Method for treating a manganese-copper mixture

Abstract

The application discloses a treatment method of a manganese-copper mixed solution, comprising the following steps: step (S1): adjusting the pH value of the manganese-copper mixed solution to 6.5-7, and obtaining a solution defined as a first solution; step (S2): adding an oxidizing agent to the first solution, and obtaining a solution defined as a second solution, wherein the oxidizing agent is oxidized with Mn 2+ to generate MnO2 in the range of the pH value of 6.5-7; and step (S3): collecting a first precipitate. The method has the advantages that the manganese ion can be separated in a short time, high-purity manganese ions can be recovered, the treatment method of waste liquid after recovery is simple, and the environment is less polluted.

Description

Technical Field

[0001] The present application relates to the field of batteries and the field of manganese ion recovery, and relates to a method for treating a manganese-copper mixed solution, and in particular to a method for recovering manganese ions from waste liquid after dealloying of manganese-copper alloy during the preparation of battery pole pieces or current collectors. Background Art

[0002] Manganese copper alloy is a precision resistance alloy with good piezoresistive effect and small resistance temperature coefficient. It is used in the preparation of battery electrodes and current collectors. However, in the process of preparing battery electrodes or current collectors, the waste liquid after dealloying of the manganese copper alloy contains a large amount of manganese ions and a small amount of copper ions. In order to avoid cost losses, it is necessary to separate and recover the manganese ions in the waste liquid after dealloying of the manganese copper alloy. Moreover, the manganese ions and copper ions in the waste liquid after dealloying of the manganese copper alloy do not meet the discharge standards of the "Comprehensive Wastewater Discharge Standard" and cannot be discharged directly. The existing method of recovering manganese ions from manganese copper mixed liquor usually adopts extraction technology. However, the extraction technology is used to separate manganese ions and copper ions, and the operation steps are complicated, the time required is long, and the purity of the obtained manganese ions is low. In addition, organic solution is used in the extraction process, which makes the waste liquid treatment process complicated and difficult to meet the discharge standards. Summary of the Invention

[0003] In view of the above problems, the present application provides a method for treating a manganese-copper mixed solution. This method takes a short time to separate manganese ions and can recover high-purity manganese ions. Moreover, the waste liquid treatment method after recovery is simple and can meet emission standards.

[0004] The present application provides a method for treating a manganese-copper mixed solution, comprising the following steps:

[0005] Step (S1): adjusting the pH value of the manganese-copper mixed solution to 6.5-7, and the resulting solution is defined as the first solution;

[0006] Step (S2): adding an oxidant to the first solution, the resulting solution is defined as the second solution, the oxidant reacts with Mn in a pH range of 6.5-7. 2+ Producing MnO2; and

[0007] Step (S3): collecting the first precipitate.

[0008] In the technical solution of the embodiment of the present application, the pH value of the waste liquid is adjusted to 6.5-7, and the waste liquid is added with Mn at this pH value. 2+ The reaction generates MnO2 precipitation, and after precipitation, Mn 2+ After adding the oxidant according to the method provided in this application, Mn 2+ It precipitates quickly, and then Mn 2+The separation is short in time, simple in operation steps, and Mn 2+ does not react with the oxidizing agent and is separated out 2+ has high purity.

[0009] In some embodiments, in step (S2), further comprising:

[0010] According to the amount of substance of Mn 2+ , an oxidizing agent is added, and the ratio of the amount of substance of the oxidizing agent to the amount of substance of Mn 2+ is 3:1-30:1.

[0011] Too small an amount of the oxidizing agent added will cause Mn 2+ in the mixed solution of the manganese-copper mixed waste liquid to be not completely separated out, and the recovery rate is small; too large an amount added will cause cost waste. By controlling the amount of the oxidizing agent added to be in a ratio of 3:1-30:1 of the amount of substance of the oxidizing agent to the amount of substance of Mn 2+ , as much Mn 2+ as possible in the manganese-copper mixed solution is caused to react with the oxidizing agent to form a precipitate, and then Mn 2+ is separated out to the greatest extent, without causing cost waste.

[0012] In some embodiments, the oxidizing agent includes at least one of H2O2, ammonium dithionate (NH4)2S2O3, hypochlorous acid, hypochlorite, chloric acid, chlorate, and chlorine water.

[0013] The H2O2, (NH4)2S2O3, hypochlorous acid, hypochlorite, chloric acid, chlorate, and chlorine water in the present application all belong to inorganic substances, so that the subsequent waste liquid treatment process is simpler, more economical, and better in effect, and causes less environmental pollution.

[0014] In some embodiments, the oxidizing agent is H2O2, and the ratio of the amount of substance of H2O2 to the amount of substance of Mn 2+ is 11:1-17:1.

[0015] By controlling the amount of H2O2 added to be in a ratio of 11:1-17:1 of the amount of substance of H2O2 to the amount of substance of Mn 2+ , the recovery efficiency of H2O2 on Mn 2+ in the manganese-copper mixed solution is high.

[0016] In some embodiments, in step (S2), the oxidizing agent is added dropwise in the first solution.

[0017] Since H2O2 is added to the manganese-copper mixed solution, H2O2 will first react with Mn 2+MnO2 is generated, and the generated MnO2 will act as a catalyst to catalyze the decomposition of H2O2. If the H2O2 droplet acceleration is too fast, it will cause a large amount of H2O2 to decompose, affecting the oxidation effect. Adding an oxidant dropwise to the first solution can alleviate the decomposition of H2O2 and improve the oxidation effect.

[0018] In some embodiments, the manganese-copper mixed solution is the waste liquid after the copper-manganese alloy is dealloyed during the preparation of battery pole pieces or current collectors.

[0019] The manganese content in the waste liquid after dealloying of the manganese-copper alloy during the preparation of battery pole pieces or current collectors is more than 1,000 times that of copper. The method of the present invention is used to separate and recover manganese ions in the waste liquid after dealloying of the manganese-copper alloy, which can reduce the production cost of the battery and alleviate the pollution to the environment caused by manganese ion emissions.

[0020] In some embodiments, after step (S3), the method further includes:

[0021] Step (S4): Collect the third solution, which is the solution left after collecting the first precipitate. Add a precipitant to the third solution. The precipitant and Mn 2+ and Cu 2+ The reaction generates a second precipitate; the second precipitate and a fourth solution are separated, the fourth solution being the solution remaining after removing the second precipitate, and a pH adjuster is added to the fourth solution to adjust the pH value of the fourth solution to 7-9.

[0022] This step can remove most of the Mn after step (S3) 2+ The third solution after Cu 2+ and residual Mn 2+ , and neutralize OH - , so that the wastewater can meet the requirements of the "Comprehensive Wastewater Discharge Standard" for the content of manganese ions and copper ions and OH - Content requirements.

[0023] In some embodiments, the amount of the precipitant added is A×B×C, where A is 5%-15%, and B is the amount of Mn in the third solution. 2+ The amount of substance, C is the molar mass of the precipitant.

[0024] By controlling the amount of precipitant added, all remaining metal ions in the mixed solution can be precipitated.

[0025] In some embodiments, the precipitant is a carbonate or an alkaline substance.

[0026] Adding carbonate or alkaline substances can make the Cu in the third solution 2+ and residual Mn 2+ Rapid precipitation and fewer side reactions.

[0027] In some embodiments, the precipitant includes at least one of Na2CO3, K2CO3, NaHCO3, and NaOH.

[0028] The addition of Na2CO3, K2CO3, NaHCO3, and NaOH can make Cu 2+ and residual Mn 2+ quickly precipitate, with fewer side reactions, and Na2CO3, K2CO3, NaHCO3, and NaOH are relatively low in price, reducing costs.

[0029] In some embodiments, the pH regulator includes at least one of acetic acid, citric acid, and carbonic acid

[0030] Acetic acid, citric acid, and carbonic acid are weak acids, which can more accurately adjust the pH value.

[0031] The above description is only a summary of the technical solutions of the present application. In order to enable the technical means of the present application to be more clearly understood, and to be implemented according to the content of the specification, and in order to enable the above and other purposes, features and advantages of the present application to be more apparent and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0032] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments, and are not meant to limit the present application. Moreover, the same reference numerals in all the drawings represent the same or similar elements. In the drawings:

[0033] Figure 1 Flow chart of the method for treating the manganese-copper mixed solution according to some embodiments of the present application;

[0034] Figure 2 Flow chart of the method for treating the manganese-copper mixed solution including treating the third solution according to some embodiments of the present application. DETAILED DESCRIPTION

[0035] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "include" and "have" and any variations thereof used in the specification and claims of the present application and the above description of drawings are intended to cover the non-exclusive inclusion.

[0037] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0038] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The occurrence of the phrase in various places in the specification is not necessarily all referring to the same embodiment, nor is it necessarily referring to a separate or alternative embodiment to the other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with each other.

[0039] Manganese-copper alloy is a kind of precision resistance alloy, which has good piezoresistive effect and small resistance temperature coefficient, and is more and more applied in the preparation process of electrode sheet and current collector of battery.

[0040] The present inventors notice that in the preparation process of battery electrode sheet or current collector, the waste liquid after dealloying of manganese-copper alloy contains a large amount of manganese ions and a small amount of copper ions, both of which do not reach the discharge standard of "Integrated Wastewater Discharge Standard", and cannot be directly discharged; and the content of manganese in the waste liquid is more than 1000 times that of copper, and the price of manganese is relatively high, in order to reduce the cost loss, it is necessary to separate and recover the manganese ions in the waste liquid after dealloying of manganese-copper alloy. The existing method for separating manganese ions usually adopts extraction technology, however, the extraction technology takes a long time to separate manganese ions and copper ions, has a low recovery rate, and the purity of the obtained manganese ions is also not high; and organic solution is used in the extraction process, resulting in a complex waste liquid treatment process, and it is difficult to reach the discharge standard.

[0041] In order to solve the above technical problems, the present application provides a treatment method for manganese-copper mixed liquid, which adjusts the pH value of the waste liquid to 6.5-7, and adds an oxidizing agent which does not react with Cu 2+ at this pH value to generate MnO2 precipitate, and separates Mn 2+ after the precipitation. According to the method provided by the present application, Mn 2+ is precipitated quickly after adding the oxidizing agent, and then Mn 2+ is separated, which has a short time, simple operation steps, and because Cu 2+ does not react with the oxidizing agent in the environment with a pH value of 6.5-7, the separated Mn 2+ has high purity. In addition, no organic solvent is added in this method, the subsequent waste liquid treatment is simple, and the pollution to the environment is small.

[0042] The application will be described in detail below with reference to the accompanying drawings and examples.

[0043] The treatment method of the manganese-copper mixed solution disclosed by the embodiments of the application can be applied to any manganese-copper mixed solution, and is not limited to the waste solution after the manganese-copper alloy is dealloyed in the battery preparation process.

[0044] According to some embodiments of the application, the application provides a treatment method of a manganese-copper mixed solution, comprising the following steps: Figure 1

[0045] Step (S1): adjusting the pH value of the manganese-copper mixed solution to 6.5-7, and the obtained solution is defined as a first solution;

[0046] Step (S2): adding an oxidizing agent to the first solution to obtain a second solution, and the oxidizing agent reacts with Mn 2+ to generate MnO2 in the pH value range of 6.5-7; and

[0047] Step (S3): collecting the first precipitate.

[0048] In the application, in step (S1), the amount of the manganese-copper mixed solution can be selected according to the experimental conditions and experimental conditions, and the amount of the selected manganese-copper mixed solution has no effect on the method of recovering manganese from the manganese-copper mixed solution. As an example, 1 mL, 5 mL, 10 mL, 200 mL, 30 L, 50 L, 100 L, 300 L, 1 t, 5 t, 30 t, etc. or a range composed of any two of the above values, for example, 1 mL-10 mL, 200 mL-30 L, 50 L-300 L, 1 t-30 t, etc.

[0049] In step (S1), the content ratio of Mn 2+ and Cu 2+ in the manganese-copper mixed solution is not limited. As an example, the content of Mn 2+ in the manganese-copper mixed solution can be greater than the content of Cu 2+ , the content of Mn 2+ may be equal to the content of Cu 2+ , and the content of Mn 2+ may be less than the content of Cu 2+ . In the actual battery tab or current collector preparation process, the manganese content in the waste solution after the manganese-copper alloy is dealloyed by HCL is more than 1000 times that of copper.

[0050] ​As an example, the pH value of the manganese-copper mixed solution is adjusted to 6.5-7, which can be: 6.5, 6.6, 6.7, 6.8, 6.9, 7, also can be 6.52, 6.55, 6.75, 6.77, 6.78, 6.79, etc., or a range composed of any two of the above values, for example, 6.5-6.7, 6.8-7, 6.52-6.75, 6.77-6.79, etc., which can be reasonably set according to actual needs, as long as the pH value of the manganese-copper mixed solution is adjusted to 6.5-7.

[0051] Under the condition of pH value of 6.5-7, the generated MnO2 precipitate in the subsequent step (S2) reduces the decomposition of the oxidizing agent such as H2O2, and further increases the amount of the oxidizing agent such as H2O2.

[0052] The method for treating the manganese-copper mixed solution provided in the present application adjusts the pH value of the waste liquid to 6.5-7, and adds a substance that does not react with Mn 2+ under the pH value to generate MnO2 precipitate, and after the precipitation, the Mn 2+ is separated out. After adding the oxidizing agent, the Mn 2+ precipitates quickly, and the Mn 2+ can be separated out, which is time-saving and simple in operation steps, and since Cu 2+ does not react with the oxidizing agent under the pH value of 6.5-7, the separated Mn 2+ has high purity. By adjusting the pH value of the waste liquid, the oxidation-reduction reaction between the oxidizing agent and Mn 2+ is more thorough, and thus the recovery rate of manganese ions is higher.

[0053] In some embodiments, in step (S1), an alkaline solution is used to adjust the pH value of the manganese-copper mixed solution to 6.5-7, as an example, the alkaline solution includes but is not limited to NaOH solution, KOH solution, etc.

[0054] In step (S2), the oxidizing agent reacts with Mn 2+ to generate MnO2, and does not react with Cu 2+ .

[0055] In some embodiments, in step (S2), it further includes:

[0056] According to the amount of substance of Mn 2+ , the oxidizing agent is added, and the ratio of the amount of substance of the oxidizing agent to the amount of substance of Mn 2+ is 3:1-30:1.

[0057] As an example, the amount of the added oxidizing agent is: the amount of substance of the oxidizing agent to the amount of substance of Mn 2+The ratio of the amount of substance of the oxidizing agent to the amount of substance of Mn can be 3:1, 4:1, 7:1, 10:1, 14:1, 19:1, 25:1, 30:1, can also be 3.2:1, 5.3:1, 7.4:1, 10.5:1, 14.6:1, 19.7:1, 25.8:1, 29.9:1, etc., or a range formed by any two of the above values, for example, can be 3:1-7:1, 10:1-14:1, 19:1-30:1, 3.2:1-7.4:1, 10.5:1-19.7:1, 25.8:1-29.9:1, etc., and can be reasonably set according to actual needs to meet the ratio of the amount of substance of the oxidizing agent to the amount of substance of Mn 2+ The ratio of the amount of substance of the oxidizing agent to the amount of substance of Mn can be 3:1-30:1.

[0058] If the amount of the oxidizing agent added is too small, the Mn 2+ in the mixed manganese-copper mixed solution cannot be completely separated, and the recovery rate is small; if the amount of the oxidizing agent added is too large, the cost is wasted. By controlling the amount of the oxidizing agent added to be the ratio of the amount of substance of the oxidizing agent to the amount of substance of Mn 2+ 3:1-30:1, as much Mn 2+ as possible in the manganese-copper mixed solution can be reacted with the oxidizing agent to form a precipitate, and the Mn 2+ is separated to the greatest extent, and the cost is not wasted.

[0059] In some embodiments, the oxidizing agent includes at least one of H2O2, ammonium dithionate (NH4)2S2O3, hypochlorous acid, hypochlorite, chloric acid, chlorate, and chlorine water.

[0060] The H2O2, (NH4)2S2O3, hypochlorous acid, hypochlorite, chloric acid, chlorate, and chlorine water of the present application all belong to inorganic substances, so that the subsequent waste liquid treatment process is simpler, more economical, and better, and the environmental pollution is smaller.

[0061] It can be understood that the oxidizing agent of the present application is not limited to H2O2, ammonium dithionate (NH4)2S2O4, hypochlorous acid, hypochlorite, chloric acid, chlorate, and chlorine water, but can also be other inorganic oxidizing agents, as long as the inorganic oxidizing agent generates MnO2 with Mn 2+ and does not react with Cu 2+ .

[0062] In some more preferred embodiments, the oxidizing agent is H2O2, and the ratio of the amount of substance of H2O2 to the amount of substance of Mn 2+ is 11:1-17:1.

[0063] Under alkaline conditions, the generated MnO2 will catalyze the decomposition of H2O2 (generating O2), increasing the amount of H2O2 used. Therefore, in step (S1), a slightly acidic condition, that is, a pH value of 6.5-7, is selected to inhibit the decomposition of H2O2.

[0064] By controlling the amount of H2O2 added, the amount of H2O2 and Mn 2+ The molar ratio of H2O2 to Mn in the manganese-copper mixture is 11:1-17:1. 2+ The recycling efficiency reaches 92% or even higher.

[0065] In some embodiments, in step (S2), an oxidizing agent is added dropwise to the first solution.

[0066] After H2O2 is added to the manganese-copper mixture, it will first react with Mn 2+ MnO2 is generated, and the generated MnO2 will act as a catalyst to catalyze the decomposition of H2O2. If the H2O2 droplet acceleration is too fast, it will cause a large amount of H2O2 to decompose, affecting the oxidation effect. Adding an oxidant dropwise to the first solution can alleviate the decomposition of H2O2 and improve the oxidation effect.

[0067] In some embodiments, the manganese-copper mixed solution is the waste liquid after the copper-manganese alloy is dealloyed during the preparation of battery pole pieces or current collectors.

[0068] The manganese content in the waste liquid after dealloying of the manganese-copper alloy during the preparation of battery pole pieces or current collectors is more than 1,000 times that of copper. The method of the present invention is used to separate and recover manganese ions in the waste liquid after dealloying of the manganese-copper alloy, which can reduce the production cost of the battery and alleviate the pollution to the environment caused by manganese ion emissions.

[0069] See also Figure 2 In some embodiments, after step (S3), the method further includes:

[0070] Step (S4): Collect the third solution, which is the solution left after collecting the first precipitate. Add a precipitant to the third solution. The precipitant and Mn 2+ and Cu 2+ The reaction generates a second precipitate; the second precipitate and a fourth solution are separated, the fourth solution being the solution remaining after removing the second precipitate, and a pH adjuster is added to the fourth solution to adjust the pH value of the fourth solution to 7-9.

[0071] This step can remove most of the Mn separated after step (S4) 2+ The third solution after Cu 2+ and residual Mn 2+ , and neutralize OH - , so that the wastewater can meet the requirements of the "Comprehensive Wastewater Discharge Standard" for the content of manganese ions and copper ions and OH- The content requirement.

[0072] In some embodiments, the amount of the precipitant added is A x B x C, A is 5%-15%, B is the amount of substance of Mn 2+ in the third solution, and C is the molar mass of the precipitant.

[0073] For example, A can be 5%, 6%, 7%, 9%, 11%, 12%, 13%, 14%, 15%, or 5.5%, 6.5%, 7.5%, 9.5%, 11.5%, 12.5%, 13.5%, 14.5%, etc., or a range between any two of the above values, for example, 5%-9%, 11%-13%, 14%-15%, 5.5%-7.5%, 9.5%-11.5%, 12.5%-14.5%, etc., which can be set according to actual needs, as long as A is 5%-15%.

[0074] The amount of the precipitant added can be calculated by measuring the amount of manganese ions and copper ions in the third solution. For the waste solution after the dealloying of the manganese-copper alloy, the amount of manganese ions in the third solution is still much larger than that of copper ions, so the amount of substance of manganese ions is used to calculate the amount of the precipitant added, which is sufficient to precipitate the copper ions and manganese ions in the third solution.

[0075] In some embodiments, the precipitant is a carbonate or a basic substance.

[0076] The addition of the carbonate or the basic substance can quickly precipitate Cu 2+ and residual Mn 2+ in the third solution, and the side reaction is less.

[0077] In addition, the precipitation of Cu 2+ and residual Mn 2+ in the third solution by adding the carbonate can reduce the introduction of OH - to a certain extent, which is more conducive to the subsequent adjustment of the pH value of the waste solution to 7-9, saves the amount of weak acid used, reduces the cost, and shortens the operation time.

[0078] In some embodiments, the precipitant includes at least one of Na2CO3, K2CO3, NaHCO3, and NaOH.

[0079] The addition of Na2CO3, K2CO3, NaHCO3, and NaOH can quickly precipitate Cu 2+ and residual Mn 2+ in the third solution, the side reaction is less, and Na2CO3, K2CO3, NaHCO3, and NaOH are relatively low in price, reducing the cost.

[0080] In some embodiments, the pH adjusting agent comprises at least one of acetic acid, citric acid and carbonic acid

[0081] Acetic acid, citric acid and carbonic acid belong to weak acid, which can more accurately adjust the pH value.

[0082] In some embodiments, the first precipitate and the second precipitate in step (S3) and step (S4) can be collected by, but not limited to, filtration, centrifugal separation and the like.

[0083] The following provides specific examples and comparative examples to introduce the preparation process and test data of the present application:

[0084] Example 1:

[0085] Step (S1): Take 30 mL of waste liquid after dealloying of manganese-copper alloy, and measure the content of Mn 2+ and Cu 2+ in the waste liquid, wherein the mass percentage of Cu 2+ in the total mass of the waste liquid is 0.04%, and the mass percentage of Mn 2+ in the total mass of the waste liquid is 7.94%; add 2 mol / L NaOH solution to adjust the pH value of the waste liquid after dealloying of manganese-copper alloy to 6.5-7 to obtain a first solution;

[0086] Step (S2): Add 15 mL of 30% H2O2 dropwise to the first solution of step (S1) to obtain a second solution;

[0087] Step (S3): After the second solution in step (S2) is left for one hour, a first precipitate is filtered out, and the solution after filtering out the first precipitate is a third solution; and

[0088] Step (S4): Waste liquid treatment 1: add Na2CO3 to the third solution in step (S3), the amount of Na2CO3 added is 10% x the amount of substance of Mn 2+ in the third solution x 106g, and then filter out a second precipitate to obtain a fourth solution; waste liquid treatment 2: add acetic acid dropwise to the fourth solution, and measure the pH of the waste liquid with pH paper until the pH is in the range of 7-9.

[0089] Examples 2-5:

[0090] Examples 2-5 are basically the same as Example 1, except that the volume of H2O2 added in step (S2) in Examples 2-5 is different from that in Example 1, and the other steps in Examples 2-5 are the same as those in Example 1, as shown in Table 1.

[0091] Example 6:

[0092] Example 6 is substantially the same as Example 1, except that in Example 6, 60 mL of 250 mg / L hypochlorous acid is added in step (S2), and the other steps in Example 6 are the same as those in Example 1, as shown in Table 1.

[0093] Comparative Example 1

[0094] Step (B1): 30 mL of the waste solution after the de-alloying of the manganese-copper alloy was taken, and the contents of Mn 2+ and Cu 2+ in the waste solution were measured, wherein the mass percentage of Cu 2+ in the total mass of the waste solution was 0.04%, and the mass percentage of Mn 2+ in the total mass of the waste solution was 7.94%.

[0095] Step (B2): 2 mol / L NaOH was added dropwise until no more precipitate was generated, and the precipitate was filtered; and

[0096] Step (B3): waste solution treatment 1: Na2CO3 was added to the solution after the filtration of the precipitate in step (S1), and then filtration was performed; waste solution treatment 2: acetic acid was added dropwise to the filtered waste solution, and the pH of the waste solution was measured by using pH paper until the pH was in the range of 7-9.

[0097]

[0098] The results of Examples 1-5 in Table 1 show that the recovery rate of Mn 2+ increases with the increase of the amount of H2O2 added, and when the amount of H2O2 added reaches 60 mL, the recovery rate of Mn 2+ remains basically unchanged with the further increase of the amount of H2O2 added, reaching the equilibrium of the reaction. According to the test results in Table 1, it can be concluded that Example 3 is the optimal example, in which the recovery rate of manganese ions reaches 92% after step (S3), that is, 92% of the high-purity manganese ions can be recovered, and the recovery rate of manganese ions and copper ions reaches 99.99% after step (S4), that is, the residual manganese ions and copper ions can be efficiently recovered.

[0099] Comparative Example 1 and Example 3 are compared, and in Comparative Example 1, the Cu ions and Mn ions in the waste solution after step (B3) are almost completely precipitated, with a recovery rate of about 100%, but the Mn and Cu precipitates cannot be distinguished, and the separation of Mn and Cu cannot be achieved.

[0100] The results of Example 6 show that when the oxidizing agent is hypochlorous acid, the recovery rate of manganese ions in the waste solution after the de-alloying of the manganese-copper alloy reaches 89%, indicating that the recovery rate of manganese ions is also relatively high when the oxidizing agent is hypochlorous acid.

[0101] By comparing the above examples with the comparative examples, it can be seen that the present invention provides a method for treating a manganese-copper mixed solution, by adjusting the pH value of the waste liquid and adding a mixture of manganese and copper at this pH value. 2+ , not with Cu 2+ The oxidant of the reaction, after precipitation, Mn 2+ After adding the oxidant according to the method provided in this application, Mn 2+ It precipitates quickly, and then Mn 2+ Separation time is short, the operation steps are simple, and because Cu 2+ It does not react with oxidants at all, and the separated Mn 2+ The purity is high, and the recovery rate of manganese can reach 92% or even higher, which is a high recovery rate.

[0102] In addition, no organic solvent is added in the method of the present invention, the waste liquid treatment is simple, and the pollution to the environment is small. 2+ and Mn 2+ and OH - They can basically meet the requirements of the "Comprehensive Sewage Discharge Standard".

[0103] 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 them. 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 make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A method for treating a manganese-copper mixed solution, characterized in that: The following steps are involved: Step (S1): adjusting the pH value of the manganese-copper mixed solution to 6.5-7, and the resulting solution is defined as the first solution; Step (S2): adding an oxidant to the first solution, and the resulting solution is defined as a second solution, wherein the oxidant reacts with Mn in a pH range of 6.5-7. 2+ Producing MnO2; and Step (S3): collecting the first precipitate.

2. The method for treating a manganese-copper mixed solution as claimed in claim 1, wherein: In the step (S2), it also includes: According to Mn 2+ The amount of the oxidant is added, and the amount of the oxidant is the same as that of the Mn 2+ The amount of substance ratio is 3:1-30:

1.

3. The method for treating the manganese-copper mixed solution according to claim 1 or 2, wherein: The oxidant includes at least one of H2O2, ammonium dithionate (NH4)2S2O3, hypochlorous acid, hypochlorite, chloric acid, chlorate, and chlorine water.

4. The method for treating the manganese-copper mixed solution according to claim 1 or 2, wherein: The oxidant is H2O2, and the amount of H2O2 is equal to that of Mn 2+ The molar ratio of the substances is 11:1-17:

1.

5. The method for treating the manganese-copper mixed solution as claimed in claim 1, wherein: In step (S2), the oxidizing agent is added dropwise to the first solution.

6. The method for treating the manganese-copper mixed solution according to claim 1, wherein: The manganese-copper mixed solution is the waste liquid after the copper-manganese alloy is dealloyed during the preparation of battery pole pieces or current collectors.

7. The method for treating the manganese-copper mixed solution according to claim 1, wherein: After step (S3), the method further includes: Step (S4): collecting a third solution, wherein the third solution is the solution remaining after collecting the first precipitate, adding a precipitant to the third solution, wherein the precipitant and Mn 2+ and Cu 2+ The reaction generates a second precipitate; the second precipitate and a fourth solution are separated, wherein the fourth solution is the solution remaining after removing the second precipitate, and a pH adjuster is added to the fourth solution to adjust the pH value of the fourth solution to 7-9.

8. The method for treating the manganese-copper mixed solution as claimed in claim 7, wherein: The amount of the precipitant added is A×B×C, wherein A is 5%-15%, and B is the amount of Mn in the third solution. 2+ The amount of substance, C is the molar mass of the precipitant.

9. The method for treating the manganese-copper mixed solution according to claim 7 or 8, wherein: The precipitant is carbonate.

10. The method for treating the manganese-copper mixed solution according to claim 7 or 8, wherein: The precipitant is an alkaline substance.

11. The method for treating a manganese-copper mixed solution according to claim 7 or 8, wherein: The precipitant includes at least one of Na2CO3, K2CO3, NaHCO3 and NaOH.

12. The method for treating a manganese-copper mixed solution according to claim 7, wherein: The pH adjuster includes at least one of acetic acid, citric acid and carbonic acid.

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