Ultrasonic electrodeposition coupling system and method for improving zinc electrodeposition quality

Abstract

The invention discloses an ultrasonic electrodeposition coupling system and method for improving zinc electrodeposition quality, and belongs to the technical field of hydrometallurgy, the system comprises an ultrasonic electrodeposition cell, an ultrasonic generation system, a solution circulation system and a heating temperature control system; a plurality of cathode plates and anode plates are alternately arranged in the ultrasonic electrodeposition cell at intervals; the ultrasonic generation system comprises an ultrasonic generator, and the ultrasonic generator is electrically connected with the ultrasonic probe and the ultrasonic vibrator through cables; the solution circulating system comprises a solution circulating tank, a peristaltic pump, a liquid inlet pipe and a liquid discharge pipe, and the peristaltic pump conveys an electrodeposition liquid in the solution circulating tank into the ultrasonic electrodeposition tank through the liquid inlet pipe for an electrodeposition reaction; the heating temperature control system comprises a heating resistor, a thermocouple, a heating resistor power supply electrically connected with the heating resistor, and a rectification power supply electrically connected with the electrode system. Through the synergistic effect of the composite additive and the ultrasonic technology, the negative influence of impurities on zinc deposition is effectively inhibited, and the current efficiency and the zinc product quality are remarkably improved.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology, and particularly relates to an ultrasonic electrowinning coupling system and method for improving the quality of zinc electrowinning. Background Technology

[0002] Zinc electrowinning is a key process in hydrometallurgical zinc refining. During electrowinning, impurity ions (such as antimony ions) in the electrodeposition solution are prone to co-deposition or adsorption on the cathode surface, resulting in a rough, brittle zinc deposit, and even dendrite formation. This severely reduces current efficiency and affects the quality of zinc products. Traditional solutions include deep purification of the electrodeposition solution or the addition of a single inhibitor (such as colloids or thiourea). However, the former is costly and time-consuming, while the latter may have limited effectiveness or introduce new impurities.

[0003] In recent years, studies have shown that some natural polyphenolic compounds (such as tannic acid) can complex with metal ions and form an adsorption film on the electrode surface, thereby suppressing the adverse effects of impurities. On the other hand, ultrasonic technology, due to the microjets and shock waves generated by its cavitation effect, can enhance mass transfer, clean the electrode surface, and promote uniform grain nucleation, and has been attempted to improve the electrodeposition process. However, there is currently no research on the synergistic effect of specific organic additives containing polyphenolic hydroxyl functional groups (as impurity inhibitors or modifiers) with customized ultrasonic fields in the zinc electrodeposition process to systematically improve current efficiency, improve the quality of the deposited layer, and explore its synergistic mechanism. Summary of the Invention

[0004] Technical problem solved: In view of the technical problems existing in the prior art, the present invention provides an ultrasonic electrowinning coupling system and method for improving the quality of zinc electrowinning. Through the synergistic effect of composite additives and ultrasonic technology, the negative impact of impurities on zinc deposition is effectively suppressed, and the current efficiency and zinc product quality are significantly improved.

[0005] Technical solution: The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to the present invention includes: An ultrasonic electrodeposition cell, wherein multiple cathode plates and anode plates are alternately arranged in the ultrasonic electrodeposition cell to form an electrode system for the electrodeposition reaction; An ultrasonic generating system includes multiple ultrasonic probes symmetrically arranged on the sidewall of an ultrasonic electrowinning tank, multiple ultrasonic transducers uniformly distributed at the bottom of the ultrasonic electrowinning tank, and an ultrasonic generator. The ultrasonic generator is electrically connected to the ultrasonic probes and ultrasonic transducers via cables. A solution circulation system, comprising a solution circulation tank, a peristaltic pump, an inlet pipe, and a drain pipe, wherein the peristaltic pump transports the electrowinning solution in the solution circulation tank to the ultrasonic electrowinning tank for electrowinning reaction through the inlet pipe, and the drain pipe is located at the bottom of the ultrasonic electrowinning tank for discharging the electrowinning solution; The heating and temperature control system includes a heating resistor, a thermocouple, a heating resistor power supply electrically connected to the heating resistor, and a rectifier power supply electrically connected to the electrode system, all located in a solution circulation tank. The rectifier power supply is used to provide adjustable voltage and adjustable current for the electrowinning process.

[0006] Preferably, the ultrasonic probe is fitted with an ultrasonic probe protective cover on its outer side for dust prevention, corrosion prevention, and physical protection.

[0007] Preferably, the ultrasonic transducers are arranged in an array uniformly at the bottom of the ultrasonic electrowinning tank, and together with the ultrasonic probe, they form an all-round, uniformly covered ultrasonic field.

[0008] Preferably, the cathode plate is a 1060 pure aluminum plate and the anode plate is a Pb-Ag alloy plate; the two are arranged alternately in parallel along the length of the ultrasonic electrowinning cell, and the spacing between adjacent electrode plates is uniform.

[0009] Preferably, the solution circulation system further includes a stirring mechanism in the solution circulation tank for enhancing the mixing of the electrolytic electrolyte.

[0010] Preferably, a conductive slide rail is provided at the top of the ultrasonic electrowinning tank along its width direction, and the conductive slide rail is used to facilitate the installation and circuit connection of the cathode plate and the anode plate.

[0011] Preferably, the ultrasonic transducer and the ultrasonic generator are covered with a bottom protective cover; the ultrasonic probe is provided with an ultrasonic probe protective cover.

[0012] Preferably, the ultrasonic electrowinning cell is a double-layered bath-type structure, comprising an outer ultrasonic cell filled with a coupling medium and an inner electrowinning cell sealed within the outer ultrasonic cell; the frequency of the bath-type ultrasonic electrowinning cell is 40kHz, and the power adjustment range is 0-100W; the inner electrowinning cell is made of polypropylene material, and its temperature tolerance range is -20-120℃; the electrode system is powered by an intelligent constant voltage power supply with a power supply voltage of 0-20V and a power supply current of 0-15A.

[0013] The present invention also discloses a zinc electrowinning method using the above-described ultrasonic electrowinning coupling system, comprising the following steps: Step 1: Prepare Zn in the solution circulation tank 2+A zinc sulfate electrodeposition solution with an ion concentration of 45-50 g / L and an H2SO4 concentration of 165-180 g / L is prepared. A composite additive is then added to the electrodeposition solution, and the stirring mechanism is activated to mix it thoroughly. The composite additive consists of an organic additive containing polyphenolic hydroxyl functional groups at a concentration of 0-100 mg / L and antimony ions at a concentration of 0-0.5 mg / L. The organic additive containing polyphenolic hydroxyl functional groups is one or more of tannic acid, gallic acid, or tea polyphenols. Subsequently, a peristaltic pump is activated, and the electrode solution is circulated to the ultrasonic electrodeposition tank through the inlet and outlet pipes for later use. Step 2: The Pb-Ag anode plate is placed in a pretreatment solution for activation treatment, forming a uniform and dense lead dioxide coating on its surface; wherein, Zn in the pretreatment solution... 2+ The concentration of H2SO4 was 160 g / L, and the activation treatment conditions were 25℃ for 24 h. Step 3: Alternately arrange multiple activated Pb-Ag anode plates and 1060 pure aluminum cathode plates at 3cm intervals in an ultrasonic electrodeposition cell. Start the ultrasonic generator and set the ultrasonic power to 10-30W, ultrasonic treatment time to 20min, electrodeposition cell temperature to 40-42℃, and current density to 500A / m. 2 Electrowinning was performed for 1 hour under the specified conditions to obtain electrowinning zinc sheets and record the cell voltage.

[0014] Preferably, the composite additive in step 1 is a combination of tannic acid and antimony ions; wherein the tannic acid concentration is 30 mg / L and the antimony ion concentration is 0.05 mg / L, or the tannic acid concentration is 60 mg / L and the antimony ion concentration is 0.1 mg / L.

[0015] Compared with the prior art, the present invention has at least the following beneficial effects: 1. The present invention provides a composite additive for the electrowinning solution. This composite additive combines organic additives containing polyphenolic hydroxyl functional groups (such as tannic acid) with antimony ions, which can improve the surface finish of zinc electrowinning and alter zinc deposition characteristics through synergistic effects. Even at low concentrations, it can significantly improve current efficiency (up to approximately 17%), reduce cell voltage and energy consumption, and improve the surface morphology and roughness of the zinc coating, making it more uniform and dense, with increased grain size, which is beneficial for subsequent processing and product performance. At the same time, it regulates the positive behavior of electrowinning, improves coating quality, and is cost-effective. In addition, this electrowinning solution system has the advantages of strong versatility and wide adaptability. 2. This invention is equipped with an ultrasonic electrowinning coupling system, which abandons the conventional application of ultrasonic cleaning machines or cleaning tanks, and realizes the precise transfer of ultrasonic energy, stable control of the electrowinning environment, and synergistic adaptation between the two, ensuring the efficient performance of ultrasonic action; in this ultrasonic-enhanced electrowinning process, the ultrasonic action of a specific power range (10-30W) promotes the mass transfer of the electrowinning solution through cavitation effect and micro-jets, removes bubbles and impurities on the electrode surface, reduces concentration polarization, and increases the deposition rate, thereby increasing the current efficiency from 91% in the traditional process to 97%, and significantly improving the uniformity of zinc coating; 3. This invention achieves synergistic effects. The organic additive containing polyphenolic hydroxyl functional groups selectively adsorbs on the electrode surface, inhibiting the activity of impurities. Ultrasonic enhancement of mass transfer and electrode surface renewal promotes uniform zinc ion deposition. The synergistic effect of these two factors simultaneously improves current efficiency and deposition quality. At the same time, it increases the tolerance limit of the electrodeposition solution to the organic additive containing polyphenolic hydroxyl functional groups (tannic acid) and antimony ions. Under ultrasonic assistance, the tolerance concentration of tannic acid can be increased from 30 mg / L to 60 mg / L, and the tolerance concentration of antimony ions can be increased from 0.05 mg / L to 0.1 mg / L, reducing the impurity purification cost in the hydrometallurgical zinc smelting industry and improving production efficiency and raw material adaptability. 4. The system has a reasonable structural design. The ultrasonic electrodeposition cell, through the coordinated arrangement of ultrasonic probes on the side walls and ultrasonic transducers at the bottom, constructs a uniform and stable three-dimensional ultrasonic field, realizing the uniform distribution of ultrasonic energy in the electrolyte. The integrated solution circulation and heating temperature control system can achieve precise control of electrolyte temperature, flow rate, and mixing state, providing reliable equipment support for the stable implementation of the method, effectively improving mass transfer on the electrode surface, suppressing polarization, and improving deposition uniformity. The system has a compact structure and sound protection, making it suitable for continuous or intermittent industrial operations, and has good practicality and reliability. 5. This method has mild process conditions, is easy to operate, and is easy to integrate with existing wet zinc smelting processes, thus having high industrial application value and economic benefits. Attached Figure Description

[0016] Figure 1 This is a flowchart of the electrowinning method of the present invention; Figure 2 This is a bar chart comparing the current efficiency of Comparative Examples 1-6 and Examples 1-6 of the present invention; Figure 3 These are scanning electron microscope (SEM) images of the zinc deposits obtained in Comparative Examples 1, 3, and 6 and Examples 1, 3, and 6 of this invention. Figure 4 The images show the three-dimensional optical surface profiles of the zinc deposited layers obtained in Comparative Examples 1, 3, and 6 and Examples 1, 3, and 6 of this invention. Figure 5This is a bar chart comparing the grain size of the zinc deposited layers obtained in Comparative Examples 1, 3, and 6 and Examples 1, 3, and 6 of the present invention. Figure 6 The bar chart shows the cyclic voltammetry curves (a) and nucleation overpotential values ​​(b) of Comparative Examples 1, 3, and 6 and Examples 1, 3, and 6 of the present invention. Figure 7 This is a schematic diagram of the ultrasonic electrocoupling system of the present invention; Figure 8 for Figure 7 Top view of the structure of a medium-intensity ultrasonic electrowinning cell; Figure 9 for Figure 7 Schematic diagram of liquid flow in a medium solution circulation system.

[0017] Reference numerals: 1. Ultrasonic electrowinning coupling system; 2. Ultrasonic electrowinning tank; 3. Ultrasonic probe; 4. Ultrasonic probe protective cover; 5. Cathode plate; 6. Drain pipe; 7. Ultrasonic transducer; 8. Ultrasonic generator; 9. Bottom protective cover; 10. Anode plate; 11. Heating resistor power supply; 12. Peristaltic pump; 13. Heating resistor; 14. Stirring mechanism; 15. Solution circulation tank; 16. Circulation system and rectifier power supply housing; 17. Rectifier power supply; 18. Thermocouple; 19. Inlet pipe; 20. Conductive slide rail. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will be described in conjunction with the accompanying drawings. Figures 1-9 The technical solutions of the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0019] like Figures 7-9 As shown, this invention discloses an ultrasonic electrowinning coupling system for improving zinc electrowinning quality. The ultrasonic electrowinning coupling system 1 includes an ultrasonic electrowinning tank 2, an ultrasonic generation system, a solution circulation system, and a heating and temperature control system. The ultrasonic electrowinning tank 2 and the solution circulation system are connected by pipes to form a closed loop, realizing the recycling of the electrolyte and precise control of the reaction environment. The specific structures are shown below: The ultrasonic electrowinning tank 2, as the core cavity of the zinc electrowinning reaction, provides space for electrode arrangement and electrolyte containment. A drain pipe 6 is located at its bottom for discharging the electrolyte after the reaction. The ultrasonic electrowinning tank 2 can adopt a double-layer bath structure, including an outer ultrasonic tank filled with a coupling medium and an inner electrowinning tank sealed within the outer ultrasonic tank. The outer ultrasonic tank can be made of sulfuric acid-resistant stainless steel, while the inner electrowinning tank is made of polypropylene, with a temperature tolerance range of -20-120℃. Its volume can be adjusted according to production scale. The outer ultrasonic tank and the inner electrowinning tank are connected in a sealed nested manner to prevent medium leakage. The side wall of the ultrasonic electrowinning tank 2 has reserved mounting ports for ultrasonic probes or ultrasonic transducers and a solution circulation interface. The mounting ports are insulated and sealed, and the circulation interface is precisely connected to the solution circulation system.

[0020] Multiple cathode plates 5 and anode plates 10 are alternately arranged within the ultrasonic electrodeposition cell 2, forming an electrode system for the electrodeposition reaction. The electrode system is powered by an intelligent constant voltage power supply with a supply voltage of 0-20V and a supply current of 0-15A. The cathode plates 5 are made of 1060 pure aluminum, and the anode plates 10 are made of Pb-Ag alloy. They are arranged alternately and parallel to each other along the length of the ultrasonic electrodeposition cell 2, with uniform spacing between adjacent electrode plates to ensure a balanced electric field distribution and provide a stable electrode environment for the electrodeposition reaction. A rectifier power supply 17 is provided in conjunction with the electrode system to provide adjustable voltage and current for the electrodeposition process.

[0021] The ultrasonic generation system includes an ultrasonic probe 3, an ultrasonic transducer 7, and an ultrasonic generator 8. The ultrasonic probe 3 comprises multiple probes symmetrically arranged at both ends of the sidewall of the ultrasonic electrowinning tank 2. The ultrasonic transducers 7 are uniformly arranged in an array at the bottom of the ultrasonic electrowinning tank 2, and together with the ultrasonic probes 3, form a comprehensive and uniformly covering ultrasonic field. The ultrasonic generator 8 is electrically connected to the ultrasonic probes 3 and ultrasonic transducers 7 via cables. By adjusting the output power and frequency, it drives the ultrasonic probes 3 and ultrasonic transducers 7 to generate ultrasonic energy, which is then transferred to the electrolyte through the tank, enhancing the mass transfer process. The ultrasonic frequency of the bath-type ultrasonic electrowinning tank is 40kHz, and the power adjustment range is 0-100W.

[0022] An ultrasonic probe protective cover 4 is fitted on the outside of the ultrasonic probe 3 for dust prevention, corrosion prevention and physical protection; the ultrasonic transducer 7 and the ultrasonic generator 8 are covered with a bottom protective cover 9 to protect and fix the bottom ultrasonic components.

[0023] The solution circulation system includes a solution circulation tank 15 and a conveying assembly. The solution circulation tank 15 serves as a buffer chamber for electrolyte storage and circulation, ensuring a stable electrolyte supply. The conveying assembly includes a peristaltic pump 12, an inlet pipe 19, and a drain pipe 6. The peristaltic pump 12 connects the solution circulation tank 15 and the ultrasonic electrowinning tank 2 through the inlet pipe 19 and the drain pipe 6 to form a continuous loop. The peristaltic pump 12 conveys the electrowinning solution in the solution circulation tank 15 to the ultrasonic electrowinning tank 2 for electrowinning reaction. The drain pipe 6 is located at the bottom of the ultrasonic electrowinning tank 2 to discharge the electrowinning solution. The flow channel inner diameter, flow rate, and rotation speed of the peristaltic pump 12 are all adjustable, allowing for flexible adjustment of the electrolyte mass transfer efficiency according to production needs.

[0024] The heating and temperature control system includes a heating resistor 13, a thermocouple 18, and a heating resistor power supply 11 electrically connected to the heating resistor 13, which are installed in the solution circulation tank 15. The heating resistor 13 and the heating resistor power supply 11 are electrically connected and work with the thermocouple 18 to achieve precise control of the temperature of the electrowinning solution, ensuring that the electrowinning reaction is carried out at a suitable temperature.

[0025] The solution circulation system also includes a stirring mechanism 14 installed in the solution circulation tank 15 to enhance the mixing of the electrolyte, further enhancing the mixing during the electrolyte circulation process, avoiding uneven additive concentration, and improving reaction consistency.

[0026] The power supply components include a rectifier power supply 17 and a conductive slide rail 20. The rectifier power supply 17 is integrated inside the circulation system and the rectifier power supply housing 16. The conductive slide rail 20 is set at the top of the ultrasonic electrowinning tank 2 along its width direction. The conductive slide rail 20 is used to facilitate the installation and circuit connection of the cathode plate 5 and the anode plate 10. The rectifier power supply 17 can provide a stable power supply with adjustable voltage and adjustable current to meet the requirements of different electrowinning processes.

[0027] When this system is working, the solution circulation system and the heating and temperature control system are started first to make the electrolyte reach the set concentration and temperature and circulate. Then, the ultrasonic generator 8 is turned on to establish a uniform ultrasonic field in the ultrasonic electrowinning tank. Finally, the rectifier power supply 17 is turned on to carry out the zinc electrowinning reaction. The introduction of the ultrasonic field effectively reduces concentration polarization and improves the deposition rate and coating quality.

[0028] like Figure 1 As shown, the present invention also discloses a zinc electrowinning method using the above-described ultrasonic electrowinning coupling system, comprising the following steps: Step 1: Prepare Zn in solution circulation tank 15 2+A zinc sulfate electrolytic solution with an ion concentration of 45-50 g / L and an H2SO4 concentration of 165-180 g / L is prepared. A composite additive is then added to the electrolytic solution, and the stirring mechanism 14 is activated to mix it evenly. The composite additive consists of an organic additive containing polyphenolic hydroxyl functional groups at a concentration of 0-100 mg / L and antimony ions at a concentration of 0-0.5 mg / L. The organic additive containing polyphenolic hydroxyl functional groups is one or more of tannic acid, gallic acid, or tea polyphenols. Preferably, the organic additive containing polyphenolic hydroxyl functional groups is tannic acid, and its concentration can be selected as 30 mg / L, 60 mg / L, or 10 mg / L. The antimony ion concentration can be selected as 0.05 mg / L or 0.1 mg / L. More preferably, the composite additive is a combination of 30 mg / L tannic acid and 0.05 mg / L antimony ions, or a combination of 60 mg / L tannic acid and 0.1 mg / L antimony ions. Then, the peristaltic pump 12 is started and the electrode solution is circulated to the ultrasonic electrowinning tank 2 through the inlet pipe 19 and the outlet pipe 6 for later use.

[0029] Step 2: Place the Pb-Ag anode plate in a pretreatment solution for activation treatment. The pretreatment solution contains Zn. 2+ The concentration of lead dioxide was 50 g / L and the concentration of H2SO4 was 160 g / L. The activation treatment conditions were 25°C for 24 h to form a uniform and dense lead dioxide coating on the surface, thereby improving the conductivity and stability of the anode.

[0030] Step 3: Alternately arrange multiple activated Pb-Ag anode plates and 1060 pure aluminum cathode plates at 3cm intervals in the ultrasonic electrodeposition cell 2. Start the ultrasonic generator 8, with ultrasonic power of 10-30W, ultrasonic treatment time of 20min, electrodeposition cell temperature of 40-42℃, and current density of 500A / m. 2 Electrowinning was performed for 1 hour under the specified conditions to obtain electrowinning zinc sheets and record the cell voltage.

[0031] In the zinc electrowinning process, current efficiency and energy consumption are calculated using the following formulas: The formula for calculating current efficiency (CE) is: η = m / (n × t × q × I) × 100%, where: η is CE / %; m is the actual weight of the electrowinning zinc sheet / g; q is the zinc electrochemical equivalent / (g / (Ah)), taken as 1.186; t is the electrowinning time / h; and I is the electrowinning current / A. The formula for calculating energy consumption is: W = V / (q × η) × 1000, where: W is the electrowinning energy consumption / kWh; and V is the electrowinning cell voltage / V.

[0032] In this embodiment of the invention, cyclic voltammetry (CV) based on a Hg / Hg₂SO₄ reference electrode is used to scan the peak potential and current density of zinc electrowinning. Scanning electron microscopy (SEM) and a three-dimensional optical surface profilometer are used to analyze the surface morphology and roughness of the electrowinning zinc sheet. X-ray diffraction is used to determine the crystal orientation of the electrowinning zinc sheet, and the grain size is estimated using the Scheele formula, calculated as follows: D = (Kλ) / (βcosθ₀); where: D is the average grain size / nm; K is the shape constant with a value of 0.9; λ is the wavelength of the X-rays, using the 0.15418 nm Cu-Kα line; β is the full width at half maximum (FWHM) of the X-ray diffraction peak; and θ₀ is the diffraction angle.

[0033] The ultrasonic electrowinning device and electrowinning method provided by this invention have the following basic process flow: Figure 1 As shown, the present invention will be further described in detail below with reference to specific embodiments.

[0034] Example 1: This embodiment of the invention specifically includes the following steps: (1) Zn is placed in the solution circulation tank 15. 2+ A zinc sulfate electrodeposition solution with an ion concentration of 45-50 g / L and an H2SO4 concentration of 165-180 g / L is prepared. Then, tannic acid with a concentration of 30 mg / L is added to the electrodeposition solution, and the stirring mechanism 14 is started to mix it evenly. Subsequently, the peristaltic pump 12 is started and the electrode solution is circulated to the ultrasonic electrodeposition tank 2 through the inlet pipe 19 and the outlet pipe 6 for later use.

[0035] (2) The Pb-Ag anode plate was placed in a pretreatment solution for activation treatment, and the pretreatment solution contained Zn 2+ The concentration of lead dioxide was 50 g / L and the concentration of H2SO4 was 160 g / L. The activation treatment conditions were 25°C for 24 h to form a uniform and dense lead dioxide coating on the surface, thereby improving the conductivity and stability of the anode.

[0036] (3) Multiple activated Pb-Ag anode plates and 1060 pure aluminum cathode plates are alternately arranged in the ultrasonic electrodeposition cell 2 at a 3cm interval. The ultrasonic generator 8 is started, and the ultrasonic power is 10W, the ultrasonic treatment time is 20min, the electrodeposition cell temperature is 40-42℃, and the current density is 500A / m. 2 Electrodeposition was performed for 1 hour under the specified conditions to obtain an electrodeposited zinc sheet, and the cell voltage was recorded. In this embodiment, the current efficiency during zinc electrodeposition was measured to be 93%.

[0037] Example 2: The difference from Example 1 is that the composite additive in this example is tannic acid at a concentration of 60 mg / L, and no antimony ions are added; the process parameters are the same as in Example 1. In this example, the current efficiency measured during zinc electrodeposition is 90%.

[0038] Example 3: The difference from Example 1 is that the composite additive in this example is antimony ions at a concentration of 0.05 mg / L, and tannic acid is not added; the process parameters are the same as in Example 1. In this example, the current efficiency measured during zinc electrodeposition is 91%.

[0039] Example 4: The difference from Example 1 is that the composite additive in this example is antimony ions at a concentration of 0.1 mg / L, and tannic acid is not added; the process parameters are the same as in Example 1. In this example, the current efficiency measured during zinc electrodeposition is 86%.

[0040] Example 5: The difference from Example 1 is that the composite additive in this example is tannic acid at a concentration of 30 mg / L and antimony ions at a concentration of 0.05 mg / L, and the process parameters are the same as in Example 1. In this example, the current efficiency measured during zinc electrodeposition is 92%.

[0041] Example 6: The difference from Example 1 is that the composite additive in this example is tannic acid at a concentration of 60 mg / L and antimony ions at a concentration of 0.1 mg / L, and the process parameters are the same as in Example 1. In this example, the current efficiency measured during zinc electrodeposition is 88%.

[0042] Comparative Example 1: The difference from Example 1 is that the ultrasonic generator system was not turned on, while other conditions remained the same. In this example, the current efficiency measured during zinc electrodeposition was 90%.

[0043] Comparative Example 2: The difference from Example 2 is that the ultrasonic generator system was not turned on, while other conditions remained the same. In this example, the current efficiency measured during zinc electrodeposition was 87%.

[0044] Comparative Example 3: The difference from Example 3 is that the ultrasonic generator system was not turned on, while other conditions remained the same. In this example, the current efficiency measured during zinc electrodeposition was 87%.

[0045] Comparative Example 4: The difference from Example 4 is that the ultrasonic generator system was not turned on, while other conditions remained the same. In this example, the current efficiency measured during zinc electrodeposition was 69%.

[0046] Comparative Example 5: The difference from Example 5 is that the ultrasonic generator system was not turned on, while other conditions remained the same. In this example, the current efficiency measured during zinc electrodeposition was 90%.

[0047] Comparative Example 5: The difference from Example 6 is that the ultrasonic generator system was not turned on, while other conditions remained the same. In this example, the current efficiency measured during zinc electrodeposition was 72%.

[0048] The zinc deposition layers obtained in Examples 1-6 and Comparative Examples 1-6 were subjected to performance analysis and testing. Current efficiency is the core indicator for evaluating the energy utilization and deposition effect of the zinc electrodeposition process. The current efficiency of each group differed significantly. The results are summarized as follows: (1) Current efficiency: Comparison Figure 2 Data shows that, under the same additive conditions, the current efficiency of the example group subjected to ultrasonic enhancement treatment was generally higher than that of the comparative example group without ultrasonic treatment. In particular, under the condition of high concentration of compound additive (60 mg / L tannic acid + 0.1 mg / L antimony ions), the promoting effect of ultrasonic enhancement treatment was the most significant (the current efficiency of Example 6 was increased by about 16% compared with Comparative Example 6).

[0049] (2) Sedimentary morphology (SEM): such as Figure 3 As shown, the zinc deposits under ultrasonic assistance (Examples 1, 3, and 6) exhibit a more uniform and dense lamellar structure and reduced defects such as dendrites and pores compared to the groups without ultrasonic reinforcement (Comparative Examples 1, 3, and 6). For example, in antimony ion-containing systems, ultrasound effectively suppresses surface irregularities caused by "antimony-type" stacking structures.

[0050] (3) Surface roughness: Three-dimensional profile test (e.g.) Figure 4 As shown in the figure, the surface roughness (Sa) of Example 1 was significantly improved compared to Comparative Example 1, increasing from 1.3 μm to 2.1 μm, an increase of 62%; the surface roughness of Example 3 was improved by 38% compared to Comparative Example 3, increasing from 4.2 μm to 5.8 μm; and the surface roughness of Example 6 decreased from 7.3 μm to 8.8 μm compared to Comparative Example 6, a decrease of 20%. In a single impurity system, ultrasonic strengthening treatment slightly increased roughness but improved uniformity; while in a complex composite impurity system (Example 6), ultrasonic assistance actually helped to reduce surface roughness and improve zinc deposition quality.

[0051] (4) Grain size: calculated by XRD analysis (e.g.) Figure 5 As shown in the figure, the grain size of Example 1 increased by 8.1 nm compared to Comparative Example 1, an increase of approximately 17%; the grain size of Example 3 increased by 10.9 nm compared to Comparative Example 3, an increase of approximately 14%; and the grain size of Example 6 increased by 32% compared to Comparative Example 6, from 56 nm to 74 nm. The grain size of all ultrasonically assisted examples was larger than that of the corresponding non-ultrasonic comparative examples, indicating that ultrasonic assistance can promote grain growth in all systems. This is because the ultrasonic vibration causes the newly generated nuclei with weak adhesion to the electrode surface to detach, reducing the number of nuclei and thus promoting the growth of the remaining nuclei, increasing the grain size. Ultrasonic stimulation promotes grain growth, which is beneficial to improving the mechanical properties of the deposited layer.

[0052] (5) Electrochemical behavior: CV test (e.g.) Figure 6As shown in the figure, the NOP of Example 1 was reduced by 7 mV compared to Comparative Example 1, a reduction of approximately 13%; the NOP of Example 3 was reduced by 43% compared to Comparative Example 3, the largest reduction among all groups; and the NOP of Example 6 was reduced by 31% compared to Comparative Example 6. Ultrasonic-assisted enhancement treatment significantly reduced the nucleation overpotential (NOP) of zinc deposition, indicating that ultrasound reduced polarization and promoted the reduction and nucleation kinetics of zinc ions.

[0053] In summary, ultrasound-assisted electrowinning (40 kHz, 10 W, 20 min) can effectively improve the impurity tolerance limits of tannic acid and antimony ions in the zinc electrowinning process by enhancing mass transfer, regulating crystal growth, and optimizing reaction kinetics. Specifically, the tolerance concentration of tannic acid increased from 30 mg / L to 60 mg / L, and the tolerance concentration of antimony ions increased from 0.05 mg / L to 0.1 mg / L. The most significant improvement in current efficiency was observed in the 0.1 mg / L antimony ion system. The current efficiency of the 60 mg / L tannic acid system under ultrasound assistance was comparable to that of the 30 mg / L tannic acid system without ultrasound. Although this method slightly increases the surface roughness of the zinc deposition layer in single impurity systems, it effectively inhibits zinc... Redissolution promotes the growth of lamellar structures, reduces surface roughness and improves the density of the deposited layer in composite impurity systems, and also increases grain size (up to 32% in composite systems). From an electrochemical performance perspective, ultrasound significantly reduces NOP (up to 43% in the 0.05 mg / L antimony ion system), accelerates ion transport and inhibits hydrogen evolution side reactions. Ultimately, without significantly increasing process complexity, it reduces the impurity purification cost in the hydrometallurgical zinc industry. Through the synergistic effect of composite additives and ultrasonic fields, it effectively improves the current efficiency and deposited layer quality of the zinc electrowinning process, enhances tolerance to specific impurities, and provides an efficient and economical process intensification solution for the hydrometallurgical zinc industry.

[0054] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An ultrasonic electrowinning coupling system for improving zinc electrowinning quality, characterized in that, include: An ultrasonic electrodeposition cell (2) is provided with multiple cathode plates (5) and anode plates (10) arranged alternately in the ultrasonic electrodeposition cell (2) to form an electrode system for electrodeposition reaction; An ultrasonic generating system includes multiple ultrasonic probes (3) symmetrically arranged on the side wall of an ultrasonic electroplating tank (2), multiple ultrasonic transducers (7) uniformly distributed at the bottom of the ultrasonic electroplating tank (2), and an ultrasonic generator (8). The ultrasonic generator (8) is electrically connected to the ultrasonic probes (3) and ultrasonic transducers (7) via cables. The solution circulation system includes a solution circulation tank (15), a peristaltic pump (12), an inlet pipe (19), and a drain pipe (6). The peristaltic pump (12) transports the electrowinning solution in the solution circulation tank (15) to the ultrasonic electrowinning tank (2) through the inlet pipe (19) for electrowinning reaction. The drain pipe (6) is located at the bottom of the ultrasonic electrowinning tank (2) to discharge the electrowinning solution. The heating and temperature control system includes a heating resistor (13) and a thermocouple (18) disposed in a solution circulation tank (15), a heating resistor power supply (11) electrically connected to the heating resistor (13), and a rectifier power supply (17) electrically connected to the electrode system. The rectifier power supply (17) is used to provide adjustable voltage and adjustable current for the electrowinning process.

2. The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to claim 1, characterized in that, The ultrasonic probe (3) is covered with an ultrasonic probe protective cover (4) for dust prevention, corrosion prevention and physical protection.

3. The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to claim 1, characterized in that, The ultrasonic transducers (7) are arranged in an array at the bottom of the ultrasonic electroplating tank (2), and together with the ultrasonic probe (3), they form an all-round, uniformly covered ultrasonic field.

4. The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to claim 1, characterized in that, The cathode plate (5) is a 1060 pure aluminum plate, and the anode plate (10) is a Pb-Ag alloy plate; the two are arranged alternately in parallel along the length of the ultrasonic electrowinning cell (2), and the spacing between adjacent electrode plates is uniform.

5. The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to claim 1, characterized in that, The solution circulation system also includes a stirring mechanism (14) provided in the solution circulation tank (15) for enhancing the mixing of the electrolytic solution.

6. The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to claim 1, characterized in that, The top of the ultrasonic electrowinning tank (2) is provided with a conductive slide rail (20) along its width direction. The conductive slide rail (20) is used to facilitate the installation and circuit connection of the cathode plate (5) and the anode plate (10).

7. The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to claim 1, characterized in that, The ultrasonic transducer (7) and the ultrasonic generator (8) are covered with a bottom protective cover (9); the ultrasonic probe (3) is provided with an ultrasonic probe protective cover (4).

8. The ultrasonic electrowinning coupling system for improving zinc electrowinning quality according to claim 1, characterized in that, The ultrasonic electrowinning cell (2) is a double-layer structure, including an outer ultrasonic cell filled with a coupling medium and an inner electrowinning cell sealed within the outer ultrasonic cell; the frequency of the inner ultrasonic electrowinning cell is 40kHz and the power adjustment range is 0-100W; the inner electrowinning cell is made of polypropylene material and its temperature tolerance range is -20-120℃; the electrode system is powered by an intelligent constant voltage power supply with a power supply voltage of 0-20V and a power supply current of 0-15A.

9. A zinc electrowinning method using the ultrasonic electrowinning coupling system according to any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Prepare Zn in the solution circulation tank (15) 2+ A zinc sulfate electrowinning solution with an ion concentration of 45-50 g / L and an H2SO4 concentration of 165-180 g / L is prepared. Then, a composite additive is added to the electrowinning solution and the stirring mechanism (14) is started to mix it evenly. The composite additive consists of an organic additive containing polyphenolic hydroxyl functional groups with a concentration of 0-100 mg / L and antimony ions with a concentration of 0-0.5 mg / L. The organic additive containing polyphenolic hydroxyl functional groups is one or more of tannic acid, gallic acid or tea polyphenols. Then, the peristaltic pump (12) is started and the electrode solution is circulated to the ultrasonic electrowinning tank (2) for later use through the inlet pipe (19) and the outlet pipe (6). Step 2: The Pb-Ag anode plate is placed in a pretreatment solution for activation treatment, forming a uniform and dense lead dioxide coating on its surface; wherein, Zn in the pretreatment solution... 2+ The concentration of H2SO4 was 160 g / L, and the activation treatment conditions were 25℃ for 24 h. Step 3: Arrange multiple activated Pb-Ag anode plates and 1060 pure aluminum cathode plates alternately at 3cm intervals in the ultrasonic electrodeposition tank (2), start the ultrasonic generator (8), and set the ultrasonic power to 10-30W, ultrasonic treatment time to 20min, electrodeposition tank temperature to 40-42℃, and current density to 500A / m. 2 Electrowinning was performed for 1 hour under the specified conditions to obtain electrowinning zinc sheets and record the cell voltage.

10. The zinc electrowinning method using an ultrasonic electrowinning coupling system according to claim 9, characterized in that, The composite additive in step 1 is a combination of tannic acid and antimony ions; wherein the tannic acid concentration is 30 mg / L and the antimony ion concentration is 0.05 mg / L, or the tannic acid concentration is 60 mg / L and the antimony ion concentration is 0.1 mg / L.

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