Method for preparing high-purity manganese carbonate for battery by recycling battery recovery manganese liquid

Abstract

The invention relates to the technical field of manganese compound preparation methods, and particularly provides a method for preparing high-purity manganese carbonate for batteries by recycling a battery recovery manganese solution, which comprises the following steps: carrying out two-gradient cooling evaporation concentration on a manganese-containing solution recovered from waste batteries, then adding a carboxyl compound into the concentrated solution, and carrying out complex reaction, the method comprises the following steps: firstly, adding a sodium hydroxide solution to selectively remove metal impurities such as Fe < 3 + >, Cu < 2 + > and Pb < 2 + >, then carrying out a spin reaction by adopting a sodium hydroxide solution so that a complex forms a spiral sedimentation block, separating a high-purity manganese solution through a spin reaction tank, finally carrying out carbonation precipitation on a manganese-containing removal solution, introducing CO2 under a stirring condition, and controlling the pH value to obtain high-purity manganese carbonate. According to the method, the recovery rate is increased, the impurity content is reduced, the purity of the final product reaches 99.5%, the specific surface area is increased to 28.5 m / g, and the method is suitable for battery material production.

Description

Technical Field

[0001] The present invention relates to the technical field of methods for preparing manganese compounds, and specifically provides a method for recycling battery recycled manganese solution to prepare high-purity manganese carbonate for batteries. Background Art

[0002] With the rapid development of the global new energy industry, the demand for lithium-ion batteries has increased significantly, and at the same time, the recycling and treatment of waste batteries have become an important environmental protection issue. Manganese, as one of the important components of battery cathode materials, has high reuse value in the process of waste battery recycling.

[0003] Currently, the manganese recovered from waste batteries mainly exists in the form of manganese solution, which usually contains a large number of impurity ions such as iron, nickel, cobalt, lead, etc. Direct use may affect the quality of subsequent products. Therefore, how to efficiently extract high-purity manganese carbonate from the recycled manganese solution to meet the requirements of battery-grade materials is an important research direction in the current fields of battery recycling and resource recycling.

[0004] Existing manganese recovery methods mainly include chemical precipitation method, electrolysis method, solvent extraction method, etc., but these methods still have many challenges in terms of separation purity, resource utilization rate and environmental protection. For example, the traditional chemical precipitation method is prone to secondary pollution, the electrolysis method has high energy consumption, and the solvent extraction method involves complex solvent recovery treatment. Therefore, it is urgent to develop an efficient, green and low-cost recycling method to prepare battery-grade high-purity manganese carbonate from waste battery recycled manganese solution, so as to improve resource utilization efficiency and reduce environmental pollution.

[0005] Typical technical routes in the prior art include: 1. Pretreatment and impurity removal: The recycled manganese solution is pretreated by methods such as oxidation, precipitation or adsorption to remove impurities such as iron, nickel, cobalt, etc. For example, Fe can be oxidized to Fe by adding an oxidant (such as hydrogen peroxide or ozone), and then the iron impurities can be removed by alkali precipitation or adsorbent (such as alumina, activated carbon) to improve the purity of the solution. 2+ oxidized to Fe 3+ , and then the iron impurities are removed by alkali precipitation or adsorbent (such as alumina, activated carbon) to improve the solution purity.

[0006] 2. Manganese carbonate precipitation and crystallization control: Carbonate (such as sodium carbonate or ammonium bicarbonate) is added to the purified manganese solution, and the precipitation process of manganese carbonate is precisely controlled by pH control and temperature adjustment to ensure that the target product has high purity and good crystallinity. At the same time, by adjusting the stirring rate, precipitation time and ion concentration, the particle morphology of manganese carbonate is optimized to meet the particle size and specific surface area requirements of battery-grade materials.

[0007] 3. Solid-liquid separation and product purification: The residual impurities in the mother liquor are removed by filtration or centrifugation separation technology, and the impurity ions such as sodium and sulfur that may remain are removed by washing. Subsequently, through drying and calcination treatment, high-purity manganese carbonate meeting the battery material standard is obtained.

[0008] 4. Recycling of waste liquid: For the by-product solution generated during the manganese carbonate precipitation process, carbonate ions and manganese ions can be recovered by solvent extraction, electrodialysis or membrane separation technology, improving the material recovery rate, reducing waste liquid discharge, and realizing clean production and efficient resource utilization.

[0009] However, the existing technologies represented by the above technical routes mainly have the following technical problems: 1. The impurity content of the recycled manganese solution is high, and it is difficult to meet the purity requirements of battery-grade manganese carbonate.

[0010] In traditional precipitation and oxidation methods for removing impurities such as iron, nickel, and cobalt, there are often problems of poor separation selectivity, resulting in insufficient purity of the final product. In addition, some impurities may form co-precipitation with manganese ions, causing large fluctuations in the quality of manganese carbonate products and affecting the performance of battery materials.

[0011] 2. The manganese carbonate precipitation process is difficult to control, and the particle morphology is unstable.

[0012] Existing precipitation methods have certain limitations in controlling the crystal morphology and particle distribution of manganese carbonate. For example, too fast precipitation rate may result in overly fine manganese carbonate particles, affecting the conductivity and specific surface area of subsequent electrode materials; while too slow precipitation rate may lead to particle agglomeration, affecting the uniformity of the material. Therefore, it is necessary to optimize the reaction conditions to obtain manganese carbonate products with suitable particle size distribution and high specific surface area.

[0013] 3. The waste liquid treatment cost is high and the recycling rate is low.

[0014] Since a large amount of waste liquid containing by-products such as sodium and sulfate radicals is generated during the manganese carbonate precipitation process, traditional treatment methods usually use chemical neutralization or wastewater discharge, which not only increases the environmental governance cost but also causes resource waste.

[0015] In summary, how to optimize the impurity removal method of the recycled manganese solution, precisely control the precipitation and crystallization process of manganese carbonate, and combine with efficient waste liquid recycling technology to achieve an efficient, environmentally friendly and low-cost solution for preparing high-purity manganese carbonate from recycled manganese solution of waste batteries is an important research method for the sustainable development of future new energy battery materials. Summary of the Invention

[0016] In view of the above problems, the object of the present invention is to propose a method for recycling battery-recycled manganese solution to prepare high-purity manganese carbonate for batteries, including the following steps: S1. Concentrate the manganese-containing solution obtained from the recycling of waste batteries to obtain a manganese concentrate solution; S2. Add an organic chemical reagent to carry out an organic complex reaction; S3. Carry out a complex knotting reaction with a sodium hydroxide solution; S4. Use the knotting reaction to separate the polymer in it in the form of a spiral mass sedimentation to obtain a manganese-containing polymer removal solution; S5. Prepare high-purity manganese carbonate for batteries by carbonation precipitation method for the manganese-containing polymer removal solution.

[0017] Furthermore, it is characterized in that: the manganese concentration of the manganese-containing solution obtained from the recycling of waste batteries is in the range of 50-75 g / L; the liquid concentration treatment is two-gradient cooling evaporation concentration.

[0018] Furthermore, the steps of the two-gradient cooling evaporation concentration are as follows: S11. Lower the temperature of the manganese-containing solution to zero degree, crystallize trace water-soluble impurities, and evaporate a part of the water to initially increase the concentration of the manganese-containing solution; obtain a primary concentrated manganese solution; S12. Heat the primary concentrated manganese solution to 80 °C and keep it warm, and continuously evaporate a part of the water to further increase the concentration of the primary concentrated manganese solution; obtain a manganese concentrate solution; S13. The end mark of the liquid concentration treatment is that the manganese concentration of the manganese concentrate solution reaches 80±5 g / L.

[0019] Furthermore, the organic chemical reagent is a carboxyl compound solution, which satisfies the following chemical formula:

[0020] Among them, represents the metal impurities in the manganese concentrate solution, represents the carboxyl compound as the solute in the carboxyl compound solution; represents the metal impurities react with the carboxyl compound to form a complex or precipitate, and the anion of the carboxyl compound combines with the metal impurities to form a stable metal-carboxylic acid complex or precipitate.

[0021] Furthermore, the metal impurities are , , , , , , , , and one or more of those in, said carboxyl compound is one of formic acid, acetic acid, propionic acid, sodium acetate, and acetamide.

[0022] Furthermore, the complex knotting reaction satisfies the following chemical formula: ; wherein: represents a previously formed metal-carboxylic acid complex or coordination compound; represents sodium hydroxide solution, providing for precipitation reaction; represents metal hydroxide precipitate, which precipitates in the form of an insoluble substance during the reaction; represents the single carboxyl organic matter removal liquid, representing the types of carboxylate radicals released and forming new soluble substances; represents sodium ion.

[0023] Furthermore, the carbonation precipitation method in step S5 includes the following steps: S51. Adjust the temperature of the manganese-containing polymer removal liquid to ; S52. Slowly introduce gaseous carbon dioxide into the temperature-adjusted solution to carry out a precipitation reaction with the manganese-containing polymer removal liquid. Use a gas diffusion tube to introduce carbon dioxide gas into the reaction kettle, and the stirring speed is 115 - 160 r / min; S53. When the pH value of the reaction solution drops to 6.5 - 6.8, stop the reaction and carry out solid-liquid separation of manganese carbonate; S54. Rinse the obtained manganese carbonate filter cake to obtain hydrated manganese carbonate; S55. Dry the hydrated manganese carbonate at to obtain high-purity manganese carbonate for batteries; Furthermore, in step S4, the specific steps for separating the polymer in the knotting reaction in a way of spiral block settlement include: S41. Manganese liquid distribution: Flow the manganese-containing polymer removal liquid along the stainless-steel inner wall of the knotting reaction tank in a spiral shape downward and inject it into the manganese liquid solution in the manganese liquid tank; S42. Polymerization reaction: While injecting the manganese liquid, start stirring with the stainless-steel blade to make the manganese liquid settle downward in a spiral shape; at the same time, drip the sodium carboxylate solution into the reaction tank to cause a polymerization reaction to form a precipitate block similar to gravel; S43. Scraping the sticking wall: After the sedimentation reaction in the spin - knot reaction tank is completed, stop the rotation of the blades, and slowly inject hot water into the manganese polymer deposited on the pool wall by means of spraying, while stirring; control the water temperature at 40 - 45 °C, remove a small amount of polymer adhering to the pool wall, and continuously wash until the inner wall is completely clean; S44. Discharge of the reaction solution: The polymer in the spin - knot reaction tank settles to the bottom of the tank. The high - purity manganese solution on the upper layer of the liquid surface is used as the reaction solution. Use a hydraulic cylinder to control the scraper to guide the reaction solution to the drain port. The height of the scraper is automatically adjusted by the hydraulic system according to the manganese solution level detected by the inductor in the manganese solution tank. Finally, the high - purity manganese solution in the tank is extracted, and the remaining liquid becomes the manganese - containing polymer removal liquid.

[0024] Furthermore, step S4 also includes: S45. After the reaction in the spin - knot reaction tank is completed, first extract the high - quality and high - purity water - containing polymer manganese solution in the tank; S46. When the concentration of the remaining manganese solution in the tank is lower than 85 g / L, automatically supplement the manganese solution to convert it into the primary concentrated manganese - containing solution, and carry out a polymerization reaction in the tank. The separated mono - carboxyl organic matter removal liquid is used to maintain the sodium chloride salt concentration in the reaction manganese solution stable between 120 - 140 g / L.

[0025] The present invention also provides a high - purity manganese carbonate for batteries, which is prepared according to the method for recycling battery - recovered manganese solution to prepare high - purity manganese carbonate for batteries described above.

[0026] Advantages of the present invention: The present invention provides a method for recycling battery - recovered manganese solution and preparing high - purity manganese carbonate for batteries, which can efficiently remove organic impurities and metal impurities in the recovered manganese solution, and at the same time improve the purity and quality of the manganese carbonate product. The present invention has the following technical advantages and effects: 1. Efficient recovery and resource recycling: Adopt the two - gradient cooling evaporation concentration technology, at low temperature, water - soluble impurities are separated out, and through evaporation for further concentration, the concentration of manganese ions is increased, minimizing the impurities in the solution to the greatest extent and improving the recovery rate of manganese.

[0027] 2. Precise removal of organic impurities: Use a carboxyl - compound solution for complexation reaction to achieve the removal of metal impurities (such as Fe 3+ , Cu 2 + , Pb 2+ , Zn 2+Selectively complex with (such as) to form a stable metal-carboxylic acid complex, effectively remove organic impurities and specific metal ions, reduce the interference with the subsequent carbonation precipitation process, and improve the purity of the final manganese carbonate product.

[0028] 3. Innovative spinodal reaction separation technology: In the spinodal reaction, use sodium hydroxide solution to induce the spinodal reaction of the complex to form a metal hydroxide precipitate with good sedimentation properties, and separate it by the spiral block sedimentation method, which can effectively improve the separation efficiency, make the extraction of high-purity aqueous polymer manganese solution in the reaction tank more accurate, and at the same time ensure the compactness of the precipitate particles and improve the stability of subsequent processing.

[0029] 4. High-efficiency carbonation precipitation process: Adopt the carbonation precipitation method, and through controlling the solution temperature and the diffusion mode of carbon dioxide gas, realize precise pH regulation, ensure the uniform growth of crystal grains during the precipitation process, and the optimization of the stirring speed helps to form uniform particles, improve the purity of manganese carbonate, reduce the impurity content, and make it meet the application requirements of battery-grade materials.

[0030] The high-purity manganese carbonate finally prepared by this method, after being dried at 90 - 105 °C, meets the purity requirements of battery materials, can improve the electrochemical performance and cycle life of the battery. Compared with the traditional chemical precipitation method, the technical route provided by the present invention can ensure the high purity of manganese carbonate while increasing the product yield, reducing production energy consumption, and realizing green and sustainable production. Brief Description of the Drawings

[0031] Figure 1 SEM photographs of manganese carbonate particles prepared by the method of the present invention, where (a), (b), and (c) are the experimental group T1, control group C1, and control group C2 in Example 4 respectively; Figure 2 The purity of manganese carbonate prepared by the method of the present invention; Figure 3 The specific surface area of manganese carbonate particles prepared by the method of the present invention. Detailed Description of the Invention

[0032] To deepen the understanding of the present invention, the following will further elaborate on the present invention in combination with embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0033] Example 1 According to Figure 1 As shown, this example provides a method for recycling battery-recovered manganese solution to prepare high-purity manganese carbonate for batteries, including the following steps: S1. Concentrate the manganese-containing solution obtained from the recycling of waste batteries through liquid concentration to obtain a manganese concentrate solution. The liquid concentration process is two-gradient cooling evaporation concentration, and the steps of the two-gradient cooling evaporation concentration are as follows: S11. Cool the temperature of the manganese-containing solution to zero degree Celsius to crystallize trace water-soluble impurities and evaporate a part of the water to initially increase the concentration of the manganese-containing solution; obtain a primary concentrated manganese solution. S12. Heat the primary concentrated manganese solution to 80 °C and keep it warm, and continuously evaporate a part of the water to further increase the concentration of the primary concentrated manganese solution to obtain a manganese concentrate solution. S13. The end mark of the liquid concentration process is that the manganese concentration of the manganese concentrate solution reaches 80 ± 5 g / L.

[0034] S2. Add an organic chemical reagent to carry out an organic matter complexation reaction. The organic chemical reagent is a carboxyl compound solution, which satisfies the following chemical formula: ; Among them, represents the metal impurities in the manganese concentrate solution, represents the carboxyl compound with the carboxyl compound solution as the solute; represents the metal impurity and the carboxyl compound react to form a complex or precipitate, and the anion of the carboxyl compound combines with the metal impurity to form a stable metal-carboxylic acid complex or precipitate; The metal impurity is , , , , , , , , and one or more of them, and the carboxyl compound is one of formic acid, acetic acid, propionic acid, sodium acetate, and acetamide.

[0035] S3. Carry out a complex knotting reaction with sodium hydroxide solution. The complex knotting reaction satisfies the following chemical formula: ; Among them: represents the previously generated metal-carboxylic acid complex or complex; Indicates sodium hydroxide solution, providing to carry out a precipitation reaction; Indicates the metal hydroxide precipitate, which precipitates in the form of an insoluble substance during the reaction; Indicates the removal liquid of monocarboxylic organic matter, representing the types of carboxylate ions released and forming new soluble substances; Indicates sodium ions.

[0036] S4. Use the spin knot reaction to separate the polymer in it by the way of helical block sedimentation to obtain the manganese-containing polymer removal liquid; The specific steps of separating the polymer in it by the spin knot reaction in the way of helical block sedimentation include: S41. Manganese liquid distribution: Flow the manganese-containing polymer removal liquid along the stainless steel inner wall of the spin knot reaction tank in a helical shape downward and inject it into the manganese liquid solution in the manganese liquid tank; S42. Polymerization reaction: While injecting the manganese liquid, start the stainless steel blade stirring to make the manganese liquid settle downward in a helical shape; at the same time, drip the sodium carboxylate solution into the reaction tank to cause a polymerization reaction to form a precipitate block similar to gravel; S43. Scraping the adhered wall: When the sedimentation reaction in the spin knot reaction tank is completed, stop the blade rotation, and slowly inject hot water onto the manganese polymer deposited on the tank wall in a spraying manner while stirring; control the water temperature at 40 - 45 °C, remove the small amount of polymer adhered to the tank wall, and continuously clean until the inner wall is completely clean; S44. Reaction liquid discharge: The polymer in the spin knot reaction tank settles to the bottom of the tank, and the high-purity manganese liquid on the upper layer of the liquid surface is used as the reaction liquid. Use the hydraulic cylinder to control the scraper to guide the reaction liquid to the drain port. The height of the scraper is automatically adjusted by the hydraulic system according to the manganese liquid level detected by the inductor in the manganese liquid tank. Finally, the high-purity manganese liquid in the tank is extracted, and the remaining liquid becomes the manganese-containing polymer removal liquid; S45. After the reaction in the spin knot reaction tank is completed, first extract the high-quality and high-purity water-containing polymer manganese liquid in the tank.

[0037] S5. Carry out carbonation precipitation on the manganese-containing polymer removal liquid to prepare high-purity manganese carbonate for batteries; The carbonation precipitation method includes the following steps: S51. Adjust the temperature of the manganese-containing polymer removal liquid to ; S52. Slowly introduce gaseous carbon dioxide into the temperature-adjusted solution to carry out a precipitation reaction with the manganese-containing polymer removal liquid. Use a gas diffusion tube to introduce carbon dioxide gas into the reaction kettle, and the stirring speed is 115 - 160 r / min; S53. When the pH value of the reaction solution drops to 6.5 - 6.8, stop the reaction and carry out solid-liquid separation of manganese carbonate; S54. Rinse the obtained manganese carbonate filter cake to obtain manganese carbonate hydrate; S55. Dry the manganese carbonate hydrate at to obtain high-purity manganese carbonate for batteries.

[0038] Example Two This example provides a method for recycling battery-recovered manganese solution and preparing high-purity manganese carbonate for batteries, which includes the following steps: S1. Concentration treatment of manganese-containing solution: Concentrate the manganese-containing solution recovered from waste batteries to obtain a high-concentration manganese solution. In this example, two-gradient cooling evaporation concentration is adopted, and the specific steps are as follows: S11. Low-temperature pre-concentration: Cool the manganese-containing solution to 0 °C to promote the precipitation of microcrystals of water-soluble impurities, and at the same time evaporate part of the water to initially increase the concentration of the manganese solution and obtain a primary concentrated manganese solution.

[0039] S12. High-temperature fine-concentration: Heat the primary concentrated manganese solution to 80 °C and keep it at a constant temperature, continuously evaporate part of the water to further concentrate the manganese solution, and finally obtain a manganese concentrate.

[0040] S13. Concentration end-point control: When the manganese mass concentration of the manganese concentrate reaches 80 ± 5 g / L, end the concentration treatment and enter the next stage.

[0041] S2. Complexation reaction of organic impurities: Add a carboxyl compound solution to the manganese concentrate to make the organic impurities react with the carboxyl compound to form a separable metal-carboxylic acid complex. The reaction conforms to the following chemical formula: ; Among them, represents the metal impurities in the manganese concentrate, represents the carboxyl compound with the carboxyl compound solution as the solute; represents the metal impurities reacting with the carboxyl compound to form a complex or precipitate, where the anion of the carboxyl compound combines with the metal impurities to form a stable metal-carboxylic acid complex or precipitate.

[0042] S3. Spinning reaction of the complex: Add sodium hydroxide solution to the complexed solution to make the complex undergo a spinning reaction to form a sedimentable hydroxide precipitate and release the carboxyl compound. The reaction chemical formula is as follows: ; Wherein: represents a previously generated metal-carboxylic acid complex or coordination compound; represents a sodium hydroxide solution, providing for the precipitation reaction; represents a metal hydroxide precipitate, which precipitates in the form of an insoluble substance during the reaction; represents a monocarboxylic organic matter removal solution, representing the types of carboxylate ions released and forming new soluble substances; represents sodium ions.

[0043] S4. Spinning reaction to separate manganese-containing polymer: Using the spinning reaction method, the polymer is settled and separated to obtain a manganese-containing polymer removal solution. The specific separation process is as follows: S41. Manganese solution distribution: The manganese-containing polymer removal solution is flowed downward in a spiral along the stainless-steel inner wall of the spinning reaction tank and injected into the manganese solution tank.

[0044] S42. Polymerization reaction: At the same time, start the stainless-steel blade stirring to make the manganese solution settle in a spiral, and gradually drop the sodium carboxylate solution to promote the polymerization reaction, and finally form a precipitate mass similar to gravel.

[0045] S43. Scraping the adhered wall: After the sedimentation reaction is completed, stop the blade rotation, and slowly inject hot water onto the manganese polymer deposited on the tank wall by spraying, while stirring; the water temperature is controlled at 40 - 45 °C to remove the polymer residues on the tank wall and ensure the cleanliness inside the equipment.

[0046] S44. Discharge of the reaction solution: Solid polymer is settled at the bottom of the spinning reaction tank, and the high-purity manganese solution on the upper layer can be extracted. Use a hydraulic cylinder to control the scraper, adjust the height of the liquid discharge port, and automatically adjust the height of the scraper according to the feedback of the liquid level sensor to ensure the efficient separation of the high-purity manganese solution in the tank, and the remaining liquid is continued to be processed as the manganese-containing polymer removal solution.

[0047] S45. Collection of high-purity manganese solution: After the reaction in the spinning reaction tank is completed, extract the high-quality and high-purity water-containing polymer manganese solution in the tank.

[0048] S5. Preparation of high-purity manganese carbonate by carbonation precipitation: Perform carbonation precipitation treatment on the separated manganese-containing polymer removal solution to obtain high-purity manganese carbonate. The specific steps are as follows: S51. Temperature adjustment: Heat the manganese-containing polymer removal solution to 50 °C.

[0049] S52. Carbon dioxide introduction: Slowly introduce CO 2 gas, use a diffusion tube to ensure uniform gas distribution, and control the stirring speed at 115 - 160 r / min to promote the precipitation reaction.

[0050] S53. pH regulation: When the solution pH drops to 6.5 - 6.8, stop the reaction and perform solid-liquid separation to obtain manganese carbonate precipitate.

[0051] S54. Cleaning: Rinse the obtained manganese carbonate filter cake to remove residual impurities in the solution to obtain manganese carbonate hydrate.

[0052] S55. Drying: Dry the manganese carbonate hydrate at 90 - 105 °C to finally obtain battery-grade high-purity manganese carbonate.

[0053] Example 3 This example provides a system for recycling battery-recovered manganese solution to remove organic impurities and prepare high-purity manganese carbonate for batteries. This system can efficiently recover manganese elements from waste batteries and remove organic and metal impurities through a series of optimized treatment steps, and finally obtain high-purity manganese carbonate. This system mainly includes a liquid concentration module, a complexation reaction module, a spinodal reaction module, a sedimentation separation module, a carbonation precipitation module, and an automatic control module. Its specific structure is as follows: 1. Liquid concentration module: 1.1 Evaporation concentration device: Used for two-gradient cooling evaporation concentration of the recovered manganese-containing solution to increase the manganese ion concentration.

[0054] 1.2 Cooling crystallization device: Control the temperature to drop to 0 °C to precipitate water-soluble impurities.

[0055] 1.3 Heating concentration device: Heat to 80 °C for deep evaporation until the manganese concentration reaches 80 ± 5 g / L.

[0056] 1.4 Concentrate collection device: Collect the final manganese concentrate and transport it to the next processing unit.

[0057] 2. Complexation reaction module: 2.1 Reagent storage unit: Store carboxyl compound solutions (formic acid, acetic acid, propionic acid, etc.).

[0058] 2.2 Complexation reaction kettle: Used to add carboxylic acid complexing agent to the manganese concentrate to form stable metal-carboxylic acid complexes with metal impurities.

[0059] 2.3 Stirring device: Control the stirring speed to ensure full progress of the complexation reaction.

[0060] 2.4 Complex detection sensor: Monitor the completion of the complexation reaction and control the flow to enter the next step of processing.

[0061] 3. Spinning Reaction Module: 3.1 Sodium Hydroxide Solution Storage Unit: Provides NaOH solution for precipitating metal impurities in the complex.

[0062] 3.2 Spinning Reaction Kettle: Causes the complex to react with NaOH to form metal hydroxide precipitate and release carboxyl compounds.

[0063] 3.3 Sedimentation Control System: Controls reaction time, temperature, and NaOH addition rate to ensure full reaction.

[0064] 4. Sedimentation and Separation Module: 4.1 Spinning Reaction Pool: Used to separate the polymer produced by the spinning reaction in the form of spiral block sedimentation.

[0065] 4.2 Stainless Steel Blade Stirring Device: Used to control the flow state of the manganese solution to form spiral sedimentation.

[0066] 4.3 Cleaning Device: Sprays hot water (40 - 45 °C) to clean the residual polymer on the pool wall.

[0067] 4.4 Scraper Control Device (Hydraulic Drive): Automatically adjusts the scraper height according to the liquid level sensor to precisely control the discharge of high-purity manganese solution.

[0068] 5. Carbonation Precipitation Module: 5.1 Temperature Adjusting Device: Heats the manganese-containing removal liquid to 50 °C.

[0069] 5.2 Gas Diffusion System: Introduces , controls the diffusion rate to fully react with the manganese solution.

[0070] 5.3 Stirring System: Controls the stirring speed (115 - 160 r / min) to ensure uniform carbonation precipitation.

[0071] 5.4 pH Monitoring and Control System: Automatically monitors the pH of the solution. When the pH drops to 6.5 - 6.8, stops introducing carbon dioxide and conducts solid-liquid separation.

[0072] 5.5 Filtration and Washing Device: Removes excess impurities to obtain manganese carbonate containing water.

[0073] 5.6 Drying Device: Controls the temperature at 90 - 105 °C to remove moisture and obtain high-purity manganese carbonate product.

[0074] 6. Automatic Control Module: 6.1 PLC Control System: Conducts centralized control over each subsystem, including parameter adjustment such as temperature, flow rate, stirring speed, and reaction time.

[0075] 6.2 Sensor system: including liquid level sensor, pH monitoring sensor, flowmeter, etc., to achieve precise monitoring.

[0076] 6.3 Data acquisition and feedback system: Real-time record parameters at each stage, optimize the production process, and provide remote monitoring function.

[0077] The system working process includes: Concentration of manganese solution: The manganese-containing solution recovered from waste batteries is concentrated by two-gradient cooling evaporation to remove impurities and increase the concentration of manganese ions.

[0078] Complexation of organic impurities: Add carboxyl compound reagent to complex metal impurities to form stable compounds.

[0079] Complex compound knotting reaction: Introduce NaOH for precipitation reaction to form hydroxide precipitation and release carboxyl compound.

[0080] Spiral sedimentation separation: Conduct spiral block sedimentation separation in the knotting reaction tank, and the high-purity manganese solution is discharged under the control of a hydraulic scraper.

[0081] Carbonation precipitation: The manganese-containing solution reacts with CO 2 to form high-purity manganese carbonate, and the final product is obtained after solid-liquid separation and drying.

[0082] Example 4 This example provides a comparative experiment based on the solution of the present invention.

[0083] 1. Experimental purpose: Through comparative experiments, verify the technical effects of the method of recycling battery-recovered manganese solution and preparing high-purity manganese carbonate for batteries in removing organic impurities, improving the purity of manganese carbonate and product performance of the present invention.

[0084] The experimental group uses the method of the present invention and conducts comparative analysis with the control group outside the parameter range and the control group of the existing technology respectively.

[0085] 2. Experimental scheme The experiment is divided into three groups: experimental group (the solution of the present invention), control group outside the parameter range, and control group of the existing technology. Manganese solution concentration, complexation, knotting reaction, and carbonation precipitation are carried out respectively, and the key indicators of the final manganese carbonate product are detected.

[0086] Settings of the experimental group and the control group: Experimental group T1: Concentration temperature range: 0°C - 80°C; Manganese concentration range: 80 ± 5 g / L; Carboxyl compounds for complexation reaction: acetic acid, formic acid; Amount of NaOH in the knotting reaction: appropriate amount (to ensure complete precipitation); pH end point of carbonation reaction: 6.5 - 6.8; Carbonation reaction temperature: 50°C; Stirring rate: 150 r / min.

[0087] Control group C1 outside the parameter range: Concentration temperature: 90 °C (high temperature environment); Manganese concentration: 30 g / L (low concentration environment); Carboxyl compound for complexation reaction: Acetic acid; Amount of NaOH for spinodal reaction: Appropriate amount (to ensure complete precipitation); pH end point of carbonation reaction: 5 (acidic environment); Carbonation reaction temperature: 30 °C (low temperature environment); Stirring rate: 150 r / min.

[0088] Control group C2 of the prior art: Single evaporation concentration is adopted, without a low-temperature crystallization process. Temperature setting: Continuously heated to 90 - 100 °C, directly evaporating water; Selection of complexation reaction reagent: Using phosphate or sulfate as a precipitant, precipitant concentration: 0.1 - 0.5 mol / L, reaction temperature: 50 - 60 °C, stirring speed: 100 r / min; 2.0 mol / L NaOH is used for the sodium hydroxide solution, which is directly added dropwise to the complexation solution; Carbonation precipitation is carried out by bubbling and steam heating to control the solution temperature at 40 - 60 °C.

[0089] 3. Experimental results: As shown in Tables 1 - 3.

[0090] Table 1 Manganese carbonate purity of the final product (ICP-MS test)

[0091] Table 2 Morphology of manganese carbonate particles (SEM)

[0092] Table 3 BET test of the specific surface area of the product

[0093] Summary: This experiment shows that the method of the present invention has the following advantages compared with the control groups outside the parameter range and the control group of the prior art: 1. As Figure 2 shown, the method of the present invention improves the purity of manganese carbonate (99.5%) and reduces the impurity content (<50 ppm).

[0094] 2. As Figure 1 shown, the optimized spinodal sedimentation method of the method of the present invention improves the sedimentation effect and makes the manganese carbonate particles more uniform.

[0095] 3. Precise pH control (6.5 - 6.8) avoids excessive precipitation of manganese carbonate and improves product consistency.

[0096] 4. As Figure 3As shown, the method of the present invention increases the specific surface area (28.5 m² / g), which is beneficial to the optimization of the performance of battery active materials.

[0097] In summary, the method of the present invention has significant technical advantages in the preparation of manganese carbonate, superior to the control groups outside the parameter range and the prior art control group.

[0098] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only to illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and all these changes and improvements fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A method for recycling manganese liquid recovered from batteries to prepare high-purity manganese carbonate for batteries, characterized in that: The following steps are involved: S1, subjecting the manganese-containing solution obtained by recycling waste batteries to liquid concentration treatment to obtain a manganese concentrate; S2, adding organic chemical reagents to carry out organic complexation reaction; S3, carrying out complex rotation reaction with sodium hydroxide solution; S4, separating the polymer in the solution by spiral block sedimentation to obtain a manganese-containing polymer removal solution; S5. The manganese-containing polymer removal solution is subjected to a carbonation precipitation method to prepare high-purity manganese carbonate for battery.

2. The method for preparing high-purity manganese carbonate for batteries by recycling manganese liquid recovered from batteries according to claim 1, characterized in that: The manganese concentration of the manganese-containing solution obtained based on the recovery of waste batteries is in the range of 50-75 g / L; the liquid concentration treatment is a two-gradient cooling evaporation concentration.

3. The method for preparing high-purity manganese carbonate for battery by recycling manganese liquid recovered from battery according to claim 2, characterized in that: The steps of the two-gradient cooling evaporation concentration are as follows: S11, lowering the temperature of the manganese-containing solution to zero degrees, crystallizing trace water-soluble impurities, and evaporating a portion of water to preliminarily increase the concentration of the manganese-containing solution; obtaining a primary concentrated manganese solution; S12, heating the primary concentrated manganese solution to 80° C. and keeping the temperature, and continuously evaporating a portion of the water to further increase the concentration of the primary concentrated manganese solution; obtaining a manganese concentrated solution; S13. The end mark of the liquid concentration treatment is that the manganese concentration of the manganese concentrated solution reaches 80±5 g / L.

4. The method for preparing high-purity manganese carbonate for battery by recycling manganese liquid recovered from battery according to claim 1, characterized in that: The organic chemical reagent is a carboxyl compound solution that satisfies the following chemical formula: ； in, Indicates the metal impurities in manganese concentrate. represents a carboxyl compound solution with a carboxyl compound as a solute; Indicates metal impurities With carboxyl compounds The complex or precipitate formed after the reaction, in which the anion of the carboxyl compound Combines with metal impurities to form stable metal-carboxylic acid complexes or precipitates.

5. The method for preparing high-purity manganese carbonate for battery by recycling manganese liquid recovered from battery according to claim 4, characterized in that: The metal impurities for , , , , , , , , and One or more of the carboxyl compound It is one of formic acid, acetic acid, propionic acid, sodium acetate and ammonium acetate.

6. The method for preparing high-purity manganese carbonate for battery by recycling manganese liquid recovered from battery according to claim 1, characterized in that: The complex kinetic reaction satisfies the following chemical formula: ； in: represents a previously formed metal-carboxylic acid complex or coordination compound; represents a sodium hydroxide solution, providing performing a precipitation reaction; It means that the metal hydroxide precipitates in the form of insoluble substances during the reaction; It indicates the removal liquid of monocarboxylic organic matter, which represents the type of carboxylate released and formed into new soluble substances; Represents sodium ion.

7. The method for preparing high-purity manganese carbonate for battery by recycling manganese liquid recovered from battery according to claim 1, characterized in that: The carbonation precipitation method in step S5 comprises the following steps: S51, adjusting the temperature of the manganese-containing polymer removal solution to ; S52, slowly introducing gaseous carbon dioxide into the temperature-adjusting solution to cause precipitation reaction with the manganese-containing polymer removal solution, and introducing carbon dioxide gas into the reactor through a gas diffusion tube at a stirring speed of 115-160 r / min; S53, when the pH value of the reaction solution drops to 6.5-6.8, stop the reaction and perform solid-liquid separation of manganese carbonate; S54, washing the obtained manganese carbonate filter cake to obtain hydrous manganese carbonate; S55, the hydrous manganese carbonate The product is dried under reduced pressure to obtain high-purity manganese carbonate for battery use.

8. The method for preparing high-purity manganese carbonate for batteries by recycling manganese liquid recovered from batteries according to claim 7, characterized in that: In step S4, the spinning reaction separates the polymer in the form of spiral block sedimentation. The specific steps include: S41, manganese liquid distribution: The manganese-containing polymer removal liquid flows downward in a spiral along the stainless steel inner wall of the spin reaction tank and is injected into the manganese liquid solution in the manganese liquid tank; S42, polymerization reaction: While the manganese liquid is being injected, the stainless steel blades are started to stir, so that the manganese liquid is spirally precipitated downward; at the same time, sodium carboxylate solution is dripped into the reaction tank to cause a polymerization reaction to form a gravel-like precipitate block; S43, scraping the sticky wall: When the settling reaction in the swirl reaction tank is completed, stop the blade rotation, and slowly inject hot water into the manganese polymer deposited on the tank wall by splashing, while stirring; the water temperature is controlled at 40-45°C, remove the small amount of polymer adhering to the tank wall, and continue to clean until the inner wall is thoroughly clean; S44, reaction liquid discharge: The polymer in the swirl reaction tank settles to the bottom of the tank, and the high-purity manganese liquid on the surface of the liquid serves as the reaction liquid. The scraper is controlled by a hydraulic cylinder to guide the reaction liquid to the drain port. The height of the scraper is automatically adjusted by the hydraulic system according to the manganese liquid level detected by the sensor in the manganese liquid tank. Finally, the high-purity manganese liquid in the tank is extracted, and the remaining liquid becomes the manganese-containing polymer removal liquid.

9. The method for preparing high-purity manganese carbonate for battery by recycling manganese liquid recovered from battery according to claim 8, characterized in that: Step S4 further comprises: S45, after the reaction in the swirl reaction tank is completed, first extracting high-quality, high-purity aqueous polymer manganese liquid in the tank; S46. When the concentration of the remaining manganese solution in the pool is lower than 85g / L, the manganese solution is automatically replenished to convert it into the primary concentrated manganese-containing solution, and a polymerization reaction is carried out in the pool. The separated monocarboxyl organic matter removal solution is used to maintain the sodium chloride salt concentration in the reaction manganese solution stable between 120 and 140g / L.

10. High-purity manganese carbonate for batteries, wherein the high-purity manganese carbonate for batteries is prepared according to the method for preparing high-purity manganese carbonate for batteries by recycling manganese liquid recovered from batteries according to any one of claims 1 to 9.

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