Based on precision blasting and integrated downhole mining and beneficiation technology

Abstract

This application provides a precision blasting-based integrated underground mining and beneficiation process, belonging to the field of underground mining. The process includes the following steps: obtaining the borehole spacing and charge length based on the ore particle size distribution after blasting in existing blasting tests; employing a composite charge structure of "bottom explosive layer - middle air layer - orifice water bag sealing layer"; then, progressively blasting from the central borehole to auxiliary boreholes and then to the peripheral boreholes; beneficiating the blasted ore using a fully integrated small-scale beneficiation plant process established underground, encompassing "screening - photoelectric separation - fine crushing - grinding - flotation," and filling the goaf with the tailings obtained from the beneficiation. This application utilizes the synergy between blasting parameters and charge parameters, employs a composite charge structure, and optimizes the detonation sequence to obtain ore with the required particle size, providing favorable conditions for underground beneficiation, and directly filling the goaf with tailings, reducing ore transportation costs.

Description

Technical Field

[0001] This invention relates to the field of underground mining technology, specifically to an integrated underground mining and beneficiation process based on precision blasting. Background Technology

[0002] Gold mining, as a crucial sector of precious metal resource development, directly impacts economic benefits and environmental sustainability through its mining efficiency and resource utilization. Traditional gold mining processes typically employ a segmented model of "underground mining – surface beneficiation," where ore blasted underground is transported to the surface for crushing, sorting, and tailings treatment. However, as gold mining shifts towards deeper deposits, traditional processes face numerous challenges: high ore transportation costs from deep shafts, especially the inefficient transport of low-grade ore, further exacerbates resource waste; surface beneficiation facilities require large land areas, and the construction and maintenance of tailings ponds place significant pressure on the ecological environment; and the separation of mining and beneficiation leads to complex and inefficient processes, making it difficult to adapt to the demands of modern, intelligent, and green mining development.

[0003] Underground pre-selection technology aims to reduce ore transportation volume and improve resource utilization through underground sorting, and has gradually become a research hotspot in the mining field. However, existing underground pre-selection technologies mostly rely on physical screening or simple gravity separation, which are effective for simple minerals such as coal or iron ore. However, in gold mines, the ore particle size distribution is uneven during the mining blasting process (such as excessively high proportion of large pieces or over-crushing). Physical screening or simple gravity separation cannot meet the beneficiation requirements and will increase the difficulty of subsequent crushing and sorting, as well as increase energy consumption. Summary of the Invention

[0004] In view of the technical problems existing in the background art, this application provides a precision blasting-based integrated underground mining and beneficiation process, which aims to solve the technical problem that the existing underground pre-selection technology cannot meet the beneficiation requirements of gold mines due to the uneven particle size distribution of ore during the gold mine blasting process.

[0005] This application provides a precision blasting-assisted downhole mining and beneficiation integrated process, including the following steps:

[0006] S1. Obtain the borehole spacing and charge length based on the distribution of ore particle size after blasting in existing blasting tests.

[0007] S2. The explosive charge is constructed using a composite structure of "bottom explosive layer - middle air layer - orifice water bag sealing layer"; then, the detonation is carried out step by step from the central hole to the auxiliary holes and then to the peripheral holes.

[0008] S3. The blasted ore is processed using a small-scale beneficiation plant built underground, which integrates screening, photoelectric separation, fine crushing, grinding, and flotation processes. The tailings obtained from the beneficiation are then used to fill the goaf.

[0009] In the technical solution of this application embodiment, the blasting parameters and charge parameters are dynamically adjusted through mutual coordination. At the same time, an innovative composite structure charge method of "bottom explosive layer - middle air layer - orifice water bag sealing layer" is adopted, and the detonation sequence is optimized, so as to obtain ore with the required particle size, which further provides favorable conditions for subsequent underground mineral processing. The obtained ore is then processed underground, and the tailings are directly filled into the goaf, reducing ore transportation costs and reducing the scale and pressure of the surface mineral processing plant.

[0010] In some embodiments, in step S1, the borehole spacing is calculated according to the following formula:

[0011] w = (25~30)d, a = k1w;

[0012] Where w is the minimum resistance line, m; d is the set borehole diameter, m; a is the borehole spacing, m; k1 is the borehole spacing correction coefficient. When the proportion of ore with a particle size of 4-8cm after blasting is ≥80%, k1=1; when the proportion of ore with a particle size greater than 8cm after blasting is ≥20%, 0.7≤k1<1; when the proportion of ore with a particle size less than 4cm after blasting is ≥20%, 1<k1≤1.5.

[0013] In the technical solution of this application embodiment, different hole spacing correction coefficients are selected according to specific circumstances to obtain a more accurate hole spacing, thereby enabling the ore particle size after blasting to better meet production requirements.

[0014] In some embodiments, the charge length is calculated according to the following formula:

[0015] L=L1+L2+L3, L1=(0.1~0.2)L3, L3=(4k2×q b ×w 3 ) / (ρ1×π×d 2 );

[0016] Where L is the borehole length (m); L1 is the water bag sealing layer length (m); L2 is the air layer length (m); L3 is the explosive layer length (m); q b The amount of explosive consumed per unit volume of rock to form a standard thrown blasting funnel, kg / m 3 ρ1 is the density of the explosive, kg / m³ 3 k2 is the blasting correction coefficient. When the proportion of ore with a particle size of 4-8cm after blasting is ≥80%, 1.9≤k2<2.2; when the proportion of ore with a particle size greater than 8cm after blasting is ≥20%, 2.2≤k2≤2.3; when the proportion of ore with a particle size less than 4cm after blasting is ≥20%, 1.8≤k2<1.9.

[0017] In the technical solution of this application embodiment, different blasting correction coefficients are selected according to specific circumstances to obtain a more accurate charge structure, thereby enabling the ore particle size after blasting to better meet production requirements.

[0018] In some embodiments, the values ​​of k1 and k2 are calculated according to the following formula:

[0019] P=β0+β1k1+β2k2+∈

[0020] C=c1Δk1 2 +c2Δk2 2

[0021]

[0022] Wherein, P is the set percentage of ore with a particle size of 4-8cm after blasting, P≥80%; β0 is the benchmark pass rate when k1=0 and k2=0; β1 is the regression coefficient of k1; β2 is the regression coefficient of k2; ∈ is the random error; Δk1 is the adjustment amount of k1; Δk2 is the adjustment amount of k2; c1 is the unit cost coefficient for hole spacing adjustment; c2 is the unit cost coefficient for charge parameter adjustment; λ is the Lagrange function; λ is the Lagrange multiplier; k1′ is the initial value of the hole spacing correction coefficient; k2′ is the initial value of the blasting correction coefficient.

[0023] In the technical solution of this application embodiment, cost is used as a reference standard. The weight ratio of the adjustment amount of the borehole spacing correction coefficient and the blasting correction coefficient is obtained through a specific calculation model. By utilizing the mutual synergy between the borehole spacing correction coefficient and the blasting correction coefficient, new blasting parameters and charge parameters are obtained, thereby improving the blasting effect while controlling costs.

[0024] In some embodiments, in step S2, the blasting specifically involves: using the micro-delay initiation technology of electronic digital detonators to first blast the central hole, then blast the auxiliary holes 15-25ms later, and then blast the peripheral holes 15-25ms later.

[0025] In the technical solution of this application embodiment, the micro-delay initiation technology of electronic digital detonators is used to form a blasting funnel that expands layer by layer by using a multi-stage initiation mode, so that the blasting energy of the explosive between the non-connected blast holes is continuously transferred, and the blasting effect is ensured while the amount of explosive is small.

[0026] In some embodiments, step S3 specifically involves: screening out ore with a particle size greater than 8 cm and crushing it to a particle size of 4-8 cm; pre-discarding all ore using an XRF separator to obtain waste rock and pre-selected ore, and transporting the waste rock to the goaf; finely crushing the pre-selected ore using a fine crusher and then grinding it in a grinding mill to obtain slurry; beneficiating the slurry using a gravity / flotation device to obtain gold concentrate and tailings; transporting the gold concentrate to the surface and using the tailings to make filling slurry to fill the goaf.

[0027] In the technical solution of this application embodiment, waste rock in the ore is removed by pre-disposal, which reduces the amount of ore to be processed in subsequent flotation, and at the same time, the waste rock is rationally utilized to avoid being transported to the ground.

[0028] In some embodiments, a filling slurry preparation system is set up at the outlet end of the flotation cell used in the flotation process, and the filling slurry is prepared by the filling system to fill the goaf.

[0029] In the technical solution of this application embodiment, by setting up a filling slurry preparation system at the discharge end of the flotation tank, the tailings from the flotation are directly prepared into filling slurry through the filling slurry preparation system and filled into the goaf, without having to transport them to the ground.

[0030] In some embodiments, the filling system includes a buffer tank and a sand bin connected to the buffer tank. The buffer tank is located at the outlet end of the bottom of the flotation tank, and the sand bin is located in the lower middle section. The bottom of the sand bin is provided with a filling pipeline connected to the goaf area, and the inlet end of the sand bin is also provided with a flocculant storage tank for holding flocculant.

[0031] In the technical solution of this application embodiment, by setting the sand bin in the lower middle section, the tailings flow into the sand bin through a stepped gravity flow and mix with the flocculant solution before being directly used for filling the goaf, saving the installation of a large number of filling pipelines.

[0032] In some embodiments, a 3D scanner is used to obtain the particle size distribution of the ore after blasting and to assess the uniformity of blasting.

[0033] In the technical solution of this application embodiment, the analysis of ore particle size is performed by using a three-dimensional scanner, which is simple and convenient to operate, and the three-dimensional scanner has high analysis accuracy.

[0034] In some embodiments, step S3 further includes transporting the blasted ore to the processing plant area using a trackless method before screening.

[0035] In the technical solution of this application embodiment, the blasted ore is transported to the beneficiation plant area for direct beneficiation using a trackless transportation method, avoiding long-distance transportation to the ground beneficiation plant and saving transportation costs.

[0036] 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, the following are specific embodiments of this application. Attached Figure Description

[0037] 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.

[0038] Figure 1 This is a process flow diagram of the integrated downhole mining and beneficiation process based on precision blasting in the embodiments of this application;

[0039] Figure 2 This is a schematic diagram of the charge structure in an embodiment of this application;

[0040] Figure 3 A schematic diagram of the filling slurry preparation system;

[0041] Figure 4 This is a schematic diagram of the structure of the central hole, auxiliary holes, and peripheral holes in Example 1;

[0042] Explanation of reference numerals in the attached diagram: 1-Water bag sealing layer at the orifice; 2-Middle air layer; 3-Bottom explosive layer; 4-Buffer tank; 5-Flocculant storage tank; 6-Sand bin; 7-Upper middle section; 8-Lower middle section; 9-Filling pipeline; 10-Flotation tank; 11-Central hole; 12-Auxiliary hole; 13-Peripheral hole. Detailed Implementation

[0043] 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.

[0044] 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.

[0045] 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.

[0046] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. 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.

[0047] To address the issues of high ore transportation costs in deep mines and large land area requirements of surface beneficiation facilities in the traditional "underground mining-surface beneficiation" segmented model used in gold mining, underground pre-selection technology has been continuously researched. However, due to the uneven particle size distribution of ore during gold blasting and mining, existing underground pre-selection technologies relying on physical screening or simple gravity separation cannot meet the requirements for gold ore beneficiation.

[0048] To address the technical problem that existing underground pre-sorting technologies cannot meet the requirements of gold ore beneficiation due to uneven ore particle size distribution during gold mining blasting, this application provides a precision blasting-based integrated underground mining and beneficiation process. Through innovative design of the integrated underground mining and beneficiation process and system, the overall efficiency of gold mining is significantly improved. Specifically, in terms of economy, precision blasting controls the feed particle size of the ore, pre-sorting technology reduces the ineffective transportation of low-grade ore, and the combination of pneumatic conveying systems and tailings cemented backfilling technology reduces overall operating costs. In terms of environmental protection, a centralized underground small-scale beneficiation plant and a closed-loop tailings backfilling system achieve a tailings backfilling rate of over 85%, significantly reducing the need for surface tailings ponds. Combined with precision blasting technology (ore particle size 4-8cm accounting for ≥80%) and closed-loop pipeline transportation, underground dust concentration is reduced by 40%. Technically, an innovative blasting method is proposed. This solution employs dynamic and coordinated adjustment of parameters and charge parameters, a composite charge structure consisting of a bottom explosive layer, a middle air layer, and a water-filled sealing layer at the orifice, and precise detonation timing. Through the organic integration of precise blasting, intelligent sorting, and tailings backfilling, it achieves intelligent linkage across the entire "blasting-sorting-backfilling" process. This enables simultaneous optimization of underground mining and mineral processing, overcoming the technical bottlenecks of low sorting accuracy and high energy consumption in traditional processes. Equipment crushing energy consumption is reduced by 20%-30%, significantly lowering transportation costs, improving resource recovery rates, and reducing environmental pollution, providing a new solution for efficient deep gold mining. This solution is also adaptable to deep mines, effectively controlling subsidence risks through real-time backfilling of goaf areas, providing a high-resource-utilization and environmentally friendly technological model for green mine construction.

[0049] Please refer to Figure 1 This application provides a precision blasting-assisted downhole mining and beneficiation integrated process, including the following steps:

[0050] S1. Obtain the borehole spacing and charge length based on the distribution of ore particle size after blasting in existing blasting tests.

[0051] Specifically, the mining area is first delineated, and geological information of the area to be mined is collected. Based on the characteristics of the mine, blasting parameters (including borehole diameter and borehole spacing) and charge parameters (including charge structure and charge length) are set through blasting dynamics analysis. The hole depth is set according to the mechanization of the drilling rig. Then, shallow-hole blasting is used to blast the ore body, and the particle size distribution of the ore after blasting is detected and analyzed. If the proportion of ore with a particle size of 4-8 cm after blasting is ≥80%, the blasting requirements are met, and blasting continues according to the set borehole diameter, borehole spacing, hole depth, charge structure, and charge length. If the particle size of the ore after blasting does not meet the above requirements, it is necessary to analyze the particle size distribution of the ore after blasting in the previous blasting tests, and reset the borehole spacing and charge length, while keeping the borehole diameter and hole depth unchanged. Understandably, the particle size of the ore needs to be detected and analyzed after each blasting to promptly grasp the blasting effect and adjust the blasting parameters accordingly.

[0052] S2, such as Figure 2 As shown, the explosive charge uses a composite structure of "bottom explosive layer 3 - middle air layer 2 - orifice water bag sealing layer 1"; then, it is detonated step by step from the central hole 11 to the auxiliary hole 12 and then to the peripheral hole 13. Specifically, the bottom explosive layer 3 is charged using a continuous coupling method of emulsion explosive.

[0053] S3. The blasted ore will be processed using a small-scale beneficiation plant built underground, encompassing a complete process of screening, photoelectric separation, fine crushing, grinding, and flotation. The tailings obtained from the beneficiation process will be used to fill the goaf. Specifically, the equipment for the small-scale beneficiation plant should fully consider the height limitations of the underground space. For processes with height differences, the plant can be constructed across intermediate sections.

[0054] In the technical solution of this application embodiment, the initial blasting parameters and charge parameters are first set based on the collected geological information of the mine, and the particle size of the ore obtained after blasting is analyzed. When the particle size is qualified, blasting continues using the set parameters. When the particle size is unqualified, the blasting parameters and charge parameters are adjusted in time. That is, during the continuous blasting process, the particle size distribution of the ore after blasting is detected in real time, and the blasting parameters and charge parameters are dynamically adjusted by mutual coordination to ensure the best blasting effect to the greatest extent, thus providing favorable conditions for subsequent underground mineral processing.

[0055] In this embodiment, an innovative composite structure charging method of "bottom explosive layer 3 - middle air layer 2 - orifice water bag sealing layer 1" is adopted. By setting the bottom explosive layer 3 in a continuous coupling manner, the synergistic blasting effect between different boreholes can be improved. By setting the air layer in the middle as a spacer layer, the blasting fracture propagation time can be extended, the fracture penetration efficiency can be improved, and the risk of over-fragmentation can be reduced. By setting the orifice sealing layer with a water bag to fill the orifice, the water medium is used to buffer the blasting stress wave, balance the fragmentation energy distribution, and concentrate the ore particle size of the blasted ore to 4-8cm, reducing the generation of large fragments. At the same time, by optimizing the detonation sequence, the detonation is carried out step by step from the central hole 11 to the auxiliary hole 12 and then to the peripheral hole 13, forming a blasting funnel that expands layer by layer, controlling the proportion of large ore particles with a particle size greater than 10cm to less than 5%. That is, by combining the central air layer 2, the orifice water bag sealing layer 1, and the gradual blasting, the blasted ore is prevented from being too fragmented or too large, thereby obtaining ore with the required particle size, which further provides favorable conditions for subsequent underground ore beneficiation.

[0056] In this embodiment, the obtained ore is beneficiated underground, and the tailings are directly filled into the mined-out area, reducing ore transportation costs and reducing the size and pressure of the surface beneficiation plant.

[0057] Furthermore, in some embodiments, in step S1, the borehole spacing is calculated according to the following formula:

[0058] w = (25~30)d, a = k1w;

[0059] Where w is the minimum resistance line (m); d is the set borehole diameter (m, a known value); a is the borehole spacing (m); and k1 is the borehole spacing correction coefficient. When the proportion of ore particles with a diameter of 4-8 cm after blasting is ≥80%, k1 = 1; when the proportion of ore particles with a diameter greater than 8 cm after blasting is ≥20%, 0.7 ≤ k1 < 1; and when the proportion of ore particles with a diameter less than 4 cm after blasting is ≥20%, 1 < k1 ≤ 1.5. Specifically, the minimum resistance line is obtained based on the borehole diameter, and then the borehole spacing is derived based on the minimum resistance line and the borehole spacing correction coefficient.

[0060] In the technical solution of this application embodiment, based on the distribution of ore particle size after blasting in existing blasting tests, different blast hole spacing correction coefficients are selected to obtain a more accurate blast hole spacing, thereby enabling the ore particle size after blasting to better meet production requirements.

[0061] Furthermore, in some embodiments, the charge length is calculated according to the following formula:

[0062] L=L1+L2+L3, L1=(0.1~0.2)L3, L3=(4k2×q b ×w 3) / (ρ1×π×d 2 );

[0063] Where L is the borehole length, in meters (a known value); L1 is the length of the water-bag sealing layer 1 at the borehole opening, in meters; L2 is the length of the middle air layer 2, in meters; L3 is the length of the bottom explosive layer 3, in meters; q b The amount of explosive consumed per unit volume of rock to form a standard thrown blasting funnel, kg / m 3 The known value; ρ1 is the density of the explosive, kg / m³ 3 The values ​​are known; k2 is the blasting correction coefficient. When the proportion of ore with a particle size of 4-8cm after blasting is ≥80%, 1.9≤k2<2.2; when the proportion of ore with a particle size greater than 8cm after blasting is ≥20%, 2.2≤k2≤2.3; when the proportion of ore with a particle size less than 4cm after blasting is ≥20%, 1.8≤k2<1.9. Specifically, based on the blasting correction coefficient, the explosive consumption per unit volume of rock forming a standard throwing blasting funnel, the minimum resistance line, and the borehole diameter, the length of the bottom explosive layer 3 is calculated, and then the length of the orifice water bag sealing layer 1 and the length of the middle air layer 2 are calculated.

[0064] In the technical solution of this application embodiment, based on the distribution of ore particle size after blasting in existing blasting tests, different blasting correction coefficients are selected to obtain more accurate lengths of the orifice water bag sealing layer 1, the middle air layer 2, and the bottom explosive layer 3, thus obtaining a precise charge structure, which in turn enables the ore particle size after blasting to better meet production requirements.

[0065] Furthermore, in some embodiments, the values ​​of k1 and k2 are calculated according to the following formula:

[0066] P=β0+β1k1+β2k2+∈

[0067] Wherein, P is the set percentage of ore with a particle size of 4-8cm after blasting, P≥80%; β0 is the baseline pass rate when k1=0 and k2=0; β1 is the regression coefficient of k1, reflecting the strength of k1's influence on the pass rate. β1 is usually negative because increasing the hole spacing may reduce the crushing effect; β2 is the regression coefficient of k2, reflecting the strength of k2's influence on the pass rate. β2 is usually negative because increasing the charge amount may improve the crushing effect; ∈ represents random error, indicating random factors not considered by the calculation model, such as rock inhomogeneity, measurement error, etc. Specifically, β0, β1, and β2 are known values ​​determined by fitting existing blasting data, and k1 and k2 are set known values.

[0068] C=c1Δk1 2 +c2Δk2 2

[0069] Where C represents the total cost incurred in adjusting the hole spacing and charge parameters; Δk1 represents the adjustment amount of k1; Δk2 represents the adjustment amount of k2; c1 represents the unit cost coefficient for hole spacing adjustment, such as the difficulty or resource consumption of adjusting the hole spacing; and c2 represents the unit cost coefficient for charge parameter adjustment. Specifically, c1 and c2 are known values ​​determined through engineering economic analysis (such as drilling cost, explosive cost, etc.).

[0070] Using the pass rate P≥0.8 as a constraint and the total cost C as the objective value, the following Lagrangian function is constructed:

[0071]

[0072] in, λ is the Lagrange function; k1′ is the initial value of the hole spacing correction coefficient (i.e., the value before adjustment); k2′ is the initial value of the blasting correction coefficient (i.e., the value before adjustment). Specifically, λ is the value calculated under the constraints of balancing cost and yield rate.

[0073] By differentiating and solving the above system of equations, we obtain the formula for the optimal adjustment ratio of k1 and k2, i.e., the weight ratio:

[0074]

[0075] As can be seen from the above formula, the weight ratio of k1 and k2 adjustment is jointly determined by the regression coefficients (β1, β2) and the cost coefficients (c1, c2). If the absolute value of the regression coefficient of a certain parameter is large (significantly affecting the pass rate) or the cost coefficient is low (low adjustment cost), then its weight is higher.

[0076] If the ore particle size does not meet the requirements after blasting according to the new blasting parameters and charge parameters, the values ​​of the borehole spacing correction coefficient and the blasting correction coefficient should be reset according to the weight ratio of the adjustment amount of the obtained borehole spacing correction coefficient and the blasting correction coefficient, so as to obtain the blasting parameters and charge parameters again.

[0077] In the technical solution of this application embodiment, with cost as the reference standard, the weight ratio of the adjustment amount of the borehole spacing correction coefficient and the blasting correction coefficient is obtained through a specific calculation model, thereby obtaining the proportional relationship between the borehole spacing correction coefficient and the blasting correction coefficient in the adjustment process. By utilizing the mutual synergy between the borehole spacing correction coefficient and the blasting correction coefficient, new blasting parameters and charge parameters are obtained, thereby improving the blasting effect while controlling costs.

[0078] Furthermore, in some embodiments, in step S2, the blasting is specifically performed by using the micro-delay initiation technology of electronic digital detonators to first blast the central hole 11, then blast the auxiliary hole 12 after 15-25ms, and then blast the peripheral hole 13 after 15-25ms.

[0079] In the technical solution of this application embodiment, the micro-delay initiation technology of electronic digital detonator is used to precisely control the blasting time difference of the central hole 11, auxiliary hole 12 and peripheral hole 13. Through multi-stage initiation mode, a blasting funnel that expands layer by layer is formed, so that the blasting energy of the explosive between the non-connected blasting holes is continuously transferred, and the blasting effect is ensured while the amount of explosive is small.

[0080] Further, in some embodiments, step S3 specifically involves: using a screen to separate ore particles larger than 8 cm and crushing them to a particle size of 4-8 cm; pre-discarding all ore using an XRF separator to obtain waste rock and pre-selected ore, and transporting the waste rock to the goaf via a trackless transport method; further crushing the pre-selected ore using a fine crusher and then grinding it in a grinding mill to obtain slurry; beneficiating the slurry using a gravity / flotation device to obtain gold concentrate and tailings; transporting the gold concentrate to the surface via pneumatic transport, and preparing the tailings into filling slurry, which is then used to fill the goaf. Specifically, the pre-discarding process can discard approximately 30% of the waste rock.

[0081] In the technical solution of this application embodiment, the ore with a particle size greater than 8cm is first screened out and crushed to a particle size of 4-8cm to provide favorable conditions for subsequent mineral processing; by pre-discarding waste, the waste rock in the ore is removed, reducing the amount of ore to be processed in subsequent flotation, while making reasonable use of the waste rock to avoid transporting it to the ground.

[0082] Furthermore, in some embodiments, a backfill slurry preparation system is established at the discharge end of the flotation cell 10 used in the flotation process. The backfill slurry is prepared using the backfill system and used to fill the goaf. Specifically, the amount of cementitious material is dynamically adjusted according to the characteristics of the tailings to ensure that the strength of the backfill body meets the standards.

[0083] In the technical solution of this application embodiment, by setting up a filling slurry preparation system at the discharge port of the flotation tank 10, the tailings from the flotation are directly prepared into filling slurry through the filling slurry preparation system and filled into the goaf, without having to transport them to the ground.

[0084] Furthermore, in some embodiments, such as Figure 3As shown, the filling system includes a buffer tank 4 and a sand bin 6 connected to the buffer tank 4. The buffer tank 4 is located at the outlet end of the bottom of the flotation tank 10, and the sand bin 6 is located in the lower middle section 8 (the flotation tank 10, buffer tank 4, and flocculant storage tank 5 are located in the upper middle section 7). The bottom of the sand bin 6 is equipped with a filling pipeline 9 connected to the goaf. The inlet end of the sand bin 6 is also equipped with a flocculant storage tank 5 for holding flocculant. Tailings flowing out from the bottom of the flotation tank 10 enter the sand bin 6 through the buffer tank 4. At the same time, flocculant enters the sand bin 6 from the flocculant storage tank 5. The tailings and flocculant are mixed in the sand bin 6 to form a filling slurry, which enters the goaf through the filling pipeline 9. In addition, the waste rock that has been disposed of in advance also enters the goaf. The filling slurry wraps around and solidifies the waste rock to form a filling body. Specifically, during the preparation of the filling slurry, the strength of the filling body is monitored, the proportion of cementitious materials is dynamically adjusted, the filling cost is calculated, and the resource recovery rate and explosive costs are balanced. Data exchange is achieved through a downhole 5G industrial ring network, and the sorting threshold is adjusted in real time. The volume of the flocculant storage tank 5 is 1.5m³. 3 .

[0085] In the technical solution of this application embodiment, by setting the sand bin 6 in the lower middle section 8, the tailings flow into the sand bin 6 through a stepped gravity flow and mix with the flocculant solution before being directly used for filling the goaf. This eliminates the need for laying a large number of filling pipelines 9 and avoids the risk of blockage in the filling pipelines 9, making it suitable for deep well mining. Only the gold concentrate is transported to the surface via pneumatic pipelines, reducing resource loss during transportation.

[0086] Furthermore, in some embodiments, a 3D scanner is used to acquire the particle size distribution of the ore after blasting to assess the uniformity of the blasting. Specifically, the 3D laser scanner can be integrated onto the loader.

[0087] In the technical solution of this application embodiment, a three-dimensional scanner is used to analyze the particle size of the ore. The three-dimensional laser scanner can be integrated into the loader, and particle size analysis is performed during the loader's handling process. The operation is simple and convenient, and the three-dimensional scanner has high analysis accuracy.

[0088] Furthermore, in some embodiments, step S3 further includes transporting the blasted ore to the processing plant area using a trackless method (e.g., a loader) before screening.

[0089] In the technical solution of this application embodiment, the blasted ore is transported to the beneficiation plant area for direct beneficiation using a trackless transportation method, avoiding long-distance transportation to the ground beneficiation plant and saving transportation costs.

[0090] The present application will be described in detail below through specific embodiments.

[0091] Example 1

[0092] A precision blasting-assisted downhole mining and beneficiation integrated process includes the following steps:

[0093] S1. Delineate the mining area and collect geological information of the area to be mined. Based on the characteristics of the mine, set the initial blasting parameters and charge parameters through blasting dynamics analysis. Based on the drill rod diameter of the drilling rig, select a borehole diameter of 0.04m and a hole depth of 3m. Set the borehole spacing correction factor k1 to 0.825. The borehole spacing calculated based on w = 25d and a = k1w is 0.825m. Set the blasting correction factor k2 to 2. Based on L = L1 + L2 + L3, L1 = 0.15L3, L3 = (4k2 × q b ×w 3 ) / (ρ1×π×d 2 The calculated length of the water-filled sealing layer 1 at the orifice is 0.33m, the length of the middle air layer 2 is 0.44m, and the length of the bottom explosive layer 3 is 2.23m. Where, q b =1.4kg / m 3 ρ1=1000kg / m 3 After blasting, 74% of the ore particles had a diameter of 4-8 cm, while 21% had a diameter greater than 8 cm, which does not meet the requirements. Therefore, a weight analysis of k1 and k2 is necessary.

[0094] P=β0+β1k1+β2k2+∈

[0095] Among them, by fitting multiple sets of existing blasting data (including P, k1, k2), β0 = 43.27, β1 = -0.2, and β2 = 0.3 were calculated.

[0096] C=c1Δk1 2 +c2Δk2 2

[0097] In this study, the engineering economic analysis yielded c1 = 1 and c2 = 2. Specifically, the calculated ratio of the cost change resulting from adjusting each unit of k1 and each unit of k2 was 1:2; therefore, c1 was set to 1 and c2 to 2. 。

[0098] Using the pass rate P≥0.8 as a constraint and the total cost C as the objective value, the following Lagrangian function is constructed:

[0099] By differentiating and solving the above system of equations, we obtain the formula for the optimal adjustment ratio of k1 and k2, i.e., the weight ratio:

[0100]

[0101] The weight ratio of the adjustment amount of the borehole spacing correction coefficient and the blasting correction coefficient calculated by the formula is 0.94:1. The reset borehole spacing correction coefficient k1 is 0.8 and the blasting correction coefficient k2 is 2.027. With the borehole diameter and depth unchanged, the borehole spacing is calculated to be 0.8m based on w = 25d and a = k1w.

[0102] According to L = L1 + L2 + L3, L1 = 0.15L3, L3 = (4k² × q) b ×w 3 ) / (ρ1×π×d 2 ) calculate, where q b =1.4kg / m 3 ρ1=1000kg / m 3 The length of the water bag sealing layer 1 at the orifice was calculated to be 0.34m, the length of the middle air layer 2 was 0.40m, and the length of the bottom explosive layer 3 was 2.26m. The particle size distribution of the ore after blasting was obtained by a 3D scanner. The proportion of ore with a particle size of 4-8cm after blasting was 82.15%, and the particle size distribution met the standard.

[0103] S2. The explosive charge uses a composite structure of "bottom explosive layer 3 - middle air layer 2 - orifice water bag sealing layer 1"; it employs micro-delay initiation technology with electronic digital detonators, detonating the central hole 11 first, then the auxiliary hole 12 15-25ms later, and finally the peripheral hole 13 20ms later. The arrangement of the central hole 11, auxiliary hole 12, and peripheral hole 13 is as follows: Figure 4 As shown.

[0104] S3. The blasted ore is transported to the beneficiation plant area using a trackless method (e.g., a loader). Ores larger than 8cm are screened using a screen and crushed to a particle size of 4-8cm. All ore is pre-discarded using an XRF separator to obtain waste rock and pre-selected ore. The waste rock is then transported to the goaf via a trackless transport method. The pre-selected ore is further crushed using a fine crusher and then ground in a grinding mill to obtain slurry. The slurry is then beneficiated using gravity / flotation equipment to obtain gold concentrate and tailings. The gold concentrate is transported to the surface via pneumatic transport, and the tailings are made into filling slurry and filled into the goaf.

[0105] 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 precision blasting-assisted downhole mining and beneficiation integrated process, characterized in that, Includes the following steps: S1. Obtain the borehole spacing and charge length based on the distribution of ore particle size after blasting in existing blasting tests. The borehole spacing is calculated using the following formula: w=(25~30)d, a=k1w; Where w is the minimum resistance line, and m; d is the set borehole diameter, in meters; a is the borehole spacing, in meters; k1 is the hole spacing correction coefficient. When the proportion of ore with a particle size of 4-8cm after blasting is ≥80%, k1=1; when the proportion of ore with a particle size greater than 8cm after blasting is ≥20%, 0.7≤k1<1; when the proportion of ore with a particle size less than 4cm after blasting is ≥20%, 1<k1≤1.

5. Calculate the charge length using the following formula: L = L1 + L2 + L3, L1 = (0.1 ~ 0.2)L3, L3 = (4k² × q) b xw 3 ) / (ρ1×π×d 2 ); Where L is the borehole length, in meters; L1 is the length of the water bag sealing layer, in meters; L2 is the length of the air layer, in meters; L3 is the length of the explosive layer, in meters; q b The amount of explosive consumed per unit volume of rock to form a standard thrown blasting funnel, kg / m 3 ; ρ1 is the density of the explosive, kg / m³ 3 ; k2 is the blasting correction coefficient. When the proportion of ore with a particle size of 4-8cm after blasting is ≥80%, 1.9≤k2<2.2; when the proportion of ore with a particle size greater than 8cm after blasting is ≥20%, 2.2≤k2≤2.3; when the proportion of ore with a particle size less than 4cm after blasting is ≥20%, 1.8≤k2<1.

9. The values ​​of k1 and k2 are calculated according to the following formula: P = β0 + β1k1 + β2k2 + ϵ C=c1Δk1 2 + c2Δk2 2 L=c1Δk1 2 + c2Δk2 2 +λ(0.8-(β0+β1(k1′+Δk1)+ β2(k2′+Δk2))) = Wherein, P is the set percentage of ore with a particle size of 4-8cm after blasting, P≥80%; β0 is the benchmark pass rate when k1=0 and k2=0; β1 is the regression coefficient of k1; β2 is the regression coefficient of k2; ϵ represents random error; Δk1 is the adjustment amount of k1; Δk2 is the adjustment amount of k2; c1 is the unit cost coefficient for hole spacing adjustment; c2 is the unit cost coefficient for adjusting the charge parameters; Լ is the Lagrange function; λ is the Lagrange multiplier; k1′ is the initial value of the hole spacing correction coefficient; k2′ is the initial value of the blasting correction coefficient; S2. The explosive charge is constructed using a composite structure of "bottom explosive layer - middle air layer - orifice water bag sealing layer"; then, the detonation is carried out step by step from the central hole to the auxiliary holes and then to the peripheral holes. S3. The blasted ore is processed using a small-scale beneficiation plant built underground, which integrates screening, photoelectric separation, fine crushing, grinding, and flotation processes. The tailings obtained from the beneficiation process are then used to fill the goaf.

2. The integrated downhole mining and beneficiation process based on precision blasting as described in claim 1, characterized in that, In step S2, the blasting is specifically performed by using the micro-delay initiation technology of electronic digital detonators to first blast the center hole, then blast the auxiliary holes 15-25ms later, and then blast the peripheral holes 15-25ms later.

3. The integrated downhole mining and beneficiation process based on precision blasting as described in claim 1, characterized in that, Step S3 specifically involves: screening out ore particles larger than 8 cm and crushing them to a particle size of 4-8 cm; pre-discarding all ore using an XRF separator to obtain waste rock and pre-selected ore, and transporting the waste rock to the goaf; finely crushing the pre-selected ore using a fine crusher and then grinding it in a grinding mill to obtain slurry; beneficiating the slurry using a gravity / flotation device to obtain gold concentrate and tailings; transporting the gold concentrate to the surface and using the tailings to make filling slurry to fill the goaf.

4. The integrated downhole mining and beneficiation process based on precision blasting as described in claim 3, characterized in that, A filling slurry preparation system is set up at the discharge end of the flotation cell used in the flotation process. The filling slurry is prepared by the filling system and used to fill the goaf.

5. The integrated downhole mining and beneficiation process based on precision blasting as described in claim 4, characterized in that, The filling system includes a buffer tank and a sand bin connected to the buffer tank. The buffer tank is located at the outlet end of the bottom of the flotation tank, and the sand bin is located in the lower middle section. The bottom of the sand bin is provided with a filling pipeline connected to the goaf area. The inlet end of the sand bin is also provided with a flocculant storage tank for holding flocculant.

6. The integrated downhole mining and beneficiation process based on precision blasting as described in claim 1, characterized in that, A 3D scanner is used to obtain the particle size distribution of the ore after blasting and to assess the uniformity of the blasting.

7. The integrated downhole mining and beneficiation process based on precision blasting as described in claim 3, characterized in that, Step S3 also includes transporting the blasted ore to the beneficiation plant area using a trackless method before screening.

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