Method and device for grading and filtering mud in high-impurity copper anode electrolytic refining circulating electrolyte

Abstract

The application belongs to the technical field of hydrometallurgy, and specifically discloses a high-impurity copper anode electrolytic refining circulating electrolyte grading filtration and desliming method and device. The method is to extract electrolyte from an electrolytic cell loaded with high-impurity copper anodes and pass it into a rough filtration unit for rough filtration, then pass it into a fine filtration unit for fine filtration, then continuously pass it through a functional filter layer with organic functional groups and inorganic trapping components loaded on the surface for specific trapping and purification, and the purified electrolyte is returned to the electrolytic cell; a controller obtains electrolyte parameters before and after filtration in real time, and controls parameters of the electrolyte according to the obtained parameters; when the real-time parameters of the electrolyte exceed the threshold value, a backwashing unit is started to backwash the rough filtration unit, the fine filtration unit and / or the functional filter layer, and the backwashing liquid is collected into an anode slime collection tank. The device comprises an electrolytic cell, a liquid extraction port, a rough filtration unit, a fine filtration unit, a functional filter layer, an online monitoring unit, a controller and a backwashing unit.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology, specifically relating to a method and apparatus for graded filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining. Background Technology

[0002] Copper electrolytic refining is the core process in the pyrometallurgical copper production of high-purity cathode copper. With the continuous depletion of high-grade primary copper concentrate resources, the smelting capacity of recycled copper and complex polymetallic symbiotic ores has been increasing year by year. The content of harmful impurities such as arsenic, lead, antimony, bismuth, tin, and nickel in the copper anodes used in the electrolytic process has increased significantly. Among them, As, Pb, Sb, and Bi have the most prominent negative impact on the electrolytic system. They not only disrupt the normal dissolution behavior of the anode and change the ion composition distribution of the electrolyte, but also deteriorate the phase structure of the anode mud, ultimately leading to the deterioration of the cathode copper deposition quality.

[0003] During the electrolysis of high-impurity copper anodes, impurities exist in two forms: First, lead ions combine with sulfate ions to form the insoluble solid phase PbSO4, while noble metal elements and multi-metal oxides settle directly as large-particle primary anode mud. Second, dissolved arsenic, antimony, and bismuth ions in the electrolyte undergo oxidation and hydrolysis to form arsenate, antimonyate, and bismuth arsenate composite precipitates, resulting in a large number of floating anode mud colloidal particles with particle sizes ranging from submicron to several micrometers. These fine particles can continuously migrate to the cathode plate surface through the electrolyte circulation pipeline and embed themselves inside the copper deposition layer, directly causing quality defects such as cathode surface roughness, large-area nodule formation, solid particle inclusions, and excessive arsenic, antimony, and bismuth impurities, significantly reducing the grade of cathode copper and the added value of the product.

[0004] Existing electrolyte sludge and impurity removal technologies in the industry mainly fall into several categories, including gravity sedimentation, anode bag retention, chemical flocculation sedimentation, large bypass chemical purification, ion exchange, and single-stage membrane filtration. Each of these technologies has the following shortcomings: 1. Natural gravity settling and bottom settling path: It can only remove large particles of anode mud larger than tens of micrometers, and has no ability to retain arsenic, antimony and bismuth colloids floating in the submicron range. This causes fine particles to continue to circulate in the electrolyte, thus failing to solve the cathode inclusion problem at its root.

[0005] 2. Anode bags wrapping the anode path: can only block large pieces of anode mud that fall off in situ on the anode surface, but cannot intercept colloidal floating mud that has diffused into the main circulating electrolyte. In addition, the anode bags are prone to clogging, increasing the cell voltage, and the long-term operation and maintenance costs are high.

[0006] 3. Chemical flocculation and sedimentation route: Flocculants and flocculation aids need to be added to the electrolyte. These agents will disrupt the ratio of special electrolyte additives such as gelatin, thiourea, and chloride ions in the electrolyte system, thereby disrupting the normal electrodeposition of copper ions and exacerbating abnormal cathode crystallization. At the same time, the flocculent slag components are dispersed, resulting in low enrichment of antimony, bismuth, and precious metals, making resource recovery difficult.

[0007] 4. Electrolyte bypass chemical precipitation, solvent extraction, and electrowinning purification route: The target of treatment is dissolved arsenic, antimony, and bismuth ions in the electrolyte, which cannot separate solid suspended anode mud; moreover, the purification system is an intermittent large-scale equipment, which occupies a large area and has high investment costs. It will also change the concentration of copper and free sulfuric acid in the electrolyte, disturb the stable operation of the electrolytic cell, and cannot achieve continuous online purification of the electrolyte.

[0008] 5. Ion exchange resin purification route: only for free Sb in the electrolyte. 3+ Bi 3+ Dissolved ions have an adsorption effect, but they have no effect on removing colloidal particles formed by hydrolysis and precipitation, or floating anode mud, and cannot solve the core problem of particles entrained in the cathode.

[0009] 6. Single-stage ceramic membrane and fiber conventional filtration route: Relying solely on physical pore size sieving mechanisms to retain solid particles has significant technical shortcomings: ① Single-stage filtration means large anode mud particles directly impact the filter media, causing rapid pore blockage, a sharp increase in filtration differential pressure in a short time, severe filtration flux attenuation, and a short continuous operating cycle; ② Arsenic, antimony, and bismuth colloidal particles smaller than the filter media pore size can directly penetrate the filter layer, resulting in a low fine particle removal rate; ③ Lack of specific adsorption sites prevents the capture of precursor particles in the electrolyte, achieving only limited coarse particle interception; simultaneously, conventional filtration equipment only has a single differential pressure timed backflushing control logic, which cannot adapt to fluctuating high-impurity anode impurities and lacks multi-parameter linkage intelligent control capabilities.

[0010] Therefore, there is an urgent need for a graded filtration and sludge removal method and device suitable for circulating electrolytes in high-impurity copper anode electrolytic refining. This method should efficiently remove large-particle anode sludge, fine floating anode sludge, and precipitate precursors containing arsenic, antimony, and bismuth from the circulating electrolyte without significantly interfering with the normal electrolyte composition and cathode additive system, thereby reducing the risk of cathode quality degradation. Summary of the Invention

[0011] To address the problems of high anode mud particle content, difficulty in removing fine As-Sb-Bi floating anode mud, particle migration to the cathode leading to inclusions and nodules, and insufficient removal effect of ordinary filtration on colloidal or precipitated precursors in existing high-impurity copper anode electrolytic refining circulating electrolytes, this invention provides a graded filtration method for removing mud from high-impurity copper anode electrolytic refining circulating electrolytes, and also provides a graded filtration device for removing mud from high-impurity copper anode electrolytic refining circulating electrolytes.

[0012] The method for staged filtration and sludge removal of circulating electrolyte in the high-impurity copper anode electrolytic refining process of the present invention is implemented as follows: it includes electrolyte extraction, primary coarse filtration, secondary fine filtration, tertiary collection, online control, and backwashing steps, the specific contents of each step are as follows: A. Electrolyte extraction: Extract electrolyte from at least one of the following locations in the electrolytic cell containing high-impure copper anodes: anode area, bottom area, anode bag outlet area, and main circulation pipeline; B. Primary coarse filtration: The extracted electrolyte is passed through a coarse filtration unit with a filtration accuracy of 20-100μm for coarse filtration. C. Secondary fine filtration: The electrolyte after coarse filtration is passed into a fine filtration unit with a filtration accuracy of 0.1 to 20 μm for fine filtration; D. Three-stage collection: The electrolyte after fine filtration continuously passes through the functionalized filter material layer for specific collection and purification. After purification, the electrolyte is returned to the electrolytic cell for recycling. The functionalized filter material layer can be any one of the following: replaceable filter element, coated filter membrane, functionalized fiber layer, ceramic membrane loaded with inorganic particles, polymer membrane loaded with functional groups, or composite porous material. The surface of the functionalized filter material layer is loaded with organic functional groups and / or inorganic collection components. E. Online control: The controller can acquire parameters of the electrolyte before and after filtration by the coarse filtration unit, fine filtration unit and / or functionalized filter media layer in real time, or acquire cathode quality detection data, and adjust the electrolyte filtration flow rate, bypass filtration ratio, filter media backwashing cycle and / or standby filter unit switching status in linkage according to the acquired parameters or detection data. F. Backwashing: When the detected electrolyte turbidity, fine particle ratio, filtration pressure difference and / or redox potential exceed the preset threshold, the backwashing unit is activated to backwash the coarse filtration unit, fine filtration unit and / or functionalized filter media layer, and the backwash liquid is collected in the anode mud collection tank.

[0013] Further, in step A, the As content in the high-impregnation copper anode is 0.01–2 wt%, the Pb content is 0.01–2 wt%, the Sb content is 0.005–1 wt%, and the Bi content is 0.001–1 wt%; the electrolyte is a sulfuric acid-copper sulfate system, wherein the free sulfuric acid concentration is 100–250 g / L, the copper ion concentration is 30–60 g / L, and the electrolyte temperature is 45–75 °C.

[0014] Furthermore, in step C, the filtration accuracy of the fine filtration unit is 0.5 to 5 μm, and the fine filtration unit is selected from one or more combinations of cross-flow membrane filtration unit, ceramic membrane filtration unit, microporous filtration unit, fiber filtration unit, and dynamic membrane filtration unit.

[0015] Further, in step D, the organic functional group is selected from at least one of amino group, quaternary ammonium group, phosphonic acid group, carboxyl group, sulfonic acid group, and hydroxyl group, and the inorganic trapping component is selected from at least one of FeOOH, Fe2O3, TiO2, MnO2, BaSO4, PbSO4, BiAsO4, and SbAsO4.

[0016] Furthermore, the loading amount of the inorganic trapping component composed of at least one of FeOOH, TiO2, and MnO2 is 12–35 g / m², the loading amount of the inorganic trapping component composed of sulfate and / or arsenate seed crystals is 30–40 g / m², and the loading amount of the organic functional groups is 16–22 g / m².

[0017] Furthermore, in step D, the electrolyte after specific collection and purification is returned to at least one of the cathode inlet area, anode area, and main circulation pipeline of the electrolytic cell or recycled in the electrolyte storage tank; in step E, the parameters of the electrolyte before and after filtration are at least two of turbidity, particle size distribution, filtration pressure difference, and redox potential.

[0018] Further, in step E, the controller presets the upper limit of turbidity and the upper limit of suspended particle volume fraction of the filtered electrolyte, as well as the upper limit of the inlet and outlet pressure difference of at least one of the coarse filtration unit, fine filtration unit, and functionalized filter media layer; when the inlet and outlet pressure difference of any filtration unit reaches or exceeds the corresponding upper limit, the controller controls the standby filtration unit connected in parallel with the filtration unit to start operation, and reduces or stops the electrolyte flow rate through the filtration unit, while starting the backwashing operation of the filtration unit; when the turbidity or suspended particle volume fraction of the filtered electrolyte reaches or exceeds the corresponding upper limit, the controller reduces the bypass flow rate ratio and / or increases the electrolyte flow rate through the filtration unit within the preset operating range; when the aforementioned adjusted turbidity or suspended particle volume fraction still exceeds the corresponding upper limit, the controller switches to the standby filtration unit for operation.

[0019] The high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device of the present invention is implemented as follows: it includes an electrolytic cell, a liquid extraction port, a coarse filtration unit, a fine filtration unit, a functionalized filter media layer, an online monitoring unit, a controller, and a backwashing unit. The electrolytic cell is loaded with a high-impregnation copper anode, and the liquid extraction port is located in the anode area, the bottom area, the anode bag outlet area and / or the main circulation pipeline in the electrolytic cell. The inlet of the coarse filtration unit is connected to the outlet of the liquid extraction, and the filtration accuracy of the coarse filtration unit is 20-100μm. The inlet of the fine filtration unit is connected to the outlet of the coarse filtration unit, and the fine filtration unit is provided with a fine filter material with a filtration accuracy of 0.1 to 20 μm. The functionalized filter media layer is disposed on the filtrate outlet side of the fine filtration unit, or independently disposed at the rear end of the fine filtration unit and connected to the filtrate outlet end of the fine filtration unit, to specifically capture and purify the filtrate after fine filtration. The purified electrolyte is returned to the electrolytic cell for recycling through pipelines. The functionalized filter media layer can be any one of the following: replaceable filter element, coated filter membrane, functionalized fiber layer, ceramic membrane loaded with inorganic particles, polymer membrane loaded with functional groups, or composite porous material. The surface of the functionalized filter media layer is loaded with organic functional groups and inorganic capturing components. The online monitoring unit is located at the inlet of the coarse filtration unit, the outlet of the fine filtration unit, and / or the outlet of the functionalized filter material layer. The online monitoring unit integrates at least two of the following: turbidity sensor, particle size analyzer, differential pressure sensor, and redox potential electrode. The signal input terminal of the controller is electrically connected to the online monitoring unit, and the signal output terminal is respectively connected to the flow regulating valve, bypass valve, and backwash valve of the coarse filtration unit, fine filtration unit, and / or functionalized filter media layer. The backwash outlet of the backwash unit is connected to the coarse filtration unit, the fine filtration unit and / or the functionalized filter media layer through a pipeline, and is used to backwash the corresponding coarse filtration media, fine filtration media and functionalized filter media layer.

[0020] Furthermore, the fine filter material in the fine filtration unit is selected from one or more combinations of cross-flow membrane filtration unit, ceramic membrane filtration unit, microporous filtration unit, fiber filtration unit, and dynamic membrane filtration unit; the organic functional groups loaded on the surface of the functionalized filter material layer are selected from at least one of amine group, quaternary ammonium group, phosphonic acid group, carboxyl group, sulfonic acid group, and hydroxyl group, and the inorganic trapping component is selected from at least one of FeOOH, Fe2O3, TiO2, MnO2, BaSO4, PbSO4, BiAsO4, and SbAsO4.

[0021] Furthermore, the present invention also includes an anode mud collection tank whose mud inlet is connected to the mud discharge outlet of the coarse filtration unit, the fine filtration unit and / or the functionalized filter media layer. A mud discharge valve is provided on the pipeline connecting the mud discharge outlet of the coarse filtration unit, the fine filtration unit and / or the functionalized filter media layer to the mud inlet of the anode mud collection tank. The mud discharge valve is electrically connected to the controller.

[0022] The present invention has the following beneficial effects: 1. This invention addresses the problems of traditional single-stage filtration, easy clogging due to gravity settling, and penetration of fine colloids. It adopts a three-stage gradient filtration system: coarse filtration to pre-remove large lead salt particles and anode mud agglomerates, fine filtration to intercept micron-sized floating mud, and functionalized filter media to capture submicron colloids and precipitation precursors. By retaining anode mud of different particle sizes in layers, the turbidity reduction rate of the electrolyte can reach 84.8% to 93.2%, and the removal rate of fine particles below 5μm can reach 79.6% to 89.1%. This effectively alleviates the problems of rapid increase in filter media pressure difference and flux decay, thereby significantly improving the mud removal efficiency.

[0023] 2. This invention breaks through the limitations of ordinary filtration that relies solely on pore size sieving. The functionalized filter media layer loads composite functional components such as amine groups, FeOOH, and BaSO4 seeds onto the filter media. Through electrostatic adsorption, surface complexation, and heterogeneous nucleation, it overcomes the inability of conventional capture processes to retain arsenic, antimony, and bismuth colloids. Moreover, the functionalized filter media layer can be acid-washed and regenerated, and the colloid removal rate still exceeds 80% after multiple regenerations, making up for the shortcomings of ion exchange and ordinary membrane filtration in treating solid floating sludge.

[0024] 3. This invention can significantly reduce the amount of colloidal suspended matter in the electrolyte, thereby reducing the number of cathode nodules by 70.3% to 82.6%, decreasing the Sb+Bi impurity content in the cathode by 61.7% to 72.4%, and significantly reducing the electrolysis voltage fluctuation under high current density. It effectively solves quality defects such as cathode surface roughness, particle inclusions, and excessive harmful impurities, thus stabilizing and improving the product quality of cathode copper.

[0025] 4. Unlike chemical flocculation and chemical purification processes that involve the addition of large amounts of chemicals and damage the original electrolyte additives such as gelatin, thiourea, and chloride ions, this invention relies solely on physical sieving and interfacial adsorption for purification. It does not change the copper and acid concentrations of the electrolyte, has no external chemical interference, and can protect the original electrolyte additive system.

[0026] 5. This invention employs backwashing and cross-flow concentration, resulting in Sb and Bi enrichment factors of up to 3.8 times in the produced anode mud. The high-grade mud facilitates the subsequent extraction of antimony, bismuth, and precious metals. Furthermore, the centralized collection of arsenic-containing solid phases allows for unified stabilization and treatment, thereby achieving both resource recovery and harmless arsenic disposal, effectively improving the overall economic and environmental benefits of the process.

[0027] 6. This invention relies on closed-loop intelligent control of multiple parameters such as turbidity, particle size, filtration pressure difference, ORP and cathode quality detection data to automatically adjust the bypass ratio and backwash cycle; moreover, it can automatically switch to the backup filter unit when the index exceeds the limit, without the need for shutdown maintenance. The long-term operating throughput retention rate of the system can reach more than 92.4%, and it can be adapted to industrial electrolytic refining processes with large anode compositions such as recycled scrap copper and complex ores.

[0028] In summary, this invention addresses the shortcomings of existing technologies such as gravity sedimentation, anode bags, chemical flocculation, bypass chemical purification, ion exchange, and single-stage ordinary filtration. It innovatively sets up a three-stage filtration system consisting of coarse filtration, fine filtration, and composite functionalized filter media, along with multi-parameter intelligent control and a cross-flow concentration backwashing structure. This system can simultaneously remove large-particle anode mud, micron-sized floating mud, and arsenic-antimony-bismuth colloids from the electrolyte without the need for chemicals. It not only effectively improves the quality of cathode copper but also enriches valuable metals. Furthermore, it can adapt to fluctuating impurities and ensure continuous and stable electrolysis operation. Attached Figure Description

[0029] Figure 1 This is a flowchart of the high-impurity copper anode electrolytic refining circulating electrolyte staged filtration sludge removal method of the present invention; Figure 2 This is a schematic diagram of the graded filtration and sludge removal device for the circulating electrolyte in the high-impurity copper anode electrolytic refining process of the present invention. In the diagram: 1-Electrolytic cell, 2-Liquid extraction port, 3-Coarse filtration unit, 4-Fine filtration unit, 5-Functionalized filter media layer, 6-Online monitoring unit, 7-Controller, 8-Backwashing unit, 9-Anode mud collection tank, 10-Cathode, 11-High-impurity copper anode. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this does not limit the present invention in any way. Any changes or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0031] like Figure 1 As shown, the method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining of the present invention includes electrolyte extraction, primary coarse filtration, secondary fine filtration, tertiary collection, online control, and backwashing steps. The specific details of each step are as follows: A. Electrolyte extraction: Extract electrolyte from at least one location in the electrolytic cell containing high-impure copper anodes, including the anode area, bottom area, anode bag outlet area, and main circulation pipeline; selecting locations where anode mud is easily accumulated or migrated to extract electrolyte is beneficial to improving the retention efficiency of anode mud. B. Primary coarse filtration: The extracted electrolyte is passed through a coarse filtration unit with a filtration accuracy of 20-100μm for coarse filtration to remove large particles of primary anode mud, anode mud agglomerates, and coarse lead sulfate particles in the electrolyte, thereby reducing the particle load on the downstream fine filtration unit and the functionalized filter media layer, and slowing down clogging and pressure differential growth. C. Secondary fine filtration: The coarsely filtered electrolyte is passed through a fine filtration unit with a filtration accuracy of 0.1 to 20 μm for fine filtration to remove micron-sized floating anode mud from the electrolyte; D. Three-stage capture: The electrolyte after fine filtration continuously passes through a functionalized filter layer for specific capture and purification. After purification, the electrolyte is returned to the electrolytic cell for recycling, forming a continuous circulation purification path and reducing the migration of anode mud particles to the cathode surface. The functionalized filter layer can be any one of the following: a replaceable filter element, a coated filter membrane, a functionalized fiber layer, a ceramic membrane loaded with inorganic particles, a polymer membrane loaded with functional groups, or a composite porous material. The surface of the functionalized filter layer is loaded with organic functional groups and / or inorganic capture components. The functionalized filter layer captures submicron-sized floating anode mud particles, colloidal particles, and precipitate precursors containing arsenic, antimony, and bismuth that cannot be intercepted by conventional filtration through one or more of the following synergistic effects: electrostatic adsorption, surface complexation, heterogeneous nucleation, and particle bridging. E. Online control: The controller acquires the parameters of the electrolyte before and after filtration in the coarse filtration unit, fine filtration unit and / or functionalized filter media layer in real time online, or acquires cathode quality detection data. Based on the acquired parameters or detection data, the controller adjusts the electrolyte filtration flow rate, bypass filtration ratio, filter media backwashing cycle and / or standby filter unit switching status in linkage to maintain the continuous and stable operation of the filtration process. F. Backwashing: When the detected electrolyte turbidity, fine particle ratio, filtration differential pressure and / or redox potential exceed the preset threshold, the backwashing unit is activated to backwash the coarse filtration unit, fine filtration unit and / or functionalized filter media layer, and the backwash liquid containing arsenic-antimony-bismuth-enriched anode mud is collected into the anode mud collection tank for subsequent antimony-bismuth precious metal recovery or arsenic harmless treatment.

[0032] In step A, the high-mixed copper anode contains 0.01–2 wt% As, 0.01–2 wt% Pb, 0.005–1 wt% Sb, and 0.001–1 wt% Bi; the electrolyte is a sulfuric acid-copper sulfate system, wherein the free sulfuric acid concentration is 100–250 g / L, the copper ion concentration is 30–60 g / L, and the electrolyte temperature is 45–75 °C.

[0033] In step C, the filtration accuracy of the fine filtration unit is 0.5 to 5 μm, and the fine filtration unit is selected from one or more combinations of cross-flow membrane filtration unit, ceramic membrane filtration unit, microporous filtration unit, fiber filtration unit, and dynamic membrane filtration unit.

[0034] In step C, the fine filtration unit employs a cross-flow membrane filtration unit, and the high-concentration anode mud concentrate produced by filtration is separately discharged to the anode mud collection tank. Using a cross-flow filtration unit reduces filter cake accumulation by allowing the electrolyte to flow along the surface of the filter medium, and facilitates the introduction of the high-concentration anode mud concentrate into the anode mud collection tank.

[0035] In step D, the organic functional group is selected from at least one of amino group, quaternary ammonium group, phosphonic acid group, carboxyl group, sulfonic acid group, and hydroxyl group, and the inorganic trapping component is selected from at least one of FeOOH, Fe2O3, TiO2, MnO2, BaSO4, PbSO4, BiAsO4, and SbAsO4.

[0036] The loading amount of the inorganic trapping component composed of at least one of FeOOH, TiO2, and MnO2 is 12–35 g / m², the loading amount of the inorganic trapping component composed of sulfate and / or arsenate seed crystals is 30–40 g / m², and the loading amount of the organic functional groups is 16–22 g / m².

[0037] In step D, the electrolyte after specific collection and purification is returned to at least one of the cathode inlet area, anode area, and main circulation pipeline of the electrolytic cell or recycled in the electrolyte storage tank; in step E, the parameters of the electrolyte before and after filtration are at least two of turbidity, particle size distribution, filtration pressure difference, and redox potential.

[0038] In step E, the controller presets the upper limit of turbidity and the upper limit of suspended particle volume fraction of the filtered electrolyte, as well as the upper limit of the inlet and outlet pressure difference of at least one of the coarse filtration unit, fine filtration unit, and functionalized filter media layer. When the inlet and outlet pressure difference of any filtration unit reaches or exceeds the corresponding upper limit, the controller controls the standby filtration unit connected in parallel with the filtration unit to start operation, and reduces or stops the electrolyte flow rate through the filtration unit, while starting the backwashing operation of the filtration unit. When the turbidity or suspended particle volume fraction of the filtered electrolyte reaches or exceeds the corresponding upper limit, the controller reduces the bypass flow rate ratio and / or increases the electrolyte flow rate through the filtration unit within the preset operating range. When the turbidity or suspended particle volume fraction after the aforementioned adjustment still exceeds the corresponding upper limit, the controller switches to the standby filtration unit for operation.

[0039] It should be noted that the bypass mainly refers to the pipeline that is connected in parallel with the filter unit or the entire filter system, so that some electrolyte can flow around the corresponding filter unit.

[0040] In step E, the controller presets upper limits for the number of cathode nodules, surface roughness, and Sb / Bi content; when any of the cathode detection data reaches or exceeds the corresponding upper limit, the controller increases the filtration cycle ratio and shortens the backwashing cycle according to a preset strategy.

[0041] In step F, the anode mud collected in the anode mud collection tank can be further used for the recovery of antimony, bismuth, precious metals, or the safe disposal of arsenic.

[0042] like Figure 2As shown, the high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device of the present invention includes an electrolytic cell 1, a liquid extraction port 2, a coarse filtration unit 3, a fine filtration unit 4, a functionalized filter media layer 5, an online monitoring unit 6, a controller 7, and a backwashing unit 8. The electrolytic cell 1 is loaded with a high-impregnation copper anode 11, and the liquid extraction port 2 is located in the anode area, the bottom area, the anode bag outlet area and / or the main circulation pipeline in the electrolytic cell 1. The inlet of the coarse filtration unit 3 is connected to the outlet 2, and the filtration accuracy of the coarse filtration unit 3 is 20-100μm. The inlet of the fine filtration unit 4 is connected to the outlet of the coarse filtration unit 3, and the fine filtration unit 4 is provided with a fine filter material with a filtration accuracy of 0.1 to 20 μm. The functionalized filter material layer 5 is disposed on the filtrate outlet side of the fine filtration unit 4, or is independently disposed at the rear end of the fine filtration unit 4 and connected to the outlet end of the fine filtration unit 4, to specifically capture and purify the filtrate after fine filtration. The purified electrolyte is returned to the electrolytic cell 1 through the pipeline for recycling. The functionalized filter material layer 5 can be any one of the following: replaceable filter element, coated filter membrane, functionalized fiber layer, ceramic membrane loaded with inorganic particles, polymer membrane loaded with functional groups, or composite porous material. The surface of the functionalized filter material layer 5 is loaded with organic functional groups and inorganic capturing components. The online monitoring unit 6 is arranged at the liquid inlet of the coarse filtration unit 3, the liquid outlet of the fine filtration unit 4 and / or the liquid outlet of the functionalized filter material layer 5. The online monitoring unit 6 integrates at least two of the following: turbidity sensor, particle size analyzer, differential pressure sensor and redox potential electrode. The signal input terminal of the controller 7 is electrically connected to the online monitoring unit 6, and the signal output terminal is respectively connected to the flow regulating valve, bypass valve, and backwash valve of the coarse filtration unit 3, the fine filtration unit 4, and / or the functional filter media layer 5. The backwash outlet of the backwash unit 8 is connected to the coarse filter unit 3, the fine filter unit 4 and / or the functional filter media layer 5 through a pipeline, and is used to backwash the corresponding coarse filter media, fine filter media and functional filter media layer 5.

[0043] The coarse filtration unit 3 is a bag filter, basket filter, screen filter, plate and frame filter, or core filter.

[0044] The fine filter material in the fine filtration unit 4 is selected from one or more combinations of cross-flow membrane filtration unit, ceramic membrane filtration unit, microporous filtration unit, fiber filtration unit, and dynamic membrane filtration unit; the organic functional groups loaded on the surface of the functionalized filter material layer 5 are selected from at least one of amine group, quaternary ammonium group, phosphonic acid group, carboxyl group, sulfonic acid group, and hydroxyl group, and the inorganic trapping component is selected from at least one of FeOOH, Fe2O3, TiO2, MnO2, BaSO4, PbSO4, BiAsO4, and SbAsO4.

[0045] The present invention also includes an anode mud collection tank 9, which is connected to the mud discharge port of the coarse filter unit 3, the fine filter unit 4 and / or the functional filter material layer 5. A mud discharge valve is provided on the pipeline connecting the mud discharge port of the coarse filter unit 3, the fine filter unit 4 and / or the functional filter material layer 5 and the mud inlet of the anode mud collection tank 9. The mud discharge valve is electrically connected to the controller 7.

[0046] The cross-flow membrane filtration unit includes a concentrate outlet and a filtrate outlet. The concentrate outlet is connected to the sludge inlet of the anode sludge collection tank 9, which facilitates the introduction of concentrated anode sludge particles into subsequent collection or resource recovery units.

[0047] The present invention also includes a backup filtration unit connected in parallel with the coarse filtration unit 3, the fine filtration unit 4 and the functionalized filter media layer 5. The backup filtration unit includes the coarse filtration unit 3, the fine filtration unit 4 and the functionalized filter media layer 5 connected in series. The signal output terminal of the controller 7 is electrically connected to the backup filtration unit switching valve. When the received turbidity, filtration pressure difference and / or suspended particle volume fraction reach or exceed the threshold, the controller 7 controls the backup filtration unit to automatically switch to operation, so as to reduce the impact of the maintenance or backwashing process of the filtration unit on the continuous operation of electrolytic refining.

[0048] Example 1

[0049] In this embodiment, the coarse filtration unit 3 of the high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device uses a polypropylene wedge mesh filter with a filtration accuracy of 50 μm, and the fine filtration unit 4 uses a cross-flow ceramic membrane filter with a filtration accuracy of 1 μm; the functionalized filter media layer 5 uses FeOOH / phosphonic acid-based composite modified porous filter media, wherein the FeOOH loading is 35 g / m 2 The loading of the phosphonic acid functional layer is 18 g / m 2 .

[0050] During assembly, the coarse filtration unit 3 is connected to the liquid extraction port 2 in the bottom area or anode area of ​​the electrolytic cell 1, and the liquid inlet of the fine filtration unit 4 is connected to the liquid outlet of the coarse filtration unit 3. The FeOOH / phosphonic acid-based composite modified porous filter material (i.e., functionalized filter material layer 5) is placed on the filtrate outlet side of the fine filtration unit 4. The electrolyte filtered by the functionalized filter material layer 5 is returned to the main circulation inlet in the electrolytic cell 1 through a pipeline. A turbidity sensor, a particle size analyzer, and a differential pressure sensor are connected to the liquid inlet of the coarse filtration unit 3, the liquid outlet of the fine filtration unit 4, and the liquid outlet of the functionalized filter material layer 5, respectively. The aforementioned monitoring elements are electrically connected to the controller 7. The backwash outlet of the backwash unit 8 is connected to the coarse filtration unit 3, the fine filtration unit 4, and the functionalized filter material layer 5 through a pipeline. The backwash unit 8 is electrically connected to the controller 7.

[0051] The specific process of the circulating electrolyte staged filtration sludge removal method is as follows: S100: From the extraction port 2 of the anode area or bottom area of ​​the electrolytic cell 1 containing the high-pollution copper anode 11, electrolyte containing anode mud is extracted at a rate of 15% of the main circulation volume. The high-pollution copper anode 11 contains: 0.35 wt% As, 1.20 wt% Pb, 0.28 wt% Sb, and 0.08 wt% Bi; the electrolyte is a sulfuric acid-copper sulfate system and contains 45 g / L Cu. 2+ The electrolyte solution contained 180 g / L free H₂SO₄, 8.0 g / L As, 0.45 g / L Sb, and 0.12 g / L Bi. The electrolyte temperature was adjusted to 60 °C, and the current density was 280 A / m³. 2 .

[0052] S200: The extracted electrolyte is passed into a coarse filtration unit 3 with a filtration accuracy of 50μm for coarse filtration to remove large particles of primary anode mud, anode mud agglomerates, and coarse lead sulfate particles in the electrolyte.

[0053] S300: The electrolyte after coarse filtration is passed into the cross-flow ceramic membrane fine filtration unit 4 with a filtration accuracy of 1μm for fine filtration to remove micron-sized fine floating anode mud in the electrolyte.

[0054] S400: The electrolyte after fine filtration is continuously collected and purified by FeOOH / phosphonic acid-based composite modified porous filter material (i.e., functionalized filter material layer 5). After purification, the electrolyte is returned to the electrolytic cell 1 for recycling.

[0055] S500: Controller 7 acquires the filtration pressure difference of the electrolyte before and after filtration in the coarse filtration unit 3, fine filtration unit 4, and functionalized filter media layer 5 online in real time.

[0056] S600: When the filtration pressure difference reaches or exceeds 0.12 MPa, the controller 7 starts the backwashing unit 8, and at the same time closes the bypass valve and opens the backwashing valve and sludge discharge valve of the coarse filter unit 3, fine filter unit 4 and functionalized filter media layer 5 to perform backwashing for 45 seconds. The backwash liquid enters the anode sludge collection tank 9 for subsequent antimony and bismuth precious metal recovery or arsenic harmless treatment.

[0057] The results showed that after 72 hours of operation, the turbidity of the electrolyte filtered by the functionalized filter media layer 5 decreased by 91.6%, the number of suspended particles smaller than 5 μm decreased by 86.4%, the number of nodules on the cathode 10 surface decreased by 78.2%, and the Sb+Bi content in the cathode 10 decreased by 68.5%. The Sb+Bi content in the backwash solution was 3.8 times that in the influent suspended solids. After 10 consecutive backwash cycles, the filtration flux remained at 92.4%, and no significant membrane clogging or abnormal roughness was observed on the cathode 10 surface.

[0058] Example 2

[0059] In this embodiment, the coarse filtration unit 3 of the high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device uses an acid-resistant fiber filter with a filtration accuracy of 80 μm, and the fine filtration unit 4 uses a microporous polytetrafluoroethylene filter with a filtration accuracy of 3 μm; the functionalized filter media layer 5 uses an amine-based / BaSO4 seed composite modified fiber filter media, wherein the BaSO4 seed loading is 40 g / m³. 2 The loading of the amine functional layer is 22 g / m 2 .

[0060] During assembly, the coarse filtration unit 3 is connected to the extraction port 2 of the anode bag outlet area in the electrolytic cell 1. The coarse filtration unit 3, the fine filtration unit 4, and the functionalized filter media layer 5 are connected in series. The electrolyte filtered by the functionalized filter media layer 5 is returned to the electrolytic cell 1 through a pipeline. The functionalized filter media layer 5 is designed as a detachable filter element structure for offline acid washing or replacement after anode sludge is collected. The backwash outlet of the backwash unit 8 is connected to the fine filtration unit 4 and the functionalized filter media layer 5 through a pipeline. The backwash unit 8 is electrically connected to the controller 7.

[0061] The specific process of the circulating electrolyte staged filtration sludge removal method is as follows: S100: Electrolyte containing anode mud is extracted from the extraction port 2 of the anode bag outlet area inside the electrolytic cell 1, which contains the high-impregnation copper anode 11, at a rate of 10% of the main circulation volume. The high-impregnation copper anode 11 contains: 0.42 wt% As, 0.95 wt% Pb, 0.35 wt% Sb, and 0.10 wt% Bi; the electrolyte is a sulfuric acid-copper sulfate system and contains 42 g / L Cu. 2+The electrolyte solution contained 170 g / L free H₂SO₄, 9.5 g / L As, 0.52 g / L Sb, and 0.15 g / L Bi. The electrolyte temperature was adjusted to 62 °C, and the current density was 300 A / m³. 2 .

[0062] S200: The extracted electrolyte is passed into the coarse filtration unit 3 with a filtration accuracy of 80μm for coarse filtration to remove large particles of primary anode mud, anode mud agglomerates, and coarse lead sulfate particles in the electrolyte.

[0063] S300: The electrolyte after coarse filtration is passed into the fine filtration unit 4 with a filtration accuracy of 3μm for fine filtration to remove micron-sized floating anode mud in the electrolyte.

[0064] S400: The finely filtered electrolyte continuously passes through an amine / BaSO4 seed composite modified fiber filter material (i.e., functionalized filter material layer 5) for specific capture and purification. After purification, the electrolyte is returned to the electrolytic cell 1 for recycling. The amine groups are partially protonated in the acidic electrolyte to enhance the electrostatic adsorption of fine arsenate and antimonate particles; the BaSO4 seed layer provides heterogeneous nucleation and particle attachment sites.

[0065] S500: Controller 7 starts backwashing unit 8 every 6 hours for backwashing. At the same time, it closes the bypass valve and opens the backwashing valve and sludge discharge valve of fine filtration unit 4 and functionalized filter media layer 5. The backwash liquid enters anode sludge collection tank 9 for subsequent antimony and bismuth precious metal recovery or arsenic harmless treatment.

[0066] The results showed that after 72 hours of operation, the turbidity of the electrolyte filtered by the functionalized filter media layer 5 decreased by 84.8%, the number of suspended particles smaller than 5 μm decreased by 79.6%, the number of nodules on the cathode 10 surface decreased by 70.3%, and the Sb+Bi content in the cathode 10 decreased by 61.7%. After the functionalized filter media layer 5 was disassembled and regenerated by acid washing five times, the turbidity removal rate remained above 80%, indicating that the functionalized filter media layer 5 has good regeneration and reuse performance.

[0067] Example 3

[0068] In this embodiment, the coarse filtration unit 3 of the high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device has a filtration accuracy of 30 μm, and the fine filtration unit 4 has a filtration accuracy of 0.5 μm; the functionalized filter media layer 5 adopts TiO2 / MnO2 composite functionalized ceramic filter media, wherein the TiO2 loading is 25 g / m 2 The loading of MnO2 is 12 g / m 2 .

[0069] During assembly, the coarse filtration unit 3 is connected to the liquid extraction port 2 at the bottom of the electrolytic cell 1, and the fine filtration unit 4 is connected in series with the coarse filtration unit 3. The TiO2 / MnO2 composite functionalized ceramic filter material (i.e., functionalized filter material layer 5) is placed on the filtrate outlet side of the fine filtration unit 4. The spare filtration unit (including the fine filtration unit 4 and its functionalized filter material layer 5) is connected in parallel with the fine filtration unit 4. The electrolyte filtered by the functionalized filter material layer 5 is returned to the electrolytic cell 1 through a pipeline. A turbidity sensor, a particle size analyzer, a differential pressure sensor, and an ORP electrode are connected to the inlet and outlet of the fine filtration unit 4, respectively, and the aforementioned monitoring elements are electrically connected to the controller 7. The controller 7 has three preset control thresholds: an upper limit of turbidity of the filtered electrolyte of 20 NTU, an upper limit of differential pressure across the fine filtration unit 4 of 0.15 MPa, and an upper limit of volume fraction of particles smaller than 5 μm of 8%. The backwash outlet of the backwash unit 8 is connected to the fine filtration unit 4 and the functionalized filter media layer 5 through a pipeline, and the backwash unit 8 is electrically connected to the controller 7.

[0070] The specific process of the circulating electrolyte staged filtration sludge removal method is as follows: S100: Electrolyte containing anode mud is extracted from the extraction port 2 at the bottom of the electrolytic cell 1, which contains the high-impregnation copper anode 11. The high-impregnation copper anode 11 contains: 0.28 wt% As, 1.50 wt% Pb, 0.40 wt% Sb, and 0.06 wt% Bi; the electrolyte is a sulfuric acid-copper sulfate system and contains 48 g / L Cu. 2+ The electrolyte solution contained 190 g / L free H₂SO₄, 7.2 g / L As, 0.60 g / L Sb, and 0.09 g / L Bi. The electrolyte temperature was adjusted to 58 °C, and the current density was 320 A / m³. 2 .

[0071] S200: The extracted electrolyte is passed into a coarse filtration unit 3 with a filtration accuracy of 30μm for coarse filtration to remove large particles of primary anode mud, anode mud agglomerates, and coarse lead sulfate particles in the electrolyte.

[0072] S300: The electrolyte after coarse filtration is passed into the fine filtration unit 4 with a filtration accuracy of 0.5μm for fine filtration to remove micron-sized floating anode mud in the electrolyte.

[0073] S400: The electrolyte after fine filtration is continuously collected and purified by TiO2 / MnO2 composite functionalized filter material (i.e., functionalized filter material layer 5). After purification, the electrolyte is returned to the electrolytic cell 1 for recycling.

[0074] S500: Controller 7 acquires the turbidity, particle size and filtration pressure difference of the electrolyte before and after filtration by the fine filtration unit 4 and the functionalized filter media layer 5 in real time online.

[0075] S600: When the filtration pressure difference reaches or exceeds 0.15MPa, the controller 7 automatically switches the backup filter unit switching valve, turns on the backup filter unit, and simultaneously starts the backwash unit 8 and closes the corresponding bypass valve, and opens the backwash valve and sludge discharge valve of the fine filter unit 4 and the functional filter media layer 5 to perform backwashing. The backwash liquid enters the anode sludge collection tank 9 for subsequent antimony and bismuth precious metal recovery or arsenic harmless treatment.

[0076] The results showed that after 96 hours of operation, the turbidity of the electrolyte filtered by the functionalized filter media layer 5 decreased by 93.2%, the number of suspended particles smaller than 5 μm decreased by 89.1%, the number of nodules on the cathode 10 surface decreased by 82.6%, and the Sb+Bi content in the cathode 10 decreased by 72.4%. The device operated stably under high current density conditions, and the voltage fluctuation amplitude was reduced by 35.8% compared with the unfiltered system, indicating that the device can alleviate the problem of floating anode mud and cathode 10 quality fluctuations under high current density conditions in the high-impurity anode 11.

[0077] Example 4

[0078] In this embodiment, the coarse filtration unit 3 of the high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device has a filtration accuracy of 60 μm, and the fine filtration unit 4 uses a cross-flow membrane fine filter with a filtration accuracy of 2 μm; the functionalized filter media layer 5 uses FeOOH / quaternary ammonium-based composite modified porous filter media, wherein the FeOOH loading is 30 g / m 2 The loading of the quaternary ammonium functional layer is 16 g / m 2 .

[0079] During assembly, the coarse filtration unit 3 is connected to the liquid extraction port 2 located 50-150 mm below the anode 11 in the electrolytic cell 1. The cross-flow membrane fine filter (i.e., fine filtration unit 4) is connected in series with the coarse filtration unit 3. The FeOOH / quaternary ammonium-based composite modified porous filter material (i.e., functionalized filter material layer 5) is placed on the filtrate outlet side of the fine filtration unit 4. The electrolyte filtered by the functionalized filter material layer 5 is returned to the electrolytic cell 1 through a pipeline. The controller 7 acquires quality detection data including the number of nodules on the cathode 10, the surface roughness of the cathode 10, and the Sb / Bi content in the cathode 10. The backwash outlet of the backwash unit 8 is connected to the fine filtration unit 4 and the functionalized filter material layer 5 through a pipeline. The backwash unit 8 is electrically connected to the controller 7.

[0080] The specific process of the circulating electrolyte staged filtration sludge removal method is as follows: S100: Extract electrolyte containing anode mud from the extraction port 2 located 50–150 mm below the anode zone in the electrolytic cell 1 containing the high-impregnation copper anode 11. The high-impregnation copper anode 11 contains: 0.50 wt% As, 1.10 wt% Pb, 0.22 wt% Sb, and 0.12 wt% Bi; the electrolyte is a sulfuric acid-copper sulfate system and contains 46 g / L Cu. 2+ The electrolyte solution contained 175 g / L free H₂SO₄, 10.0 g / L As, 0.38 g / L Sb, and 0.18 g / L Bi. The electrolyte temperature was adjusted to 65 °C, and the current density was 300 A / m³. 2 .

[0081] S200: The extracted electrolyte is passed into a coarse filtration unit 3 with a filtration accuracy of 60μm for coarse filtration to remove large particles of primary anode mud, anode mud agglomerates, and coarse lead sulfate particles in the electrolyte.

[0082] S300: The electrolyte after coarse filtration is passed into a cross-flow membrane fine filter (i.e., fine filtration unit 4) with a filtration accuracy of 2μm for fine filtration to remove micron-sized floating anode mud in the electrolyte.

[0083] S400: The electrolyte after fine filtration is continuously collected and purified by FeOOH / quaternary ammonium-based composite modified porous filter material (i.e., functionalized filter material layer 5). After purification, the electrolyte is returned to the electrolytic cell 1 for recycling.

[0084] The electrolyte in the anode region is introduced into a staged filtration device, passing sequentially through a 60μm coarse filter, a 2μm cross-flow membrane fine filter, and a FeOOH / quaternary ammonium-based composite functionalized filter media layer. When the number of cathode 10 nodules or the cathode 10Sb / Bi content increases, the controller 7 automatically increases the filtration circulation ratio and shortens the backwashing cycle.

[0085] S500: Controller 7 monitors the number of nodules on cathode 10, the surface roughness of cathode 10, and the Sb / Bi content of cathode 10 in real time online.

[0086] S600: When the number of nodules on cathode 10 or the Sb / Bi content of cathode 10 increases, controller 7 automatically increases the filtration cycle ratio and shortens the backwashing cycle.

[0087] The results showed that after 120 hours of operation, the turbidity of the electrolyte filtered by the functionalized filter media layer 5 decreased by 88.7%, the number of suspended particles smaller than 5 μm decreased by 82.9%, the number of nodules on the cathode 10 surface decreased by 76.5%, and the Sb+Bi content in the cathode 10 decreased by 66.8%. No significant decrease in filtration flux was observed after 20 consecutive backwashing cycles, and the surface smoothness of the cathode 10 was significantly better than that of the system without the functionalized filter media layer 5.

[0088] Comparative Example 1 To verify the performance advantages of the graded filtration and functionalized filter media layer 5 of the present invention, a comparative experiment was conducted using a non-circulating filtration method. In the comparative example, the electrolytic cell 1 did not have a coarse filtration unit 3, a fine filtration unit 4, or a functionalized filter media layer 5, and only used conventional electrolyte circulation.

[0089] The specific process is as follows: The high-impurity copper anode 11 and the basic electrolyte composition are the same as in Example 1. The electrolyte temperature is adjusted to 60°C, and the current density is 280 A / m. 2 The electrolysis time is 72 hours. The electrolyte circulates in electrolytic cell 1 in a conventional manner. The anode sludge generated in the anode area and the bottom area of ​​the cell is removed by natural sedimentation without online filtration or functional collection.

[0090] The results showed that after 72 hours of operation, the turbidity of the circulating electrolyte continued to increase, and the proportion of suspended particles smaller than 5 μm increased significantly; numerous small nodules and particle inclusions appeared on the surface of cathode 10. Based on Example 1, the turbidity removal rate, particle size reduction rate (smaller than 5 μm), cathode 10 nodule count reduction rate, and cathode 10 Sb+Bi content reduction rate were all 0% in this comparative example. These results indicate that under high As, Pb, Sb, and Bi anode 11 conditions, natural sedimentation alone is insufficient to effectively control fine floating anode sludge.

[0091] Comparative Example 2 A comparative experiment was conducted using only the coarse filtration unit 3. The filtration device consisted only of the bottom liquid extraction port 2 and a 50μm polypropylene wedge mesh coarse filtration unit (i.e., coarse filtration unit 3), without the fine filtration unit 4 and the functionalized filter media layer 5.

[0092] The specific process is as follows: The high-impurity copper anode 11 and the basic electrolyte composition are the same as in Example 1. The electrolyte temperature is 60°C, and the current density is 280 A / m³. 2 The circulating electrolyte is drawn from the bottom extraction port 2 and returned directly to the electrolytic cell 1 after passing through the 50μm coarse filter unit 3. When the filtration pressure difference of the coarse filter unit 3 reaches or exceeds 0.08 MPa, the coarse filter unit 3 is backwashed, and the backwash liquid enters the anode mud collection tank 9.

[0093] The results showed that after 72 hours of operation, the turbidity of the filtered electrolyte decreased by 31.5%, the suspended particles smaller than 5 μm decreased by 16.8%, the number of nodules on cathode 10 decreased by 18.6%, and the Sb+Bi content in cathode 10 decreased by 11.3%. These results indicate that the device and method can remove some large primary anode mud and detached agglomerates, but its effectiveness in removing fine As-Sb-Bi floating anode mud in the 0.1–10 μm range is limited, and significant particle inclusions still exist on the surface of cathode 10.

[0094] Comparative Example 3 A comparative experiment was conducted using coarse filtration followed by ordinary fine filtration. In this comparative example, the circulating electrolyte was sequentially passed through a 50 μm coarse filtration unit 3 and a 1 μm ordinary ceramic membrane fine filtration unit (i.e., fine filtration unit 4). The surface of the ordinary ceramic membrane fine filtration unit did not contain charged groups, complexing groups, metal oxide seeds, or sulfate seeds.

[0095] The specific process is as follows: The high-impurity copper anode 11 and the basic electrolyte composition are the same as in Example 1. The electrolyte temperature is 60°C, and the current density is 280 A / m³. 2 The circulating electrolyte is drawn from the extraction port 2 in the bottom area or anode area and passed sequentially through a 50μm coarse filtration unit 3 and a 1μm ordinary ceramic membrane fine filtration unit (i.e., fine filtration unit 4). After fine filtration, the electrolyte is directly returned to the electrolytic cell 1. When the filtration pressure difference of the fine filtration unit 4 reaches or exceeds 0.12 MPa, the fine filtration unit 4 is backwashed.

[0096] The results showed that after 72 hours of operation, the turbidity of the electrolyte after fine filtration decreased by 63.4%, the suspended particles smaller than 5 μm decreased by 54.2%, the number of nodules in cathode 10 decreased by 43.7%, and the Sb+Bi content in cathode 10 decreased by 34.5%. During operation, the filtration differential pressure of the ordinary ceramic membrane fine filtration unit (i.e., fine filtration unit 4) increased rapidly, and the filtration flux retention rate was 71.6%. These results indicate that coarse filtration combined with ordinary fine filtration can retain some fine particles, but due to the lack of functionalized trapping sites, its removal capacity for colloidal particles containing As-Sb-Bi and precipitate precursors is insufficient, and its operational stability is lower than that of the functionalized filter material system of this invention.

[0097] Comparative Example 4 Comparative experiments were conducted using a combination of coarse filtration, fine filtration, and non-functionalized inert filter layers. In the comparative examples, the inert filter layer was a polypropylene fiber filter layer, without any functionalized trapping components such as FeOOH, TiO2, MnO2, BaSO4, PbSO4, amine groups, quaternary ammonium groups, phosphonic acid groups, or carboxyl groups.

[0098] The specific process is as follows: The high-impurity copper anode 11 and the basic electrolyte composition are the same as in Example 1. The electrolyte temperature is 60°C, and the current density is 280 A / m³. 2 The circulating electrolyte is sequentially passed through a 50μm coarse filtration unit 3, a 1μm cross-flow ceramic membrane fine filtration unit (i.e., fine filtration unit 4), and a non-functionalized polypropylene fiber filter layer. After filtration, the electrolyte is returned to electrolytic cell 1, and backwashing is performed after the filtration pressure difference reaches the set value.

[0099] The results showed that after 72 hours of operation, the turbidity of the filtered electrolyte decreased by 70.2%, the number of suspended particles smaller than 5 μm decreased by 60.7%, the number of nodules on cathode 10 decreased by 49.5%, and the Sb+Bi content in cathode 10 decreased by 39.8%. The enrichment factor of Sb+Bi in the backwash solution was significantly lower than that in Example 1. These results indicate that although the non-functionalized inert filter layer can provide a certain degree of deep retention, it is difficult to effectively capture colloidal particles containing As, Sb, and Bi, as well as precipitate precursors, due to the lack of electrostatic adsorption, surface complexation, and heterogeneous nucleation sites.

[0100] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining, characterized in that: The process includes electrolyte extraction, primary coarse filtration, secondary fine filtration, tertiary collection, online control, and backwashing. The specific details of each step are as follows: A. Electrolyte extraction: Extract electrolyte from at least one of the following locations in the electrolytic cell containing high-impure copper anodes: anode area, bottom area, anode bag outlet area, and main circulation pipeline; B. Primary coarse filtration: The extracted electrolyte is passed through a coarse filtration unit with a filtration accuracy of 20-100μm for coarse filtration. C. Secondary fine filtration: The electrolyte after coarse filtration is passed into a fine filtration unit with a filtration accuracy of 0.1 to 20 μm for fine filtration; D. Three-stage collection: The electrolyte after fine filtration continuously passes through the functionalized filter material layer for specific collection and purification. After purification, the electrolyte is returned to the electrolytic cell for recycling. The functionalized filter material layer can be any one of the following: replaceable filter element, coated filter membrane, functionalized fiber layer, ceramic membrane loaded with inorganic particles, polymer membrane loaded with functional groups, or composite porous material. The surface of the functionalized filter material layer is loaded with organic functional groups and / or inorganic collection components. E. Online control: The controller can acquire parameters of the electrolyte before and after filtration by the coarse filtration unit, fine filtration unit and / or functionalized filter media layer in real time, or acquire cathode quality detection data, and adjust the electrolyte filtration flow rate, bypass filtration ratio, filter media backwashing cycle and / or standby filter unit switching status in linkage according to the acquired parameters or detection data. F. Backwashing: When the detected electrolyte turbidity, fine particle ratio, filtration pressure difference and / or redox potential exceed the preset threshold, the backwashing unit is activated to backwash the coarse filtration unit, fine filtration unit and / or functionalized filter media layer, and the backwash liquid is collected in the anode mud collection tank.

2. The method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining according to claim 1, characterized in that: In step A, the high-mixed copper anode contains 0.01–2 wt% As, 0.01–2 wt% Pb, 0.005–1 wt% Sb, and 0.001–1 wt% Bi; the electrolyte is a sulfuric acid-copper sulfate system, wherein the free sulfuric acid concentration is 100–250 g / L, the copper ion concentration is 30–60 g / L, and the electrolyte temperature is 45–75 °C.

3. The method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining according to claim 1, characterized in that: In step C, the filtration accuracy of the fine filtration unit is 0.5 to 5 μm, and the fine filtration unit is selected from one or more combinations of cross-flow membrane filtration unit, ceramic membrane filtration unit, microporous filtration unit, fiber filtration unit, and dynamic membrane filtration unit.

4. The method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining according to claim 1, characterized in that: In step D, the organic functional group is selected from at least one of amino group, quaternary ammonium group, phosphonic acid group, carboxyl group, sulfonic acid group, and hydroxyl group, and the inorganic trapping component is selected from at least one of FeOOH, Fe2O3, TiO2, MnO2, BaSO4, PbSO4, BiAsO4, and SbAsO4.

5. The method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining according to claim 4, characterized in that: The loading amount of the inorganic trapping component composed of at least one of FeOOH, TiO2, and MnO2 is 12–35 g / m², the loading amount of the inorganic trapping component composed of sulfate and / or arsenate seed crystals is 30–40 g / m², and the loading amount of the organic functional groups is 16–22 g / m².

6. The method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining according to claim 1, characterized in that: In step D, the electrolyte after specific collection and purification is returned to at least one of the cathode inlet area, anode area, and main circulation pipeline of the electrolytic cell or recycled in the electrolyte storage tank; in step E, the parameters of the electrolyte before and after filtration are at least two of turbidity, particle size distribution, filtration pressure difference, and redox potential.

7. The method for staged filtration and sludge removal of circulating electrolyte in high-impurity copper anode electrolytic refining according to any one of claims 1 to 6, characterized in that: In step E, the controller presets the upper limit of turbidity of the filtered electrolyte, the upper limit of suspended particle volume fraction, and the upper limit of inlet and outlet pressure difference of at least one of the coarse filtration unit, fine filtration unit and functionalized filter media layer. When the inlet and outlet pressure difference of any filter unit reaches or exceeds the corresponding pressure difference limit, the controller controls the standby filter unit set in parallel with the filter unit to start operation, and reduces or stops the electrolyte flow through the filter unit, while starting the backwashing operation of the filter unit. When the turbidity or suspended particle volume fraction of the filtered electrolyte reaches or exceeds the corresponding upper limit, the controller reduces the bypass flow rate ratio and / or increases the electrolyte flow rate through the filtration unit within the preset operating range; when the turbidity or suspended particle volume fraction after the aforementioned adjustment still exceeds the corresponding upper limit, the controller switches to the standby filtration unit for operation.

8. A graded filtration and sludge removal device for circulating electrolyte in high-impurity copper anode electrolytic refining, characterized in that: It includes an electrolytic cell (1), a liquid extraction port (2), a coarse filtration unit (3), a fine filtration unit (4), a functionalized filter media layer (5), an online monitoring unit (6), a controller (7), and a backwashing unit (8). The electrolytic cell (1) is filled with a high-impregnation copper anode (11), and the liquid extraction port (2) is located in the anode area, bottom area, anode bag outlet area and / or main circulation pipeline of the electrolytic cell (1); The inlet of the coarse filtration unit (3) is connected to the outlet (2), and the filtration accuracy of the coarse filtration unit (3) is 20-100μm. The inlet of the fine filtration unit (4) is connected to the outlet of the coarse filtration unit (3), and the fine filtration unit (4) is provided with a fine filter material with a filtration accuracy of 0.1 to 20 μm. The functionalized filter material layer (5) is disposed on the filtrate outlet side of the fine filtration unit (4), or is independently disposed at the rear end of the fine filtration unit (4) and connected to the outlet end of the fine filtration unit (4) to specifically capture and purify the filtrate after fine filtration. The purified electrolyte is returned to the electrolytic cell (1) for recycling through the pipeline. The functionalized filter material layer (5) can be any one of the following: replaceable filter element, coated filter membrane, functionalized fiber layer, ceramic membrane loaded with inorganic particles, polymer membrane loaded with functional groups, or composite porous material. The surface of the functionalized filter material layer (5) is loaded with organic functional groups and inorganic capturing components. The online monitoring unit (6) is arranged at the liquid inlet of the coarse filtration unit (3), the liquid outlet of the fine filtration unit (4) and / or the liquid outlet of the functionalized filter material layer (5). The online monitoring unit (6) integrates at least two of the following: turbidity sensor, particle size analyzer, differential pressure sensor and redox potential electrode. The signal input terminal of the controller (7) is electrically connected to the online monitoring unit (6), and the signal output terminal is respectively connected to the flow regulating valve, bypass valve and backwash valve of the coarse filter unit (3), the fine filter unit (4) and / or the functional filter media layer (5); The backwash outlet of the backwash unit (8) is connected to the coarse filter unit (3), the fine filter unit (4) and / or the functionalized filter media layer (5) through a pipeline, and is used to backwash the corresponding coarse filter media, fine filter media and functionalized filter media layer (5).

9. The high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device according to claim 8, characterized in that: The fine filter material in the fine filtration unit (4) is selected from one or more combinations of cross-flow membrane filtration unit, ceramic membrane filtration unit, microporous filtration unit, fiber filtration unit, and dynamic membrane filtration unit; the organic functional groups loaded on the surface of the functionalized filter material layer (5) are selected from at least one of amine group, quaternary ammonium group, phosphonic acid group, carboxyl group, sulfonic acid group, and hydroxyl group, and the inorganic trapping component is selected from at least one of FeOOH, Fe2O3, TiO2, MnO2, BaSO4, PbSO4, BiAsO4, and SbAsO4.

10. The high-impurity copper anode electrolytic refining circulating electrolyte staged filtration and sludge removal device according to claim 8 or 9, characterized in that: It also includes an anode mud collection tank (9) whose mud inlet is connected to the mud discharge port of the coarse filter unit (3), the fine filter unit (4) and / or the functional filter material layer (5). A mud discharge valve is provided on the pipeline connecting the mud discharge port of the coarse filter unit (3), the fine filter unit (4) and / or the functional filter material layer (5) to the mud inlet of the anode mud collection tank (9). The mud discharge valve is electrically connected to the controller (7).

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