Precious metal ore surrounding rock controlled blasting separation method based on electronic detonator laneway tunneling

Abstract

A precious metal ore surrounding rock controlled blasting separation method based on electronic detonator roadway tunneling comprises the steps that ore surrounding rock partitioning is conducted on a tunnel face before blasting, differentiated charging parameters and blasting design are adopted for an ore area and a surrounding rock area, millisecond-level precise delay detonation is achieved through electronic detonators, and the blasting separation efficiency is improved. The ore is effectively thrown to form an independent pile body, the surrounding rock is loosened and exploded on site, separation and transportation are achieved according to the boundary between the ore pile and the surrounding rock pile, and the mixing rate of the surrounding rock and the ore loss rate are remarkably reduced. According to the method, physical separation of ore surrounding rocks in the tunneling blasting process is achieved, the resource recovery rate and mine benefits are improved, and the method conforms to the green mine development concept and has good industrial application prospects.

Description

Technical Field

[0001] This invention relates to the field of mining technology, and in particular to a controlled blasting separation method for precious metal ore surrounding rock in tunnel excavation using electronic detonators. Background Technology

[0002] In my country, shallow mineral resources are gradually being depleted, and the focus of mineral development has gradually shifted to deeper areas and areas with complex geological conditions. The proportion of mining thin precious metal ore bodies has shown a significant upward trend. These thin precious metal ore bodies are characterized by their small thickness (usually less than 1.5m), high grade, high value, and unstable occurrence, which places extremely stringent requirements on resource recovery rate and the precision of mining technology.

[0003] In tunneling operations involving thin precious metal ore bodies, conventional mixed blasting methods are still widely used. However, this method, due to its failure to adequately consider the actual distribution of the ore body at the working face and to differentiate construction methods in the setting of borehole layout and explosive parameters, is prone to a series of problems:

[0004] 1. Waste of resources: Because the excavation slag is treated as surrounding rock (waste rock), the ore mixed in with it is also discarded, resulting in a large amount of valuable ore resources not being effectively recovered, causing great waste.

[0005] 2. Increased costs and resource loss: If the tunneling slag is treated as a by-product (ore), a large amount of surrounding rock from the tunneling head will be mixed into the ore. This will not only increase the costs of subsequent transportation, hoisting and beneficiation, but also, during the beneficiation process, the surrounding rock will be processed into tailings and will take away the valuable metals contained therein, further aggravating the loss of resources.

[0006] 3. Violation of green mining policy: This extensive and high-emission model runs counter to the national advocacy of "resource-saving and environmentally friendly" mining development and does not meet the requirements of sustainable development.

[0007] Although foreign countries have already implemented technologies for precise blasting control using electronic detonators, China still lacks a systematic and widely applicable solution for the problem of separating ore and surrounding rock under thin orebody conditions. Currently, no complete technical system has been established to achieve the goal of "differentiated blasting separation based on orebody distribution." Summary of the Invention

[0008] The purpose of this invention is to provide a controlled blasting separation method for precious metal ore surrounding rock in tunnel excavation based on electronic detonators, which solves the problems of resource loss, increased processing costs and environmental pollution caused by mixed blasting of ore surrounding rock at the tunnel excavation site in the prior art.

[0009] To achieve the above objectives, this invention provides a controlled blasting separation method for precious metal ore surrounding rock in tunnel excavation using electronic detonators, specifically comprising the following steps:

[0010] S1. Before blasting, the working face is divided into ore zone and surrounding rock zone according to the distribution of ore body at the working face.

[0011] S2. Large hole spacing and large row spacing are adopted for blast holes in the ore area, and high charge is adopted for blast holes in the ore area.

[0012] S3. Small hole spacing and small row spacing are used for blast holes in the surrounding rock area, and low explosive charge is used for blast holes in the surrounding rock area.

[0013] S4. Electronic detonators are used to control the blasting sequence. When the area of ​​the ore zone is smaller than that of the surrounding rock zone, the blast holes in the ore zone are detonated first, and then the blast holes in the surrounding rock zone are detonated with a delay. When the area of ​​the surrounding rock zone is smaller than that of the ore zone, the blast holes in the surrounding rock zone are detonated first, and then the blast holes in the ore zone are detonated with a delay, so as to achieve spatial separation between the ore and the surrounding rock.

[0014] S5. After blasting, the distance between the ore pile and the working face is greater than the distance between the surrounding rock pile and the working face. The ore pile and the surrounding rock pile are separated by shovel loading and transportation through the boundary line between them to achieve the separation of ore and surrounding rock.

[0015] In this embodiment, the charge amount of the blast holes in the ore area is 20% to 30% higher than that in the surrounding rock area, and the hole spacing and row spacing of the blast holes in the ore area are 10% to 20% larger than those in the surrounding rock area.

[0016] In this embodiment, in step S4, the delay accuracy of the electronic detonator is ±1ms, and the delay time interval between adjacent boreholes is not less than 25ms.

[0017] In this embodiment, the borehole depth is 1.5 to 3.5 m, and the vein thickness is less than 1.5 m.

[0018] In this embodiment, in step S1, ground-penetrating radar, core drilling, or digital imaging technology is used to obtain the distribution of the ore body at the working face and determine the ore body boundary and grade distribution.

[0019] In this embodiment, in step S1, the staff divides the ore area and the surrounding rock area on the working face using marking lines based on the obtained distribution of the ore body at the working face.

[0020] In this embodiment, when the area of ​​the ore zone is smaller than that of the surrounding rock zone, a cut hole is arranged at the center of the ore zone, and auxiliary holes and peripheral holes are arranged in the ore zone with the cut hole as the center; when the area of ​​the surrounding rock zone is smaller than that of the ore zone, a cut hole is arranged at the center of the surrounding rock zone, and auxiliary holes and peripheral holes are arranged in the surrounding rock zone with the cut hole as the center.

[0021] Due to the above structure, the present invention has the following advantages:

[0022] 1. This method achieves spatial separation of ore and surrounding rock after blasting at the tunneling point along the vein of precious metal thin veins through the control of "geological exploration and face analysis → on-site zoning → differentiated blasting design → electronic detonator networking and delay design → safe initiation and process monitoring → blasting slag removal and separation", thereby improving ore recovery rate, reducing the amount of surrounding rock to beneficiation plant, and meeting the requirements of green and efficient mining.

[0023] 2. Using this method, after blasting, the ore will be piled up in front of (behind) the roadway to form an independent ore pile, and the surrounding rock will be piled up in front of (behind) the roadway to form an independent surrounding rock pile. There is a clear dividing line between the ore pile and the surrounding rock pile. After being shoveled and transported separately, the ore and surrounding rock are physically separated, improving the recovery efficiency, reducing the amount of tailings discharge and the loss of valuable metals, which meets the requirements of green mine construction.

[0024] 3. This method achieves directional throwing or on-site loosening of ore through differentiated blasting design, increasing ore recovery rate by more than 10% and significantly improving resource utilization. The surrounding rock mixing rate can be reduced from more than 30% in traditional methods to less than 15%, greatly reducing the surrounding rock mixing rate. At the same time, it reduces the amount of surrounding rock transportation and mineral processing, saving 20% ​​to 30% of the cost per meter of advance.

[0025] 4. This method uses electronic detonators, which can achieve millisecond-level precise delay. Combined with electronic detonators, it supports digital and intelligent blasting management, improves the separation effect of ore and surrounding rock, and enhances safety.

[0026] In summary, this method involves dividing the working face into ore and surrounding rock zones before blasting, employing differentiated charge parameters and blasting designs for the ore and surrounding rock zones, and utilizing electronic detonators to achieve millisecond-level precise delayed detonation between blast holes on the working face. This effectively throws the ore and surrounding rock into independent piles. After blasting, the ore and surrounding rock are separated and transported according to the boundary line, significantly reducing the mixing rate of surrounding rock and the ore loss rate. This invention achieves physical separation of ore and surrounding rock during tunneling blasting, possessing differentiated construction capabilities, directional throwing of ore and surrounding rock, and local loosening blasting capabilities. It can form a clear boundary line between ore and surrounding rock after blasting, thereby achieving effective separation of ore and surrounding rock, improving resource recovery rate and mining efficiency. It is suitable for efficient, low-loss, and green mining of thin veins of precious metals such as gold, silver, antimony, and tungsten under complex geological conditions. Attached Figure Description

[0027] Figure 1 This is a flowchart of the present invention.

[0028] Figure 2 This is a schematic diagram of the ore surrounding rock zoning at the working face of the present invention.

[0029] Figure 3(a) is a diagram of the borehole layout for pre-detonation in the surrounding rock area according to the present invention.

[0030] Figure 3(b) is a cross-sectional view of the tunnel after blasting is completed when the surrounding rock area is detonated first according to the present invention.

[0031] Figure 4(a) is a diagram of the borehole layout for the ore zone detonation of the present invention.

[0032] Figure 4(b) is a cross-sectional view of the roadway after the blasting is completed when the ore area is detonated first according to the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0035] like Figure 1 As shown, a controlled blasting separation method for precious metal ore surrounding rock in tunnel excavation based on electronic detonators is presented. In this embodiment, the ore body thickness is less than 1.5m. The invention includes the following implementation steps: "Geological exploration and face analysis → on-site zoning → differentiated blasting design → electronic detonator networking and delay design → safe detonation and process monitoring → blasting slag removal and separation".

[0036] like Figure 2 As shown, geological exploration and working face analysis include obtaining information on the lithology and ore body distribution of the working face using technologies such as ground-penetrating radar, core drilling, or digital imaging after the tunnel has been excavated to the target location, and determining the ore body boundaries and grade distribution.

[0037] On-site zoning involves technicians marking the working face with lines to delineate "ore zones" and "surrounding rock zones" based on analysis results. Zoning should avoid fault lines and fracture zones to ensure blasting safety.

[0038] Differentiated blasting operations involve setting high charge and large hole spacing blasting parameters in the "ore zone" to effectively throw the ore; and setting low charge and small hole spacing blasting parameters in the "surrounding rock zone" to loosen and break the surrounding rock without scattering it over long distances. The high charge and large hole spacing in the ore zone are relative to those in the surrounding rock zone. In this embodiment, the charge in the ore zone is 20%–30% higher than that in the surrounding rock zone, and the hole spacing and row spacing in the ore zone are 10%–20% larger than those in the surrounding rock zone. The hole depth is 1.5–3.5 m, depending on the operator's skill level during actual construction. The charge structure uses radial continuous coupling, with the borehole opening filled with stemming material. After blasting, it was observed that the ore and rock were effectively thrown to the front or side of the tunnel, forming a concentrated mass, while the surrounding rock was basically loosened in situ and accumulated near the working face.

[0039] To achieve precise blasting results, the selected explosives must be within their expiration date, and their sensitivity and explosive force must meet the relevant national standards. The selected electronic detonators must also be within their expiration date, and their detonation energy and delay accuracy must meet the relevant national standards. Their detonation performance must still be tested by the corresponding instruments before blasting.

[0040] Precision control blasting with electronic detonators includes using electronic detonators for millisecond-level precise delayed detonation, as shown in Figures 4(a) and 4(b). When the area of ​​the ore zone is smaller than that of the surrounding rock zone, the blast holes in the ore zone are detonated first, followed by a delay in detonating the blast holes in the surrounding rock zone. As shown in Figures 3(a) and 3(b), when the area of ​​the surrounding rock zone is smaller than that of the ore zone, the blast holes in the surrounding rock zone are detonated first, followed by a delay in detonating the blast holes in the ore zone, thus achieving spatial separation between the ore and the surrounding rock. The delay time interval between each blast hole within the detonation zone is not less than 25ms to avoid vibration superposition and energy interference.

[0041] Post-blast separation of slag includes the throwing of surrounding rock to form an independent surrounding rock pile after blasting, and the loose accumulation of ore on site. According to the boundary line between the ore pile and the surrounding rock pile, they are shoveled and transported separately to achieve physical separation of ore and surrounding rock.

[0042] As shown in Figures 4(a) and 4(b), when the area of ​​the ore zone is smaller than that of the surrounding rock zone, the slotting hole is arranged in the center of the "ore zone", and auxiliary holes and peripheral holes are arranged in other locations of the "ore zone".

[0043] First, the "ore zone" is detonated, and the ore is thrown to form an independent ore pile. The surrounding rock is loosely piled up on the spot. According to the boundary line between the ore pile and the surrounding rock pile, they are shoveled and transported separately to achieve physical separation of ore and surrounding rock.

[0044] Similarly, as shown in Figures 3(a) and 3(b), when the area of ​​the surrounding rock zone is smaller than that of the ore zone, the cut hole is arranged in the center of the "surrounding rock zone", and auxiliary holes and peripheral holes are arranged in other locations of the "surrounding rock zone".

[0045] The above steps should be strictly carried out in accordance with the "Safety Operating Procedures for Blasting" and with on-site guidance from professional technicians. Detonation should be carried out after confirming the warning range and personnel evacuation. The blasting seismic waves should be recorded using a vibration monitoring instrument to assess the impact on the surrounding rock. The blasting and throwing process should be recorded through video monitoring for subsequent optimization.

[0046] After blasting, ore (surrounding rock) is shoveled and piled up using a loader or other slag removal equipment. The ore is transported to the beneficiation plant processing system, and the surrounding rock is transported to the surface surrounding rock stockpile or used for on-site backfilling underground. Indicators such as ore recovery and surrounding rock incorporation rate are recorded. A database is established after each round of blasting, including geological data, blasting parameters, separation effect, ore recovery, and surrounding rock incorporation rate, to provide data basis for the next round of parameter optimization.

[0047] Example

[0048] Taking the excavation of a thin ore body tunnel in a gold mine as an example, the average thickness of the ore body is 1.2m, and the grade is 4.8g / t. After adopting the method of this invention: the ore recovery rate increased from 78% to 92%; the surrounding rock mixing rate decreased from 32% to 15%; the amount of waste rock transported per meter of advance was reduced by about 30%, resulting in annual cost savings of over one million yuan.

[0049] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for controlled blasting separation of surrounding rock in precious metal ore tunneling based on electronic detonators, characterized in that: Specifically, the steps include the following: S1. Before blasting, the working face is divided into ore zone and surrounding rock zone according to the distribution of ore body at the working face. S2. Large hole spacing and large row spacing are adopted for blast holes in the ore area, and high charge is adopted for blast holes in the ore area. S3. Small hole spacing and small row spacing are used for blast holes in the surrounding rock area, and low explosive charge is used for blast holes in the surrounding rock area. S4. Electronic detonators are used to control the blasting sequence. When the area of ​​the ore zone is smaller than that of the surrounding rock zone, the blast holes in the ore zone are detonated first, and then the blast holes in the surrounding rock zone are detonated with a delay. When the area of ​​the surrounding rock zone is smaller than that of the ore zone, the blast holes in the surrounding rock zone are detonated first, and then the blast holes in the ore zone are detonated with a delay, so as to achieve spatial separation between the ore and the surrounding rock. S5. After blasting, the distance between the ore pile and the working face is greater than the distance between the surrounding rock pile and the working face. The ore and surrounding rock are physically separated by shoveling and transporting them separately through the boundary line between the ore pile and the surrounding rock pile.

2. The method for controlled blasting and separation of surrounding rock in precious metal ore tunneling based on electronic detonators according to claim 1, characterized in that: The charge amount in the blast holes in the ore area is 20% to 30% higher than that in the surrounding rock area, and the hole spacing and row spacing in the ore area are 10% to 20% larger than those in the surrounding rock area.

3. The method for controlled blasting and separation of surrounding rock in precious metal ore tunneling based on electronic detonators according to claim 1, characterized in that: In step S4, the delay accuracy of the electronic detonator is ±1ms, and the delay time interval between adjacent boreholes is not less than 25ms.

4. The method for controlled blasting and separation of surrounding rock in precious metal ore tunneling based on electronic detonators according to claim 1, characterized in that: The depth of the blast hole is 1.5 to 3.5 meters.

5. The method for controlled blasting and separation of surrounding rock in precious metal ore tunneling based on electronic detonators according to claim 1, characterized in that: The thickness of the ore vein layer is less than 1.5m.

6. The method for controlled blasting and separation of surrounding rock in precious metal ore tunneling based on electronic detonators according to claim 1, characterized in that: In step S1, ground-penetrating radar, core drilling, or digital imaging technology is used to obtain the distribution of the ore body at the working face and determine the ore body boundary and grade distribution.

7. The method for controlled blasting and separation of surrounding rock in precious metal ore tunneling based on electronic detonators according to claim 6, characterized in that: Based on the distribution of the ore body at the working face, the staff used marking lines to delineate the ore area and the surrounding rock area on the working face.

8. The method for controlled blasting and separation of surrounding rock in precious metal ore tunneling based on electronic detonators according to claim 7, characterized in that: When the area of ​​the ore zone is smaller than that of the surrounding rock zone, a cut hole is arranged in the center of the ore zone, and auxiliary holes and peripheral holes are arranged in the ore zone with the cut hole as the center. When the area of ​​the surrounding rock zone is smaller than that of the ore zone, a cut hole is arranged in the center of the surrounding rock zone, and auxiliary holes and peripheral holes are arranged in the surrounding rock zone with the cut hole as the center.

Images