A method and system for beneficiation of lead-zinc ore in a polymetallic ore

Abstract

The application discloses a kind of lead-zinc ore beneficiation method and system in polymetallic ore, it is related to the technical field of beneficiation, including the following steps: S1, crushing;S2, grinding;S3, lead flotation: the ore pulp after grinding is sent to lead flotation tank, flotation reagent includes 25# black medicine, butyl xanthate, foaming agent and zinc inhibitor, using 1 rough 2 sweep 3 precise flotation, and output lead concentrate and lead tailings;S4, zinc flotation: lead tailings are sent to zinc flotation tank, and flotation reagent includes copper sulfate, butyl xanthate and foaming agent, using 1 rough 2 sweep 3 precise flotation, and output zinc concentrate and zinc tailings;S5, tailings, wastewater treatment: the fluorite tailings produced by flotation are subjected to solid-liquid separation, and the liquid phase is sent to a sewage treatment station for treatment, and the treated water is recycled to the beneficiation section;Solid phase is sent to mine for filling treatment or used as building material, solve the problem that there is no efficient, environmentally friendly, economic lead-zinc ore comprehensive recovery beneficiation process suitable for the ore properties in Sichuan Mabian area in the prior art.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, specifically to a method and system for beneficiating lead-zinc ore from polymetallic ores. Background Technology

[0002] Lead and zinc are indispensable basic metallic materials in modern industrial systems, widely used in key sectors of the national economy such as electrical and electronic industries, machinery manufacturing, chemical metallurgy, and national defense. They are strategic mineral resources that ensure the stable operation of my country's industrial system and the security of its industrial chain. my country is a major global producer and consumer of lead and zinc. However, as domestic easily beneficiated single-metal lead and zinc mineral resources are gradually depleted, mining targets are continuously shifting towards complex and difficult-to-process ores with low grades, fine dissemination, and multi-element symbiosis. The efficient and comprehensive recovery and clean utilization of complex and difficult-to-process polymetallic symbiotic ores has become an inevitable trend and core technological direction for the high-quality development of my country's lead and zinc mining industry.

[0003] Located in the core section of the southwestern Sichuan metallogenic belt, the Mabian area of ​​Leshan, Sichuan Province, boasts superior mineral geological conditions. Fifteen mineral types, including phosphorus, lead, zinc, and fluorite, have been discovered, with four large deposits and three medium-sized deposits identified. It is an important mineral resource-rich area in southwestern my country. In recent years, with the continuous advancement of regional geological exploration, a large amount of lead-zinc symbiotic mineral resources have been discovered in the area, possessing significant comprehensive development and utilization value. However, for a long time, mineral development in Mabian has mainly focused on the mining and processing of phosphate ore. Only a few mines have incidentally recovered lead and zinc minerals during phosphate mining. Lead-zinc symbiotic resources have not been developed on a large scale, systematically, and efficiently, resulting in an overall low level of comprehensive utilization of regional mineral resources.

[0004] Currently, a relatively mature technology system and mainstream process routes have been formed in the lead-zinc ore beneficiation field. However, for the lead-zinc symbiotic ores in the Mabian area, existing conventional beneficiation processes still have many technical bottlenecks and are difficult to adapt to the special properties of the ores in this region. These bottlenecks are mainly reflected in the following aspects: First, the liberation of individual minerals is difficult, resulting in low recovery rates. Lead-zinc ores in the Mabian area are characterized by fine-grained intergrowth and complex symbiotic relationships. Lead and zinc minerals are intertwined and closely coexist. Conventional grinding fineness cannot achieve sufficient liberation of valuable minerals, directly leading to low recovery rates of lead and zinc concentrates. A large amount of valuable metals are lost with the tailings, resulting in serious resource waste.

[0005] Secondly, the lead-zinc separation effect is poor, resulting in insufficient quality of concentrate products. Affected by factors such as poor compatibility of flotation reagent systems and insufficient precision in process control, the existing process is not ideal in separating lead and zinc from ores in this region. There is a common problem of excessive lead impurities in zinc concentrate, which significantly reduces the product grade and market value of zinc concentrate.

[0006] Third, the reagent system poses significant environmental risks and does not meet the requirements of green development. Conventional lead-zinc separation processes generally suffer from large reagent volumes and complex reagent types, with some processes still using cyanide as a zinc mineral inhibitor. Cyanide is a highly toxic controlled reagent, which not only significantly increases the operating costs of mineral processing but also poses major safety hazards and environmental pollution risks, making it incompatible with the current industrial development requirements of green mine construction and ecological environmental protection.

[0007] Therefore, developing a high-efficiency, environmentally friendly, and economical comprehensive recovery and beneficiation process for lead-zinc ore that is suitable for the ore properties of Mabian County, Sichuan Province, and realizing the sequential and efficient separation and recovery of the two valuable minerals, lead and zinc, is of great practical significance and industrial application value for improving the comprehensive utilization rate of mineral resources in the region, increasing the economic benefits of mining enterprises, and ensuring the supply security of my country's strategic lead-zinc mineral resources. Summary of the Invention

[0008] The purpose of this invention is to address the lack of an efficient, environmentally friendly, and economical comprehensive lead-zinc ore beneficiation process adapted to the ore properties of the Mabian area in Sichuan Province in the existing technology. This invention proposes a lead-zinc ore beneficiation method for polymetallic ores, which can achieve efficient separation and recovery of the two valuable minerals, lead and zinc, in this area at a low cost.

[0009] This invention is achieved through the following technical solution: A method for beneficiating lead-zinc ore from polymetallic deposits includes the following steps: S1. Crushing: The raw ore is sent to the crushing station for processing to make the particle size of the raw ore <20mm; S2. Grinding: Control the particle size distribution of the grinding product to meet the requirement that the mass fraction of the -0.074mm particle size is 75~80%, and adjust the mass concentration of the grinding discharge slurry to 30~33%; S3, Lead Flotation: The slurry after grinding is fed to the lead flotation cell at a rate of 20-21 tons / h, and the flotation reagents are fed to the flotation cell at a rate of 210-420 mL / h. The flotation reagents include No. 25 black reagent, butyl xanthate, frother and zinc inhibitor. The pH is controlled at 7.5-8. The flotation process is 1 roughing, 2 scavenging and 3 cleaning to produce lead concentrate and lead tailings. S4. Zinc Flotation: Lead tailings are fed to the zinc flotation cell at a rate of 20-21 tons / h, and flotation reagents are fed to the flotation cell at a rate of 210-420 mL / h. The flotation reagents include copper sulfate, butyl xanthate and frother. The pH is controlled at 7.5-8. The flotation process is 1 roughing, 2 scavenging and 3 cleaning to produce zinc concentrate and zinc tailings. S5. Tailings and wastewater treatment: The fluorite tailings produced by flotation are separated into solid and liquid phases. The liquid phase is sent to the wastewater treatment plant for treatment, and the treated water is recycled to the mineral processing section. The solid phase is sent to the mine for backfilling or used as building material.

[0010] Furthermore, in steps S3 and S4, the foaming agent is No. 2 oil; in step S3, the zinc inhibitor is zinc sulfate.

[0011] Furthermore, in step S3, the flotation reagents used in the lead flotation process include 25# black reagent, butyl xanthate, 2# oil, and zinc sulfate. In the lead roughing, lead scavenging and lead cleaning processes, the dosage of each reagent, based on the slurry quality, is as follows: 25# black reagent 10~20g / ton, butyl xanthate 50~100g / ton, 2# oil 5~10g / ton, and zinc sulfate 400~600g / ton.

[0012] Furthermore, in step S4, the reagents used in the zinc flotation process include copper sulfate, butyl xanthate, and No. 2 oil; In the zinc roughing, zinc scavenging and zinc cleaning processes, the dosage of each reagent, based on the slurry quality, is as follows: copper sulfate 250~400g / ton, butyl xanthate 50~60g / ton, and No. 2 oil 8~15g / ton.

[0013] Furthermore, in steps S3 and S4, the height of the lead flotation cell, zinc flotation cell, and fluorite flotation cell is 1500mm, and the liquid level in the cell is kept stable during the flotation operation. In lead and zinc flotation, the liquid level is controlled at 1300~1350mm for roughing, 1400~1460mm for scavenging, and 1100~1200mm for cleaning.

[0014] Furthermore, in step S5, the wastewater treatment plant includes a first equalization tank, a pH equalization tank, a stirring tank, a catalytic oxidation tank, a neutralization reaction tank, a first reaction tank, an inclined tube sedimentation tank, a pH adjustment tank, a softening reaction tank, a first filter, and an activated carbon filter connected in sequence. The wastewater treatment method of the wastewater treatment plant includes the following steps: S5.1 The wastewater to be treated is received in the first equalization tank, sulfuric acid is added, and the pH is initially adjusted before being sent to the pH equalization tank. S5.2. Continue to add sulfuric acid to the pH adjustment tank to adjust the pH of the wastewater to acidic, and then send the wastewater through the stirring tank and the catalytic oxidation tank in sequence. S5.3 The wastewater is degraded for COD and organic pollutants in the mixing tank and catalytic oxidation tank, and then sent to the neutralization reaction tank. S5.4 Add sodium hydroxide and lime to the neutralization reaction tank to adjust the pH of the liquid in the tank to 9-10, so that the heavy metal ions form hydroxide precipitates, and then send the liquid phase to the first reaction tank. S5.5. Add calcium chloride, sodium sulfide, and sodium hypochlorite to the first reaction tank to remove fluoride, mercury, and cadmium from the wastewater and oxidize CN. - Alternatively, after decolorization, the treated material is transported to an inclined tube sedimentation tank; S5.6 Add polyacrylamide to the inclined tube sedimentation tank to achieve mud-water separation, and the supernatant enters the pH adjustment tank. S5.7 Add sulfuric acid to the pH adjustment tank to adjust the pH of the effluent in the tank to 6.5~7.5, and send the liquid phase to the softening reaction tank. S5.8. Add sodium carbonate to the softening reaction tank to react with Ca in the water. 2+ Mg 2+ The reaction is carried out, and the resulting material is then sent to the first filter and the activated carbon filter in sequence. S5.9 Add polyferric sulfate and polyacrylamide to the first filter. After the liquid phase is treated by the first filter and the activated carbon filter in sequence, residual suspended solids, colloids and trace organic matter in the water are removed to obtain purified water.

[0015] A lead-zinc ore beneficiation system in a polymetallic mine includes a crushing unit, a closed-circuit grinding and classification unit, a lead flotation unit, a zinc flotation unit, and a tailings wastewater treatment unit, which are connected in series via a slurry conveying pipeline and a conveying pump. The purified water output end of the tailings wastewater treatment unit is connected to the water supply interface of each of the aforementioned units through a recycled water pipeline, forming a closed-loop circulating water supply structure. The lead flotation unit includes interconnected lead roughing flotation cells, two-stage lead scavenging flotation cells, and three-stage lead cleaning flotation cells; each flotation cell is equipped with a stirring device and a bubble scraping mechanism, and a liquid level sensor and a pH meter are installed on the flotation cells; the concentrate outlet of the lead flotation unit is connected to the lead concentrate washing and filtration section, and the lead tailings outlet is connected to the feed end of the zinc flotation unit. The zinc flotation unit includes interconnected zinc roughing flotation cells, two-stage zinc scavenging flotation cells, and three-stage zinc cleaning flotation cells; each flotation cell is equipped with a stirring device and a bubble scraping mechanism, and a liquid level sensor and a pH meter are installed on the flotation cells; the concentrate outlet of the zinc flotation unit is connected to the zinc concentrate washing and filtration section, and the lead tailings outlet is connected to the feed end of the desulfurization unit.

[0016] Furthermore, the crushing unit is a crushing station, and the discharge particle size control accuracy of the crushing station meets the requirement that the maximum discharge particle size does not exceed 20mm. The discharge end of the crushing station is connected to the feed end of the closed-circuit grinding and classification unit through a material conveying mechanism.

[0017] Furthermore, the closed-circuit grinding and classification unit includes a ball mill and a hydrocyclone. The discharge port of the ball mill is connected to the feed port of the hydrocyclone, and the sand outlet of the hydrocyclone flows back to the feed port of the ball mill, thus forming a closed-circuit grinding and classification structure. The overflow outlet of the hydrocyclone is connected to the feed end of the lead flotation unit.

[0018] Furthermore, the lead flotation unit is also equipped with a lead flotation reagent supply assembly, which includes a 25# black reagent storage tank, a butyl xanthate storage tank, a frother storage tank, and a zinc inhibitor storage tank. Each reagent storage tank is connected to the dosing port of the corresponding flotation cell through a reagent metering pump.

[0019] Furthermore, the zinc flotation unit is also equipped with a zinc flotation reagent supply assembly, which includes a copper sulfate storage tank, a butyl xanthate storage tank, and a frother storage tank. Each reagent storage tank is connected to the dosing port of the corresponding flotation cell via a reagent metering pump.

[0020] Furthermore, the tailings wastewater treatment unit includes a wastewater treatment station, which comprises, in sequence, a first equalization tank, a pH equalization tank, a stirring tank, a catalytic oxidation tank, a neutralization reaction tank, a first reaction tank, an inclined tube sedimentation tank, a pH adjustment tank, a softening reaction tank, a first filter, and an activated carbon filter. The first equalization tank is equipped with a filter press water inlet pipe, a thickener water inlet pipe, and a first sulfuric acid inlet pipe; the pH equalization tank is equipped with a second sulfuric acid inlet pipe; the stirring tank is equipped with a ferrous sulfate inlet pipe; the catalytic oxidation tank is equipped with a hydrogen peroxide inlet pipe; the neutralization reaction tank is equipped with a sodium hydroxide inlet pipe and a lime inlet pipe; the first reaction tank is equipped with a calcium chloride inlet pipe, a sodium sulfide inlet pipe, and a sodium hypochlorite inlet pipe; the inclined tube sedimentation tank is equipped with a first polyacrylamide inlet pipe; the pH adjustment tank is equipped with a third sulfuric acid inlet pipe; the softening reaction tank is equipped with a sodium carbonate inlet pipe; and the first filter is equipped with a polyferric sulfate inlet pipe and a second polyacrylamide inlet pipe.

[0021] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention proposes a beneficiation method for lead-zinc ore in polymetallic ores. By optimizing the crushing and grinding stages and selecting specific lead and zinc flotation reagents, lead and zinc concentrates can be obtained sequentially. By controlling the dosage of each flotation reagent, the recovery rates of lead and zinc can be maintained at a high level within the industry. Simultaneously, the tailings-containing slurry in the process undergoes solid-liquid separation, and the wastewater is purified. The purified water is then reused in the flotation stage, achieving wastewater recycling.

[0022] Second, in this invention, the yield of the -0.074mm particle size in the grinding section of the mineral processing is controlled within the range of 75-80%, which helps to fully liberate the useful minerals, improve the recovery rate of lead and zinc concentrates, and reduce the loss of valuable metals with tailings.

[0023] Third, this invention innovatively selects new lead and zinc flotation reagents and controls their dosage to maintain a weakly alkaline flotation environment of 7.5-8.0 in the flotation system. This eliminates the need for lime to adjust the slurry, reducing the total reagent usage by more than 18% compared to conventional processes. The tailings wastewater pH is close to neutral, significantly reducing the amount of neutralizing reagent used in the wastewater treatment stage and lowering the overall beneficiation cost by more than 10%. In contrast, existing lead-zinc-fluorite polymetallic ore flotation processes generally use lime to adjust the slurry pH to a strongly alkaline environment of 9.0 or higher. This not only consumes large amounts of lime but also leads to a surge in the use of fatty acid collectors. Furthermore, the treatment of high-calcium, high-alkaline wastewater is difficult and costly.

[0024] Fourth, by optimizing the flotation reagent formulation of the lead flotation section, this invention breaks through the technical limitation of existing conventional processes that can only recover lead sulfide minerals, and realizes the simultaneous recovery of lead sulfide and some difficult-to-process lead oxide minerals, which greatly improves the comprehensive utilization rate of lead resources and increases the economic benefits of mining enterprises.

[0025] V. In this invention, a lead-zinc ore beneficiation system for polymetallic ores is proposed, comprising interconnected crushing units, closed-circuit grinding and classification units, lead flotation units, zinc flotation units, and tailings wastewater treatment units, thus constructing a complete polymetallic ore combined beneficiation system that can simultaneously achieve the separation and recovery of lead and zinc minerals, thereby improving the comprehensive utilization efficiency of associated mineral resources.

[0026] VI. In this invention, a closed-circuit grinding and classification unit with a preferred structure is proposed. The closed-circuit structure consists of a ball mill and a hydrocyclone, which can be equipped with an online particle size detection component to stably control the mass fraction of the -0.074mm particle size in the grinding product at 75~80%. This parameter setting ensures sufficient individual mineral liberation, avoiding the problem of low recovery rate of lead and zinc concentrate due to insufficient liberation, and also prevents a significant increase in grinding energy consumption and equipment wear caused by excessively high particle size yield, effectively balancing the separation quality and production economy.

[0027] VII. In this invention, both the lead flotation unit and the zinc flotation unit are equipped with pH meters, and the entire process maintains a weakly alkaline environment with a pulp pH of 7.5 to 8, so that the matching collectors and depressants can exert their optimal selectivity. Compared with conventional strongly alkaline flotation systems, the total amount of reagents can be reduced, and the difficulty and cost of subsequent tailings wastewater treatment can be significantly reduced.

[0028] 8. In this invention, the lead flotation unit adopts a flotation cell group structure of 1 coarse flotation cell, 2 scavenging cells, and 3 fine flotation cells, and is equipped with corresponding reagent supply components. Its reagent system has good collection performance for lead sulfide minerals, and also has the ability to collect some difficult-to-process lead oxide minerals associated with the ore. Compared with conventional lead flotation systems, it can effectively improve the overall recovery level of lead resources.

[0029] 9. In this invention, both the lead flotation unit and the zinc flotation unit adopt a pool group configuration of 1 rougher, 2 scavengers, and 3 cleaners. Each flotation pool is uniformly set with a body height and corresponding working liquid level range, and is equipped with stirring, aeration, foam scraping, and liquid level adjustment devices. The structural parameters of each section are highly matched, which can remove impurities step by step, improve the grade of concentrate, and stably produce lead concentrate and zinc concentrate that meet the requirements of industrial grade.

[0030] 10. In this invention, the tailings wastewater treatment unit is set up in combination with a solid-liquid separation device (such as a thickener or filter press) and a wastewater treatment station. The solid phase obtained after tailings concentration and filter press can be used for mine backfilling or as building materials. At the same time, the wastewater of the whole process is centrally treated and recycled in a closed loop, which reduces water consumption and pollutant discharge, and meets the production requirements of green mines. Attached Figure Description

[0031] Figure 1 This is a flowchart of the present invention.

[0032] Figure 2 This is a schematic diagram of the beneficiation structure for lead-zinc ore in polymetallic mines.

[0033] Figure 3 This is a schematic diagram of a closed-circuit grinding and classification unit.

[0034] Figure 4 This is a schematic diagram of the lead flotation unit.

[0035] Figure 5 This is a schematic diagram of the structure of a Class I lead refining flotation cell.

[0036] Figure 6 This is a schematic diagram of the zinc flotation unit.

[0037] Figure 7 This is a schematic diagram of the structure of a Class I zinc sweep flotation cell.

[0038] Figure 8 This is a schematic diagram of the tailings wastewater treatment unit.

[0039] Figure 9 This is a flowchart of the wastewater treatment process at a sewage treatment plant.

[0040] The components include: 1. Crushing unit; 2. Closed-circuit grinding and classification unit; 3. Lead flotation unit; 4. Zinc flotation unit; 5. Tailings wastewater treatment unit; 6. Reclaimed water pipeline; 7. Tailings collection unit; 8. Stirring device; 9. Foam scraping mechanism; 10. Liquid level sensor; 11. pH meter; 12. Lead concentrate washing and filtration section; 13. No. 25 black powder storage tank; 14. Butyl xanthate storage tank; 15. Foaming agent storage tank; 16. Zinc inhibitor storage tank. 17. Copper sulfate storage tank; 18. Zinc concentrate washing and filtration section; 19. Fluorite concentrate washing and filtration section; 2.1. Water supply interface I; 2.2. Ball mill; 2.3. Hydrocyclone; 2.4. Circulation pipeline; 2.2.1. Feed inlet I; 2.3.1. Grit outlet; 2.3.2. Hydrocyclone discharge outlet; 3.1. Water supply interface II; 3.2. Lead concentrate discharge pipe; 3.3. Lead roughing flotation cell; 3.4. Grade I lead 3.5 Scavenging flotation cell; 3.6 Class I lead cleaning flotation cell; 3.7 Class II lead cleaning flotation cell; 3.8 Class III lead cleaning flotation cell; 3.9 Lead tailings outlet; 3.10 Feed inlet II; 3.11 Class I lead concentrate froth discharge pipe; 3.12 Pipeline I; 3.13 Pipeline II; 4.1 Water supply interface III; 4.2 Zinc concentrate discharge pipe; 4.3 Zinc roughing flotation cell; 4.4 4.5. Grade I zinc scavenging flotation cell; 4.6. Grade I zinc cleaning flotation cell; 4.7. Grade II zinc cleaning flotation cell; 4.8. Grade III zinc cleaning flotation cell; 4.9. Zinc tailings outlet; 4.10. Feed inlet III; 4.11. Pipeline III; 4.12. Pipeline IV; 4.13. Pipeline V; 5.1. Clean water outlet; 5.2. Solid phase discharge outlet; 5.3. Solid-liquid separation device; 5.4. Wastewater treatment plant. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0042] Example 1 To facilitate public understanding of the present invention, this embodiment uses a lead and zinc ore beneficiation production line of Mabian Fuma Phosphate Co., Ltd. as an example for further illustration.

[0043] Multiple batches of sampling and testing revealed that, by mass percentage, the lead ore grade in the region was 1.0-1.5%, and the zinc ore grade was 0.8-1.5%.

[0044] A beneficiation method for lead-zinc ore in polymetallic ores, with a beneficiation process reference. Figure 1 This includes the following steps: Step S1: Crushing.

[0045] The raw ore is sent to a crushing station for processing to reduce the particle size of the raw ore to <20mm.

[0046] Step S2: Grinding.

[0047] The crushed raw ore is transported to the grinding section, where a closed-circuit grinding system consisting of a ball mill and a hydrocyclone is used for grinding and classification. The particle size distribution of the grinding product is controlled to meet the requirement that the mass fraction of the -0.074mm particle size is 75~80%, and the mass concentration of the grinding discharge slurry is adjusted to 30~33%.

[0048] This step involves grinding and classifying the ore, with the core control parameter being the yield of the -0.074mm particle size. If this parameter is too low, the minerals will not be sufficiently liberated, leading to a decrease in the floatation rate of lead and zinc minerals during subsequent flotation, ultimately resulting in reduced lead and zinc concentrate recovery rates and substandard grades. Limited by the ball mill's processing capacity, the efficiency of the classification equipment, and on-site production conditions, increasing the -0.074mm particle size yield to over 80% would significantly increase grinding energy consumption and equipment wear, resulting in a substantial decrease in economic efficiency. Therefore, considering equipment load, product quality requirements, and mineral processing costs, this embodiment controls the -0.074mm particle size yield of the ore at 75-80%.

[0049] Step S3: Lead flotation.

[0050] Objective: To perform priority flotation on qualified grinding pulp to selectively enrich lead minerals such as lead ore, separate and remove gangue and zinc mineral impurities, and produce lead concentrate products that meet industrial grade requirements. At the same time, the lead tailings produced are transported to the subsequent zinc flotation section.

[0051] The slurry after grinding is fed to the lead flotation cell at a rate of 20-21 tons / h, and the flotation reagents are fed to the flotation cell at a rate of 210-420 mL / h. The flotation reagents include No. 25 black reagent, butyl xanthate, frother and zinc inhibitor. The pH is controlled at 7.5-8. The flotation process is 1 roughing, 2 scavenging and 3 cleaning to produce lead concentrate and lead tailings.

[0052] In this embodiment, the pH value of the pulp is uniformly controlled at 7.5~8.0 throughout the flotation process to maintain a weakly alkaline pulp environment. The pulp pH value is closely related to the dissolution, dispersion, and adsorption behavior of flotation reagents. Under these weakly alkaline conditions, the collectors and depressants selected in this invention can achieve optimal selectivity. Compared with conventional strongly alkaline flotation processes, the total reagent dosage can be reduced by 15~20%. At the same time, the weakly alkaline pulp does not require the addition of large amounts of lime for pulp conditioning, reducing the introduction of calcium and magnesium ions and significantly reducing the difficulty and cost of subsequent tailings wastewater treatment.

[0053] In this step, the frother is No. 2 oil (pine oil), and the zinc depressant is zinc sulfate. The flotation reagents are added to the lead flotation cell, with the following dosages based on the mass of the ore pulp: 10-20 g / ton of No. 25 black reagent, 50-100 g / ton of butyl xanthate, 5-10 g / ton of No. 2 oil, and 400-600 g / ton of zinc sulfate. During the lead roughing stage, the flotation reagents of this invention are added for flotation treatment. These reagents exhibit good collecting performance for lead sulfide minerals and also have a certain collecting ability for some difficult-to-recover lead oxide minerals associated with the ore. However, the reagents used in existing conventional lead flotation processes are only effective for lead sulfide minerals and cannot recover lead oxide minerals. Compared with existing technologies, the total recovery rate of lead minerals using the reagents of this invention is significantly improved (by approximately 8%).

[0054] The height of the lead flotation cell and zinc flotation cell is 1500mm. During flotation operations, the liquid level in the cell should be kept stable; the liquid level should be controlled at 1300~1350mm for roughing operations, 1400~1460mm for scavenging operations, and 1100~1200mm for cleaning operations.

[0055] The specific implementation method is as follows: I. Preparations before the assignment.

[0056] Equipment status check: Confirm that the roughing mixing tank, each flotation tank, slurry transfer pump, reagent metering pump, online pH meter and flow meter are operating normally, the flotation tank level adjustment device and the froth scraping mechanism are sensitive, and the equipment is well lubricated and sealed.

[0057] Reagent preparation and storage: Prepare flotation reagents according to the following standards and pump them into the corresponding reagent storage tanks for later use: Zinc inhibitor (zinc sulfate): Prepare a 10-15% aqueous solution; Butyl xanthate: Prepare a 5-10% aqueous solution and use immediately. 25# Black Powder: Use the undiluted solution directly or prepare a 10% aqueous solution; Foaming agent (2# oil): Use the undiluted solution directly.

[0058] II. The operating procedure is as follows.

[0059] S3.1 System startup and feeding.

[0060] Start the stirring motor, aeration motor and foam scraping motor of each section of the flotation tank in sequence, and adjust the aeration amount to form a uniform and fine foam layer on the surface of the flotation tank.

[0061] Start the slurry transfer pump from the grinding section to the lead flotation roughing cell, and transport the qualified slurry from the grinding section to the lead roughing flotation cell at a constant rate of 20~21 tons / h.

[0062] Simultaneously start the metering pumps of each reagent to deliver zinc inhibitor, butyl xanthate, No. 25 black reagent and frother to the corresponding flotation cells according to the preset ratio. The total delivery rate of the four reagents is stably controlled within the range of 210~420mL / h.

[0063] In practice, a mixing tank can be set up at the front end of the flotation tank as needed to mix various flotation reagents, and then the flotation reagents can be continuously added to the slurry at a stable rate.

[0064] S3.2 Lead roughing operation.

[0065] Add the aforementioned reagents (25# black reagent, butyl xanthate, frother, and zinc inhibitor) to the No. 1 mixing tank of lead roughing, precisely controlling the pH of the roughing pulp within the range of 7.5~8.0, and the flotation time within 15~20 minutes. Adjust the froth scraping speed to promptly scrape off the lead-rich froth product from the surface. The lead roughing froth product is the lead concentrate, which is transported to the No. 1 mixing tank of lead finishing; the lead roughing underflow (tailings) is transported to the first lead scavenging operation.

[0066] S3.3 Lead sweeping operation (2 times in total).

[0067] Objective: To recover low-grade lead minerals lost in roughing tailings and improve the overall lead recovery rate.

[0068] First scavenging: The reagents used are the same as those used in the lead roughing operation, but adjustments can be made based on the flotation foam condition on site. Scavenging foam #1 is returned to the lead roughing mixing tank; the underflow from scavenging foam #1 is transported to the second lead scavenging operation, with a flotation time of 12-15 minutes.

[0069] Second scavenging: The same reagents are used as in the lead roughing operation. The foam from scavenging #2 is returned to the first lead scavenging operation. The underflow from scavenging #2 is the final lead tailings, which are transported to the subsequent zinc flotation section. The flotation time is 12-15 minutes.

[0070] S3.4 Lead Refining Operation (3 times in total).

[0071] Objective: To gradually remove zinc minerals and gangue impurities from the rough concentrate and improve the grade of lead concentrate.

[0072] First cleaning operation: Lead rough concentrate enters the No. 1 cleaning mixing tank, and reagents are added (the reagent dosage is the same as in the lead cleaning section. In this section, the dosage of zinc inhibitor may be reduced or omitted depending on the specific situation). After stirring for 3 minutes, it is sent to the No. 1 cleaning flotation tank, where flotation time is 12-15 minutes. The froth from the No. 1 cleaning tank enters the second cleaning process; the underflow from the No. 1 cleaning tank is returned to the lead roughing mixing tank. In practice, a separate reagent mixing tank / vessel can be designed according to actual needs, or the corresponding reagents can be added to the flotation tank and stirred first using a stirring mechanism before adding the slurry.

[0073] Second purification operation: The foam from Purification 1# enters Purification 2# mixing tank, where reagents are added (same as in the first purification operation). After mixing for 3 minutes, it is sent to Purification 2# flotation tank for 10-12 minutes. Purification 2# foam then enters the third purification operation; the underflow from Purification 2# is returned to Purification 1# mixing tank.

[0074] The third refining operation: The No. 2 froth from the refining process is fed into the No. 3 mixing tank, where reagents are added (same as in the first refining operation). After stirring for 3 minutes, it is sent to the No. 3 flotation tank for flotation, where the flotation time is 10-12 minutes. The No. 3 froth is the final qualified lead concentrate and is transported to the concentrate filtration and dewatering section; the No. 3 underflow is returned to the No. 2 mixing tank.

[0075] Step S4: Zinc flotation.

[0076] Lead tailings are fed to the zinc flotation cell at a rate of 20-21 tons / h, and flotation reagents, including copper sulfate, butyl xanthate and frother, are fed to the flotation cell at a rate of 210-420 mL / h. The pH is controlled at 7.5-8. The flotation process consists of 1 roughing, 2 scavenging, and 3 cleaning flotation steps to produce zinc concentrate and zinc tailings.

[0077] In this step, No. 2 oil is selected as the foaming agent.

[0078] The height of the zinc flotation tank is 1500mm, and the liquid level in the tank is kept stable during the flotation operation. The liquid level is controlled at 1300~1350mm for roughing operation, 1400~1460mm for scavenging operation, and 1100~1200mm for cleaning operation.

[0079] The specific steps are as follows: S4.1 Zinc roughing operation.

[0080] Objective: To maximize the activation and harvesting of sphalerite in lead tailings to obtain zinc concentrate.

[0081] After adding the flotation reagents to the zinc flotation cell, the dosage of each reagent, based on the mass of the slurry, is as follows: copper sulfate 250-400 g / ton, butyl xanthate 50-60 g / ton, and No. 2 oil 8-15 g / ton. The flotation time is controlled at 18-20 minutes. The surface foam rich in zinc minerals is promptly skimmed off. The zinc roughing froth product is zinc concentrate, which is transported to the No. 1 mixing tank for zinc refining. The zinc roughing underflow is transported to the first zinc scavenging operation.

[0082] S4.2 Zinc scavenging operation (2 times in total).

[0083] Objective: To recover insufficiently activated and collected sphalerite lost in the roughing tailings, thereby improving the overall zinc recovery rate. The reagents and their concentrations used in the zinc scavenging operation are the same as those in the zinc roughing section.

[0084] First scavenging: Scavenger No. 1 foam is returned to the zinc roughing mixing tank; Scavenger No. 1 underflow is transported to the second zinc scavenging operation, with a flotation time of 15~18 minutes.

[0085] Second scavenging: The foam from scavenging #2 is returned to the zinc from the first scavenging operation; the underflow from scavenging #2 is the final zinc tailings, which is transported to the desulfurization section in step S5.

[0086] S4.3 Zinc Refining Operation (3 times in total).

[0087] Objective: To gradually remove impurities from zinc roughing concentrate and improve the zinc concentrate grade to industrial requirements. The reagents and their concentrations used in zinc beneficiation are the same as those in the zinc roughing section.

[0088] First cleaning: Zinc rough concentrate enters the No. 1 cleaning tank and is floated for 12-15 minutes. The froth from the No. 1 cleaning tank enters the second cleaning tank; the underflow from the No. 1 cleaning tank is returned to the zinc roughing tank.

[0089] Second purification: Selected foam #1 enters the mixing tank of purification #2, with a flotation time of 10-12 minutes. Selected foam #2 enters the third purification; the underflow of selected foam #2 is returned to the first purification operation.

[0090] Third refining: The No. 2 froth from the refining process enters the No. 3 refining mixing tank, where flotation takes 10-12 minutes. The No. 3 refining froth is the final qualified zinc concentrate and is transported to the concentrate filtration and dewatering section; the No. 3 refining underflow is returned to the second refining operation.

[0091] Step S5: Tailings and wastewater treatment.

[0092] The fluorite tailings produced by flotation are sent to a thickener to be concentrated to a concentration of 50-60%, and then sent to a filter press workshop for filtration. The treated tailings are then transported to the mine for backfilling. The wastewater generated throughout the process is sent to the wastewater treatment plant 5.4 for treatment, and the treated water is recycled back to the mineral processing section.

[0093] One of the more preferred embodiments is described below. Figure 9 The wastewater treatment plant includes, in sequence, a first equalization tank, a pH equalization tank, a stirring tank, a catalytic oxidation tank, a neutralization reaction tank, a first reaction tank, an inclined tube sedimentation tank, a pH adjustment tank, a softening reaction tank, a first filter, and an activated carbon filter. The wastewater treatment method of the wastewater treatment plant includes the following steps: S5.1 The wastewater to be treated is received in the first equalization tank, sulfuric acid is added, and the pH is initially adjusted before being sent to the pH equalization tank. S5.2. Continue to add sulfuric acid to the pH adjustment tank to adjust the pH of the wastewater to acidic, and then send the wastewater through the stirring tank and the catalytic oxidation tank in sequence. S5.3 The wastewater is degraded for COD and organic pollutants in the mixing tank and catalytic oxidation tank, and then sent to the neutralization reaction tank. S5.4 Add sodium hydroxide and lime to the neutralization reaction tank to adjust the pH of the liquid in the tank to 9-10, so that the heavy metal ions form hydroxide precipitates, and then send the liquid phase to the first reaction tank. S5.5. Add calcium chloride, sodium sulfide, and sodium hypochlorite to the first reaction tank to remove fluoride, mercury, and cadmium from the wastewater and oxidize CN. - Alternatively, after decolorization, the treated material is transported to an inclined tube sedimentation tank; S5.6 Add polyacrylamide to the inclined tube sedimentation tank to achieve mud-water separation, and the supernatant enters the pH adjustment tank. S5.7 Add sulfuric acid to the pH adjustment tank to adjust the pH of the effluent in the tank to 6.5~7.5, and send the liquid phase to the softening reaction tank. S5.8. Add sodium carbonate to the softening reaction tank to react with Ca in the water. 2+ Mg 2+ The reaction is carried out, and the resulting material is then sent to the first filter and the activated carbon filter in sequence. S5.9 Add polyferric sulfate and polyacrylamide to the first filter. After the liquid phase is treated by the first filter and the activated carbon filter in sequence, residual suspended solids, colloids and trace organic matter in the water are removed to obtain purified water.

[0094] The yield, grade, and recovery rate of lead concentrate, zinc concentrate, and tailings produced from multiple batches of raw ore were examined. The statistical results are shown in Table 1.

[0095] Table 1

[0096] As shown in Table 1, the lead concentrate recovery rate reaches 50% or higher, even as high as 60%. The recovered lead concentrate contains not only conventional lead sulfide but also some lead oxide, with the recovered lead oxide accounting for 20-30% of the lead concentrate, significantly improving the lead recovery rate. Compared with traditional processes, the lead recovery rate is increased by approximately 50%.

[0097] The recovery rate of zinc concentrate reaches 40% or more, and even as high as 50%.

[0098] Example 2 This embodiment provides a lead-zinc ore beneficiation system for polymetallic ores, which is also applicable to the process method of Embodiment 1. (Refer to...) Figure 2 It includes a crushing unit 1, a closed-circuit grinding and classification unit 2, a lead flotation unit 3, a zinc flotation unit 4, and a tailings wastewater treatment unit 5, which are connected by slurry conveying pipelines and conveying pumps.

[0099] The tailings wastewater treatment unit 5 has a clean water outlet 5.1 that is connected to the water supply interface I2.1 of the closed-loop grinding and classification unit 2, the water supply interface II3.1 of the lead flotation unit 3, and the water supply interface III4.1 of the zinc flotation unit 4 via a recycled water pipeline 6, forming a closed-loop circulating water supply structure.

[0100] The raw ore is fed into crushing unit 1 (crushing station) for processing. The crushed ore is then transported to closed-circuit grinding and classification unit 2 for grinding and classification. After grinding to a suitable particle size, it is sent to lead flotation unit 3 for further processing. The resulting lead concentrate is discharged from lead concentrate discharge pipe 3.2; the resulting lead tailings are discharged from lead tailings outlet 3.9 and sent to zinc flotation unit 4 for further processing. The resulting zinc concentrate from zinc flotation unit 4 is discharged from zinc concentrate discharge pipe 4.2; the resulting zinc tailings are sent from zinc tailings outlet 4.9 to tailings wastewater treatment unit 5 for solid-liquid separation. The solid phase is sent to tailings collection unit 7 for centralized treatment, and the liquid phase, after centralized purification, supplies water to the upstream units.

[0101] In one preferred embodiment, the crushing unit 1 is a crushing station, the discharge particle size of the crushing station is less than 20mm, and the discharge end of the crushing station is connected to the feed end of the closed-circuit grinding and classification unit 2 through a material conveying mechanism.

[0102] In one preferred embodiment, the closed-circuit grinding and classification unit 2 includes a ball mill 2.2 and a hydrocyclone 2.3. (See reference) Figure 3 The discharge port of the ball mill 2.2 is connected to the feed port of the hydrocyclone 2.3. The sand outlet 2.3.1 of the hydrocyclone 2.3 flows back to the feed port of the ball mill 2.2 through the circulation pipeline 2.4, forming a closed-circuit grinding and classification structure. After grinding to a suitable particle size (the mass fraction of -0.074mm particles in the classification overflow product is 75~80%, and the slurry mass concentration is 30~33%), it is transported from the discharge port 2.3.2 of the hydrocyclone to the lead flotation unit 3.

[0103] In one preferred embodiment, the lead flotation unit 3 includes a lead roughing flotation cell 3.3, a first-stage lead scavenging flotation cell 3.4, a second-stage lead scavenging flotation cell 3.5, a first-stage lead cleaning flotation cell 3.6, a second-stage lead cleaning flotation cell 3.7, and a third-stage lead cleaning flotation cell 3.8, connected sequentially. (Reference) Figure 4 Each flotation cell is equipped with a stirring device 8 and a bubble scraping mechanism 9. Each flotation cell is equipped with a liquid level sensor 10 and a pH meter 11. The concentrate outlet of the lead flotation unit 3 is connected to the lead concentrate washing and filtration section 12 via the lead concentrate discharge pipe 3.2, and the lead tailings outlet 3.9 is connected to the feed end of the zinc flotation unit 4.

[0104] More preferably, the lead flotation unit 3 is also equipped with a lead flotation reagent supply assembly. This assembly includes a 25# black reagent storage tank 13, a butyl xanthate storage tank 14, a frother storage tank 15, and a zinc inhibitor storage tank 16, each storing 25# black reagent, butyl xanthate, frother, and zinc inhibitor, respectively. Each reagent storage tank is connected to the dosing port of the corresponding flotation cell via a reagent metering pump. The lead roughing flotation cell 3.3, the two-stage lead scavenging flotation cell, and the three-stage lead cleaning flotation cell are all connected to the 25# black reagent storage tank 13, the butyl xanthate storage tank 14, and the frother storage tank 15. (Reference) Figure 5 , Figure 5 The diagram illustrates the structure of flotation cell 3.6 for Class I lead refining.

[0105] The operating procedure for lead flotation unit 3 is as follows: (1) First lead coarse selection.

[0106] The slurry is fed from feed inlet II 3.10 to lead roughing flotation cell 3.3. The aforementioned reagents (25# black reagent, butyl xanthate, frother, and zinc inhibitor) are added to lead roughing flotation cell 3.3 in the following amounts based on the mass of the slurry: 10-20 g / ton of 25# black reagent, 50-100 g / ton of butyl xanthate, 5-10 g / ton of 2# oil, and 400-600 g / ton of zinc sulfate. The pH value of the roughing slurry is precisely controlled within the range of 7.5-8.0 (real-time slurry pH value is fed back via pH meter 11), and the flotation time is controlled within 15-20 minutes.

[0107] Adjust the scraping speed of the scraping mechanism 9 to promptly scrape off the foam product rich in lead minerals from the surface. The lead roughing foam product is lead concentrate, which is transported to the first-stage lead cleaning flotation cell 3.6; the lead roughing underflow (tailings) is transported to the first-stage lead scavenging flotation cell 3.4 for the first lead scavenging operation.

[0108] (2) Two lead sweeps.

[0109] First scavenging: The reagents and dosages used are the same as those used in the lead roughing operation, but adjustments can be made based on the flotation froth conditions on site. The froth from scavenging #1 is returned to the lead roughing flotation cell 3.3; the underflow from scavenging #1 is transported to the second-stage lead scavenging flotation cell 3.5 for the second lead scavenging operation, with a flotation time of 12-15 minutes.

[0110] Second scavenging: The same reagents are used as in the lead roughing operation. The foam from scavenging #2 is returned to the first lead scavenging operation. The underflow from scavenging #2 is the final lead tailings, which are transported to the subsequent zinc flotation section. The flotation time is 12-15 minutes.

[0111] (3) Three-stage lead selection.

[0112] First cleaning operation: Lead rough concentrate enters the Class I lead cleaning flotation cell 3.6, and reagents (25# black reagent, butyl xanthate, frother, and zinc inhibitor, flotation reagent concentrations are the same as in the lead scavenging section) are added. After stirring for 3 minutes, the flotation time is 12-15 minutes. The No. 1 cleaned froth enters the Class II lead cleaning flotation cell 3.7 for the second cleaning operation; the No. 1 cleaned underflow is returned to the lead roughing flotation cell 3.3.

[0113] Second purification operation: Selected froth #1 enters the Class II lead purification flotation cell 3.7, adds reagents (flotation reagents and their concentrations are the same as in the lead scavenging section), stirs for 3 minutes, and then floats for 10-12 minutes. Selected froth #2 enters the Class III lead purification flotation cell 3.8 for the third purification operation; the underflow of selected froth #2 is returned to the Class I lead purification flotation cell 3.6.

[0114] The third refining operation: The No. 2 froth is fed into the Class III lead refining flotation cell 3.8, where reagents (flotation reagents and their concentrations are the same as in the lead scavenging section) are added. After stirring for 3 minutes, the flotation time is 10-12 minutes. The No. 3 froth, being the final qualified lead concentrate, is transported to the lead concentrate filtration and dewatering section 14 through the lead concentrate discharge pipe 3.2; the underflow from the No. 3 froth is returned to the Class II lead refining flotation cell 3.7.

[0115] In one preferred embodiment, the zinc flotation unit 4 includes interconnected zinc roughing flotation cell 4.3, stage I zinc scavenging flotation cell 4.4, stage II zinc scavenging flotation cell 4.5, stage I zinc cleaning flotation cell 4.6, stage II zinc cleaning flotation cell 4.7, and stage III zinc cleaning flotation cell 4.8. The height of each flotation cell is 1500 mm, and the liquid level in the cell is kept stable during the flotation operation. The liquid level is controlled at 1300~1350 mm for roughing operation, 1400~1460 mm for scavenging operation, and 1100~1200 mm for cleaning operation.

[0116] refer to Figure 6 Each flotation cell is equipped with a stirring device 8 and a bubble scraping mechanism 9. Each flotation cell is also equipped with a liquid level sensor 10 and a pH meter 11. The zinc flotation unit 4 is connected to the zinc concentrate washing and filtration section 18 through the zinc concentrate discharge pipe 4.2, and the zinc tailings outlet 4.9 is connected to the feed end of the desulfurization unit.

[0117] More preferably, the zinc flotation unit 4 is also equipped with a zinc flotation reagent supply assembly, which includes a copper sulfate storage tank 17, a butyl xanthate storage tank 14, and a frother storage tank 15, respectively storing copper sulfate, butyl xanthate, and frother. Each reagent storage tank is connected to the dosing port of the corresponding flotation cell via a reagent metering pump. Figure 7 , Figure 7The diagram illustrates the structure of the Stage I zinc scavenging flotation cell 4.4, which is connected to a copper sulfate storage tank 17, a butyl xanthate storage tank 14, and a frother storage tank 15.

[0118] The operating procedure for zinc flotation unit 4 is as follows: (1) First zinc roughing.

[0119] Lead tailings are fed into the zinc roughing flotation cell 4.3 at a rate of 20-21 tons / hour from feed inlet III 4.10. Flotation reagents are added to the zinc flotation cell, with the following amounts based on the mass of the slurry: copper sulfate 250-400 g / ton, butyl xanthate 50-60 g / ton, and No. 2 oil 8-15 g / ton. The flotation time is controlled at 18-20 minutes. The surface foam rich in zinc minerals is promptly skimmed off. The zinc roughing froth product is zinc concentrate, which is transported to the primary zinc cleaning flotation cell 4.6. The zinc roughing underflow is transported through pipeline IV 4.12 to the primary zinc scavenging flotation cell 4.4 for the first zinc scavenging operation.

[0120] (2) Two zinc sweeps.

[0121] First scavenging: Scavenging No. 1 foam is returned to zinc roughing flotation cell 4.3 via pipeline III 4.11; Scavenging No. 1 underflow is transported to the second-stage zinc scavenging flotation cell 4.5 via pipeline V 4.13 for the second zinc scavenging operation, with a flotation time of 15~18 minutes.

[0122] Second scavenging: The foam from scavenging #2 is returned to the first zinc scavenging flotation cell 4.4 for the first zinc scavenging operation; the underflow from scavenging #2 is the final zinc tailings, which is transported to the tailings wastewater treatment unit 5 through the zinc tailings outlet 4.9.

[0123] (3) Three-stage zinc selection.

[0124] First cleaning: The zinc rough concentrate enters the first-stage zinc cleaning flotation cell 4.6, with a flotation time of 12-15 minutes. The froth from the first cleaning stage enters the second-stage zinc cleaning flotation cell 4.7 for a second cleaning; the underflow from the first cleaning stage is returned to the zinc roughing flotation cell 4.3.

[0125] Second purification: Selected foam #1 enters the Stage II zinc purification flotation cell (4.7-4.5) for 10-12 minutes. Selected foam #2 enters the Stage III zinc purification flotation cell (4.8) for the third purification; the underflow from selected foam #2 is returned to the Stage I zinc purification flotation cell (4.6) to repeat the first purification operation.

[0126] Third refining: The No. 2 froth is fed into the Class III zinc refining flotation cell 4.8, with a flotation time of 10-12 minutes. The No. 3 froth is the final qualified zinc concentrate, which is transported to the zinc concentrate filtration and dewatering section through the zinc concentrate discharge pipe 4.2; the underflow of the No. 3 froth is returned to the Class II zinc refining flotation cell 4.7 for a second refining operation.

[0127] In one preferred embodiment, the tailings wastewater treatment unit 5 includes a solid-liquid separation device 5.3 and a wastewater treatment station 5.4, as shown in the reference. Figure 8 Tailings wastewater treatment unit 5 collects zinc tailings and other materials, which are then separated by solid-liquid separation device 5.3. The solid phase is discharged through solid phase discharge port 5.2 and temporarily stored in tailings collection unit 7, which can be sent to the mine for backfilling or used as building materials. The liquid phase (wastewater) is sent to sewage treatment station 5.4 for centralized treatment. The purified water is discharged through clean water outlet 5.1 and connected to the water supply interface of each of the aforementioned units through recycled water pipeline 6, forming a closed-loop circulating water supply structure.

[0128] In one preferred embodiment, the wastewater treatment plant includes a first equalization tank, a pH equalization tank, a stirring tank, a catalytic oxidation tank, a neutralization reaction tank, a first reaction tank, an inclined tube sedimentation tank, a pH adjustment tank, a softening reaction tank, a first filter, and an activated carbon filter connected in sequence.

[0129] The first equalization tank is equipped with a filter press water inlet pipe, a thickener water inlet pipe, and a first sulfuric acid inlet pipe; the pH equalization tank is equipped with a second sulfuric acid inlet pipe; the stirring tank is equipped with a ferrous sulfate inlet pipe; the catalytic oxidation tank is equipped with a hydrogen peroxide inlet pipe; the neutralization reaction tank is equipped with a sodium hydroxide inlet pipe and a lime inlet pipe; the first reaction tank is equipped with a calcium chloride inlet pipe, a sodium sulfide inlet pipe, and a sodium hypochlorite inlet pipe; the inclined tube sedimentation tank is equipped with a first polyacrylamide inlet pipe; the pH adjustment tank is equipped with a third sulfuric acid inlet pipe; the softening reaction tank is equipped with a sodium carbonate inlet pipe; and the first filter is equipped with a polyferric sulfate inlet pipe and a second polyacrylamide inlet pipe.

[0130] One preferred embodiment is that aeration devices are installed in the first equalization tank, pH equalization tank, stirring tank, catalytic oxidation tank, neutralization reaction tank, and first reaction tank. The aeration devices simultaneously achieve the triple functions of oxygenation and stirring, rapid reagent mixing, and prevention of suspended solids sedimentation. Especially in the Fenton oxidation section (stirred tank + catalytic oxidation tank), aeration can promote Fe... 2+ / Fe3 + The recycling process increases the yield of ·OH free radicals, thereby reducing the amount of hydrogen peroxide added by about 15% to 25%. In the neutralization and reaction tank sections, aeration can accelerate the homogenization reaction between sodium hydroxide / lime and wastewater, avoid precipitation and encapsulation caused by local over-alkaliness, and improve the efficiency of heavy metal removal.

[0131] One preferred implementation involves sequentially configuring a first clear water tank, a first sedimentation tank, a second clear water tank, and a reclaimed water tank after the activated carbon filter. This "two-stage clear water tank + intermediate sedimentation tank" buffer configuration after activated carbon filtration serves two purposes: firstly, the first clear water tank collects trace amounts of activated carbon powder that have naturally settled and detached from the effluent; secondly, the first sedimentation tank traps any biofilm detachment or fine particles that may form. Finally, the second clear water tank performs final water quality homogenization, ensuring long-term stable water quality (SS < 5 mg / L) entering the reclaimed water tank. This design effectively prevents secondary contamination of the reclaimed water pipeline by activated carbon penetration particles and improves the safety redundancy of the reclaimed water system.

[0132] In one preferred embodiment, a transfer pump is provided between the first conditioning tank, pH conditioning tank, stirring tank, catalytic oxidation tank, neutralization reaction tank, first reaction tank, inclined tube sedimentation tank, pH adjustment tank, softening reaction tank, first filter, activated carbon filter, first clear water tank, first sedimentation tank, second clear water tank and recycled water tank.

[0133] In one preferred embodiment, pH meters are installed on the first conditioning tank, pH conditioning tank, neutralization reaction tank, first reaction tank and pH adjustment tank to monitor the pH value of the fluid in the tank.

[0134] In this embodiment, a closed-loop control network of "feedforward + feedback" is constructed by online monitoring at five key pH control nodes. Specifically, this manifests as follows: ① The first equalization tank predicts fluctuations in the influent's acidity and alkalinity; ② The pH equalization tank ensures the optimal acidity window (pH value approximately 4) for the Fenton stage; ③ The neutralization reaction tank ensures alkaline conditions (pH value 9-10) for complete precipitation of heavy metals; ④ The first reaction tank monitors pH shifts for specific precipitation reactions (such as sulfide precipitation requiring weak alkalinity); ⑤ The pH adjustment tank precisely restores the effluent to neutral. This design can significantly reduce the risk of corrosion or scaling in reclaimed water pipelines due to excessive pH levels.

[0135] In this embodiment, a preferred wastewater treatment plant structure is proposed. In the first equalization tank, filter press water and thickener overflow are received, homogenized, and the pH is initially adjusted to prevent subsequent shocks. In the pH equalization tank, the wastewater pH is adjusted to acidic (approximately pH 4) to create optimal conditions for Fenton oxidation. In the stirring tank and catalytic oxidation tank, a Fenton system is formed, generating •OH free radicals that powerfully degrade COD and organic pollutants. In the neutralization reaction tank, the pH is adjusted to alkaline (approximately pH 9-10) to cause heavy metal ions to precipitate as hydroxides. In the first reaction tank, calcium chloride (for fluoride removal), sodium sulfide (for mercury / cadmium removal), and sodium hypochlorite (for CN oxidation) are added. -(Or decolorization) to target and remove specific pollutants; flocculation and sedimentation are aided in the inclined tube sedimentation tank to achieve mud-water separation, with the supernatant entering subsequent treatment; the pH of the effluent is adjusted to neutral (6.5~7.5) in the pH adjustment tank to meet the requirements of subsequent softening and filtration; calcium and magnesium hardness are removed in the softening reaction tank to prevent membrane / filter scaling; polyferric sulfate (PFS) + PAM (coagulant aid) are used in the first filter and activated carbon filter to remove residual suspended solids, colloids, and trace organic matter, ensuring clear effluent. Wastewater from mineral processing is treated and reused, achieving "zero discharge" and reducing production water consumption.

[0136] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for beneficiating lead-zinc ore from polymetallic deposits, characterized in that, Includes the following steps: S1. Crushing: The raw ore is sent to the crushing station for processing to make the particle size of the raw ore <20mm; S2. Grinding: Control the particle size distribution of the grinding product to meet the requirement that the mass fraction of the -0.074mm particle size is 75~80%, and adjust the mass concentration of the grinding discharge slurry to 30~33%; S3, Lead Flotation: The slurry after grinding is fed to the lead flotation cell at a rate of 20-21 tons / h, and the flotation reagents are fed to the flotation cell at a rate of 210-420 mL / h. The flotation reagents include No. 25 black reagent, butyl xanthate, frother and zinc inhibitor. The pH is controlled at 7.5-8. The flotation process is 1 roughing, 2 scavenging and 3 cleaning to produce lead concentrate and lead tailings. S4. Zinc Flotation: Lead tailings are fed to the zinc flotation cell at a rate of 20-21 tons / h, and flotation reagents are fed to the flotation cell at a rate of 210-420 mL / h. The flotation reagents include copper sulfate, butyl xanthate and frother. The pH is controlled at 7.5-8. The flotation process is 1 roughing, 2 scavenging and 3 cleaning to produce zinc concentrate and zinc tailings. S5. Tailings and wastewater treatment: The fluorite tailings produced by flotation are separated into solid and liquid phases. The liquid phase is sent to the wastewater treatment plant for treatment, and the treated water is recycled to the mineral processing section. The solid phase is sent to the mine for backfilling or used as building material.

2. The method for beneficiating lead-zinc ore in polymetallic ores according to claim 1, characterized in that: In steps S3 and S4, the foaming agent is No. 2 oil; in step S3, the zinc inhibitor is zinc sulfate.

3. The method for beneficiating lead-zinc ore in polymetallic ores according to claim 2, characterized in that: In step S3, the flotation reagents used in the lead flotation process include No. 25 black reagent, butyl xanthate, No. 2 oil, and zinc sulfate. In the lead roughing, lead scavenging and lead cleaning processes, the dosage of each reagent, based on the slurry quality, is as follows: 25# black reagent 10~20g / ton, butyl xanthate 50~100g / ton, 2# oil 5~10g / ton, and zinc sulfate 400~600g / ton.

4. The method for beneficiating lead-zinc ore in polymetallic ores according to claim 2, characterized in that: In step S4, the reagents used in the zinc flotation process include copper sulfate, butyl xanthate, and No. 2 oil; In the zinc roughing, zinc scavenging and zinc cleaning processes, the dosage of each reagent, based on the slurry quality, is as follows: copper sulfate 250~400g / ton, butyl xanthate 50~60g / ton, and No. 2 oil 8~15g / ton.

5. The method for beneficiating lead-zinc ore in polymetallic ores according to claim 2, characterized in that: In steps S3 and S4, the height of the lead flotation cell, zinc flotation cell, and fluorite flotation cell is 1500mm, and the liquid level in the cell is kept stable during the flotation operation. In lead and zinc flotation, the liquid level is controlled at 1300~1350mm for roughing, 1400~1460mm for scavenging, and 1100~1200mm for cleaning.

6. The method for beneficiating lead-zinc ore in polymetallic ores according to claim 1, characterized in that: In step S5, the wastewater treatment plant includes a first equalization tank, a pH equalization tank, a stirring tank, a catalytic oxidation tank, a neutralization reaction tank, a first reaction tank, an inclined tube sedimentation tank, a pH adjustment tank, a softening reaction tank, a first filter, and an activated carbon filter connected in sequence. The wastewater treatment method of the wastewater treatment plant includes the following steps: S5.1 The wastewater to be treated is received in the first equalization tank, sulfuric acid is added, and the pH is initially adjusted before being sent to the pH equalization tank. S5.

2. Continue to add sulfuric acid to the pH adjustment tank to adjust the pH of the wastewater to acidic, and then send the wastewater through the stirring tank and the catalytic oxidation tank in sequence. S5.3 The wastewater is degraded for COD and organic pollutants in the mixing tank and catalytic oxidation tank, and then sent to the neutralization reaction tank. S5.4 Add sodium hydroxide and lime to the neutralization reaction tank to adjust the pH value of the liquid in the tank to 9-10, so that the heavy metal ions form hydroxide precipitates, and then send the liquid phase to the first reaction tank. S5.

5. Add calcium chloride, sodium sulfide, and sodium hypochlorite to the first reaction tank to remove fluoride, mercury, and cadmium from the wastewater and oxidize CN. - Alternatively, after decolorization, the treated material is transported to an inclined tube sedimentation tank; S5.6 Add polyacrylamide to the inclined tube sedimentation tank to achieve mud-water separation, and the supernatant enters the pH adjustment tank. S5.7 Add sulfuric acid to the pH adjustment tank to adjust the pH of the effluent in the tank to 6.5~7.5, and send the liquid phase to the softening reaction tank. S5.8 Add sodium carbonate to the softening reaction tank to react with the calcium in the water. 2+ Mg 2+ The reaction is carried out, and the resulting material is then sent to the first filter and the activated carbon filter in sequence. S5.9 Add polyferric sulfate and polyacrylamide to the first filter. After the liquid phase is treated by the first filter and the activated carbon filter in sequence, residual suspended solids, colloids and trace organic matter in the water are removed to obtain purified water.

7. A lead-zinc ore beneficiation system for polymetallic mines, characterized in that: It includes a crushing unit, a closed-circuit grinding and classification unit, a lead flotation unit, a zinc flotation unit, and a tailings wastewater treatment unit, which are connected in series via slurry conveying pipelines and conveying pumps. The purified water output end of the tailings wastewater treatment unit is connected to the water supply interface of each of the aforementioned units through a recycled water pipeline, forming a closed-loop circulating water supply structure. The lead flotation unit includes interconnected lead roughing flotation cells, two-stage lead scavenging flotation cells, and three-stage lead cleaning flotation cells; each flotation cell is equipped with a stirring device and a bubble scraping mechanism, and a liquid level sensor and a pH meter are installed on the flotation cells; the concentrate outlet of the lead flotation unit is connected to the lead concentrate washing and filtration section, and the lead tailings outlet is connected to the feed end of the zinc flotation unit. The zinc flotation unit includes interconnected zinc roughing flotation cells, two-stage zinc scavenging flotation cells, and three-stage zinc cleaning flotation cells; each flotation cell is equipped with a stirring device and a bubble scraping mechanism, and a liquid level sensor and a pH meter are installed on the flotation cells; the concentrate outlet of the zinc flotation unit is connected to the zinc concentrate washing and filtration section, and the lead tailings outlet is connected to the feed end of the desulfurization unit.

8. A lead-zinc ore beneficiation system in a polymetallic mine according to claim 7, characterized in that: The crushing unit is a crushing station. The discharge particle size control accuracy of the crushing station meets the requirement that the maximum discharge particle size does not exceed 20mm. The discharge end of the crushing station is connected to the feed end of the closed-circuit grinding and classification unit through a material conveying mechanism.

9. A lead-zinc ore beneficiation system in a polymetallic mine according to claim 7, characterized in that: The closed-circuit grinding and classification unit includes a ball mill and a hydrocyclone. The discharge port of the ball mill is connected to the feed port of the hydrocyclone, and the sand outlet of the hydrocyclone flows back to the feed port of the ball mill, forming a closed-circuit grinding and classification structure. The overflow outlet of the hydrocyclone is connected to the feed end of the lead flotation unit.

10. A lead-zinc ore beneficiation system in a polymetallic mine according to claim 7, characterized in that: The lead flotation unit is also equipped with a lead flotation reagent supply assembly, which includes a No. 25 black reagent storage tank, a butyl xanthate storage tank, a frother storage tank, and a zinc inhibitor storage tank. Each reagent storage tank is connected to the dosing port of the corresponding flotation cell through a reagent metering pump.

11. A lead-zinc ore beneficiation system in a polymetallic mine according to claim 7, characterized in that: The zinc flotation unit is also equipped with a zinc flotation reagent supply assembly, which includes a copper sulfate storage tank, a butyl xanthate storage tank, and a frother storage tank. Each reagent storage tank is connected to the dosing port of the corresponding flotation cell through a reagent metering pump.

12. A lead-zinc ore beneficiation system in a polymetallic mine according to claim 7, characterized in that: The tailings wastewater treatment unit includes a wastewater treatment plant, which comprises, in sequence, a first equalization tank, a pH equalization tank, a stirring tank, a catalytic oxidation tank, a neutralization reaction tank, a first reaction tank, an inclined tube sedimentation tank, a pH adjustment tank, a softening reaction tank, a first filter, and an activated carbon filter. The first equalization tank is equipped with a filter press water inlet pipe, a thickener water inlet pipe, and a first sulfuric acid inlet pipe; the pH equalization tank is equipped with a second sulfuric acid inlet pipe; the stirring tank is equipped with a ferrous sulfate inlet pipe; the catalytic oxidation tank is equipped with a hydrogen peroxide inlet pipe; the neutralization reaction tank is equipped with a sodium hydroxide inlet pipe and a lime inlet pipe; the first reaction tank is equipped with a calcium chloride inlet pipe, a sodium sulfide inlet pipe, and a sodium hypochlorite inlet pipe; the inclined tube sedimentation tank is equipped with a first polyacrylamide inlet pipe; the pH adjustment tank is equipped with a third sulfuric acid inlet pipe; the softening reaction tank is equipped with a sodium carbonate inlet pipe; and the first filter is equipped with a polyferric sulfate inlet pipe and a second polyacrylamide inlet pipe.

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