Method for preparing battery grade manganese sulfate solution
By combining neutralization, extraction, stripping and chemical reactions, battery-grade manganese sulfate solution is prepared, which solves the problems of high preparation costs and complex processes in the prior art, and achieves short-process, low-cost and efficient manganese resource utilization.
Patent Information
- Application Number
- CN202510097273.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-04-22
AI Technical Summary
The prior art has a high cost for preparing battery-grade manganese sulfate from P204 anti-copper manganese liquid, and the process is complicated, making it difficult to achieve short process and low cost preparation.
By mixing lithium battery positive electrode waste, nickel-cobalt hydroxide and acidic compounds, neutralization, extraction and stripping treatment, combining chemical reactions of manganese metal, and finally using sodium soap and manganese soap to prepare battery-grade manganese sulfate solution.
It realizes short process and low-cost preparation of battery-grade manganese sulfate, reduces the loss of impurities, deeply removes impurities such as Zn/Ca, and meets the requirements of green, low-carbon, energy-saving and environmental protection.
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Figure CN119858940A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of battery recycling, and in particular to a method for preparing a battery-grade manganese sulfate solution. Background Art
[0002] Battery-grade manganese sulfate (MnSO4·H2O) is a type of manganese sulfate specifically used for the preparation of battery materials. It is an important component in the preparation of lithium battery ternary precursors. The addition of manganese plays a vital role in the structural stability of ternary lithium batteries.
[0003] The industry mainly recycles and purchases manganese ore to obtain manganese resources. For example, pyrolusite is purchased to prepare battery-grade manganese sulfate. The preparation method is generally reduction acid leaching, neutralization / sulfurization to remove impurities, fluorination to remove calcium and magnesium, and multiple recrystallization. Although battery-grade manganese sulfate can be prepared using manganese ore resources, the raw materials are too single. Nickel cobalt hydroxide (MHP for short, an intermediate product of hydrometallurgical ore) and waste ternary lithium-ion batteries have a manganese content of 5%-10%, which can be used as the main source of battery-grade manganese sulfate. However, the current cost of preparing battery-grade manganese sulfate from these two raw materials is relatively high, and the process generally used is to extract the P204 anti-copper manganese solution through C272.
[0004] Therefore, it is urgent to develop a method for preparing battery-grade manganese sulfate from P204 reverse copper-manganese solution to achieve the purpose of preparing battery-grade manganese sulfate in a short process and at a low cost, and to provide a new idea for the preparation of battery-grade manganese sulfate. Summary of the invention
[0005] The purpose of the present application is to provide a method for preparing a battery-grade manganese sulfate solution to solve the above problems.
[0006] To achieve the above objectives, the present application provides a method for preparing a battery-grade manganese sulfate solution, comprising: Mixing lithium battery positive electrode waste / lithium extraction slag (obtained after lithium extraction from positive electrode waste) / nickel cobalt hydroxide (MHP) and an acidic compound to obtain an acid leaching solution; neutralizing and removing impurities from the acid leaching solution to obtain an impurity-removed solution; mixing the impurity-removed solution, a first extractant and a first diluent to perform a first extraction to obtain a first extract; mixing the first extract and a first stripping solution to perform a first stripping to obtain a first mixed metal solution; The first mixed metal solution and metal manganese are mixed and reacted to obtain a post-reaction solution; the post-reaction solution and an acid conditioning agent are mixed to obtain an acid-adjusted solution; The second extractant is mixed with liquid alkali, and sodium soap is carried out to obtain a sodium soap post-extractant; the sodium soap post-extractant is mixed with manganese sulfate solution, and manganese soap is carried out to obtain a treated extractant; The acid-adjusted solution, the treated extractant, and a second diluent are mixed to perform a second extraction to obtain a battery-grade manganese sulfate solution; The first extractant and the second extractant are each independently a phosphoric acid extractant.
[0007] Optionally, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. The lithium battery positive electrode waste includes ternary lithium battery active materials and nickel, cobalt and manganese scraps generated during the production process of positive electrode materials; B. the phosphoric acid extractant comprises P204; C. the particle size of the metal manganese is greater than or equal to 200 mesh; D. the acid regulating agent includes sulfuric acid; E. The first diluent and the second diluent are independently selected from one or more of sulfonated kerosene, Escaid 110 / 100, hexane, heptane, and dodecane; F. The first stripping solution includes sulfuric acid.
[0008] Optionally, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the pH value during the neutralization and impurity removal process is greater than or equal to 5; B. the pH of the solution during the first stripping is 1-3; C. the end point pH of the reaction is 6-7; D. The pH value of the acid-adjusted solution is 1-4.
[0009] Optionally, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the manganese ion concentration in the first mixed metal solution is 80 g / L-120 g / L; B. The manganese ion concentration of the battery-grade manganese sulfate solution is 50 g / L-100 g / L.
[0010] Optionally, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the molar amount of the metal manganese is 3 to 10 times the total molar amount of the hydrogen ions, copper ions and zinc ions in the mixed metal solution; B. the molar ratio of the second extractant to the liquid caustic soda is 1:0.6-1; C. the molar ratio of the sodium soap post-extractant to the manganese in the manganese sulfate solution is 1:0.3-0.5; D. the volume ratio of the treated extractant to the second diluent is 1:0.05-0.3; E. The molar amount of the treated extractant is 1 to 10 times the molar amount of calcium ions in the acid-adjusted solution.
[0011] Optionally, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. The reaction temperature is 20°C-90°C and the reaction time is 1h-5h; B. The temperature of the second extraction is 10°C-40°C, and the time is 2 min-20 min.
[0012] Optionally, the saponification rates of the sodium soap and manganese soap are independently 20%-100%.
[0013] Optionally, the second extraction further obtains a second extract; The second extract and the second stripping solution are mixed and subjected to a second stripping to obtain a second mixed metal solution.
[0014] Optionally, the second stripping solution comprises hydrochloric acid.
[0015] Optionally, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the iron content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; B. the zinc content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; C. the copper content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; D. The calcium content in the battery-grade manganese sulfate solution is less than or equal to 0.01 g / L.
[0016] Compared with the prior art, the beneficial effects of this application include: The present application provides a method for preparing a battery-grade manganese sulfate solution. First, most of the non-metallic impurities and iron, aluminum and copper are precipitated by neutralization and impurity removal, and then most of the metal impurities (iron, aluminum, copper, calcium, zinc and manganese) are removed by a first extraction. Then, the residual iron and aluminum impurities in the stripping solution are separated from the first mixed metal solution by a first stripping. Secondly, metallic manganese is added for a chemical reaction to reduce copper ions and zinc ions to metal elements, so that a large amount of manganese ions and a small amount of calcium ions are retained in the solution after the reaction. Then, the hydrogen ions in the second extractant are replaced by manganese ions by sodium soap and manganese soap to obtain a treated extractant containing manganese. Finally, the treated extractant containing manganese is used for extraction, and the prepared raffinate is a battery-grade manganese sulfate solution. The method basically achieves the dual purpose of replacing the difficult-to-extract component Mn with the easily-extractable component Zn / Ca in the extraction process, that is, no Mn is extracted, and the near-zero loss rate of manganese and deep removal of impurities Zn / Ca are achieved. In addition, the method has a short process, low cost, simple operation, and no foreign impurities are introduced in the process, which meets the requirements of green, low-carbon, energy-saving and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.
[0018] Figure 1 A schematic flow chart of a method for preparing a battery-grade manganese sulfate solution provided in the present application. DETAILED DESCRIPTION
[0019] As used herein: "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.
[0020] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.
[0021] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.
[0022] In these examples, parts and percentages are by mass unless otherwise indicated.
[0023] "Mass parts" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass parts of component A are a parts and the mass parts of component B are b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass parts of all components is not limited to 100 parts.
[0024] “And / or” is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).
[0025] The present application provides a method for preparing a battery-grade manganese sulfate solution, comprising: The positive electrode waste of lithium battery and an acidic compound are mixed to obtain an acid leaching solution; the acid leaching solution is neutralized and impurities are removed to obtain an impurity-removed solution; the impurity-removed solution, a first extractant and a first diluent are mixed to perform a first extraction to obtain a first extract solution; the first extract solution and a first stripping solution are mixed to perform a first stripping to obtain a first mixed metal solution; In some embodiments, the volume ratio of the first extractant to the first diluent is 1:0.05-0.3; The first mixed metal solution and metal manganese are mixed and reacted to obtain a post-reaction solution; the post-reaction solution and an acid conditioning agent are mixed to obtain an acid-adjusted solution; It should be noted that the reaction between the first mixed metal solution and metallic manganese is mainly as follows: Mn+2H + (aq)=Mn 2+ (aq)+H2(g); Mn+Ni 2+ (aq)=Mn 2+ (aq)+Ni; Mn+Co 2+ (aq)=Mn 2+ (aq)+Co; Mn+Zn 2+ (aq)=Mn 2+ (aq)+Zn; Mn+Cu 2+ (aq)=Mn 2+ (aq)+Cu; Ni 2 +(aq)+2H2O=Ni(OH)2+2H + (aq); Co 2+(aq)+2H2O=Co(OH)2+2H + (aq); It should be noted that the impurities Zn / Cu / Ni / Co can be removed through the above reaction, especially the removal effect of Zn and Cu is the best; The second extractant is mixed with liquid alkali, and sodium soap is carried out to obtain a sodium soap post-extractant; the sodium soap post-extractant is mixed with manganese sulfate solution, and manganese soap is carried out to obtain a treated extractant; In some embodiments, the concentration of the liquid caustic soda is 30%-42%; In some embodiments, the manganese content of the manganese sulfate solution for manganese soap is 80 g / L-100 g / L; The acid-adjusted solution, the treated extractant, and a second diluent are mixed to perform a second extraction to obtain a battery-grade manganese sulfate solution; The first extractant and the second extractant are each independently a phosphoric acid extractant.
[0026] In some embodiments, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. The lithium battery positive electrode waste includes ternary lithium battery active materials and nickel, cobalt and manganese scraps generated during the production process of positive electrode materials; B. the phosphoric acid extractant comprises P204; It should be noted that the order of metal ions extracted by P204 extraction agent is Fe 3+ >Zn 2+ >Ca 2+ >Al 3+ >Mn 2 + Therefore, the pH value of the extraction solution can be controlled, low-concentration Zn and Ca are extracted in the organic phase, and high-concentration Mn is left in the raffinate, which is a battery-grade manganese sulfate solution. It can accurately remove low-concentration impurities and greatly reduce the consumption of extractants and acid-base reagents, thereby reducing the production cost of battery-grade manganese sulfate. C. the particle size of the metal manganese is greater than or equal to 200 mesh; Optionally, the particle size of the manganese metal may be 200 mesh, 300 mesh, 400 mesh, 500 mesh, 1000 mesh, or any value greater than or equal to 200 mesh; D. the acid regulating agent includes sulfuric acid; E. The first diluent and the second diluent are independently selected from one or more of sulfonated kerosene, Escaid 110 / 100, hexane, heptane, and dodecane; F. The first stripping solution includes sulfuric acid.
[0027] In some specific experiments, the concentration of sulfuric acid is 2 mol / L-6 mol / L.
[0028] In some embodiments, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the pH value during the neutralization and impurity removal process is greater than or equal to 5; Optionally, the pH value during the neutralization and impurity removal process may be 5, 6, 7, 8, 9, or any value greater than or equal to 5; Preferably, the pH value during the neutralization and impurity removal process is 5-6.2; B. the pH of the solution during the first stripping is 1-3; Optionally, the pH of the solution during the first stripping may be 1, 1.5, 2, 2.5, 3 or any value between 1 and 3; C. the end point pH of the reaction is 6-7; Optionally, the endpoint pH of the reaction can be 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7 or any value between 6 and 7; D. The pH value of the acid-adjusted solution is 1-4.
[0029] Optionally, the pH value of the solution after acid adjustment can be 1, 1.5, 2, 2.5, 3, 3.5, 4 or any value between 1 and 4.
[0030] Preferably, the pH value of the solution after acid adjustment is 1.5-3.
[0031] In some embodiments, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the manganese ion concentration in the first mixed metal solution is 80 g / L-120 g / L; Optionally, the manganese ion concentration in the first mixed metal solution may be 80 g / L, 90 g / L, 100 g / L, 110 g / L, 120 g / L or any value between 80 g / L and 120 g / L; It should be noted that when the manganese ion concentration in the first mixed metal solution is 80 g / L-120 g / L, the solution volume and the evaporation amount of the solution for preparing manganese sulfate crystals can be reduced, thereby reducing equipment investment and processing costs; B. The manganese ion concentration of the battery-grade manganese sulfate solution is 50 g / L-100 g / L.
[0032] Optionally, the manganese ion concentration of the battery-grade manganese sulfate solution can be 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, 100 g / L or any value between 50 g / L and 100 g / L.
[0033] In some embodiments, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the molar amount of the metal manganese is 3 to 10 times the total molar amount of the hydrogen ions, copper ions and zinc ions in the mixed metal solution; Optionally, the molar amount of metallic manganese may be 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times or any value between 3 times and 10 times the total molar amount of hydrogen ions, copper ions and zinc ions in the mixed metal solution; Preferably, the molar amount of metallic manganese is 4 to 8 times the total molar amount of hydrogen ions, copper ions and zinc ions in the mixed metal solution; B. the molar ratio of the second extractant to the liquid caustic soda is 1:0.6-1; Optionally, the molar ratio of the second extractant to the liquid caustic soda can be 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1 or any value between 1:0.6 and 1; C. the molar ratio of the sodium soap post-extractant to the manganese in the manganese sulfate solution is 1:0.3-0.5; Optionally, the molar ratio of the sodium soap post-extractant to manganese in the manganese sulfate solution may be 1:0.3, 1:0.4, 1:0.5 or any value between 1:0.3 and 0.5; D. the volume ratio of the treated extractant to the second diluent is 1:0.05-0.3; Optionally, the volume ratio of the treated extractant to the second diluent may be 1:0.05, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3 or 1:0.05-0.3; E. The molar amount of the treated extractant is 1 to 10 times the molar amount of calcium ions in the acid-adjusted solution.
[0034] Optionally, the molar amount of the extractant after treatment can be 1 times, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times or any value between 1 times and 10 times the molar amount of calcium ions in the acid-adjusted solution.
[0035] Preferably, the molar amount of the extractant after treatment is 1 to 5 times the molar amount of calcium ions in the solution after acid adjustment.
[0036] In some embodiments, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. The reaction temperature is 20°C-90°C and the reaction time is 1h-5h; Optionally, the reaction temperature may be 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or any value between 20°C and 90°C, and the reaction time may be 1h, 2h, 3h, 4h, 5h or any value between 1h and 5h; B. The temperature of the second extraction is 10°C-40°C, and the time is 2min-20min.
[0037] Optionally, the temperature of the second extraction can be 10°C, 20°C, 30°C, 40°C or any value between 10°C and 40°C, and the time can be 2 min, 5 min, 10 min, 15 min, 20 min or any value between 2 min and 20 min.
[0038] Preferably, the second extraction time is 3 min-8 min.
[0039] In some embodiments, the saponification rates of the sodium soap and the manganese soap are independently 20%-100%.
[0040] Optionally, the saponification rates of the sodium soap and the manganese soap can be independently 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100% or any value between 20% and 100%.
[0041] Preferably, the saponification rates of sodium soap and manganese soap are independently 65%-100%.
[0042] It should be noted that when the extractant treated with sodium soap and manganese soap is used to extract a solution containing low concentrations of Zn and Ca, the theoretical amount of the extractant is small, which can control the low proportion of the extractant in the organic phase and increase the saponification rate to more than 65%, or even more than 85%, thereby solving the problem of stickiness, phase separation or difficulty in flow of the loaded organic phase caused by excessive saponification rate, and basically achieving the replacement of the difficult-to-extract Mn component with the easily-extractable component Zn / Ca in the extraction process, that is, no Mn is extracted, thereby achieving the dual goals of near-zero manganese loss rate and deep removal of impurities Zn / Ca.
[0043] In some embodiments, washing is performed after the second extraction, and after washing is completed, the extractant is subjected to a second back extraction.
[0044] In some embodiments, chlorine washing is performed after the second stripping, and after the chlorine washing is completed, the extractant is subjected to a second stripping.
[0045] In some embodiments, the second extraction further produces a second extract (loaded organic phase); The second extract and the second stripping solution are mixed and subjected to a second stripping to obtain a second mixed metal solution.
[0046] In some embodiments, the second stripping solution comprises hydrochloric acid.
[0047] In some specific experiments, the concentration of hydrochloric acid is 2 mol / L-4 mol / L.
[0048] In some embodiments, the method for preparing a battery-grade manganese sulfate solution satisfies at least one of the following conditions: A. the iron content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; Optionally, the iron content in the battery-grade manganese sulfate solution may be 0.00001 g / L, 0.0001 g / L, 0.001 g / L, 0.0015 g / L, 0.002 g / L, or any value less than or equal to 0.002 g / L; B. the zinc content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; Optionally, the zinc content in the battery-grade manganese sulfate solution may be 0.00001 g / L, 0.0001 g / L, 0.001 g / L, 0.0015 g / L, 0.002 g / L, or any value less than or equal to 0.002 g / L; C. the copper content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; Optionally, the copper content in the battery-grade manganese sulfate solution may be 0.00001 g / L, 0.0001 g / L, 0.001 g / L, 0.0015 g / L, 0.002 g / L, or any value less than or equal to 0.002 g / L; D. The calcium content in the battery-grade manganese sulfate solution is less than or equal to 0.01 g / L.
[0049] Optionally, the calcium content in the battery-grade manganese sulfate solution may be 0.00001 g / L, 0.0001 g / L, 0.001 g / L, 0.005 g / L, 0.01 g / L, or any value less than or equal to 0.01 g / L.
[0050] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.
[0051] The lithium battery positive electrode waste used in the embodiments and comparative examples is a ternary lithium battery active material, and the specific element composition content is shown in Table 1.
[0052] Table 1 Active materials for ternary lithium batteries
[0053] Example 1 This embodiment provides a method for preparing a battery-grade manganese sulfate solution, and the specific steps are as follows: S1: The ternary lithium battery active material, concentrated sulfuric acid and water are mixed at a solid-liquid ratio of 1kg:3L, and filtered to obtain an acid-leached solution; the acid-leached solution is added with a neutralizing agent, lime milk, to obtain a decontaminated solution, wherein the pH value range during the neutralization and decontamination process is 5-6.2; the decontaminated solution is mixed with an organic phase (the volume ratio of the extractant P204 and the diluent sulfonated kerosene is 1:3, and liquid alkali saponification is performed, and the saponification rate is 60%) at a volume ratio of 1:2 to perform a first extraction, and the pH of the solution during the first stripping is controlled to be 1-3, the temperature of the first extraction is 25°C, and the time is 3min to obtain a first extract, and the first extract is mixed with sulfuric acid for a first stripping to obtain a first mixed metal solution, wherein the manganese ion concentration in the first mixed metal solution is 100g / L; S2: mixing the first mixed metal solution and metallic manganese (particle size 300 mesh), wherein the molar amount of the metallic manganese is 5 times the total molar amount of the hydrogen ions, copper ions and zinc ions in the mixed metal solution, and reacting to obtain a post-reaction solution, wherein the end point pH of the reaction is 6.5, and then mixing the post-reaction solution and sulfuric acid to obtain a post-adjustment solution having a pH value of 3; S3: The extractant P204 and the diluent sulfonated kerosene are mixed in a volume ratio of 1:9 to prepare an organic phase, and the amount of liquid alkali added is added according to the saponification rate of the extractant P204 of 65%, and the sodium soap is obtained to obtain the organic phase after sodium soap, and then the organic phase after sodium soap is mixed with manganese sulfate solution, and the amount of manganese sulfate added is half of the molar ratio of the amount of liquid alkali added, that is, the saponification rates of sodium soap and manganese soap are 65% and 100% respectively; S4: the acid-adjusted solution and the organic phase after manganese soap are mixed, the molar amount of the extractant in the organic phase is 5 times the molar amount of calcium ions in the acid-adjusted solution, and then a second extraction is performed to obtain a battery-grade manganese sulfate solution (raffinate) and an extract (loaded organic phase); S5: The loaded organic phase obtained in step S4 and the stripping solution hydrochloric acid (with a concentration of 6N) are mixed in a volume ratio of 1:1, and stripping is performed. The stripping solution can be recycled to obtain a second mixed metal solution.
[0054] Example 2 The difference from Example 1: the saponification rate of the sodium soap in the second extraction process is 20%.
[0055] Example 3 The difference from Example 1: the saponification rate of the sodium soap in the second extraction process is 85%.
[0056] Comparative Example 1 The difference from Example 1 is that the first extraction and the first stripping in step S1 are not performed.
[0057] Comparative Example 2 The difference from Example 1 is that step S2 is not performed.
[0058] Comparative Example 3 The difference from Example 1 is that step S3 is not performed.
[0059] The contents of relevant elements in the manganese sulfate solutions obtained in the above examples and comparative examples are shown in Table 2.
[0060] Table 2 Element content of manganese sulfate solution
[0061] analyze: As can be seen from Table 2, by comparing Examples 1 / 2 / 3, it is found that the higher the sodium soap saponification rate, the smaller the manganese loss rate, mainly because a high saponification rate means that the number of hydrogen groups in P204 is reduced, and manganese is easily replaced with hydrogen during the extraction process, resulting in an increase in the manganese extraction rate and a large loss rate; Comparative Example 1 found that without taking the S1 step, manganese and nickel and cobalt could not be separated, and the effect of extracting manganese in the P204 impurity extraction process was not achieved; Comparative Example 2 found that without taking the S2 step, the copper in the manganese sulfate solution exceeded the standard, mainly because copper was basically not extracted during the extraction process and coexisted with the manganese sulfate solution in the raffinate; Comparative Example 3 found that without taking the S3 step, the impurities in the obtained manganese sulfate solution exceeded the standard and did not meet the requirements of battery-grade manganese sulfate solution (see Table 3).
[0062] Table 3 Technical requirements for manganese sulfate solution for batteries
[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.
[0064] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.
Claims
1. A method for preparing a battery-grade manganese sulfate solution, characterized in that: include: Mixing lithium battery cathode waste and an acid compound to obtain an acid-leached solution; The acid-leached solution is neutralized and impurities are removed to obtain an impurity-removed solution; The impurity-removed solution, the first extractant and the first diluent are mixed to perform a first extraction to obtain a first extract; The first extracting liquid and the first stripping liquid are mixed to perform a first stripping to obtain a first mixed metal solution; The first mixed metal solution and metal manganese are mixed and reacted to obtain a post-reaction solution; The post-reaction solution and the acid adjusting agent are mixed to obtain an acid-adjusted solution; The second extractant is mixed with liquid alkali, and sodium soap is carried out to obtain a sodium soap post-extractant; the sodium soap post-extractant is mixed with manganese sulfate solution, and manganese soap is carried out to obtain a treated extractant; The acid-adjusted solution, the treated extractant, and a second diluent are mixed to perform a second extraction to obtain a battery-grade manganese sulfate solution; The first extractant and the second extractant are each independently a phosphoric acid extractant.
2. The method for preparing a battery-grade manganese sulfate solution according to claim 1, characterized in that: At least one of the following conditions is met: A. The lithium battery positive electrode waste includes ternary lithium battery active materials and nickel, cobalt and manganese scraps generated during the production process of positive electrode materials; B. the phosphoric acid extractant comprises P204; C. the particle size of the metal manganese is greater than or equal to 200 mesh; D. the acid regulating agent includes sulfuric acid; E. The first diluent and the second diluent are independently selected from one or more of sulfonated kerosene, Escaid 110 / 100, hexane, heptane, and dodecane; F. The first stripping solution includes sulfuric acid.
3. The method for preparing a battery-grade manganese sulfate solution according to claim 1, characterized in that: At least one of the following conditions is met: A. the pH value during the neutralization and impurity removal process is greater than or equal to 5; B. the pH of the solution during the first stripping is 1-3; C. the end point pH of the reaction is 6-7; D. The pH value of the acid-adjusted solution is 1-4.
4. The method for preparing a battery-grade manganese sulfate solution according to claim 1, characterized in that: At least one of the following conditions is met: A. the manganese ion concentration in the first mixed metal solution is 80 g / L-120 g / L; B. The manganese ion concentration of the battery-grade manganese sulfate solution is 50 g / L-100 g / L.
5. The method for preparing a battery-grade manganese sulfate solution according to claim 1, characterized in that: At least one of the following conditions is met: A. the molar amount of the metal manganese is 3 to 10 times the total molar amount of the hydrogen ions, copper ions and zinc ions in the mixed metal solution; B. the molar ratio of the second extractant to the liquid caustic soda is 1:0.6-1; C. the molar ratio of the sodium soap post-extractant to the manganese in the manganese sulfate solution is 1:0.3-0.5; D. the volume ratio of the treated extractant to the second diluent is 1:0.05-0.3; E. The molar amount of the treated extractant is 1 to 10 times the molar amount of calcium ions in the acid-adjusted solution.
6. The method for preparing a battery-grade manganese sulfate solution according to claim 1, characterized in that: At least one of the following conditions is met: A. The reaction temperature is 20°C-90°C and the reaction time is 1h-5h; B. The temperature of the second extraction is 10°C-40°C, and the time is 2 min-20 min.
7. The method for preparing a battery-grade manganese sulfate solution according to claim 1, characterized in that: The saponification rates of the sodium soap and the manganese soap are independently 20%-100%.
8. The method for preparing a battery-grade manganese sulfate solution according to claim 1, characterized in that: The second extraction also obtains a second extract; The second extract and the second stripping solution are mixed and subjected to a second stripping to obtain a second mixed metal solution.
9. The method for preparing a battery-grade manganese sulfate solution according to claim 8, characterized in that: The second stripping solution includes hydrochloric acid.
10. The method for preparing a battery-grade manganese sulfate solution according to any one of claims 1 to 9, characterized in that: At least one of the following conditions is met: A. the iron content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; B. the zinc content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; C. the copper content in the battery-grade manganese sulfate solution is less than or equal to 0.002 g / L; D. The calcium content in the battery-grade manganese sulfate solution is less than or equal to 0.01 g / L.