2) because (3) (4)

[0058] Therefore, according to formulas (1) and (2), we can obtain: (5)

[0059] (5) Based on the volume relationship, the rock drilling tunnel sections L1 and L2 corresponding to the intermediate profile have the following relationship: (6)

[0060] The ore body varies uniformly across all sections, with the size of the ore body in the middle section being approximately the average of the two symmetrical sections. Therefore, the ratio of the length of the lower section of each borehole (8-2) to the total length of the boreholes can be approximated by the following relationship: (7)

[0061] (8) After the emulsion explosive is installed, the ore body in the upper section of each row of blast holes is blasted in one go. The ore is squeezed and crushed by the stress wave generated by the blast to the adjacent loose medium and the bottom rock drilling chamber to achieve the first squeezing and ore dropping.

[0062] (9) The loader performs ore extraction through the unblasted rock drilling tunnel. After the ore formed by the first compression blasting is extracted, area E is formed to provide sufficient space for subsequent ore body blasting.

[0063] (10) A second blasting operation was carried out to remove ore. The drilling chamber was destroyed, and the loader entered the mining area through the connection between the drilling chamber and the original drilling tunnel to carry out ore extraction operations.

[0064] The specific applications of the present invention will be described in detail below with reference to the embodiments.

[0065] In this embodiment (Anqing Copper Mine), the specific details of the residual edge ore are as follows:

[0066] The ore body has a footwall dip angle of 21°, a hanging wall dip angle of 54°, an average bottom length of 28m, a stope width of approximately 15m, and a maximum height of 14.5m. Backfilling operations during the earlier large-scale mining phase caused collapses in the upper middle section of the roadway, which was then filled and covered by backfill material. Removing all the backfill material from the roadway and providing support would be extremely costly, preventing the formation of suitable cutting grooves or cut risers in the remaining ore body. Therefore, the new method provided in this invention is used for the recovery of the remaining ore. The specific implementation steps are as follows:

[0067] Five profiles, 1P to 5P, are evenly divided along the average thickness of the ore body. Profile 3P is located at the center of the average thickness of the ore body. Each profile is used to show the planned mining preparation works and to lay out the blast holes.

[0068] From the footwall outer channel 6, the footwall connecting channel 1 is developed. The footwall connecting channel has a cross-sectional dimension of 4m × 3.5m and a length of 12.8m. After the footwall connecting channel is developed, the rock drilling channel 3 is excavated at the bottom of the ore body. The rock drilling channel has a cross-sectional dimension of 4m × 3.5m and a length of 25m to the edge of the hanging wall. From the rock drilling face, the hanging wall connecting channel 5 is continued to be excavated to the footwall outer channel 6. The hanging wall connecting channel has a cross-sectional dimension of 4m × 3.5m and a length of 14m.

[0069] At the connection point between the footwall connecting roadway 1 and the drilling roadway 3, drilling chambers 4 are excavated on both sides of the ore body in a direction perpendicular to the drilling roadway. The cross-sectional dimensions of each drilling chamber are 3.7m × 3.7m, and the length of the drilling chamber is equal to the average thickness of the ore body. The drilling chambers are adjusted according to the distribution characteristics of the ore body so that, after the preparatory engineering design is completed, the boundary of the footwall ore body in the 3P section passes through the middle of the right side wall of the drilling chamber in that section, maximizing recovery production and minimizing waste rock extraction.

[0070] Calculations are performed according to the aforementioned formulas (1)-(7).

[0071] Given the cross-sectional area S of the drilling tunnel in the 3P section of the ore body, the maximum height H1 of the ore body in the 3P section, and the average thickness D of the ore body, estimate the proportion of the length of the blast hole charge in the lower half of the stope to the total length of the blast holes. Where S is 14m. 2 H1 is 14.5m and D is 15m. Calculations show that the length of the lower section of the borehole charge accounts for 0.8% of the total borehole length, including the 0.7m length of plugging material in the lower section. The length of the upper section of the borehole charge accounts for 0.2% of the total borehole length, including the 0.7m length of plugging material in the upper section.

[0072] Drilling rig points are set at positions 1P to 5P in the rock drilling chamber. The distance between the drilling rig points and the bottom plate is controlled at more than 1.5m, and the distance between the drilling rig points and the rock drilling chamber wall is controlled at more than 1.75m.

[0073] After the blast holes are drilled, they are cleaned with high-speed air pressure.

[0074] Install emulsion explosives into each row of blast holes, first installing the upper section of each hole for a single blast, and then installing the upper section of the blast hole sealing material. Next, install emulsion explosives in the lower section for a single blast, and then seal the blast holes with the lower section of the blast hole sealing material.

[0075] After the emulsion explosives are installed, the ore body within the one-time blasting range of each row of fan-shaped bundle holes is blasted in one go. The ore is squeezed and crushed by the stress wave generated by the blasting into the adjacent loose medium and the bottom drilling chamber to achieve the first squeezing and ore dropping.

[0076] The loader operates the ore extraction through the unblasted rock drilling tunnel. After the ore formed by the first compression blasting is extracted, area E is formed, providing enough space for the remaining ore body to be blasted.

[0077] A second blasting operation was carried out to extract ore, destroying the drilling chamber. The loader then entered the mining area through the connection between the drilling chamber and the original drilling tunnel to carry out ore extraction operations.

Claims

1. A method for recovering irregular residual ore, characterized in that, The method includes the following steps: (1) A ventilation circuit with a safe exit is arranged at the bottom of the ore body along the direction of the mining area; (2) Drilling chambers are arranged in the footwall of the ore body along the average thickness of the ore body through ventilation circuits for the placement of drilling rigs; (3) Set up a base number of blasting faces along the average thickness of the ore body, and set up blasting faces at the two sides and the middle position of the average thickness of the ore body respectively; (4) Arrange drilling rig positions in the rock drilling chamber corresponding to the blasting face; (5) Each blasting face is constructed with a fan-shaped cluster of blast holes by drilling rig; (6) Cleaning of blast holes; (7) Install explosives in sections of the blast holes; (8) All sections of the same borehole row are detonated simultaneously; (9) After the blasting is completed, the next blasting and ore extraction will be carried out.

2. The method for recovering irregular residual ore as described in claim 1, characterized in that, The ventilation circuit includes the lower plate external tunnel, the upper plate external tunnel, and the lower plate connecting tunnel, the drilling tunnel, and the upper plate connecting tunnel that are connected to each other in sequence. The lower plate external tunnel and the upper plate external tunnel serve as safety exits.

3. The method for recovering irregular residual ore as described in claim 1, characterized in that, At the edge of the footwall boundary of the ore body, at the connection point between the footwall connecting roadway and the drilling roadway, drilling chambers are developed on both sides of the ore body in a direction perpendicular to the drilling roadway.

4. The method for recovering irregular residual ore as described in claim 1, characterized in that, The drilling rig location should be at least 1.5m away from the bottom plate and at least 1.75m away from the rock drilling chamber wall.

5. The method for recovering irregular residual ore as described in claim 1, characterized in that, The end of the blast hole row is 2-2.5m away from the boundary of the ore body.

6. The method for recovering irregular residual ore as described in claim 1, characterized in that, The intermediate blast hole platoon installed explosives from the rock drilling tunnel, while the other blast hole platoons installed explosives from the rock drilling chamber.

7. The method for recovering irregular residual ore as described in claim 1, characterized in that, The blast hole was blasted in two stages, upper and lower. After the explosives were installed in the upper and lower stages, they were filled with sealing material.

8. The method for recovering irregular residual ore as described in claim 7, characterized in that, Determining the blasting length of the lower section of the blast hole includes the following steps: (1) Let the total blasting area of ​​the upper section of all blast holes be A, and the total blasting area of ​​the lower section be B. Based on the specifications and production needs, the ore body in area A should have at least 12% compensation space after blasting and loosening. (2) Assume the cross-section of the intermediate blasting surface is regular; (3) Let the volume of the ore body in area A be V1, the space for ore to fall in the drilling tunnel below the ore body in area A be V2, the length of the drilling tunnel corresponding to V2 be L2, the remaining length of the drilling tunnel be L1, the cross-sectional area of ​​the drilling tunnel be S, the height of the ore body be H1, the height of the blasted ore body in the lower section be H2, and the average thickness of the ore body be D. The following relationships should be ensured: (4) Based on the volume relationship, the rock drilling tunnel sections L1 and L2 corresponding to the intermediate profile have the following relationship: (5) Assuming the ore body varies uniformly across all sections, and the ore body size in the middle section is the average of the two symmetrical sections, the ratio of the length of the lower section blast hole to the total length of the blast holes has the following relationship: 。 9. The method for recovering irregular residual ore as described in claim 1, characterized in that, After the first blast, the loader transports the ore through the rock drilling tunnel and connecting tunnel to the lower vein external tunnel for ore extraction. After the ore extraction is completed, a large enough compensation space is formed for the second blast.

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