High-purity manganese sulfate solution, preparation method of positive electrode material and nickel-cobalt-manganese battery

Abstract

The present application belongs to the technical field of nickel-cobalt-manganese batteries, and provides a high-purity manganese sulfate solution, a preparation method of a positive electrode material, and a nickel-cobalt-manganese battery. The preparation method comprises: reacting a manganese sheet with sulfuric acid for a preset time to obtain a manganese sulfate solution with a first preset pH value; adding a precipitant to remove metal and filtering, and sending the filtered metal-removed manganese sulfate solution to an iron removal reaction tank; gradually adding sulfuric acid to the iron removal reaction tank according to a preset volume ratio of the metal-removed manganese sulfate solution and stirring until the pH value reaches a second preset pH value; plate-and-frame filtering the metal-removed manganese sulfate solution, and returning the filtered iron-removed manganese sulfate solution to the iron removal reaction tank, and circulating until the iron content in the iron-removed manganese sulfate solution is less than or equal to the iron content threshold; obtaining high-purity manganese sulfate; reducing the consumption cost of the oxidant, avoiding the loss of manganese element in the manganese sulfate solution, and increasing the content of manganese sulfate.

Description

Technical Field

[0001] The present application belongs to the technical field of nickel-cobalt-manganese batteries, and in particular relates to a high-purity manganese sulfate solution, a method for preparing a positive electrode material, and a nickel-cobalt-manganese battery. Background Art

[0002] At present, when manganese flakes are used to produce high-purity manganese sulfate, the addition of oxidants for iron removal increases production costs and there is also the problem of incomplete iron removal; in addition, the oxidant may also oxidize some soluble manganese ions into insoluble manganese ions, thereby causing the loss of manganese elements in the manganese sulfate solution and reducing the content of manganese sulfate.

[0003] The prior art has the problems of high production cost, incomplete iron removal and manganese loss when using oxidants to remove iron from manganese sulfate. Summary of the invention

[0004] The embodiments of the present application provide a high-purity manganese sulfate solution, a method for preparing a positive electrode material, and a nickel-cobalt-manganese battery, which aim to solve the problems of high production cost, incomplete iron removal, and manganese loss when removing iron from manganese sulfate with an oxidant to a certain extent.

[0005] In a first aspect, the present invention provides a method for preparing high-purity manganese sulfate, comprising:

[0006] Placing the manganese flakes and concentrated sulfuric acid in a chemical reaction tank for a preset time to obtain a manganese sulfate solution with a first preset pH value;

[0007] A precipitant is added to the manganese sulfate solution to remove metals and filter the solution, and the filtered manganese sulfate solution free of metals is sent to an iron removal reaction tank;

[0008] gradually adding dilute sulfuric acid to the iron removal reaction tank according to a preset volume ratio of the metal removal manganese sulfate solution and stirring until the pH value of the metal removal manganese sulfate solution reaches a second preset pH value, and the second preset pH value is less than the first preset pH value;

[0009] The metal-removing manganese sulfate solution is subjected to plate-and-frame filtration, and the filtered iron-removing manganese sulfate solution is returned to the iron-removing reaction tank, and circulated until the iron content in the iron-removing manganese sulfate solution is less than or equal to the iron content threshold;

[0010] The de-ironized manganese sulfate solution having an iron content less than or equal to the iron content threshold is transferred to a qualified solution tank to obtain high-purity manganese sulfate.

[0011] In some embodiments, the preset time is 10 h to 24 h, and the first preset pH value is greater than 4.5.

[0012] In some embodiments, the molar ratio of the manganese flakes to the sulfuric acid is 1:1.01-1.1.

[0013] In some embodiments, the metal includes zinc and iron, and adding a precipitant to the manganese sulfate solution to remove the metal includes:

[0014] A precipitant is added to the manganese sulfate solution to remove metal until the zinc content is less than or equal to a zinc content threshold value, wherein the zinc content threshold value is 1 ppm.

[0015] In some embodiments, the preset volume ratio is 0.01‰~0.05‰, and the second preset pH value ranges from 3.8 to 4.5.

[0016] In some embodiments, the filtered iron-removing manganese sulfate solution is returned to the iron-removing reaction tank, and circulated until the iron content in the iron-removing manganese sulfate solution is less than or equal to the iron content threshold, comprising:

[0017] The filtered deironing manganese sulfate solution is returned to the deironing reaction tank for oxidizing Fe with manganese ions greater than +2 and less than +4 in the deironing manganese sulfate solution. 2+ Fe 3+ , the iron content in the manganese sulfate solution circulated to the iron removal solution is less than or equal to the iron content threshold.

[0018] In some embodiments, the manganese ions with a valence greater than +2 and less than +4 in the iron removal manganese sulfate solution are used to oxidize Fe 2+ Fe 3+ The chemical formula is:

[0019] , where H + The pH value of the iron-removing manganese sulfate solution is maintained at the second preset pH value.

[0020] In some embodiments, the iron content threshold is 0.5 ppm.

[0021] In a second aspect, an embodiment of the present application provides a positive electrode material, wherein the raw material of the positive electrode material includes high-purity manganese sulfate obtained by the preparation method described in any one of the first aspects.

[0022] In a third aspect, an embodiment of the present application provides a nickel-cobalt-manganese battery, wherein the positive electrode of the nickel-cobalt-manganese battery is made of the positive electrode material described in the second aspect.

[0023] It can be understood that the beneficial effects of the second to third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0024] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0025] The method for preparing high-purity manganese sulfate provided by the present application controls the pH value of the metal-removing manganese sulfate solution to be maintained at a second preset pH value, performs plate-frame filtration on the metal-removing manganese sulfate solution, and returns the filtered iron-removing manganese sulfate solution to the iron-removing reaction tank, and circulates until the iron content in the iron-removing manganese sulfate solution is less than or equal to the iron content threshold value; compared with the prior art, since iron removal can be performed without adding an oxidant, the consumption cost of the oxidant is reduced, and at the same time, the pH value of the manganese sulfate solution is maintained at the second preset pH value, and the second preset pH value is less than the first preset pH value. In a low pH environment, it is difficult for the manganese sulfate solution to regenerate Fe after iron removal. 2+ It avoids the repeated changes in iron content and protects the manganese ions in the manganese sulfate solution from being oxidized by oxygen in the air to insoluble manganese ions with a valence higher than +4, thereby avoiding the loss of manganese elements in the manganese sulfate solution and increasing the content of manganese sulfate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 1 is a schematic flow chart of a method for preparing high-purity manganese sulfate provided in one embodiment of the present application;

[0028] Figure 2 It is a schematic flow chart of the preparation process of high-purity manganese sulfate in Example 1 of the present application. DETAILED DESCRIPTION

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0030] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0031] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, a~b (i.e. a and b), a~c, b~c, or a~b~c, where a, b, c can be single or multiple, respectively.

[0032] The terms "first" and "second" are used only for descriptive purposes to distinguish objects such as substances from each other, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. For example, without departing from the scope of the implementation regulations of this application, the first XX may also be referred to as the second XX, and similarly, the second XX may also be referred to as the first XX. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0033] The terms used in the embodiments of the present application are only for the purpose of describing specific implementation rules, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the implementation rules of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0034] It should be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0035] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0036] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0037] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0038] At present, when high-purity manganese sulfate is produced using manganese flakes and concentrated sulfuric acid (98% concentration), since the manganese sulfate solution after the reaction of manganese flakes with sulfuric acid contains soluble manganese ions with a valence higher than +2 and lower than +4, the existing technology adds an oxidant to remove iron, which increases the production cost and also causes incomplete iron removal; in addition, the oxidant also oxidizes part of the soluble manganese ions and converts them into insoluble manganese ions, thereby causing the loss of manganese elements in the manganese sulfate solution and reducing the content of manganese sulfate.

[0039] In order to overcome the above technical problems to a certain extent, Figure 1 As shown, the first aspect of the present application provides a method for preparing high-purity manganese sulfate, comprising:

[0040] S10, placing the manganese sheet and concentrated sulfuric acid in a chemical reaction tank for a preset time to obtain a manganese sulfate solution with a first preset pH value;

[0041] S20, adding a precipitant to the manganese sulfate solution to remove metals and filtering, and sending the filtered metal-removed manganese sulfate solution into an iron removal reaction tank;

[0042] S30, gradually adding dilute sulfuric acid to the iron removal reaction tank according to a preset volume ratio of the metal removal manganese sulfate solution and stirring until the pH value of the metal removal manganese sulfate solution reaches a second preset pH value, and the second preset pH value is less than the first preset pH value;

[0043] S40, performing plate-and-frame filtration on the metal-removing manganese sulfate solution, and returning the filtered iron-removing manganese sulfate solution to the iron removal reaction tank, and circulating until the iron content in the iron-removing manganese sulfate solution is less than or equal to the iron content threshold;

[0044] S50, transferring the iron-removed manganese sulfate solution having an iron content less than or equal to the iron content threshold to a qualified solution tank to obtain high-purity manganese sulfate.

[0045] In the present embodiment, the precipitant not only reduces the zinc content, but also precipitates most of the iron, which is different from the prior art that requires the addition of an oxidant to reduce the Fe 2+ Oxidized to Fe 3+ Compared with the conventional method, since iron removal can be performed without adding an oxidant, the consumption cost of the oxidant is reduced. At the same time, the pH value of the manganese sulfate solution is maintained at a second preset pH value, and the second preset pH value is less than the first preset pH value. In a low pH environment, the iron sulfate (Fe2(SO4)3 ) will hydrolyze in this environment to produce iron hydroxide (Fe(OH)3 ) precipitate, further remove the remaining iron, manganese sulfate solution after iron removal is difficult to regenerate Fe 2+, until the iron content is less than or equal to the iron content threshold, thus avoiding the repeated changes in iron content, and protecting the manganese ions in the manganese sulfate solution from being oxidized by oxygen in the air to insoluble manganese ions with a valence higher than +4, thereby avoiding the loss of manganese elements in the manganese sulfate solution and increasing the content of manganese sulfate.

[0046] In some embodiments, the molar ratio of manganese flakes to sulfuric acid is 1:1.01-1.1, the sulfuric acid is 98% concentrated sulfuric acid, and the amount of sulfuric acid is greater than the amount of manganese flakes, which can increase the dissolution rate of the manganese flakes and increase the content of manganese sulfate.

[0047] In some embodiments, the preset time is 10 h to 24 h, and the first preset pH value is greater than 4.5; the reaction time of the preset time of the embodiment of the present application can dissolve the manganese sheet as much as possible, thereby increasing the content of manganese sulfate; the first preset pH value of the manganese sulfate solution in which sulfuric acid reacts with the manganese sheet is controlled to be greater than 4.5, and the manganese sulfate solution can be kept to include +2-valent +3-valent soluble manganese ions. Alternatively, the first preset pH value of the manganese sulfate solution in which sulfuric acid reacts with the manganese sheet is controlled to be greater than 4.5 and less than or equal to 7.0, while maintaining the manganese sulfate solution to include +2-valent +3-valent soluble manganese ions, it can also avoid the environment with too high pH value to reduce the reaction efficiency of removing metals, thereby further improving the reaction efficiency of removing metals within the pH value range of the present embodiment.

[0048] In some embodiments, the metal includes zinc and iron, and a precipitant is added to a manganese sulfate solution to remove the metal, including: adding a precipitant to a manganese sulfate solution to remove the metal until the zinc content is less than or equal to a zinc content threshold, and the zinc content threshold is 1 ppm; in the implementation of the present application, the precipitant includes at least one of barium sulfide or barium hydroxide, and the precipitant and zinc form a precipitate, thereby removing metallic zinc and iron until the zinc content is less than or equal to 1 ppm, thereby improving the purity of manganese sulfate. Among them, adding barium sulfide generates a zinc sulfide (ZnS) precipitate to remove zinc, and generates an iron sulfide (Fe2S3) precipitate to remove iron; adding barium hydroxide generates zinc hydroxide (Zn(OH)2 ) precipitate removes zinc and generates iron hydroxide (Fe(OH)3 ) precipitate removes iron, and barium reacts with sulfate ions to form barium sulfate precipitate.

[0049] In some embodiments, the preset volume ratio is 0.01‰~0.05‰, and the pH value of the metal removal manganese sulfate solution in the iron removal reaction tank is adjusted by using dilute sulfuric acid (mass concentration is less than or equal to 70%) with a preset volume ratio, which can more accurately control the pH value of the metal removal manganese sulfate solution to prevent the pH value from exceeding the second preset pH value range; the second preset pH value range is 3.8~4.5. When the pH value of the metal removal manganese sulfate solution is between 3.8~4.5, due to the H +It is relatively small and can store manganese ions with a valence greater than +2 and less than +4, allowing manganese ions with a valence greater than +2 and less than +4 to replace oxidants to oxidize Fe 2+ , is the pH value range with the best iron removal effect. At the same time, when the pH value of the metal manganese sulfate solution is between 3.8 and 4.5, it can also protect manganese ions with a valence greater than +2 and less than +4 from being oxidized by oxygen in the air to insoluble manganese ions with a valence greater than +4, thereby avoiding the loss of manganese in the manganese sulfate solution and increasing the content of manganese sulfate.

[0050] In some embodiments, the filtered iron-removing manganese sulfate solution is returned to the iron-removing reaction tank, and circulated until the iron content in the iron-removing manganese sulfate solution is less than or equal to the iron content threshold, including: returning the filtered iron-removing manganese sulfate solution to the iron-removing reaction tank, for using the manganese ions greater than +2 and less than +4 in the iron-removing manganese sulfate solution to oxidize Fe 2+ Fe 3+ , circulated to the iron removal manganese sulfate solution, the iron content is less than or equal to the iron content threshold; using the method of the embodiment of the present application, manganese is used to oxidize Fe 2+ Iron ions are used to remove iron, without the need to use oxidants to oxidize Fe 2+ Iron ions are used to remove iron. The price of dilute sulfuric acid is much lower than that of oxidants (such as hydrogen peroxide), and the amount of dilute sulfuric acid used to adjust the pH value is also relatively less than that of oxidants. It is expected to reduce the cost of oxidants by 15 to 20 yuan per ton of finished products, greatly reducing the cost of oxidative iron removal and improving production efficiency.

[0051] In some embodiments, the manganese ions with a valence greater than +2 and less than +4 in the iron removal manganese sulfate solution are used to oxidize Fe 2+ Fe 3+ The chemical formula is:

[0052] , where H + The pH value of the iron removal manganese sulfate solution is maintained at a second preset pH value; the chemical formula of the embodiment of the present application shows that the manganese ions with a valence greater than +2 and less than +4 oxidize Fe 2+ Fe 3+ The reaction process reduces the high-valent manganese ions to +2-valent manganese ions, greatly reducing the cost of oxidative iron removal without forming insoluble manganese ions with a valence higher than +4, thus avoiding the loss of manganese in the manganese sulfate solution and increasing the content of manganese sulfate.

[0053] In some embodiments, the iron content threshold is 0.5 ppm. When the iron content of the iron-removing manganese sulfate solution is less than or equal to 0.5 ppm, the performance of the positive electrode material or the nickel-cobalt-manganese battery is improved.

[0054] In a second aspect, an embodiment of the present application provides a positive electrode material, wherein the raw material of the positive electrode material includes high-purity manganese sulfate obtained by the preparation method described in any one of the first aspects.

[0055] In a third aspect, an embodiment of the present application provides a nickel-cobalt-manganese battery, wherein the positive electrode of the nickel-cobalt-manganese battery is made of the positive electrode material described in the second aspect.

[0056] The technical solution of the present application is illustrated below through specific embodiments and comparative examples.

[0057] Example 1

[0058] like Figure 2 As shown, a method for preparing high-purity manganese sulfate comprises:

[0059] 1 mol of manganese flakes and 1.05 mol of concentrated sulfuric acid (mass concentration is 98%) are placed in a chemical reaction tank for reaction for 12 hours to obtain a manganese sulfate solution with a first preset pH value of 5.8;

[0060] Add barium hydroxide (precipitant) to the manganese sulfate solution in the precipitation tank to remove metallic zinc and iron and filter out zinc hydroxide (Zn(OH)2 ) and ferric hydroxide (Fe(OH)3 ) precipitate, before the zinc content is less than or equal to 1ppm, the manganese sulfate after filtering the precipitate through the plate and frame filter is returned to the precipitation tank for precipitation to remove zinc and iron, until the zinc content is less than or equal to 1ppm, and the filtered metal-removing manganese sulfate solution is sent to the iron removal reaction tank;

[0061] Dilute sulfuric acid (mass concentration of 60%) is gradually added to the iron removal reaction tank according to the preset volume ratio of the metal removal manganese sulfate solution of 0.03% and stirred. Before the pH value reaches 4.0, the metal removal manganese sulfate solution is stirred in the iron removal reaction tank, but at the same time, the metal removal manganese sulfate solution at the bottom is filtered through a plate and frame filter until the second preset pH value of the metal removal manganese sulfate solution is 4.0;

[0062] The metal-removing manganese sulfate solution with a second preset pH value of 4.0 is further subjected to plate-frame filtration, and the filtered iron-removing manganese sulfate solution is returned to the iron removal reaction tank for oxidizing Fe with manganese ions greater than +2 and less than +4 in the iron-removing manganese sulfate solution. 2+ Fe 3+ , the chemical reaction changes of each ion in the iron removal reaction tank are , the chemical formula of this step is: , where H +The second preset pH value of the iron-removing manganese sulfate solution is maintained at 4.0, and the iron content of the iron-removing manganese sulfate solution circulated through the plate and frame filter is less than or equal to 0.5 ppm;

[0063] The iron-free manganese sulfate solution with an iron content of less than or equal to 0.5 ppm is transferred to a qualified solution tank to obtain high-purity manganese sulfate.

[0064] Example 2 is different from Example 1 in that the precipitant is barium sulfide, and the second preset pH value of the metal manganese sulfate solution is 3.8.

[0065] Embodiment 3 is different from Embodiment 1 in that the second preset pH value of the metal manganese sulfate removal solution is 4.5.

[0066] Comparative Example 1

[0067] A method for preparing high-purity manganese sulfate comprises:

[0068] Step 1, placing 1 mol of manganese flakes and 1.05 mol of sulfuric acid in a chemical reaction tank for reaction for 12 hours to obtain a manganese sulfate solution with a pH value of 4.6;

[0069] Step 2, adding barium hydroxide (precipitant) to the manganese sulfate solution to remove metallic zinc and filtering until the zinc content is less than or equal to 1 ppm, and sending the filtered metal-removed manganese sulfate solution to an iron removal reaction tank;

[0070] Step 3, adding hydrogen peroxide (oxidant) to the metal-removing manganese sulfate solution to remove iron, until the iron content in the iron-removing manganese sulfate solution is less than or equal to 0.5 ppm;

[0071] Step 4: Transfer the iron-free manganese sulfate solution with an iron content of less than or equal to 0.5 ppm to a qualified solution tank to obtain high-purity manganese sulfate.

[0072] In Examples 1 to 3 and Comparative Example 1, the iron content, zinc content and manganese volume concentration in the combined reaction tank solution, zinc removal filtrate and iron removal filtrate during the preparation of manganese sulfate are shown in Table 1.

[0073]

[0074] Compared with Comparative Example 1, in Examples 1 to 3, since no additional oxidant is used, the cost of the oxidant is saved by 15 to 20 yuan per ton, the cost of oxidative iron removal is greatly reduced, and the production efficiency is improved. At the same time, the repeated changes in iron content are avoided, and the loss of manganese in the manganese sulfate solution is avoided, and the content of manganese sulfate is increased.

[0075] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0076] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0077] The embodiments described above 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, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for preparing high-purity manganese sulfate, characterized in that: include: Placing the manganese flakes and concentrated sulfuric acid in a chemical reaction tank for a preset time to obtain a manganese sulfate solution with a first preset pH value; A precipitant is added to the manganese sulfate solution to remove metals and filter the solution, and the filtered manganese sulfate solution free of metals is sent to an iron removal reaction tank; gradually adding dilute sulfuric acid to the iron removal reaction tank according to a preset volume ratio of the metal removal manganese sulfate solution and stirring until the pH value of the metal removal manganese sulfate solution reaches a second preset pH value, and the second preset pH value is less than the first preset pH value; The metal-removing manganese sulfate solution is subjected to plate-and-frame filtration, and the filtered iron-removing manganese sulfate solution is returned to the iron-removing reaction tank, and circulated until the iron content in the iron-removing manganese sulfate solution is less than or equal to the iron content threshold; Transferring the de-ironized manganese sulfate solution having an iron content less than or equal to the iron content threshold to a qualified solution tank to obtain high-purity manganese sulfate; The filtered iron removal manganese sulfate solution is returned to the iron removal reaction tank and circulated until the iron content in the iron removal manganese sulfate solution is less than or equal to the iron content threshold, comprising: The filtered deironing manganese sulfate solution is returned to the deironing reaction tank for oxidizing Fe with manganese ions greater than +2 and less than +4 in the deironing manganese sulfate solution. 2+ Fe 3+ , the iron content in the manganese sulfate solution circulated to the iron removal solution is less than or equal to the iron content threshold.

2. The method for preparing high-purity manganese sulfate according to claim 1, characterized in that: The preset time length is 10 h to 24 h, and the first preset pH value is greater than 4.

5.

3. The method for preparing high-purity manganese sulfate according to claim 1, characterized in that: The molar ratio of the manganese sheet to the sulfuric acid is 1:1.01-1.

1.

4. The method for preparing high-purity manganese sulfate according to claim 1, characterized in that: The metals include zinc and iron, and a precipitant is added to the manganese sulfate solution to remove the metals, including: A precipitant is added to the manganese sulfate solution to remove metal until the zinc content is less than or equal to a zinc content threshold value, wherein the zinc content threshold value is 1 ppm.

5. The method for preparing high-purity manganese sulfate according to claim 1, characterized in that: The preset volume ratio is 0.01‰~0.05‰, and the second preset pH value ranges from 3.8 to 4.

5.

6. The method for preparing high-purity manganese sulfate according to claim 1, characterized in that: The manganese ions with a valence greater than +2 and less than +4 in the iron removal manganese sulfate solution are used to oxidize Fe 2+ Fe 3+ The chemical formula is: 2FeSO4+Mn2(SO4)3 Fe2(SO4)3+2MnSO4, where H + The pH value of the iron-removing manganese sulfate solution is maintained at the second preset pH value.

7. The method for preparing high-purity manganese sulfate according to claim 1, characterized in that: The iron content threshold is 0.5 ppm.

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