A method for recovering ore powder slurry and comprehensively utilizing resources in an open-pit mine

Abstract

The present invention belongs to the technical field of full recovery and comprehensive utilization of open-pit mine resources, and particularly relates to a method for recovering ore powder slurry and comprehensively utilizing resources in an open-pit mine. First, determine the economic value and feasibility of recovering minerals from the ore powder slurry. According to the ore-rock boundary of the ore body, construct a rainfall surface runoff collection system and an ore powder slurry collection system. Based on the local hydrological data, calculate the total amount of ore powder slurry and the total amount of flood and debris flow during a single rainstorm duration, so as to determine the design parameters of the clarification and treatment system. The rainfall surface runoff is treated and then used to supplement the water for ore dressing production. After the ore powder slurry is remade into pulp, it is introduced into the grinding and flotation system to recover minerals. The present invention collects the ore powder slurry to recover minerals, improves the utilization rate of the mine's mineral resources, timely discharges the rainfall surface runoff in the open-pit mine, which is beneficial to the safety and stability of the stope slope. The comprehensive utilization of this part of water resources reduces the cost of water used in ore dressing production and reduces the treatment cost of water body and environmental pollution.

Description

Technical Field

[0001] The present invention belongs to the technical field of full recovery and comprehensive utilization of open-pit mine resources, and particularly relates to a method for recovering ore powder slurry and comprehensively utilizing resources in an open-pit mine. Background Art

[0002] For open-pit mines with abundant annual rainfall, due to heavy rainfall and large amounts of rain, in addition to directly eroding and damaging the slopes of the open-pit mine, it will also cause the slopes of the open-pit mine to collapse and slide; and heavy rainfall raises the groundwater infiltration line of the open-pit mine slope, and the seepage volume increases sharply, exacerbating the damage of groundwater to the slope and greatly reducing the safety and stability of the slope. From the perspective of the safety and stability of the open-pit mine slope, it is necessary to organize and drain the rainwater and groundwater seepage in the mine, and establish a surface water collection and drainage system for the slope.

[0003] The atmospheric rainfall and abundant fissure water in the ore body and rock mass in the open-pit mine are not effectively organized and drained, resulting in a large amount of sand and mud carried by surface runoff and fissure seepage, disorderly flowing into the mine, and interfering with normal mining operations.

[0004] During the mining process, in the ore body area of the open-pit mine, under the repeated rolling of ore and rock transportation equipment, fine-grained minerals are easily formed on the contact surface, and under the washing and transportation of surface runoff or the emergence of fissure water, the fine-grained minerals are suspended in the slurry, forming a slurry with a high concentration of ore powder. Therefore, this part of the ore powder slurry has high economic value.

[0005] Since the suspended mineral particles in this ore powder slurry are extremely fine, with a particle size below -200 mesh and a content of more than 80%, it requires a long precipitation distance and time, and is dispersed in the mining operation area of the mine, making it difficult to fully collect. There are also great technical difficulties in the recovery and comprehensive utilization of minerals. Therefore, most open-pit mines do not specifically recover and comprehensively utilize this ore powder slurry, resulting in the loss of this ore powder slurry along with rainfall surface runoff, causing a large amount of mineral waste, mixing with surface runoff and being physically precipitated or chemically treated as mine sewage, bringing environmental pollution to the mine, and also requiring a lot of energy and treatment costs. Summary of the Invention

[0006] In order to solve the problems of resource loss and environmental pollution of ore powder slurry in the open-pit mine, the present invention increases a collection system for ore powder slurry and rainfall surface runoff in the open-pit mine. The collected mixed slurry is introduced into the ore dressing production system after passing through a designed precipitation, filtration, and concentration system, so as to improve the recovery rate of mine mineral resources and the full utilization of water resources in the mine; it is applicable to the full recovery of ore powder slurry in open-pit mines with abundant atmospheric rainfall or groundwater in the mine and the comprehensive utilization of resources in the mine.

[0007] The present invention adopts the following technical solutions:

[0008] A method for recovering ore powder slurry and comprehensively utilizing water resources in an open-pit mine. By tracking and sampling the mineral particle concentration and ore grade of the ore powder slurry in the mine for a long time, and conducting experiments and data analysis, the economic value of recovering the ore powder slurry is studied.

[0009] According to the changes in the open-pit mine boundary, the areas of the ore body region and the non-ore body region in the mine are delineated. Based on the local hydrological data, the total amount of flood debris flow generated in the ore body region and the non-ore body region during a single rainstorm duration is calculated. Then, according to the ore powder slurry investigation and experimental analysis data, the total amount of ore powder slurry and the total amount of lost minerals during a single rainstorm duration are calculated.

[0010] Build a cut-off drainage system on the slope steps in the non-ore body region of the open-pit mine to collect the atmospheric rainfall and seepage water from the slope fissures in this region, and transport the water collected in this region to the rainfall surface runoff grading clarification system to precipitate the mud, sand, and stones carried by the surface runoff scouring the slope surface.

[0011] Build an ore powder slurry diversion trough and a liquid accumulation pond in the ore body region of the open-pit mine, and transport the collected ore powder slurry to the ore powder slurry sand settling tank to filter out the coarse sand and stones.

[0012] Conduct ore dressing experiments by comparing ore pulp water with different ratios: ore dressing experiments with tap water, 10%, 20%, 30%, etc. concentrations of reconstituted ore powder slurry to determine the appropriate concentration of the reconstituted ore powder slurry introduced into the ore dressing system.

[0013] The filtered ore powder slurry is reconstituted with the atmospheric rainfall and seepage water from the slope fissures in the non-ore body region of the mine after analysis and clarification. At the ore powder slurry concentration determined by the ore dressing experiment, this part of the reconstituted mixed slurry is introduced into the ore dressing production system.

[0014] After the ore powder slurry and the rainfall surface runoff collection system in the open-pit mine are recovered and treated, and the introduction concentration of the ore powder slurry is determined through ore dressing experiments and ore dressing indexes, this part of the collected mixed water body is introduced into the ore dressing production system. It can not only recover the minerals in the ore powder slurry, bringing considerable economic benefits, but also solve the problems of environmental pollution and difficult treatment caused by this part of the mixed slurry downstream.

[0015] The present invention is a method for recovering and comprehensively utilizing ore powder slurry and water resources in an open-pit mine. Adopting the above technical solutions, it has the following positive effects:

[0016] 1) The open-pit mine is drained and divided into zones according to the ore body area and the non-ore body area. A rainfall surface runoff collection system and a ore powder slurry collection system are respectively constructed for the open-pit mine. Thus, the surface water in the mine will be discharged in an orderly manner, avoiding the formation of floods that erode the slopes of the open-pit mine and inducing geological disasters such as slope collapses, landslides, and debris flows. The timely discharge of atmospheric rainfall and seepage water from slope fissures from the open-pit mine can effectively prevent the reduction of the safety and stability of the open-pit mine slopes.

[0017] 2) Under the repeated rolling of mining equipment and transportation equipment, ultrafine mineral particles are formed in the ore body. In addition, the ore powder generated from drilling blast holes in the ore body area forms ore powder slurry under the scouring of rainfall surface runoff. A large amount of ultrafine mineral particles flow wantonly, causing serious water body and environmental pollution. The ore powder slurry collection system effectively collects the ore powder slurry formed in the ore body area within the secondarily demarcated ore-rock boundary, saving a large amount of treatment costs for the ore powder slurry polluting the water body and the environment.

[0018] 3) A large amount of water is required for ore dressing. Most of the production water is recycled and used from the tailings pond. Due to ore dressing losses, a part of production water still needs to be supplemented. The operation cost of production water is also a significant expense in the ore dressing cost. The present invention uses two systems, namely the rainfall surface runoff collection system and the ore powder slurry collection system, to fully collect and utilize the water resources within the open-pit mine range, saving a large amount of production cycle water return transportation costs.

[0019] 4) The ore powder slurry in the ore body area contains a large amount of mineral particles and has a high ore grade. By collecting the ore powder slurry and introducing it into the ore dressing system to recover the metal minerals in the ore powder slurry, good economic benefits can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic plan view of the rainfall surface runoff collection system and the ore powder slurry collection system for the open-pit mine of the present invention;

[0021] Figure 2 It is a schematic plan view of the rainfall surface runoff classification and clarification system of the present invention;

[0022] Figure 3 It is a schematic diagram of the ore powder slurry sand sedimentation and pulp making treatment system of the present invention;

[0023] Figure 4 It is a schematic sectional view of the rainfall surface runoff classification and clarification system of the present invention;

[0024] Figure 5 It is a schematic sectional view of the ore powder slurry sand sedimentation and pulp making treatment system of the present invention;

[0025] Figure 6 It is a schematic diagram of the acid-proof reinforced concrete partition between various sedimentation ponds of the present invention.

[0026] The meanings of the symbols in the figure are as follows:

[0027] 1—ore-rock boundary of secondary delineation of ore body; 2—ore powder slurry collection system; 3—ore powder slurry transportation system; 4—rainfall surface runoff collection system; 5—HDPE anti-seepage membrane; 6—dredging and transportation road; 7—sedimentation tank overflow; 8—acid-resistant reinforced concrete partition between sedimentation tanks; 9—coarse gravel sedimentation tank; 10—fine mud sedimentation tank; 11—HDPE anti-seepage membrane anchoring ditch; 12—acidic water neutralization storage reservoir; 13—ore powder slurry storage and slurry making reservoir; 14—ore powder slurry sand settling tank; 15—siphon; 16—acid-proof reinforced concrete sedimentation tank body; 17—ore powder slurry transportation system; 18—acid-resistant slurry pump with slurry making function; 19—siphon gate valve; 20—production water transportation system; 21—acid-resistant submersible pump. DETAILED DESCRIPTION

[0028] To further describe the present invention, the method for recycling and comprehensively utilizing mineral powder slurry and water resources in an open pit according to the present invention is further described in detail below in conjunction with the accompanying drawings.

[0029] First, determine the economic feasibility of recovering minerals from ore powder slurry. By tracking and sampling the ore powder slurry in the mining area for a long time, conduct tests on mineral particle concentration and mineral content, and study the economic value of recovering the ore powder slurry. Use different concentrations of ore powder regeneration slurry to compare mineral processing tests (tap water, 10%, 20%, 30% and other concentrations of ore powder regeneration slurry) to determine the appropriate concentration of ore powder regeneration slurry introduced into the mineral processing system.

[0030] In the non-ore body area of the open pit, hydraulic facilities such as flood interception ditches, slope step drainage ditches, rapids troughs, and diversion channels are constructed to construct a rainfall surface runoff collection system 4 in the non-ore body area, and the rainfall surface runoff is diverted and transported to the coarse gravel sedimentation tank 9. The rainfall surface runoff in the non-ore body area is settled in the coarse gravel sedimentation tank 9 and then flows into the fine mud sedimentation tank 10 to settle the fine mud. The rainfall surface runoff in the non-ore body area is clarified in two stages and flows into the acidic water neutralization storage reservoir 12. The volume of the coarse gravel sedimentation tank 9 and the fine mud sedimentation tank 10 is determined according to the calculated amount of solid materials of the mud flow in the first design flood in the non-ore body area, and the length of the coarse gravel sedimentation tank 9 and the fine mud sedimentation tank 10 is determined according to the clarification distance of the fine mud of the rainfall surface runoff. The storage capacity of the acidic water neutralization storage reservoir 12 is determined by the total amount of the first design flood in the open pit, and the HDPE anti-seepage membrane 5 is used in the acidic water neutralization storage reservoir 12 for reservoir bottom anti-seepage. In order to facilitate the long-arm excavator to desilt, the coarse gravel sedimentation tank 9 and the fine mud sedimentation tank 10 are made of acid-resistant reinforced concrete structure, and a desilting transportation road 6 is set around the sedimentation tank. The sections of the sedimentation tanks 9 and 10 are open trapezoidal sections. The coarse gravel sedimentation tank 9, the fine mud sedimentation tank 10 and the acidic water neutralization storage tank 12 are separated by an acid-resistant reinforced concrete partition 8, and the partition 8 is provided with a sedimentation tank overflow port 7.

[0031] In the mining area within the ore-rock boundary 1 of the secondary delineation of the ore body in the open-pit stope, a mineral powder slurry collection system 2 is constructed by building open-cut drainage ditches, liquid accumulation ponds, etc. The mineral powder slurry is transported to the mineral powder slurry sand settling pond 14 through the mineral powder slurry transport system 3. After filtering and precipitating the sand and gravel contained in the slurry, it flows to the mineral powder slurry storage and slurry-making warehouse 13 for storage. The length of the mineral powder slurry sand settling pond 14 is determined according to the sedimentation distance of the sand and gravel, and the volume of the mineral powder slurry storage and slurry-making warehouse 13 is designed according to the maximum volume of the mineral powder slurry produced during the longest maintenance period of the mine. The mineral powder slurry sand settling pond 14 and the mineral powder slurry storage and slurry-making warehouse 13 are made of acid-resistant reinforced concrete structure, with an open trapezoidal cross-section, and the width is convenient for the long-arm excavator to dredge the silt. A dredging and transportation road 6 is set around the pond.

[0032] In the mineral powder slurry storage and slurry-making warehouse 13, an acid-resistant slurry pump 18 with a slurry-making function is used to stir and make slurry. After the concentration reaches the appropriate concentration determined by the beneficiation test of the concentration comparison of the reconstituted mineral powder slurry, it is transported to the semi-autogenous grinding pump sump through the mineral powder slurry transport system 17 and added to the grinding and flotation production system.

[0033] The surface runoff of rainfall in the open-pit stope flows into the acidic water neutralization and storage warehouse 12 after being clarified by the secondary sedimentation tank, and after neutralizing and removing acid, it is pumped to the high-level water tank to supplement the beneficiation water through the production water transport system 20 by an acid-resistant submersible pump 21.

[0034] When the water volume for slurry-making in the mineral powder slurry storage and slurry-making warehouse 13 is insufficient, the siphon valve 19 is opened, and the siphon 15 is used to draw water from the acidic water neutralization and storage warehouse 12 for slurry-making.

[0035] The technology provided by the present invention has been applied in the mineral powder slurry recovery and comprehensive resource utilization project in a large foreign open-pit copper mine stope. The present invention constructs two resource collection systems, namely, the rainfall surface runoff collection system and the mineral powder slurry collection system, in the open-pit stope. After the rainfall surface runoff is clarified by the grading clarification system and neutralized and deacidified, the recovery of water resources is realized to supplement the beneficiation production water; the mineral powder slurry is processed by the mineral powder slurry sand settling and slurry-making treatment system to realize the recovery of mineral resources, and after re-slurry-making, it is introduced into the grinding and flotation production system to recover metallic copper. After the successful implementation of this project, significant economic and social benefits have been achieved, improving the recovery rate of metallic copper in the mine, increasing the enterprise's revenue, making full use of the water resources in the open-pit stope, reducing the cost of beneficiation production water, preventing the acidic water and mineral powder slurry in the open-pit stope from polluting the surrounding water bodies and the environment of the mining area, and reducing the treatment costs of water pollution and environmental pollution.

Claims

1. A method for recovering ore powder slurry and comprehensively utilizing water resources in an open-pit mine, characterized in that, The method is as follows: S1. According to the ore-rock boundary (1) delineated for the second time of the ore body, the open-pit stope is divided into drainage zones according to the ore-body area and non-ore-body area, and a rainfall surface runoff collection system (4) and a ore powder slurry collection system (2) are respectively constructed; after the atmospheric rainfall and slope fissure seepage water in the non-ore-body area are effectively collected by the rainfall surface runoff collection system (4), they are transported to the rainfall surface runoff grading clarification system; after the ore powder slurry in the ore-body area is effectively collected by the ore powder slurry collection system (2), it is transported to the ore powder slurry sand settling and pulp-making treatment system; S2. Calculate the total amount of ore powder slurry in the ore-body area and the total amount of debris flow of flood generated in the non-ore-body area during the duration of a single heavy rainstorm based on the local hydrological data, so as to determine the design parameters of the rainfall surface runoff grading clarification system and the ore powder slurry sand settling and pulp-making treatment system; S3. The rainfall surface runoff grading clarification system includes three parts: a rainfall surface runoff coarse sand and gravel sedimentation tank (9), a fine mud sedimentation tank (10) and an acidic water neutralization storage tank (12). The rainfall surface runoff collected in the non-ore-body area of the open-pit stope is clarified by the rainfall surface runoff grading clarification system, and after being neutralized and deacidified in the acidic water neutralization storage tank (12), it is used to supplement the water for ore dressing production; S4. The ore powder slurry collection system (2) includes two parts: an ore powder slurry sand settling tank (14) and an ore powder slurry storage and pulp-making tank (13); the ore powder slurry collected in the ore-body area is transported to the ore powder slurry sand settling tank (14) through the first ore powder slurry conveying system (3), and after the sand and gravel contained in the slurry are filtered and precipitated, it overflows to the ore powder slurry storage and pulp-making tank (13) for storage. Using an acid-resistant slurry pump (18) with a pulp-making function, it is stirred to make pulp. After the concentration reaches the appropriate concentration determined by the comparison of the ore powder reconstituted slurry concentration in the ore dressing test, it is transported to the semi-autogenous grinding pump sump through the second ore powder slurry conveying system (17) and added to the grinding and flotation production system to recover minerals.

2. The method for recovering ore powder slurry and comprehensively utilizing water resources in an open-pit mine as claimed in claim 1, wherein By long-term tracking and sampling of the ore powder slurry in the stope, an ore dressing test is carried out to determine the economic value and feasibility of recovering minerals from the ore powder slurry; a rainfall surface runoff collection system (4) is constructed to recover the water resources in the stope, and the storage capacity of the acidic water neutralization storage tank (12) is determined by the total amount of the first design flood of the open-pit stope; an ore powder slurry collection system (2) is constructed to collect and recover minerals from the ore powder slurry in the stope, and the volume of the ore powder slurry storage and pulp-making tank (13) is designed according to the maximum ore powder slurry output during the longest maintenance period of the mine.

3. A method for recovering ore powder slurry and comprehensively utilizing water resources in an open-pit mine as claimed in claim 1 or 2, characterized in that, For the convenience of clarifying the surface runoff of rainfall and filtering the ore powder slurry into coarse sand and gravel, the coarse sand and gravel sedimentation tank (9), the fine mud sedimentation tank (10), the ore powder slurry sand settling tank (14) and the ore powder slurry storage and pulp making warehouse (13) are arranged in a folded-back type; the volumes of the coarse sand and gravel sedimentation tank (9) and the fine mud sedimentation tank (10) are determined according to the calculated amount of solid materials of the debris flow in the once-designed flood in the non-ore body area, and the lengths of the coarse sand and gravel sedimentation tank (9) and the fine mud sedimentation tank (10) are determined according to the clarification distance of the fine mud in the surface runoff of rainfall; the coarse sand and gravel sedimentation tank (9), the fine mud sedimentation tank (10), the ore powder slurry sand settling tank (14) and the ore powder slurry storage and pulp making warehouse (13) are made of acid-resistant reinforced concrete structure, with an open trapezoidal cross-section, the width is suitable for the long-arm excavator to dredge the sediment, and a dredging and transportation road (6) is set around the sedimentation tank.

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