Cooperative underground mining and selection integrated process based on precise blasting

Abstract

The invention provides a collaborative underground mining and selection integrated process based on precise blasting, and belongs to the field of underground mine mining, and the collaborative underground mining and selection integrated process based on precise blasting comprises the following steps: according to the distribution condition of ore particle sizes after blasting in an existing blasting test, obtaining the blast hole spacing and the charging length; a composite structure of a bottom explosive layer, a middle air layer and a hole opening water bag sealing layer is adopted for charging; gradually blasting by adopting a blasting mode from the center hole to the auxiliary holes and then to the peripheral holes; and the exploded ore is subjected to ore dressing through the whole-process small-size ore dressing process of screening, photoelectric ore dressing, fine crushing, ore grinding and flotation built underground, and the goaf is filled with tailings obtained through ore dressing. According to the method, the blasting parameters and the charging parameters cooperate with each other, meanwhile, the composite structure charging mode is adopted, and the detonating sequence is optimized, so that the ore with the particle size meeting the requirement is obtained, favorable conditions are provided for underground mineral separation, the goaf is directly filled with the tailings, and the ore transportation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of underground mining, and in particular to an underground mining and selection integrated process based on precise blasting coordination. Background Art

[0002] Gold mining is an important field of precious metal resource development, and its mining efficiency and resource utilization directly affect economic benefits and environmental sustainability. Traditional gold mining technology usually adopts a segmented mode of "underground mining-ground mineral processing", that is, the ore after underground blasting is transported to the ground for crushing, sorting and tailings treatment. As gold resources gradually shift to deep mining, traditional processes face many challenges: the cost of deep-well ore transportation is high, especially the ineffective transportation of low-grade ore further aggravates resource waste; ground mineral processing facilities occupy a large area, and the construction and maintenance of tailings ponds put significant pressure on the ecological environment; the separation of mining and mineral processing leads to complex process flow and low efficiency, which is difficult to adapt to the development needs of modern mine intelligence and greening.

[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 has a good effect on the separation of simple minerals such as coal or iron ore. However, in the process of gold mining blasting, the ore particle size distribution is uneven (such as too high a large block rate or over-crushing), and physical screening or simple gravity separation cannot meet the mineral processing requirements, and will increase the difficulty of subsequent crushing and sorting, and increase energy consumption. Summary of the invention

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

[0005] The embodiment of the present application provides a downhole mining and selection integrated process based on precision blasting, including the following steps:

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

[0007] S2, adopt the composite structure of "bottom explosive layer-middle air layer-hole mouth water bag sealing layer" to charge; then use the detonation method from the center hole to the auxiliary hole and then to the peripheral hole to gradually blast;

[0008] S3. The blasted ore is beneficiated using the full-process small-scale beneficiation plant process of "screening - photoelectric beneficiation - fine crushing - grinding - flotation" established underground, and the tailings obtained from the beneficiation are used to fill the mined-out areas.

[0009] In the technical solution of the embodiment of the present application, the blasting parameters and the charging parameters are dynamically adjusted by utilizing the mutual coordination of the blasting parameters and the charging parameters, and an innovative composite structure charging method of "bottom explosive layer-middle air layer-hole water bag sealing layer" is adopted, and the detonation sequence is optimized, so as to obtain ore with a particle size that meets the requirements, further providing favorable conditions for subsequent underground mineral processing; the obtained ore is processed underground, and the tailings are directly filled in the goaf, thereby reducing the ore transportation cost and reducing the scale and pressure of the ground mineral processing plant.

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

[0011] w=(25~30)d,a=k 1 w;

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

[0013] In the technical solution of the embodiment of the present application, different blasthole spacing correction coefficients are selected according to specific circumstances to obtain a more accurate blasthole spacing, so that the ore particle size after blasting can better meet production requirements.

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

[0015] L=L 1 +L 2 +L 3 , L 1 =(0.1~0.2)L 3 , L 3 =(4k 2 ×q b × 3 ) / (ρ 1 ×π×d 2 );

[0016] Where, L is the length of the blasthole, m; L 1 L is the length of the water bag sealing layer, m; 2 is the length of the air layer, m; L 3 is the length of the explosive layer, m; q b The explosive consumption per unit volume of rock to form a standard throwing blasting funnel, kg / m3 ρ 1 is the density of explosive, kg / m 3 ;k 2 is the blasting correction factor. When the proportion of ore with a particle size of 4-8 cm after blasting is ≥80%, 1.9≤k 2 <2.2, when the proportion of ore with a particle size greater than 8 cm after blasting is ≥20%, 2.2≤k 2 ≤2.3, when the proportion of ore with a particle size less than 4 cm after blasting is ≥20%, 1.8≤k 2 <1.9.

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

[0018] In some embodiments, k 1 and k 2 The value of is calculated according to the following formula:

[0019] P=β 0 +β 1 k 1 +β 2 k 2 +∈

[0020] C=c 1 Δk 1 2 +c 2 Δk 2 2

[0021]

[0022] Among them, P is the proportion of ore with a particle size of 4-8cm after blasting, P≥80%; β 0 k 1 = 0 and k 2 = The benchmark pass rate when 0; β 1 k 1 The regression coefficient of 2 k 2 The regression coefficient; ∈ is the random error; Δk 1 k 1 The adjustment amount; Δk 2 k 2 The adjustment amount; c 1 The unit cost coefficient adjusted for hole spacing; c 2 Unit cost coefficient adjusted for charge parameters; is the Lagrangian function; λ is the Lagrangian multiplier; k 1′ is the initial value of the hole spacing correction coefficient; k 2 ′ is the initial value of the blasting correction coefficient.

[0023] In the technical solution of the embodiment of the present application, cost is used as a reference standard, and the weight ratio of the borehole spacing correction coefficient and the blasting correction coefficient adjustment amount is obtained through a specific calculation model. The mutual coordination of the borehole spacing correction coefficient and the blasting correction coefficient is utilized to obtain new blasting parameters and charging parameters, thereby controlling costs while improving the blasting effect.

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

[0025] In the technical solution of the embodiment of the present application, the micro-difference initiation technology of electronic digital detonators is used to form a blasting funnel that expands layer by layer using a multi-stage initiation mode, so that the blasting energy of the explosives between the unconnected blast holes is continuously transmitted, thereby ensuring the blasting effect while reducing the amount of explosives.

[0026] In some embodiments, step S3 is specifically as follows: sieve out ores with a particle size greater than 8 cm, and crush them to a particle size of 4-8 cm; pre-discard all ores using an XRF sorter to obtain waste rock and pre-selected ore, and transport the waste rock to the goaf; crush the pre-selected ore using a fine crusher and then feed it into a grinding machine for grinding to obtain slurry; use gravity / flotation equipment to separate the slurry to obtain gold concentrate and tailings; transport the gold concentrate to the surface, and make the tailings into filling slurry to fill the goaf.

[0027] In the technical solution of the embodiment of the present application, waste rock in the ore is removed by pre-disposal, thereby reducing the amount of ore to be processed in subsequent flotation, and at the same time, the waste rock is reasonably utilized to avoid being transported to the surface.

[0028] In some embodiments, a filling slurry preparation system is set up at the discharge port 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 the embodiment of the present application, a filling slurry preparation system is set up at the discharge port of the flotation tank, and the flotation tailings are directly prepared into filling slurry by the filling slurry preparation system and filled in the goaf without being transported 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 arranged at the outlet end of the bottom of the flotation tank, the sand bin is arranged in the lower middle section, a filling pipeline connected to the goaf is provided at the bottom of the sand bin, and a flocculant storage tank for holding flocculants is also provided at the feed port end of the sand bin.

[0031] In the technical solution of the embodiment of the present application, by setting the sand bin in the lower middle section, the tailings enter the sand bin through stepped gravity flow, mix with the flocculant solution and are directly used for filling the goaf, eliminating the need to install a large number of filling pipelines.

[0032] In some embodiments, a three-dimensional scanner is used to obtain the particle size distribution of the ore after blasting and evaluate the blasting uniformity.

[0033] In the technical solution of the embodiment of the present application, a three-dimensional scanner is used to analyze the ore particle size, 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 a concentrator area in a trackless manner before screening.

[0035] In the technical solution of the embodiment of the present application, a trackless transport method is used to transport the blasted ore to the beneficiation plant area for direct ore dressing, avoiding long-distance transportation to a ground beneficiation plant, thereby saving transportation costs.

[0036] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 This is a process flow chart of the integrated underground mining and selection process based on precise blasting in the embodiment of the present application;

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

[0040] Figure 3 It is a structural schematic diagram of a filling slurry preparation system;

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

[0042] Explanation of the reference numerals: 1-hole water bag sealing layer; 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-center hole; 12-auxiliary hole; 13-peripheral hole. DETAILED DESCRIPTION

[0043] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0045] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0047] In order to solve the problem of high cost of deep-well ore transportation and large floor space occupied by surface beneficiation facilities in the segmented mode of "underground mining-surface beneficiation" used in traditional gold mining, underground pre-selection technology has been continuously studied. Due to the uneven distribution of ore particle size during the blasting process of gold mining, the existing underground pre-selection technology that relies on physical screening or simple re-selection cannot meet the requirements of gold mining beneficiation.

[0048] In order to solve the technical problem that the existing underground pre-selection technology cannot meet the gold ore dressing requirements due to the uneven distribution of ore particle size during the gold mining blasting process, this application provides an underground mining and selection integrated process based on precision blasting, wherein the comprehensive benefits of gold mining are significantly improved through the innovative design of underground mining and selection integrated process and system. Specifically, in terms of economy, the particle size of the ore is controlled by precise blasting, and the ineffective transportation of low-grade ore is reduced by pre-sorting technology. The pneumatic conveying system and tailings cementation filling technology are combined to reduce the overall operating cost; in terms of environmental protection, a tailings filling rate of more than 85% is achieved through underground centralized small-scale dressing plants and tailings filling closed-loop systems, which greatly reduces the demand for ground tailings ponds, and cooperates with precise blasting technology (ore particle size 4-8cm accounts for ≥80%) and closed pipeline transportation to reduce the underground dust concentration by 40%; on the technical level, the innovative blasting is proposed Dynamic coordinated adjustment of parameters and charging parameters, charging of the composite structure of "bottom explosive layer-middle air layer-hole water bag sealing layer", detonation sequence, and the organic combination of precise blasting, intelligent sorting and tailings filling to achieve intelligent linkage of the entire process of "blasting-sorting-filling", achieve simultaneous optimization of underground mining and beneficiation, break through the technical bottleneck of low sorting precision and high energy consumption of traditional processes, reduce equipment crushing energy consumption by 20%-30%, significantly reduce transportation costs, improve resource recovery rate and reduce environmental pollution, and provide a new solution for efficient mining of deep gold mines. This solution has the adaptability of deep mines, effectively prevents and controls the risk of collapse through real-time filling of goafs, and provides a technical model with high resource utilization and environmental friendliness for green mine construction.

[0049] Please refer to Figure 1 The embodiment of the present application provides a downhole mining and selection integrated process based on precision blasting, including the following steps:

[0050] S1. Obtain the blasthole 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 demarcated, and the mining geological information of the area to be mined is collected. According to the characteristics of the mine, the blasting parameters (including blasthole diameter, blasthole spacing) and charging parameters (including charging structure, charging length) are set through blasting dynamics analysis, and the hole depth is set according to the mechanized production of the rock drilling trolley. Then, the ore body is blasted by shallow hole blasting, and the distribution of ore particle size after blasting is detected and analyzed. If the proportion of ore with a particle size of 4-8cm after blasting is ≥80%, the blasting requirement is met, and blasting is continued according to the set blasthole diameter, blasthole spacing, hole depth, charging structure and charging length; if the ore particle size after blasting does not meet the above requirements, it is necessary to analyze the distribution of ore particle size after blasting in the existing blasting test, reset the blasthole spacing and charging length, and the blasthole diameter and hole depth remain unchanged. It can be understood that the ore particle size needs to be detected and analyzed after each blasting, so as to grasp the blasting effect in time and adjust the blasting parameters in time.

[0052] S2, such as Figure 2 As shown, the composite structure of "bottom explosive layer 3-middle air layer 2-hole water bag sealing layer 1" is used for charging; then the blasting is gradually carried out by detonating 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 by continuous coupling loading of emulsion explosives.

[0053] S3. The blasted ore is beneficiated using the full-process small-scale beneficiation plant process of "screening-photoelectric beneficiation-fine crushing-grinding-flotation" established underground, and the tailings obtained from the beneficiation are used to fill the goaf. Specifically, the full-process small-scale beneficiation plant equipment should fully consider the height restrictions of the underground space, and the height difference requirements between different processes can be built across the middle section.

[0054] In the technical solution of the embodiment of the present application, the initial blasting parameters and charging parameters are first set according to 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, the set parameters are continued to be used for blasting. When the particle size is unqualified, the blasting parameters and charging parameters are adjusted in time. That is, in the process of continuous blasting, the particle size distribution of the ore after blasting is detected in real time, and the blasting parameters and charging parameters are dynamically adjusted by using the mutual coordination of the blasting parameters and the charging parameters, so as to ensure the best blasting effect to the greatest extent, and provide 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-hole water bag sealing layer 1" is adopted. By setting the bottom explosive layer 3 in a continuous coupling mode, the coordinated blasting effect between different blastholes can be improved; by setting an air layer in the middle as a spacing layer, the blasting gap expansion time can be extended, the crack penetration efficiency can be improved, and the risk of over-crushing can be reduced; by setting a water bag sealing layer at the hole mouth to fill the hole mouth, the water medium is used to buffer the explosion stress wave, the crushing energy distribution is balanced, and the ore particle size after blasting is concentrated at 4-8cm, reducing the generation of large blasting blocks. At the same time, by optimizing the detonation sequence, the detonation method from the center hole 11 to the auxiliary hole 12 and then to the peripheral hole 13 is gradually blasted to form a blasting funnel that expands layer by layer, and the proportion of large ore with a particle size greater than 10cm is controlled to be less than 5%. That is, through the coordination of the middle air layer 2, the orifice water bag sealing layer 1 and gradual blasting, the blasted ore is prevented from being too broken or too large, so that the ore with the particle size meeting the requirements is obtained, further providing favorable conditions for subsequent underground mineral processing.

[0056] In this embodiment, the obtained ore is beneficiated underground, and the tailings are directly filled into the goaf, thereby reducing the ore transportation cost and the scale and pressure of the surface beneficiation plant.

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

[0058] w=(25~30)d,a=k 1 w;

[0059] Where w is the minimum resistance line, m; d is the set blasthole diameter, m, a is the blasthole spacing, m; k 1 is the correction coefficient for the blasthole spacing. When the proportion of ore with a particle size of 4-8 cm after blasting is ≥ 80%, k 1 =1; when the proportion of ore with a particle size greater than 8 cm after blasting is ≥20%, 0.7≤k 1 <1, when the proportion of ore with a particle size less than 4 cm after blasting is ≥20%, 1<k 1 ≤1.5. Specifically, the minimum resistance line is obtained according to the borehole diameter, and then the borehole spacing is obtained according to the minimum resistance line and the borehole spacing correction coefficient.

[0060] In the technical solution of the embodiment of the present application, different blasthole spacing correction coefficients are selected according to the distribution of ore particle size after blasting in existing blasting tests to obtain a more accurate blasthole spacing, so that the ore particle size after blasting can better meet production requirements.

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

[0062] L=L1 +L 2 +L 3 , L 1 =(0.1~0.2)L 3 , L 3 =(4k 2 ×q b × 3 ) / (ρ 1 ×π×d 2 );

[0063] Where L is the length of the blasthole, m, a known value; L 1 L is the length of the orifice water bag sealing layer 1, m; 2 is the length of the middle air layer 2, m; L 3 is the length of the bottom explosive layer 3, m; q b The explosive consumption per unit volume of rock to form a standard throwing blasting funnel, kg / m 3 , known value; ρ 1 is the density of explosive, kg / m 3 , known value; k 2 is the blasting correction factor. When the proportion of ore with a particle size of 4-8 cm after blasting is ≥80%, 1.9≤k 2 <2.2, when the proportion of ore with a particle size greater than 8 cm after blasting is ≥20%, 2.2≤k 2 ≤2.3, when the proportion of ore with a particle size less than 4 cm after blasting is ≥20%, 1.8≤k 2 Specifically, the length of the bottom explosive layer 3 is calculated based on the blasting correction coefficient, the explosive consumption per unit volume of rock to form a standard throwing blasting funnel, the minimum resistance line and the borehole diameter, and then the length of the hole mouth water bag sealing layer 1 and the length of the middle air layer 2 are calculated.

[0064] In the technical solution of the embodiment of the present application, different blasting correction coefficients are selected according to the distribution of ore particle size after blasting in existing blasting tests, so as to obtain more accurate lengths of the orifice water bag sealing layer 1, the length of the middle air layer 2 and the length of the bottom explosive layer 3, that is, to obtain a precise charging structure, so that the ore particle size after blasting can better meet production requirements.

[0065] Furthermore, in some embodiments, k 1 and k 2 The value of is calculated according to the following formula:

[0066] P=β 0 +β 1 k 1 +β 2 k 2 +∈

[0067] Among them, P is the proportion of ore with a particle size of 4-8cm after blasting, P≥80%; β 0 k 1 = 0 and k 2 = The benchmark pass rate when 0; β 1 k 1 The regression coefficient reflects k 1 The impact strength on the pass rate, β 1 Usually negative, because increasing the hole spacing may reduce the crushing effect; β 2 k 2 The regression coefficient reflects k 2 The impact strength on the pass rate, β 2 It is usually a negative value, because increasing the charge may improve the crushing effect; ∈ is the random error, which means the random factors not considered by the calculation model, such as rock heterogeneity, measurement error, etc. Specifically, in the formula, β 0 , β 1 and β 2 is a known value determined by fitting existing blast data, k 1 and k 2 is a known value that is set.

[0068] C=c 1 Δk 1 2 +c 2 Δk 2 2

[0069] Where C is the total cost of adjusting the hole spacing and charge parameters; Δk 1 k 1 The adjustment amount; Δk 2 k 2 The adjustment amount; c 1 The unit cost factor for adjusting the hole spacing, such as the difficulty or resource consumption of adjusting the hole spacing; c 2 is the unit cost coefficient of charge parameter adjustment. Specifically, in the formula, c 1 and c 2 is a known value determined through engineering economic analysis (eg, drilling cost, explosive cost, etc.).

[0070] Taking the qualified rate P ≥ 0.8 as the constraint condition and the total cost C as the target value, the following Lagrangian function is constructed:

[0071]

[0072] in, is the Lagrangian function; λ is the Lagrangian multiplier; k 1′ is the initial value of the hole spacing correction coefficient (i.e. the value before adjustment); k 2 ' is the initial value of the blast correction coefficient (i.e., the value before adjustment). Specifically, λ is the value calculated under the constraint of balancing cost and qualified rate.

[0073] By taking the derivative and solving the above system of equations, we can obtain k 1 With k 2 The formula for the optimal adjustment ratio, i.e. the weight ratio, is:

[0074]

[0075] From the above formula, we can see that k 1 With k 2 The adjusted weight ratio is determined by the regression coefficient (β 1 , β 2 ) and cost coefficient (c 1 、c 2 ) jointly determine that if the absolute value of the regression coefficient of a parameter is large (significant impact on the pass rate) or the cost coefficient is low (low adjustment cost), its weight will be higher.

[0076] If the ore particle size does not meet the requirements after blasting according to the new blasting parameters and charging parameters, the values ​​of the blasting correction coefficient and the blasting correction coefficient are reset according to the weight ratio of the obtained blasting hole spacing correction coefficient and the blasting correction coefficient adjustment amount, so as to regain the blasting parameters and charging parameters.

[0077] In the technical solution of the embodiment of the present application, with cost as a reference standard, a specific calculation model is used to obtain the weight ratio of the adjustment amount of the blasting correction coefficient and the blasting correction coefficient, thereby obtaining the proportional relationship between the blasting correction coefficient and the blasting correction coefficient during the adjustment process. By utilizing the mutual coordination of the blasting correction coefficient and the blasting correction coefficient, new blasting parameters and charging parameters are obtained, thereby controlling costs while improving the blasting effect.

[0078] Furthermore, in some embodiments, in step S2, the blasting is specifically: using the micro-difference initiation technology of electronic digital detonators, first blasting the central hole 11, blasting the auxiliary holes 12 15-25ms later, and blasting the peripheral holes 13 15-25ms later.

[0079] In the technical solution of the embodiment of the present application, the micro-difference initiation technology of electronic digital detonators is used to accurately control the blasting time difference of the central hole 11, the auxiliary hole 12 and the peripheral hole 13, and a blasting funnel that expands layer by layer is formed through a multi-stage initiation mode, so that the blasting energy of the explosives between the unconnected blast holes is continuously transmitted, thereby ensuring the blasting effect while reducing the amount of explosives.

[0080] Further, in some embodiments, step S3 is specifically as follows: using a screen to screen out ores with a particle size greater than 8 cm, and crushing them to a particle size of 4-8 cm; using an XRF sorter to pre-discard all ores to obtain waste rock and pre-selected ores, and transporting the waste rock to the goaf by trackless transportation; using a fine crusher to finely crush the pre-selected ores and then grinding them in a grinding machine to obtain slurry; using a gravity / flotation device to select the slurry to obtain gold concentrate and tailings; transporting the gold concentrate to the surface by pneumatic transportation, making the tailings into filling slurry, and filling the goaf. Specifically, the pre-discarding process can discard about 30% of the waste rock.

[0081] In the technical solution of the embodiment of the present application, the ore with a particle size greater than 8 cm is first screened out and crushed to a particle size of 4-8 cm, providing favorable conditions for subsequent mineral processing; by pre-discarding, the waste rock in the ore is removed, reducing the amount of ore processing in subsequent flotation, and at the same time, the waste rock is reasonably utilized to avoid being transported to the surface.

[0082] Furthermore, in some embodiments, a filling slurry preparation system is set up at the outlet end of the flotation tank 10 used in the flotation process, and the filling slurry is prepared by the filling system 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 filling body meets the standard.

[0083] In the technical solution of the embodiment of the present application, a filling slurry preparation system is set up at the outlet end of the flotation tank 10, and the flotation tailings are directly prepared into filling slurry by the filling slurry preparation system and filled in the goaf without being transported to the ground.

[0084] Furthermore, in some embodiments, Figure 3 As 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 arranged at the outlet end of the bottom of the flotation tank 10, and the sand bin 6 is arranged in the lower middle section 8 (the flotation tank 10, the buffer tank 4, and the flocculant storage tank 5 are arranged in the upper middle section 7). A filling pipeline 9 connected to the goaf is arranged at the bottom of the sand bin 6, and a flocculant storage tank 5 for holding flocculants is also arranged at the feed inlet end of the sand bin 6. The tailings flowing out from the bottom of the flotation tank 10 enter the sand bin 6 through the buffer tank 4, and at the same time, the flocculants enter the sand bin 6 from the flocculant storage tank 5. The tailings and the flocculants 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 discarded in advance enters the goaf together, and the filling slurry wraps and solidifies the waste rock to form a filling body. Specifically, in the process of preparing the filling slurry, by monitoring the filling body strength, dynamically adjusting the proportion of the cementitious material, calculating the filling cost, balancing the resource recovery rate and the pyrotechnic cost, and realizing data intercommunication through the underground 5G industrial ring network, the sorting threshold is adjusted in real time. The volume of the flocculant storage tank 5 is 1.5m 3 .

[0085] In the technical solution of the embodiment of the present application, by setting the sand bin 6 in the lower middle section 8, the tailings flow into the sand bin 6 through the step gravity flow and mix with the flocculant solution and then are directly used for filling the goaf, thereby eliminating the need to install a large number of filling pipelines 9 and avoiding the risk of blocking the filling pipelines 9, which is suitable for deep well mining. Only the gold concentrate is transported to the surface through the pneumatic pipeline, reducing the loss of resources during transportation.

[0086] Furthermore, in some embodiments, a three-dimensional scanner is used to obtain the particle size distribution of the ore after blasting and evaluate the blasting uniformity. Specifically, the three-dimensional laser scanner can be integrated on the loader.

[0087] In the technical solution of the embodiment of the present application, a three-dimensional scanner is used to analyze the particle size of the ore, and the three-dimensional laser scanner can be integrated on the shovel loader to perform particle size analysis during the transportation process of the shovel loader. The operation is simple and convenient, and the three-dimensional scanner has high analysis accuracy.

[0088] Furthermore, in some embodiments, step S3 also includes transporting the blasted ore to the concentrator area by a trackless method (such as a scraper) before screening.

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

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

[0091] Example 1

[0092] A process for underground mining and selection based on precision blasting and coordination, comprising the following steps:

[0093] S1. Delineate the mining area and collect the mining geological information of the area to be mined. According to the characteristics of the mine, set the initial blasting parameters and charging parameters through blasting dynamics analysis. According to the drill rod diameter of the drilling rig, select the blasthole diameter as 0.04m and the hole depth as 3m, and set the blasthole spacing correction coefficient k. 1 is 0.825, according to w = 25d, a = k 1 The calculated blast hole spacing is 0.825m; the blast correction factor k is set 2 is 2, according to L=L 1 +L 2 +L 3 , L 1 =0.15L 3 , L 3 =(4k 2 ×q b × 3 ) / (ρ 1×π×d 2 ) The calculated length of the hole water bag sealing layer 1 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 , ρ 1 =1000kg / m 3 After blasting, the ore with a particle size of 4-8cm accounts for 74%, and the ore with a particle size greater than 8cm accounts for 21%, which does not meet the requirements. Therefore, k 1 and k 2 Weight analysis.

[0094] P=β 0 +β 1 k 1 +β 2 k 2 +∈

[0095] Among them, by using multiple sets of existing blasting data (including P, k 1 , k 2 ) After fitting, β is calculated 0 =43.27, β 1 =-0.2, β 2 =0.3.

[0096] C=c 1 Δk 1 2 +c 2 Δk 2 2

[0097] Among them, c obtained through engineering economic analysis 1 =1, c 2 =2. Specifically, the calculation is adjusted per unit k 1 and per unit k 2 The ratio of the cost change caused by the value is 1:2, so c 1 Set to 1, c 2 Set to 2 。

[0098] Taking the qualified rate P ≥ 0.8 as the constraint condition and the total cost C as the target value, the following Lagrangian function is constructed:

[0099] By taking the derivative and solving the above system of equations, we can obtain k 1 With k 2 The formula for the optimal adjustment ratio, i.e. the weight ratio, is:

[0100]

[0101] The weight ratio of the correction coefficient of blast hole spacing and the adjustment amount of blast correction coefficient calculated according to the formula is 0.94:1. The reset correction coefficient k of blast hole spacing is 1 =0.8, blasting correction factor k 2 = 2.027. The diameter and depth of the blasthole remain unchanged. According to w = 25d, a = k 1 The calculated spacing between blast holes is 0.8 m.

[0102] According to L=L 1 +L 2 +L 3 , L 1 =0.15L 3 , L 3 =(4k 2 ×q b × 3 ) / (ρ 1 ×π×d 2 ) calculation, where q b =1.4kg / m 3 , ρ 1 =1000kg / m 3 The length of the hole water bag sealing layer 1 is calculated to be 0.34m, the length of the middle air layer 2 is 0.40m, and the length of the bottom explosive layer 3 is 2.26m. The ore particle size distribution after blasting is obtained by a three-dimensional scanner. The ore with a particle size of 4-8cm after blasting accounts for 82.15%, and the particle size distribution meets the standard.

[0103] S2, adopt the composite structure of "bottom explosive layer 3-middle air layer 2-hole water bag sealing layer 1" charging; adopt the micro-difference detonation technology of electronic digital detonator, first blast the center hole 11, blast the auxiliary hole 12 after 15-25ms, and blast the peripheral hole 13 after 20ms. The arrangement of the center hole 11, auxiliary hole 12 and peripheral hole 13 is as follows Figure 4 shown.

[0104] S3. Use trackless means (such as a scraper) to transport the blasted ore to the concentrator area, use a screen to screen out the ore with a particle size greater than 8 cm, and crush it to a particle size of 4-8 cm; use an XRF sorter to pre-discard all the ores to obtain waste rock and pre-selected ore, and transport the waste rock to the goaf by trackless transportation; use a fine crusher to crush the pre-selected ore and then feed it into a grinding machine for grinding to obtain ore pulp; use gravity / flotation equipment to select the ore pulp to obtain gold concentrate and tailings; transport the gold concentrate to the surface by pneumatic transportation, make the tailings into filling slurry, and fill it into the goaf.

[0105] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A process based on precise blasting and coordinated underground mining and selection, characterized in that: The following steps are involved: S1. Obtain the blasthole spacing and charge length based on the distribution of ore particle size after blasting in the existing blasting test; S2, adopt the composite structure of "bottom explosive layer-middle air layer-hole mouth water bag sealing layer" to charge; then use the detonation method from the center hole to the auxiliary hole and then to the peripheral hole to gradually blast; S3. The blasted ore is beneficiated using the full-process small-scale beneficiation plant process of "screening - photoelectric beneficiation - fine crushing - grinding - flotation" established underground, and the tailings obtained from the beneficiation are used to fill the mined-out areas.

2. The process of underground mining and selection based on precise blasting coordination according to claim 1 is characterized in that: In step S1, the blasthole spacing is calculated according to the following formula: w=(25~30)d,a=k1w; Among them, w is the minimum resistance line, m; d is the set blasthole diameter, m; a is the distance between blast holes, m; k1 is the correction coefficient for the spacing between blastholes. When the proportion of ore with a particle size of 4-8 cm after blasting is ≥80%, k1=1; when the proportion of ore with a particle size greater than 8 cm after blasting is ≥20%, 0.7≤k1<1; when the proportion of ore with a particle size less than 4 cm after blasting is ≥20%, 1<k1≤1.

5.

3. The process of underground mining and selection based on precise blasting coordination according to claim 2 is characterized in that: The charge length is calculated according to the following formula: <h2 style=";text-align:left;direction:ltr">L = L1 + L2 + L3, L1 = (0.1 x 0.2) L3, L3 = (4k2 x q)<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> ×w<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> ) / (ρ1×π×d<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> ); Where, L is the length of the blasthole, m; L1 is the length of the water bag sealing layer, m; L2 is the length of the air layer, m; L3 is the length of the explosive layer, m; q b The explosive consumption per unit volume of rock to form a standard throwing blasting funnel, kg / m 3 ; ρ1 is the density of explosive, kg / m 3 ; k2 is the blasting correction coefficient. When the proportion of ore with a particle size of 4-8 cm after blasting is ≥80%, 1.9≤k2<2.2; when the proportion of ore with a particle size greater than 8 cm after blasting is ≥20%, 2.2≤k2≤2.3; when the proportion of ore with a particle size less than 4 cm after blasting is ≥20%, 1.8≤k2<1.

9.

4. The process of underground mining and selection based on precise blasting coordination according to claim 3 is characterized in that: The values ​​of k1 and k2 are calculated according to the following formula: P=β0+β1k1+β2k2+∈ C=c1Δk1 2 +c2Δk2 2 Wherein, P is the proportion of ore with a particle size of 4-8 cm after blasting, P ≥ 80%; β0 is the baseline 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 of charge parameter adjustment; is the Lagrangian 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.

5. The process of underground mining and selection based on precise blasting coordination according to claim 1 is characterized in that: In step S2, the blasting is specifically: using the micro-difference initiation technology of electronic digital detonators, first blasting the central hole, blasting the auxiliary holes 15-25ms later, and blasting the peripheral holes 15-25ms later.

6. The process of underground mining and selection based on precise blasting coordination according to claim 1 is characterized in that: Step S3 is specifically as follows: sieve out ores with a particle size greater than 8 cm and crush them to a particle size of 4-8 cm; pre-discard all ores using an XRF sorter to obtain waste rock and pre-selected ore, and transport the waste rock to the goaf; crush the pre-selected ore using a fine crusher and then feed it into a grinding machine for grinding to obtain slurry; select the slurry using a gravity / flotation device to obtain gold concentrate and tailings; transport the gold concentrate to the surface, and make the tailings into filling slurry to fill the goaf.

7. The process of underground mining and selection based on precise blasting coordination according to claim 6 is characterized in that: A filling slurry preparation system is set up at the discharge port of the flotation tank used in the flotation process, and the filling slurry is prepared by the filling system to fill the goaf.

8. The process of underground mining and selection based on precise blasting coordination according to claim 7 is characterized in that: The filling system includes a buffer tank and a sand bin connected to the buffer tank. The buffer tank is arranged at the outlet end of the bottom of the flotation tank, and the sand bin is arranged in the lower middle section. A filling pipeline connected to the goaf is provided at the bottom of the sand bin, and a flocculant storage tank for holding flocculants is also provided at the feed inlet end of the sand bin.

9. The process of underground mining and selection based on precise blasting coordination according to claim 1 is characterized in that: Through the three-dimensional scanner, the particle size distribution of the ore after blasting is obtained and the blasting uniformity is evaluated.

10. The process of underground mining and selection based on precise blasting coordination according to claim 6 is characterized in that: Step S3 also includes transporting the blasted ore to the concentrator area in a trackless manner before screening.

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