A preparation method of high-purity ammonium manganese phosphate and its product

Abstract

The invention discloses a preparation method of high-purity ammonium manganese phosphate and a product thereof, relates to the technical field of chemical preparation of battery materials, and aims to solve the problem of low purity of products produced by existing ammonium manganese phosphate preparation methods. The invention comprises the following steps: mixing a manganese source with deionized water to obtain a manganese source slurry; dissolving monoammonium phosphate in the deionized water to obtain a monoammonium phosphate solution; adding the monoammonium phosphate solution to a reactor, adding a catalyst, a reducing agent and a surfactant, and then adding the manganese source slurry; adjusting the pH with an acidic solution and / or an alkaline solution, stirring and reacting at 20 to 90° C.; supplementally adding a reducing agent during the reaction, and obtaining ammonium manganese phosphate slurry after the reaction is complete; filtering, rinsing and drying the ammonium manganese phosphate slurry to obtain an ammonium manganese phosphate powder product. The invention has simple and easy-to-control process steps, low production cost, high product purity, few impurities, and is easily applicable to large-scale production.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical preparation of battery materials, and in particular to a preparation method of high-purity ammonium manganese phosphate and a product thereof. Background Art

[0002] Ammonium manganese phosphate, with the chemical formula NH4MnPO4·H2O, is an important chemical raw material, widely used in fertilizers, catalysts, flame retardants and other fields. In particular, it shows its unique value in the preparation of lithium-ion batteries as a precursor of lithium-ion battery positive electrode materials.

[0003] However, the traditional preparation method of manganese ammonium phosphate has some significant shortcomings, such as low purity, low production efficiency, high cost and high energy consumption. 2+ Oxidation of Mn is a major problem. During the reaction, 2+ Easily oxidized to Mn 3+ and Mn 4+ , resulting in a decrease in product purity. Furthermore, the manganese source used in conventional methods is primarily manganese sulfate or chloride, which results in residual sulfate and chloride ions in the reaction product. For example, patent application publication number CN115231544A, entitled "A Method for Preparing Ammonium Manganese Phosphate and a Lithium-Ion Battery Cathode Material," discloses the use of antioxidants to reduce oxidation and produce high-valent manganese. However, this method still fails to control impurity levels to a low level, resulting in a maximum purity of only 99.5%. Furthermore, the process steps involved are complex to control, making it unsuitable for large-scale production. Summary of the Invention

[0004] The object of the present invention is to provide a method for preparing high-purity ammonium manganese phosphate and its product, so as to solve the problem that the product purity of the existing method for preparing ammonium manganese phosphate is not high enough.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing high-purity ammonium manganese phosphate, comprising the following steps:

[0006] Step S1: mixing a manganese source with deionized water to obtain a manganese source slurry;

[0007] Step S2: dissolving monoammonium phosphate in deionized water to obtain a monoammonium phosphate solution;

[0008] Step S3: adding the monoammonium phosphate solution into the reactor, adding the catalyst, reducing agent and surfactant, and then adding the manganese source slurry;

[0009] Step S4: adjusting the pH with an acidic solution and / or an alkaline solution, and stirring the reaction at 20-90° C.;

[0010] Step S5: adding a reducing agent during the reaction process, and obtaining ammonium manganese phosphate slurry after the reaction is complete;

[0011] Step S6: filtering, rinsing and drying the ammonium manganese phosphate slurry to obtain an ammonium manganese phosphate powder product.

[0012] Preferably, in the above step S1, the manganese source is electrolytic manganese metal powder and / or high-purity manganese carbonate powder, and the manganese source is sieved through a 200-mesh sieve before being prepared into slurry; the solid content of the manganese source slurry is 30-60%.

[0013] Preferably, in the above step S2, the concentration of the monoammonium phosphate solution is 1 to 3 mol / L.

[0014] Preferably, in the above steps S1 and S2, the impurity contents of K, Ca, Na, and Mg in the manganese source are all below 100 ppm, and the contents of heavy metal impurities Zn, Cu, Ni, and Pb are all below 10 ppm; the contents of heavy metal impurities Zn, Cu, Ni, and Pb in monoammonium phosphate are all below 10 ppm.

[0015] Preferably, in the above step S3, the catalyst is one or more of ammonia water, triethanolamine, propanolamine, and isopropanolamine, and the amount of the catalyst added is 0.5-1% of the weight of the manganese source; the surfactant is one or more of sodium stearate, sodium lauryl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, and sodium dodecylbenzenesulfonate, and the amount of the surfactant added is 0.05-0.1% of the weight of the manganese source; in steps S3 and S5, the reducing agent is one or more of hydrogen peroxide, glucose, formaldehyde, and acetaldehyde, and the amount of the reducing agent added in step S3 is 1-2% of the weight of the manganese source, and the amount of the reducing agent added in step S5 is 2-3% of the weight of the manganese source. The replenishment time is after the reaction is carried out for 3 hours.

[0016] Preferably, in the above step S4, the acidic solution is one or more of phosphoric acid, formic acid, acetic acid, and citric acid, and the concentration of the acidic solution is 1 to 6 mol / L; the alkaline solution is one or more of sodium hydroxide solution, potassium hydroxide solution, and ammonia solution, and the concentration of the alkaline solution is 1 to 6 mol / L; and the pH of the reaction base solution is adjusted to 3 to 6.

[0017] Preferably, the reaction temperature is 30-50° C., and the stirring speed is 200-500 rpm.

[0018] Preferably, the total time for the above reaction is 12 to 18 hours, and the reaction is continued for another hour after no bubbles are formed.

[0019] Preferably, in the above step S6, rinsing is repeated washing with pure water at least three times to remove other free ions.

[0020] Another technical solution provided by the present invention is a product prepared by the above preparation method, namely, manganese ammonium phosphate, whose impurity content is less than 0.05%, wherein the impurity S content is less than 250ppm, the impurity Cl- is less than 200ppm, the manganese-phosphorus ratio is 0.98-1, and the specific surface area is 1-20m 2 / g.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The preparation method of high-purity ammonium manganese phosphate and its product adopt an efficient reaction pathway, using manganese carbonate or metallic manganese as raw material, adding a catalyst, a reducing agent and a surfactant at an appropriate temperature, and regulating product formation by controlling the pH value. This method has a short production cycle, improves product purity, and has an impurity content of less than 0.05%, which is conducive to improving production efficiency and reducing costs.

[0023] 2. The preparation method and product of this high-purity ammonium manganese phosphate can effectively control the oxidation of manganese ions by adding a reducing agent twice during the reaction, and the progress of the reaction can be controlled by adding a catalyst and a surfactant. The obtained ammonium manganese phosphate product has high purity and uniform particle size distribution, and is well adapted to the preparation of raw materials for lithium manganese iron phosphate battery precursors, greatly improving the quality and applicability of the product.

[0024] 3. The preparation method of high-purity manganese ammonium phosphate has simple process steps. It only requires preparing raw materials, mixing, adjusting the pH and stirring the reaction. There are no other control conditions in the process except for the replenishment of a reducing agent. The operation is convenient, reliable and easy to control. No special equipment is required except for the reactor. In addition, the raw materials are cheap and easily available, the production cost is low, and it is easy to apply to large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 1 is a SEM image of ammonium manganese phosphate prepared in Example 1 of the present invention.

[0026] Figure 2 This is an SEM image of the ammonium manganese phosphate prepared in Comparative Example 1.

[0027] Figure 3 yes Figure 1 Schematic diagram of the comparison between the XRD pattern of ammonium manganese phosphate and the standard spectrum. DETAILED DESCRIPTION

[0028] A method for preparing high-purity ammonium manganese phosphate comprises the following steps:

[0029] Step S1: Mixing a manganese source with deionized water to obtain a manganese source slurry. In a preferred embodiment, the manganese source is electrolytic manganese powder or / and high-purity manganese carbonate powder, and the manganese source is sieved through a 200-mesh sieve before being prepared into the slurry. The solid content of the manganese source slurry is preferably further controlled to be 30-60%. In addition, in order to further control product impurities, the impurity content of the raw materials is preferably slightly controlled. Therefore, preferably, the impurity content of K, Ca, Na, and Mg in the manganese source is less than 100 ppm, and the content of heavy metal impurities Zn, Cu, Ni, and Pb is less than 10 ppm.

[0030] Step S2: dissolving monoammonium phosphate in deionized water to obtain a monoammonium phosphate solution. The concentration of the monoammonium phosphate solution is preferably 1 to 3 mol / L. Regarding the impurity content of the monoammonium phosphate raw material, it is important to ensure that the content of heavy metal impurities Zn, Cu, Ni, and Pb is below 10 ppm.

[0031] Step S3: adding a monoammonium phosphate solution to a reactor, adding a catalyst, a reducing agent and a surfactant, and then adding a manganese source slurry, wherein the catalyst can be one or more of ammonia water, triethanolamine, propanolamine, and isopropanolamine, and the amount of the catalyst added can be further controlled to be 0.5-1% by weight of the manganese source; the surfactant can be one or more of sodium stearate, sodium lauryl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, and sodium dodecylbenzenesulfonate, and the amount of the surfactant added can be further controlled to be 0.05-0.1% by weight of the manganese source; the reducing agent can be one or more of hydrogen peroxide, glucose, formaldehyde, and acetaldehyde, and the amount of the reducing agent added can be further controlled to be 1-2% by weight of the manganese source;

[0032] Step S4: adjusting the pH with an acidic solution and / or an alkaline solution, wherein the acidic solution may be one or more of phosphoric acid, formic acid, acetic acid, and citric acid, and the concentration of the acidic solution may be 1 to 6 mol / L; and the alkaline solution may be one or more of sodium hydroxide solution, potassium hydroxide solution, and ammonia solution, and the concentration of the alkaline solution may be 1 to 6 mol / L; adjusting the pH of the reaction base solution to 3 to 6, and stirring the reaction at 20 to 90° C., preferably 30 to 50° C., and for reference, the stirring speed may be 200 to 500 rpm;

[0033] Step S5: During the reaction, a reducing agent is added. The reducing agent may be one or more of hydrogen peroxide, glucose, formaldehyde, and acetaldehyde. The amount of the reducing agent added may be further controlled to be 2-3% of the weight of the manganese source. The addition time is preferably after 3 hours of reaction. After the reaction is complete, ammonium manganese phosphate slurry is obtained. The total reaction time is generally 5-25 hours, preferably 12-18 hours. The specific control of the complete reaction is that the reaction is considered complete after the reaction is free of bubbles and then the reaction is continued for another hour;

[0034] Step S6: filtering, rinsing and drying the ammonium manganese phosphate slurry to obtain an ammonium manganese phosphate powder product; wherein the rinsing is preferably repeated with pure water for at least 3 times to remove other free ions.

[0035] Note: Generally speaking, in the above process, the ratio of manganese source and monoammonium phosphate can be based on a manganese to phosphorus ratio of 1:1. However, in actual production, it can also be varied within a certain range to facilitate ingredient control, for example, a manganese to phosphorus ratio of 1:0.95 to 1.2 is acceptable.

[0036] Example 1:

[0037] (1) 1149.5 g of manganese carbonate passed through a 200-mesh sieve was mixed with deionized water at a solid content of 40% to obtain a manganese carbonate slurry;

[0038] (2) Prepare 5 L of 2 mol / L monoammonium phosphate solution, 1 mol / L ammonia solution, and 1 mol / L phosphoric acid solution with deionized water;

[0039] (3) The monoammonium phosphate solution in step (2) was added to a 20 L reactor, and then 6 g of ammonia water, 40 g of 30% hydrogen peroxide solution and 1 g of sodium stearate were added to the solution, and then the slurry in step (1) was added.

[0040] (4) The phosphoric acid solution in step (2) was added to the reactor and the pH was continuously adjusted to 3.5. The stirring speed during the reaction was controlled to be 500 rpm, the reaction temperature was 35°C, and the mixture was stirred evenly.

[0041] (5) After the third hour of reaction, 80 g of 30% hydrogen peroxide solution was added, and the reaction time was 18 h. After the reaction was complete, manganese ammonium phosphate slurry was obtained;

[0042] (6) The ammonium manganese phosphate slurry after step (5) was filtered, rinsed three times and dried, and then the filtrate was dried in an oven at 70°C to obtain an ammonium manganese phosphate powder product.

[0043] The SEM and XRD patterns of the manganese ammonium phosphate product prepared in Example 1 are shown in Table 1. Figure 1 and Figure 3 ;from Figure 1 It can be seen that the particle size distribution of ammonium manganese phosphate is uniform.

[0044] Example 2:

[0045] (1) 550 g of manganese metal that had passed through a 200-mesh sieve was mixed with deionized water at a solid content of 40% to obtain a manganese metal slurry;

[0046] (2) Prepare 5 L of 2 mol / L monoammonium phosphate solution, 1 mol / L ammonia solution, and 1 mol / L phosphoric acid solution with deionized water;

[0047] (3) The monoammonium phosphate solution in step (2) was added to a 20 L reactor, and then 6 g of triethanolamine, 40 g of 30% hydrogen peroxide solution and 1 g of sodium stearate were added to the solution, and then the slurry in step (1) was added.

[0048] (4) The phosphoric acid solution in step (2) was added to the reactor and the pH was continuously adjusted to 3.5. The stirring speed during the reaction was controlled to be 500 rpm, the reaction temperature was 35°C, and the mixture was stirred evenly.

[0049] (5) After the third hour of reaction, 80 g of 30% hydrogen peroxide solution was added, and the reaction time was 18 h. After the reaction was complete, manganese ammonium phosphate slurry was obtained;

[0050] (6) The ammonium manganese phosphate slurry after step (5) was filtered, rinsed three times and dried, and then the filtrate was dried in an oven at 70°C to obtain an ammonium manganese phosphate powder product.

[0051] Example 3:

[0052] (1) 1149.5 g of manganese carbonate passed through a 200-mesh sieve was mixed with deionized water at a solid content of 40% to obtain a manganese carbonate slurry;

[0053] (2) Prepare 5 L of 2 mol / L monoammonium phosphate solution, 1 mol / L ammonia solution, and 1 mol / L phosphoric acid solution with deionized water;

[0054] (3) The monoammonium phosphate solution in step (2) was added to a 20 L reactor, and then 6 g of triethanolamine, 40 g of 30% hydrogen peroxide solution and 1 g of sodium stearate were added to the solution, and then the slurry in step (1) was added.

[0055] (4) Add the phosphoric acid solution in step (2) into the reactor and continuously adjust the pH to 3.5. Control the stirring speed of the reaction process to 500 rpm, the reaction temperature to 45°C, and stir evenly.

[0056] (5) After the third hour of reaction, 80 g of 30% hydrogen peroxide solution was added, and the reaction time was 18 h. After the reaction was complete, manganese ammonium phosphate slurry was obtained;

[0057] (6) The ammonium manganese phosphate slurry after step (5) was filtered, rinsed three times and dried, and then the filtrate was dried in an oven at 70°C to obtain an ammonium manganese phosphate powder product.

[0058] Example 4:

[0059] (1) 1149.5 g of manganese carbonate passed through a 200-mesh sieve was mixed with deionized water at a solid content of 40% to obtain a manganese carbonate slurry;

[0060] (2) Prepare 5 L of 2 mol / L monoammonium phosphate solution, 1 mol / L ammonia solution, and 1 mol / L phosphoric acid solution with deionized water;

[0061] (3) The monoammonium phosphate solution in step (2) was added to a 20 L reactor, and then 6 g of triethanolamine, 40 g of 30% hydrogen peroxide solution and 1 g of sodium stearate were added to the solution, and then the slurry in step (1) was added.

[0062] (4) The phosphoric acid solution in step (2) was added to the reactor and the pH was continuously adjusted to 3.8. The stirring speed during the reaction was controlled at 500 rpm and the reaction temperature was 35°C, and the mixture was stirred evenly.

[0063] (5) After the third hour of reaction, 80 g of 30% hydrogen peroxide solution was added, and the reaction time was 18 h. After the reaction was complete, manganese ammonium phosphate slurry was obtained;

[0064] (6) The ammonium manganese phosphate slurry after step (5) was filtered, rinsed three times and dried, and then the filtrate was dried in an oven at 70°C to obtain an ammonium manganese phosphate powder product.

[0065] Example 5:

[0066] (1) 1149.5 g of manganese carbonate passed through a 200-mesh sieve was mixed with deionized water at a solid content of 40% to obtain a manganese carbonate slurry;

[0067] (2) Prepare 5 L of 2 mol / L monoammonium phosphate solution, 1 mol / L ammonia solution, and 1 mol / L phosphoric acid solution with deionized water;

[0068] (3) The monoammonium phosphate solution in step (2) was added to a 20 L reactor, and then 6 g of triethanolamine, 40 g of 30% hydrogen peroxide solution and 1 g of sodium stearate were added to the solution, and then the slurry in step (1) was added.

[0069] (4) Add the phosphoric acid solution in step (2) into the reactor and continuously adjust the pH to 3. Control the stirring speed of the reaction process to 500 rpm, the reaction temperature to 35°C, and stir evenly.

[0070] (5) After the third hour of reaction, 80 g of 30% hydrogen peroxide solution was added, and the reaction time was 18 h. After the reaction was complete, manganese ammonium phosphate slurry was obtained;

[0071] (6) The ammonium manganese phosphate slurry after step (5) was filtered, rinsed three times and dried, and then the filtrate was dried in an oven at 70°C to obtain an ammonium manganese phosphate powder product.

[0072] Example 6:

[0073] (1) 550 g of manganese metal that had passed through a 200-mesh sieve was mixed with deionized water at a solid content of 40% to obtain a manganese metal slurry;

[0074] (2) Prepare 5 L of 2 mol / L monoammonium phosphate solution, 1 mol / L ammonia solution, and 1 mol / L phosphoric acid solution with deionized water;

[0075] (3) The monoammonium phosphate solution in step (2) was added to a 20 L reactor, and then 6 g of triethanolamine, 40 g of 30% hydrogen peroxide solution and 1 g of sodium stearate were added to the solution, and then the slurry in step (1) was added.

[0076] (4) The phosphoric acid solution in step (2) was added to the reactor and the pH was continuously adjusted to 4. The stirring speed during the reaction was controlled to be 500 rpm, the reaction temperature was 35°C, and the mixture was stirred evenly.

[0077] (5) After the third hour of reaction, 80 g of 30% hydrogen peroxide solution was added, and the reaction time was 18 h. After the reaction was complete, manganese ammonium phosphate slurry was obtained;

[0078] (6) The ammonium manganese phosphate slurry after step (5) was filtered, rinsed three times and dried, and then the filtrate was dried in an oven at 70°C to obtain an ammonium manganese phosphate powder product.

[0079] Comparative Example 1:

[0080] (1) Prepare 10 L of 1 mol / L battery-grade manganese sulfate solution with deionized water;

[0081] (2) Prepare 5 L of 2 mol / L monoammonium phosphate solution, 1 mol / L ammonia solution, and 1 mol / L phosphoric acid solution with deionized water;

[0082] (3) The monoammonium phosphate solution in step (2) was added to a 20 L reactor, and then 6 g of ammonia water, 40 g of 30% hydrogen peroxide solution and 1 g of sodium stearate were added to the solution, and then the slurry in step (1) was added.

[0083] (4) The phosphoric acid solution in step (2) was added to the reactor and the pH was continuously adjusted to 3.5. The stirring speed during the reaction was controlled to be 500 rpm, the reaction temperature was 35°C, and the mixture was stirred evenly.

[0084] (5) After the third hour of reaction, 80 g of 30% hydrogen peroxide solution was added, and the reaction time was 18 h. After the reaction was complete, manganese ammonium phosphate slurry was obtained;

[0085] (6) The ammonium manganese phosphate slurry after step (5) was filtered, rinsed three times and dried, and then the filtrate was dried in an oven at 70°C to obtain an ammonium manganese phosphate powder product.

[0086] The SEM image of the manganese ammonium phosphate product prepared in Comparative Example 1 is shown in FIG. Figure 2 , it is obvious that its particle size distribution is uneven, which may lead to uneven product quality.

[0087] The physical and chemical indicators of the products obtained in the examples and comparative examples were tested, and the results are shown in Table 1 below:

[0088] Table 1 Physical and chemical indicators of ammonium manganese phosphate

[0089]

[0090] As can be seen from Table 1, the purity of the manganese ammonium phosphate prepared by the method of the present invention is higher than 99.95%, that is, the impurity content is less than 0.05%, wherein the impurity S content is less than 250ppm, the impurity Cl- is less than 200ppm, the manganese to phosphorus ratio is 0.98-1, and the specific surface area is 1-20m 2 / g; however, the purity of manganese ammonium phosphate prepared in the prior art is difficult to reach the level of the present invention, and after a large number of preparation experiments using different methods, the S content is basically between 1,000 and 2,000 ppm, and the manganese-phosphorus ratio is usually above 1.0. All indicators are difficult to meet the needs of downstream customers. Therefore, the method and product of the present invention are significantly superior.

[0091] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims.

[0092] Any matters not described in detail in the present invention are well-known technologies to those skilled in the art.

Claims

1. A method for preparing high-purity ammonium manganese phosphate, characterized in that: The following steps are involved: Step S1: mixing a manganese source with deionized water to obtain a manganese source slurry; Step S2: dissolving monoammonium phosphate in deionized water to obtain a monoammonium phosphate solution; Step S3: adding a monoammonium phosphate solution to a reactor, adding a catalyst, a reducing agent, and a surfactant, and then adding a manganese source slurry; wherein the catalyst is one or more of ammonia water, triethanolamine, propanolamine, and isopropanolamine; the surfactant is one or more of sodium stearate, sodium lauryl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, and sodium dodecylbenzenesulfonate; and the reducing agent is one or more of hydrogen peroxide, glucose, formaldehyde, and acetaldehyde; Step S4: adjusting the pH with an acidic solution and / or an alkaline solution, and stirring the reaction at 20-90° C.; Step S5: After the reaction is carried out for 3 hours, a reducing agent is added, wherein the reducing agent is one or more of hydrogen peroxide, glucose, formaldehyde, and acetaldehyde, and after the reaction is complete, a manganese ammonium phosphate slurry is obtained; Step S6: filtering, rinsing and drying the ammonium manganese phosphate slurry to obtain an ammonium manganese phosphate powder product.

2. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: In step S1, the manganese source is electrolytic manganese metal powder and / or high-purity manganese carbonate powder, and the manganese source is sieved through a 200-mesh sieve before being prepared into the slurry; the solid content of the manganese source slurry is 30-60%.

3. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: In step S2, the concentration of the monoammonium phosphate solution is 1 to 3 mol / L.

4. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: In steps S1 and S2, the impurity contents of K, Ca, Na, and Mg in the manganese source are all below 100 ppm, and the contents of heavy metal impurities Zn, Cu, Ni, and Pb are all below 10 ppm; the contents of heavy metal impurities Zn, Cu, Ni, and Pb in monoammonium phosphate are all below 10 ppm.

5. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: In step S3, the amount of the catalyst added is 0.5-1% of the weight of the manganese source, and the amount of the surfactant added is 0.05-0.1% of the weight of the manganese source; the amount of the reducing agent added in step S3 is 1-2% of the weight of the manganese source, and the amount of the reducing agent added in step S5 is 2-3% of the weight of the manganese source.

6. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: In step S4, the acidic solution is one or more of phosphoric acid, formic acid, acetic acid, and citric acid, and the concentration of the acidic solution is 1 to 6 mol / L; the alkaline solution is one or more of sodium hydroxide solution, potassium hydroxide solution, and ammonia solution, and the concentration of the alkaline solution is 1 to 6 mol / L; and the pH of the reaction base solution is adjusted to 3 to 6.

7. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: The reaction temperature is 30-50° C., and the stirring speed is 200-500 rpm.

8. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: The total time for the reaction is 12 to 18 hours, and the reaction is continued for another hour after no bubbles are formed.

9. The method for preparing high-purity ammonium manganese phosphate according to claim 1, wherein: In step S6, rinsing is repeated washing with pure water at least three times to remove other free ions.

10. A product obtained by the method for preparing high-purity ammonium manganese phosphate according to any one of claims 1 to 9, characterized in that: The product is manganese ammonium phosphate, and the impurity content is less than 0.05%, wherein the impurity S content is less than 250ppm, and the impurity Cl - Less than 200ppm, manganese-phosphorus ratio 0.98-1, specific surface area 1-20m 2 / g.

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