A continuous purification apparatus for separating fluorine or chlorine ions from a zinc sulfate solution and a method thereof

Abstract

This invention relates to a continuous purification device and method for separating fluoride or chloride ions from zinc sulfate solution, belonging to the field of hydrometallurgical purification technology. The continuous purification device for separating fluoride or chloride ions from zinc sulfate solution consists of n identical separation units connected in series. Each separation unit includes an anode chamber K1, a treatment chamber K2, a cathode chamber K3, a purification liquid inlet F1, a purification liquid outlet F2, an enrichment liquid outlet F3, a cathode electrode liquid outlet F4, a cathode electrode liquid inlet F5, an anode electrode liquid outlet F6, an anode electrode liquid inlet F7, an ion channel F8, a cathode electrode F9, an anode electrode F10, an anion exchange membrane F11, and a cation exchange membrane F12. This invention can achieve continuous, efficient, environmentally friendly, and low-cost separation of impurity ions from zinc sulfate solution, with controllable purification depth, avoiding the disadvantages of high cost, low removal rate, and inconvenience for industrialization in traditional methods.

Description

Technical Field

[0001] This invention relates to a continuous purification device and method for separating fluoride or chloride ions from zinc sulfate solution, belonging to the field of hydrometallurgical purification technology. Background Technology

[0002] During zinc electrowinning, the presence of fluoride and chloride ions can cause various hazards. Chloride ions corrode the anode, causing lead-based anodes to dissolve and resulting in a decline in the quality of the obtained zinc; they also easily generate chlorine gas, polluting the working environment. Fluoride ions corrode the cathode, making it difficult to peel off the electrowinning zinc. Therefore, in industrial production, it is generally required that the chloride ion content in the solution not exceed 100 mg / L and the fluoride ion content not exceed 80 mg / L.

[0003] Existing methods for removing chloride ions mainly include: copper slag dechlorination, extraction, and ion exchange. However, the copper slag dechlorination method has difficulty establishing a connection between Cu and Cu. 2+ The equilibrium point is difficult to achieve for deep solution purification; the extractant used in extraction methods is difficult to completely separate from the zinc sulfate solution, leading to reduced current efficiency during electrodeposition; and the removal rate of ion exchange methods is low. Existing research mainly focuses on copper slag dechlorination methods and extraction methods. Research on copper slag dechlorination methods mainly focuses on two directions: adjusting the molar ratio of copper slag to chloride ions in the system, adjusting pH and temperature; or adding additional oxidants or reducing agents to establish Cu-Cu... 2+ The goal is to find the equilibrium point to remove chloride ions from zinc sulfate solution as much as possible. Patent CN113846354A discloses a process for removing chloride ions by reducing copper ions with zinc sulfite to generate cuprous ions: Equal molar amounts of zinc sulfite and copper sulfate are simultaneously added to a zinc sulfate solution, stirred until the precipitate no longer increases, and then filtered to obtain a dechlorinated solution. This method can reduce the chloride ion concentration to 700 mg / L. Patent CN101113015A discloses a process for removing chloride ions by oxidizing copper slag with potassium permanganate or manganese dioxide to generate cuprous ions: Copper slag is slurried with water, sulfuric acid and potassium permanganate are added and stirred to oxidize elemental copper to copper ions, thereby generating cuprous ions; the mixture is then mixed with a zinc sulfate solution, stirred, and treated for 1.5 hours to generate cuprous chloride precipitate, thus removing chloride ions; the precipitate is then separated using a solid-liquid separation device. This method can reduce the chloride ion concentration to 240 mg / L. Research on extraction methods mainly focuses on developing novel extractants. Patent CN106834682A discloses a process for extracting chloride ions using a mixed extractant: A mixture of 5-40% (v / v) N235, 3-10% sec-octanol, and sulfonated kerosene is used as the extractant to extract chloride ions from a zinc sulfate solution. Tartaric acid, a complexing agent, is mixed with the zinc sulfate solution, controlling the acidity at 10-100 g / L, and then the extractant is added and thoroughly mixed for extraction. This method can extract up to 80% of the chloride ions in the solution.

[0004] Existing methods for removing fluoride ions mainly include adsorption, extraction, and precipitation. Adsorption has low removal efficiency; extraction is complex and difficult to automate industrial processes; and precipitation results in poor solution filtration performance. Current research on defluorination methods primarily focuses on precipitation and adsorption, aiming to maximize the removal of fluoride ions from zinc sulfate solutions by developing novel precipitants and adsorbents. Patent CN114807626A discloses a method for defluorination using lead-based defluorinating agent powder: lead oxide or lead hydroxide is added to a fluoride-free zinc sulfate solution at a solid-liquid ratio (g / mL) of 1–5:1 and wet-milled to form a slurry; the slurry is added to the zinc sulfate solution to be defluorinated and stirred evenly, controlling the mass ratio of defluorinating agent to fluoride at 100–200:1; then, industrial sulfuric acid with a mass percentage greater than 90% is added to the mixture, the temperature is controlled at 40–85℃, and the reaction is stirred for 90–150 minutes before filtration to obtain a defluorinated zinc sulfate solution. Patent CN105483378B discloses a method for defluorinating silicon slag: Water glass solution and dilute sulfuric acid solution are repeatedly added to a sulfate medium solution, and nano-sized silicon slag is precipitated under conditions of 40–90℃ and pH 7–10, followed by calcination. The calcined silicon slag is then added to a fluorine-containing zinc sulfate solution with pH ≤ 5.0, controlling the mass ratio of silicon slag to fluorine to be 20–80:1. After stirring and adsorption for 1–2 hours, fluoride ions in the zinc sulfate solution are removed. The silicon slag can be recycled after water washing and alkali washing.

[0005] There are also studies on the use of the EST method for defluorination and dechlorination of zinc sulfate solution. Patent CN109626482B discloses a method for removing fluoride and chloride ions using electro-induced adsorption: activated carbon and fly ash-based zeolite are mixed in a weight ratio of 1:1 to 5 as an intermediate electrode. An external voltage and a stirring device are applied to adsorb fluoride and chloride ions from the zinc sulfate solution. After adsorption, the adsorbent can be regenerated by applying a reverse potential. This method can remove more than 90% of fluoride ions and more than 60% of chloride ions from the system.

[0006] Existing methods for removing fluoride and chlorine are costly, have low removal rates, are not easily industrialized, and are even less suitable for deep purification of fluoride and chlorine to reduce their content to meet industrial standards. Therefore, a method for deep purification of fluoride and chlorine in solution is needed. Summary of the Invention

[0007] To address the problems and shortcomings of the existing technology, this invention provides a continuous purification device and method for separating fluoride or chloride ions from zinc sulfate solution. This invention provides a method for continuously separating fluoride and chloride ions from zinc sulfate solution by utilizing an external electric field and constructing ion channels. This invention can achieve continuous, efficient, environmentally friendly, and low-cost separation of impurity ions from zinc sulfate solution, with controllable purification depth, avoiding the disadvantages of high cost, low removal rate, and inconvenience for industrialization of traditional methods. This invention is achieved through the following technical solutions.

[0008] The pH of the leachate obtained from the wet zinc leaching process is approximately 4–5. Under these conditions, fluoride and chloride elements in the solution exist in ionic form. Because fluoride or chloride ions differ from sulfate ions in their hydration radius and mass-to-charge ratio, their migration rates differ under a uniform electric field. By constructing ion channels to enhance the difference in migration rates between fluoride or chloride ions and sulfate ions, they can be separated, achieving the purpose of separation and purification.

[0009] A continuous purification device for separating fluoride or chloride ions from zinc sulfate solution is composed of n identical separation units connected in series. Each separation unit includes an anode chamber K1, a treatment chamber K2, a cathode chamber K3, a purification liquid inlet F1, a purification liquid outlet F2, an enrichment liquid outlet F3, a cathode electrode liquid outlet F4, a cathode electrode liquid inlet F5, an anode electrode liquid outlet F6, an anode electrode liquid inlet F7, an ion channel F8, a cathode electrode F9, an anode electrode F10, an anion exchange membrane F11, and a cation exchange membrane F12.

[0010] The interior of the treatment chamber K2 is divided into a cathode chamber K3, an ion channel F8, and an anode chamber K1 by an anion exchange membrane F11 and a cation exchange membrane F12, respectively. The anode chamber K1 is equipped with an anode electrode F10, and the cathode chamber K3 is equipped with a cathode electrode F9. The anode electrode F10 and the cathode electrode F9 are connected to an external electric field (the anode electrode F10 and the cathode electrode F9 are connected to a potentiometer through wires). The lower side of the anode chamber K1 is equipped with an anode electrode liquid inlet F7 and the upper side is equipped with an anode electrode liquid outlet F6. The lower side of the cathode chamber K3 is equipped with a cathode electrode liquid inlet F5 and the upper side is equipped with a cathode electrode liquid outlet F4.

[0011] The upper end of the treatment chamber K2 is equipped with a purification liquid inlet F1 that connects to the ion channel F8. At the bottom of the ion channel F8, there is a enrichment liquid outlet F3 next to the anode chamber K1 and a purification liquid outlet F2 next to the cathode chamber K3.

[0012] The purified liquid outlet F2 of the n-1 stage separation unit in the n-stage separation unit is connected to the purified liquid inlet F1 of the n-stage separation unit, and the enriched liquid outlet F3 of the n-stage separation unit is connected to the purified liquid inlet F1 of the n-1 stage separation unit. The enriched liquid outlet F3 in the separation unit 1 is returned to the purified liquid inlet F1 in the separation unit 1 after the fluoride or chloride ions are removed by chemical method.

[0013] The ion channel F8 is filled with one or more of the following materials: silicon powder, graphite powder, graphene, charcoal powder, bamboo charcoal powder, coke powder, carbon black, biomass carbon, silicon carbide, boron carbide, boron nitride, silicon nitride, COF material, and MOF-COF hybrid material, with a particle size of 5 to 100 μm.

[0014] The cathode electrode F9 and anode electrode F10 are platinum-plated titanium mesh electrodes, carbon cloth electrodes, graphite electrodes, or gold electrodes.

[0015] A method for applying a continuous purification device for separating fluoride or chloride ions in zinc sulfate solution, the specific steps of which are as follows:

[0016] S1. Calculate the required number of separation units n based on the concentrations of fluoride and chloride ions in the pre-purification liquid, the purification index requirements, and the separation ratio; and set the n-stage separation units in series.

[0017] S2. The pre-purification liquid is introduced into the device through the purification liquid inlet F1 of the separation unit 1.

[0018] S3. The electrode liquid is introduced into the cathode chamber K3 and anode chamber K1 through the cathode electrode liquid inlet F5 and anode electrode liquid inlet F7 of each separation unit. The electrode liquid is collected from the cathode electrode liquid outlet F4 and anode electrode liquid outlet F6 of each separation device for recycling. A constant potentiometer is used to provide a stable electric field for each separation unit device.

[0019] S4. Purified zinc sulfate solution can be continuously obtained at the purified liquid outlet F2 of separation unit n.

[0020] The rates of controlling the pre-purification solution and electrode solution in S2 and S3 are 1×10 -6 ~3×10 -5 m / s.

[0021] The voltage of the potentiometer in S3 is 1.0 to 3.0V.

[0022] The electrode solution in S3 is a sulfuric acid solution with a sulfuric acid content of 100-200 g / L.

[0023] The separation ratio is defined as the ratio of the concentration of fluoride or chlorine in the solution obtained from the enriched liquid outlet F3 and the purified liquid outlet F2 after separation and purification by each separation unit. The separation ratio is related to factors such as the structure of the separation unit device, the type of packing, and the voltage, and was measured by previous experiments.

[0024] The method for calculating the number of separation units n is as follows:

[0025] The concentration of fluoride or chloride ions in the initial solution is calculated by dividing twice the concentration by the separation ratio. Similarly, the concentration of fluoride or chloride ions in the purified solution 1 after separation by separation unit 1 is calculated by dividing twice the concentration by the separation ratio. The concentration of fluoride or chloride ions in the purified solution 1 after separation by separation unit 2 is calculated by dividing twice the concentration by the separation ratio. This process is repeated for each unit. By comparing the concentration of fluoride or chloride ions in the purified solution obtained from each unit with the required purification standards, it is determined whether the number of separation units needs to be increased. The minimum number of separation units required to meet the purification standards is denoted as n.

[0026] Its process flow is as follows:

[0027] The pre-purification liquid was diluted with 1×10 -6 ~3×10 -5 The electrode solution is introduced into the device through the purified liquid inlet F1 of separation unit 1 at a rate of 1 × 10 m / s. -6 ~3×10 -5 A flow rate of m / s is introduced into the cathode chamber K3 and anode chamber K1 through the cathode electrode liquid inlet F5 and anode electrode liquid inlet F7 of each separation unit. The electrode liquid from the cathode electrode liquid outlet F4 and anode electrode liquid outlet F6 of each separation unit is collected for recycling. The electrode liquid is a sulfuric acid solution, with a sulfuric acid content preferably of 100-200 g / L. After separation and purification in separation unit 1, enriched liquid 1 and purified liquid 1 are obtained. Fluorine and chloride ions can be removed from enriched liquid 1 using chemical methods. The resulting defluorinated and dechlorinated liquid is mixed with the unpurified liquid and then separated and purified again through separation unit 1. Purified liquid 1 directly enters separation unit 2 for further separation and purification. After separation and purification in separation unit 2, enriched liquid 2 and purified liquid 2 are obtained. Enriched liquid 2 is mixed with the unpurified liquid and then separated and purified again through separation unit 1. Purified liquid 2 directly enters separation unit 3 for further separation and purification. This process continues until separation and purification in separation unit n, where enriched liquid n and purified liquid n-1 are obtained. Enriched liquid n is mixed with purified liquid n-1 and then separated and purified again through separation unit n-1.

[0028] The beneficial effects of this invention are:

[0029] 1. This invention utilizes an external electric field and constructs ion channels to separate fluoride and chloride ions from zinc sulfate solution, achieving controllable purification depth and low operating costs.

[0030] 2. This invention is easy to operate, meets the needs of continuous industrial production, and facilitates the realization of industrial process and automation. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of the present invention.

[0032] Figure 2 This is a schematic diagram of the separation unit device of the present invention; wherein K1-anode chamber, K2-processing chamber, K3-cathode chamber, F1-purified liquid inlet, F2-purified liquid outlet, F3-enriched liquid outlet, F4-cathode electrode liquid outlet, F5-cathode electrode liquid inlet, F6-anode electrode liquid outlet, F7-anode electrode liquid inlet, F8-ion channel, F9-cathode electrode, F10-anode electrode, F11-anion exchange membrane, F12-cation exchange membrane.

[0033] Figure 3 This is a graph showing the change in chloride ion content obtained in Example 1 of the present invention.

[0034] Figure 4 This is a graph showing the change in chloride ion content obtained in Example 2 of the present invention.

[0035] Figure 5 This is a graph showing the change in fluoride ion content obtained in Example 3 of the present invention.

[0036] Figure 6 This is a graph showing the change in fluoride ion content obtained in Example 4 of the present invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] like Figure 2 As shown, the continuous purification device for separating fluoride or chloride ions in zinc sulfate solution is composed of n identical separation units connected in series. Each separation unit includes an anode chamber K1, a treatment chamber K2, a cathode chamber K3, a purification liquid inlet F1, a purification liquid outlet F2, an enrichment liquid outlet F3, a cathode electrode liquid outlet F4, a cathode electrode liquid inlet F5, an anode electrode liquid outlet F6, an anode electrode liquid inlet F7, an ion channel F8, a cathode electrode F9, an anode electrode F10, an anion exchange membrane F11, and a cation exchange membrane F12.

[0040] The interior of the treatment chamber K2 is divided into a cathode chamber K3, an ion channel F8, and an anode chamber K1 by an anion exchange membrane F11 and a cation exchange membrane F12, respectively. The anode chamber K1 is equipped with an anode electrode F10, and the cathode chamber K3 is equipped with a cathode electrode F9. The anode electrode F10 and the cathode electrode F9 are connected to an external electric field (the anode electrode F10 and the cathode electrode F9 are connected to a potentiometer through wires). The lower side of the anode chamber K1 is equipped with an anode electrode liquid inlet F7 and the upper side is equipped with an anode electrode liquid outlet F6. The lower side of the cathode chamber K3 is equipped with a cathode electrode liquid inlet F5 and the upper side is equipped with a cathode electrode liquid outlet F4.

[0041] The upper end of the treatment chamber K2 is equipped with a purification liquid inlet F1 that connects to the ion channel F8. At the bottom of the ion channel F8, there is a enrichment liquid outlet F3 next to the anode chamber K1 and a purification liquid outlet F2 next to the cathode chamber K3.

[0042] The purified liquid outlet F2 of the n-1 stage separation unit in the n-stage separation unit is connected to the purified liquid inlet F1 of the n-stage separation unit, and the enriched liquid outlet F3 of the n-stage separation unit is connected to the purified liquid inlet F1 of the n-1 stage separation unit. The enriched liquid outlet F3 in the separation unit 1 is returned to the purified liquid inlet F1 in the separation unit 1 after the fluoride or chloride ions are removed by chemical method.

[0043] The anion exchange membrane F11 is a Fumasep FAA-3-20 anion exchange membrane and the cation exchange membrane F12 is a Nafion117 cation exchange membrane. The ion channels are filled with graphene with a particle size of 5-10 μm. The anode electrode F10 and the cathode electrode F9 are both platinum-plated titanium mesh.

[0044] like Figure 1 As shown, the application method of the continuous purification device for separating fluoride or chloride ions in the zinc sulfate solution is as follows:

[0045] S1. Based on the concentrations of fluoride and chloride ions in the pre-purification liquid, the purification requirements, and the separation ratio, calculate the required number of separation units, n; and connect the n-stage separation units in series. The separation ratio corresponding to this separation unit is 12.5. The chloride ion content in the pre-purification liquid is 538.9 mg / L. After one stage of separation, the chloride ion content in the purified liquid should be 86.22 mg / L, meeting the purification requirement that the chloride ion content should not exceed 100 mg / L. Therefore, the required number of separation stages is 1, and the required number of separation units is 1.

[0046] S2. The pre-purification liquid is introduced into the device through the purified liquid inlet F1 of separation unit 1; the pre-purification liquid is introduced at a rate of 7.5 × 10⁻⁶. -6 A flow rate of m / s is introduced into the treatment chamber K2 through the purification liquid inlet F1;

[0047] S3. The electrode solution is introduced into the cathode chamber K3 and anode chamber K1 from the cathode electrode solution inlet F5 and anode electrode solution inlet F7 of each separation unit. The electrode solution from the cathode electrode solution outlet F4 and anode electrode solution outlet F6 of each separation device is collected for recycling (electrode solution at a rate of 6.25 × 10⁻⁶). -6 A flow rate of m / s is introduced into the cathode chamber K3 and anode chamber K1 through the cathode electrode liquid inlet F5 and the anode electrode liquid inlet F7; a constant potentiometer is used to provide a stable electric field for each separation unit (the anode electrode F10 and the cathode electrode F9 are connected to the negative and positive terminals of the constant potentiometer respectively through wires, and the constant potentiometer provides a voltage of 2.0V to the device).

[0048] S4. Purified zinc sulfate solution can be continuously obtained at the purified liquid outlet F2 of separation unit n.

[0049] Before purification, the zinc ion content in the solution was 60 g / L; the sulfuric acid content in the electrode solution was 160 g / L. During purification, the average concentration of sulfuric acid in the electrode solution remained stable at 160 ± 3.5 g / L, allowing for recycling.

[0050] The changes in chloride ion content at the purified liquid outlet F2 and the enriched liquid outlet F3 obtained in this embodiment are shown in the figure below. Figure 3 As shown, from Figure 3 As can be seen, after 2.5 hours of separation and purification, the chloride ion concentration in the purified liquid outlet F2 stabilized at 81±10 mg / L, and the zinc ion content remained at 60±2.5 g / L; the chloride ion concentration in the enriched liquid outlet F3 stabilized at 1±0.03 g / L. The enriched liquid from outlet F3 can be treated with copper sponge to remove chloride ions, followed by solid-liquid separation. The dechlorinated liquid is then mixed with the pre-purification liquid and subjected to further separation and purification by this device.

[0051] Example 2

[0052] like Figure 2 As shown, the continuous purification device for separating fluoride or chloride ions in zinc sulfate solution is composed of n identical separation units connected in series. Each separation unit includes an anode chamber K1, a treatment chamber K2, a cathode chamber K3, a purification liquid inlet F1, a purification liquid outlet F2, an enrichment liquid outlet F3, a cathode electrode liquid outlet F4, a cathode electrode liquid inlet F5, an anode electrode liquid outlet F6, an anode electrode liquid inlet F7, an ion channel F8, a cathode electrode F9, an anode electrode F10, an anion exchange membrane F11, and a cation exchange membrane F12.

[0053] The interior of the treatment chamber K2 is divided into a cathode chamber K3, an ion channel F8, and an anode chamber K1 by an anion exchange membrane F11 and a cation exchange membrane F12, respectively. The anode chamber K1 is equipped with an anode electrode F10, and the cathode chamber K3 is equipped with a cathode electrode F9. The anode electrode F10 and the cathode electrode F9 are connected to an external electric field (the anode electrode F10 and the cathode electrode F9 are connected to a potentiometer through wires). The lower side of the anode chamber K1 is equipped with an anode electrode liquid inlet F7 and the upper side is equipped with an anode electrode liquid outlet F6. The lower side of the cathode chamber K3 is equipped with a cathode electrode liquid inlet F5 and the upper side is equipped with a cathode electrode liquid outlet F4.

[0054] The upper end of the treatment chamber K2 is equipped with a purification liquid inlet F1 that connects to the ion channel F8. At the bottom of the ion channel F8, there is a enrichment liquid outlet F3 next to the anode chamber K1 and a purification liquid outlet F2 next to the cathode chamber K3.

[0055] The purified liquid outlet F2 of the n-1 stage separation unit in the n-stage separation unit is connected to the purified liquid inlet F1 of the n-stage separation unit, and the enriched liquid outlet F3 of the n-stage separation unit is connected to the purified liquid inlet F1 of the n-1 stage separation unit. The enriched liquid outlet F3 in the separation unit 1 is returned to the purified liquid inlet F1 in the separation unit 1 after the fluoride or chloride ions are removed by chemical method.

[0056] The anion exchange membrane F11 is a Fumasep FAA-3-30 anion exchange membrane and the cation exchange membrane F12 is a Nafion 115 cation exchange membrane. The ion channels are filled with silicon carbide with a particle size of 5 μm. The anode electrode F10 and the cathode electrode F9 are both carbon cloth electrodes.

[0057] like Figure 1 As shown, the application method of the continuous purification device for separating fluoride or chloride ions in the zinc sulfate solution is as follows:

[0058] S1. Based on the concentrations of fluoride and chloride ions in the pre-purification liquid, the purification requirements, and the separation ratio, calculate the required number of separation units, n; and connect the n-stage separation units in series. The separation ratio corresponding to this separation unit is 6.4, and the chloride ion content in the pre-purification liquid is 275.8 mg / L. After two-stage separation, the chloride ion content in the purified liquid should be 86.20 mg / L, meeting the purification requirement that the chloride ion content should not exceed 100 mg / L. Therefore, the required number of separation stages is 2, and the number of separation units is 2.

[0059] S2. The pre-purification liquid is introduced into the device through the purified liquid inlet F1 of separation unit 1; the pre-purification liquid is introduced at a rate of 4.25 × 10⁻⁶. - 6 A flow rate of m / s is introduced into the treatment chamber K2 through the purification liquid inlet F1;

[0060] S3. The electrode solution is introduced into the cathode chamber K3 and anode chamber K1 from the cathode electrode solution inlet F5 and anode electrode solution inlet F7 of each separation unit. The electrode solution from the cathode electrode solution outlet F4 and anode electrode solution outlet F6 of each separation device is collected for recycling (electrode solution at a rate of 6.25 × 10⁻⁶). -6 A flow rate of m / s is introduced into the cathode chamber K3 and anode chamber K1 through the cathode electrode liquid inlet F5 and the anode electrode liquid inlet F7; a constant potentiometer is used to provide a stable electric field for each separation unit (the anode electrode F10 and the cathode electrode F9 are connected to the negative and positive terminals of the constant potentiometer respectively through wires, and the constant potentiometer provides a voltage of 1.8V to the device).

[0061] S4. Purified zinc sulfate solution can be continuously obtained at the purified liquid outlet F2 of separation unit n.

[0062] Before purification, the zinc ion content in the solution was 60 g / L; the sulfuric acid content in the electrode solution was 100 g / L. During purification, the average concentration of sulfuric acid in the electrode solution remained stable at 100 ± 3 g / L, allowing for recycling.

[0063] The changes in chloride ion content at the outlet F2 of the purified liquid from separation unit 2 and the outlet F3 of the enriched liquid from separation unit 1 obtained in this embodiment are shown in the figure below. Figure 4 As shown, from Figure 4 As can be seen, after 2.5 hours of separation and purification, the chloride ion concentration in the purified liquid outlet F2 of separation unit 2 remained stable at 85±10 mg / L, and the zinc ion content remained at 60±2.5 g / L; the chloride ion concentration in the enriched liquid outlet F3 of separation unit 1 remained stable at 1.68±0.035 g / L. The enriched liquid from outlet F3 of separation unit 1 can be treated with copper sponge to remove chloride ions, followed by solid-liquid separation. The dechlorinated liquid is then mixed with the pre-purification liquid and further separated and purified by separation unit 1.

[0064] Example 3

[0065] like Figure 2 As shown, the continuous purification device for separating fluoride or chloride ions in zinc sulfate solution is composed of n identical separation units connected in series. Each separation unit includes an anode chamber K1, a treatment chamber K2, a cathode chamber K3, a purification liquid inlet F1, a purification liquid outlet F2, an enrichment liquid outlet F3, a cathode electrode liquid outlet F4, a cathode electrode liquid inlet F5, an anode electrode liquid outlet F6, an anode electrode liquid inlet F7, an ion channel F8, a cathode electrode F9, an anode electrode F10, an anion exchange membrane F11, and a cation exchange membrane F12.

[0066] The interior of the treatment chamber K2 is divided into a cathode chamber K3, an ion channel F8, and an anode chamber K1 by an anion exchange membrane F11 and a cation exchange membrane F12, respectively. The anode chamber K1 is equipped with an anode electrode F10, and the cathode chamber K3 is equipped with a cathode electrode F9. The anode electrode F10 and the cathode electrode F9 are connected to an external electric field (the anode electrode F10 and the cathode electrode F9 are connected to a potentiometer through wires). The lower side of the anode chamber K1 is equipped with an anode electrode liquid inlet F7 and the upper side is equipped with an anode electrode liquid outlet F6. The lower side of the cathode chamber K3 is equipped with a cathode electrode liquid inlet F5 and the upper side is equipped with a cathode electrode liquid outlet F4.

[0067] The upper end of the treatment chamber K2 is equipped with a purification liquid inlet F1 that connects to the ion channel F8. At the bottom of the ion channel F8, there is a enrichment liquid outlet F3 next to the anode chamber K1 and a purification liquid outlet F2 next to the cathode chamber K3.

[0068] The purified liquid outlet F2 of the n-1 stage separation unit in the n-stage separation unit is connected to the purified liquid inlet F1 of the n-stage separation unit, and the enriched liquid outlet F3 of the n-stage separation unit is connected to the purified liquid inlet F1 of the n-1 stage separation unit. The enriched liquid outlet F3 in the separation unit 1 is returned to the purified liquid inlet F1 in the separation unit 1 after the fluoride or chloride ions are removed by chemical method.

[0069] The anion exchange membrane F11 is a Fumasep FAA-3-PE-30 anion exchange membrane and the cation exchange membrane F12 is a Nafion117 cation exchange membrane. The ion channels are filled with boron nitride with a particle size of 50 μm. The anode electrode F10 and the cathode electrode F9 are both platinum-plated titanium mesh electrodes.

[0070] like Figure 1 As shown, the application method of the continuous purification device for separating fluoride or chloride ions in the zinc sulfate solution is as follows:

[0071] S1. Based on the concentrations of fluoride and chloride ions in the pre-purification liquid, the purification requirements, and the separation ratio, calculate the required number of separation units, n; and connect the n-stage separation units in series. The separation ratio corresponding to this separation unit is 10.5. The fluoride ion content in the pre-purification liquid is 247.4 mg / L. After one stage of separation, the fluoride ion content in the purified liquid should be 47.18 mg / L, meeting the purification requirement that the fluoride ion content should not exceed 80 mg / L. Therefore, the required number of separation stages is 1, and the required number of separation units is 1.

[0072] S2. The pre-purification liquid is introduced into the device through the purified liquid inlet F1 of separation unit 1; the pre-purification liquid is then introduced into the device at a rate of 3×10 -5 A flow rate of m / s is introduced into the treatment chamber K2 through the purification liquid inlet F1;

[0073] S3. The electrode solution is introduced into the cathode chamber K3 and anode chamber K1 from the cathode electrode solution inlet F5 and anode electrode solution inlet F7 of each separation unit. The electrode solution from the cathode electrode solution outlet F4 and anode electrode solution outlet F6 of each separation device is collected for recycling (electrode solution at a rate of 1×10⁻⁶). -5 A velocity of m / s is introduced into the cathode chamber K3 and anode chamber K1 through the cathode electrode liquid inlet F5 and the anode electrode liquid inlet F7; a constant potentiometer is used to provide a stable electric field for each separation unit (the anode electrode F10 and the cathode electrode F9 are connected to the negative and positive terminals of the constant potentiometer respectively through wires, and the constant potentiometer provides a voltage of 1.0V to the device).

[0074] S4. Purified zinc sulfate solution can be continuously obtained at the purified liquid outlet F2 of separation unit n.

[0075] Before purification, the zinc ion content in the solution was 60 g / L; the sulfuric acid content in the electrode solution was 80 g / L. During purification, the average concentration of sulfuric acid in the electrode solution remained stable at 80 ± 2 g / L, allowing for recycling.

[0076] The changes in fluoride ion concentrations at the purified liquid outlet F2 and the enriched liquid outlet F3 obtained in this embodiment are as follows: Figure 5 As shown, from Figure 5 As can be seen, after 1.5 hours of separation and purification, the fluoride ion concentration in the purified liquid outlet F2 stabilized at 38±9 mg / L, and the zinc ion content remained at 60±3 g / L; the fluoride ion concentration in the enriched liquid outlet F3 stabilized at 455±35 mg / L. The enriched liquid from the enriched liquid outlet F3 of separation unit 1 can be treated with lime slurry to remove fluoride ions, followed by solid-liquid separation. The dechlorinated liquid is then mixed with the pre-purification liquid, and the pH is adjusted to 4-5 before further separation and purification by this device.

[0077] Example 4

[0078] like Figure 2 As shown, the continuous purification device for separating fluoride or chloride ions in zinc sulfate solution is composed of n identical separation units connected in series. Each separation unit includes an anode chamber K1, a treatment chamber K2, a cathode chamber K3, a purification liquid inlet F1, a purification liquid outlet F2, an enrichment liquid outlet F3, a cathode electrode liquid outlet F4, a cathode electrode liquid inlet F5, an anode electrode liquid outlet F6, an anode electrode liquid inlet F7, an ion channel F8, a cathode electrode F9, an anode electrode F10, an anion exchange membrane F11, and a cation exchange membrane F12.

[0079] The interior of the treatment chamber K2 is divided into a cathode chamber K3, an ion channel F8, and an anode chamber K1 by an anion exchange membrane F11 and a cation exchange membrane F12, respectively. The anode chamber K1 is equipped with an anode electrode F10, and the cathode chamber K3 is equipped with a cathode electrode F9. The anode electrode F10 and the cathode electrode F9 are connected to an external electric field (the anode electrode F10 and the cathode electrode F9 are connected to a potentiometer through wires). The lower side of the anode chamber K1 is equipped with an anode electrode liquid inlet F7 and the upper side is equipped with an anode electrode liquid outlet F6. The lower side of the cathode chamber K3 is equipped with a cathode electrode liquid inlet F5 and the upper side is equipped with a cathode electrode liquid outlet F4.

[0080] The upper end of the treatment chamber K2 is equipped with a purification liquid inlet F1 that connects to the ion channel F8. At the bottom of the ion channel F8, there is a enrichment liquid outlet F3 next to the anode chamber K1 and a purification liquid outlet F2 next to the cathode chamber K3.

[0081] The purified liquid outlet F2 of the n-1 stage separation unit in the n-stage separation unit is connected to the purified liquid inlet F1 of the n-stage separation unit, and the enriched liquid outlet F3 of the n-stage separation unit is connected to the purified liquid inlet F1 of the n-1 stage separation unit. The enriched liquid outlet F3 in the separation unit 1 is returned to the purified liquid inlet F1 in the separation unit 1 after the fluoride or chloride ions are removed by chemical method.

[0082] The anion exchange membrane F11 is a Fumasep FAA-3-PK-130 anion exchange membrane and the cation exchange membrane F12 is a SIN-D117 cation exchange membrane. The ion channels are filled with graphite powder with a particle size of 30μm. The anode electrode F10 and the cathode electrode F9 are both platinum electrodes.

[0083] like Figure 1 As shown, the application method of the continuous purification device for separating fluoride or chloride ions in the zinc sulfate solution is as follows:

[0084] S1. Based on the concentrations of fluoride and chloride ions in the pre-purification liquid, the purification requirements, and the separation ratio, calculate the required number of separation units, n; and connect the n-stage separation units in series. The separation ratio corresponding to this separation unit is 5.5. The fluoride ion content in the pre-purification liquid is 392.5 mg / L. After the first-stage separation, the fluoride ion content in the purified liquid should be 142.7 mg / L; after the second-stage separation, the fluoride ion content in the purified liquid should be 51.90 mg / L, meeting the purification requirement that the fluoride ion content should not exceed 80 mg / L. Therefore, the required number of separation stages is 2, and the required number of separation units is 2.

[0085] S2. The pre-purification liquid is introduced into the device through the purified liquid inlet F1 of separation unit 1; the pre-purification liquid is then introduced into the device at a rate of 1×10 -5 A flow rate of m / s is introduced into the treatment chamber K2 through the purification liquid inlet F1;

[0086] S3. The electrode solution is introduced into the cathode chamber K3 and anode chamber K1 from the cathode electrode solution inlet F5 and anode electrode solution inlet F7 of each separation unit. The electrode solution from the cathode electrode solution outlet F4 and anode electrode solution outlet F6 of each separation device is collected for recycling (electrode solution at a rate of 8.75 × 10⁻⁶). -6 A flow rate of m / s is introduced into the cathode chamber K3 and anode chamber K1 through the cathode electrode liquid inlet F5 and the anode electrode liquid inlet F7; a constant potentiometer is used to provide a stable electric field for each separation unit (the anode electrode F10 and the cathode electrode F9 are connected to the negative and positive terminals of the constant potentiometer respectively through wires, and the constant potentiometer provides a voltage of 1.8V to the device).

[0087] S4. Purified zinc sulfate solution can be continuously obtained at the purified liquid outlet F2 of separation unit n.

[0088] Before purification, the zinc ion content in the solution was 60 g / L; the sulfuric acid content in the electrode solution was 120 g / L. During purification, the average concentration of sulfuric acid in the electrode solution remained stable at 120 ± 3 g / L, allowing for recycling.

[0089] The changes in fluoride ion concentrations at the outlet F2 of the purified liquid from separation unit 2 and the outlet F3 of the enriched liquid from separation unit 1 obtained in this embodiment are as follows: Figure 6 As shown, from Figure 6 As can be seen, after 1.5 hours of separation and purification, the fluoride ion concentration in the purified liquid outlet F2 of separation unit 2 remained stable at 38±8 mg / L, and the zinc ion content remained at 60±2 g / L; the fluoride ion concentration in the enriched liquid outlet F3 of separation unit 1 remained stable at 740±20 mg / L. The enriched liquid from outlet F3 of separation unit 1 can be treated with lime slurry to remove fluoride ions, followed by solid-liquid separation. The dechlorinated liquid is then mixed with the pre-purification liquid, the pH is adjusted to 4-5, and then further separated and purified by separation unit 1.

[0090] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A continuous purification apparatus for separating fluorine or chlorine ions from a zinc sulfate solution, characterized by: The n-stage separation unit is composed of n-stage separation units in series, each of which comprises an anode chamber (K1), a treatment chamber (K2), a cathode chamber (K3), a purified liquid inlet (F1), a purified liquid outlet (F2), an enriched liquid outlet (F3), a cathode electrode liquid outlet (F4), a cathode electrode liquid inlet (F5), an anode electrode liquid outlet (F6), an anode electrode liquid inlet (F7), an ion channel (F8), a cathode electrode (F9), an anode electrode (F10), a negative ion exchange membrane (F11) and a positive ion exchange membrane (F12); The treatment chamber (K2) is divided into the cathode chamber (K3), the ion channel (F8) and the anode chamber (K1) by the negative ion exchange membrane (F11) and the positive ion exchange membrane (F12) on both sides of the treatment chamber (K2) respectively, the anode chamber (K1) is provided with the anode electrode (F10) inside, the cathode chamber (K3) is provided with the cathode electrode (F9) inside, the anode electrode (F10) and the cathode electrode (F9) are connected to an electric field, the anode chamber (K1) is provided with the anode electrode liquid inlet (F7) at the lower side and the anode electrode liquid outlet (F6) at the upper side, and the cathode chamber (K3) is provided with the cathode electrode liquid inlet (F5) at the lower side and the cathode electrode liquid outlet (F4) at the upper side; The treatment chamber (K2) is provided with the purified liquid inlet (F1) at the upper end, which is communicated with the ion channel (F8), the ion channel (F8) is provided with the enriched liquid outlet (F3) beside the anode chamber (K1) and the purified liquid outlet (F2) beside the cathode chamber (K3) respectively; The purified liquid outlet (F2) of the n-1th separation unit in the n-stage separation unit is communicated with the purified liquid inlet (F1) of the nth separation unit, the enriched liquid outlet (F3) of the nth separation unit is communicated with the purified liquid inlet (F1) of the n-1th separation unit, and the enriched liquid outlet (F3) in the first separation unit returns to the purified liquid inlet (F1) in the first separation unit after the fluorine or chlorine ions are removed by a chemical method.

2. The continuous purification apparatus for separating fluorine or chlorine ions from a zinc sulfate solution according to claim 1, characterized in that: The ion channel (F8) is filled with one or a mixture of several of silicon powder, graphite powder, graphene, charcoal powder, bamboo charcoal powder, coke powder, carbon black, silicon carbide, boron carbide, boron nitride, silicon nitride, COF material, MOF-COF hybrid material, and the particle size is 5-100 μm.

3. The continuous purification apparatus for separating fluorine or chlorine ions from a zinc sulfate solution according to claim 1, characterized in that: The cathode electrode (F9) and the anode electrode (F10) are platinized titanium mesh electrodes, carbon cloth electrodes, graphite electrodes or gold electrodes.

4. Use of a continuous purification device for separating fluorine or chlorine ions from a zinc sulfate solution according to any one of claims 1 to 3, characterized in that The specific steps are as follows: S1, according to the fluorine and chlorine ion concentration in the liquid before purification, the index requirement of purification and the separation ratio, the number n of required separation units is calculated, and the n-stage separation units are arranged in series; S2, the liquid before purification is introduced into the device from the purified liquid inlet (F1) of the first separation unit; S3, the electrode liquid is introduced into the cathode chamber (K3) and the anode chamber (K1) from the cathode electrode liquid inlet (F5) and the anode electrode liquid inlet (F7) of each separation unit, the electrode liquid of the cathode electrode liquid outlet (F4) and the anode electrode liquid outlet (F6) of each separation device is collected for recycling, and a constant potential device is used to provide a stable electric field for each separation unit. S4, the purified zinc sulfate solution can be continuously obtained at the purification liquid outlet (F2) of the nth stage separation unit.

5. The method of using the continuous purification device for separating fluorine or chlorine ions from a zinc sulfate solution according to claim 4, characterized in that: The rate of the liquid before purification and the electrode liquid in S2 and S3 is 1 x 10 -6 -3 x 10 -5 m / s.

6. The method of using the continuous purification device for separating fluorine or chlorine ions from a zinc sulfate solution according to claim 4, characterized in that: The constant potential voltage in S3 is 1.0-3.0 V.

7. The method of using the continuous purification device for separating fluorine or chlorine ions from a zinc sulfate solution according to claim 5, characterized in that: The electrode liquid in S3 is a sulfuric acid solution, and the sulfuric acid content is 100-200 g / L.

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