Preparation method of manganese sulfate

Abstract

The invention relates to the technical field of metallurgy, in particular to a preparation method of manganese sulfate. The preparation method of the manganese sulfate comprises the following steps: in the presence of a solvent, mixing a manganese source and an alkaline substance, adjusting the pH value to 7.0-8.0, and taking precipitate; and mixing the precipitate with an acid, adjusting the pH value to 4.5-5.0, and concentrating to obtain manganese sulfate. Starting from a manganese source, manganese is subjected to precipitation, dissolution, impurity removal and concentration through a series of steps, impurities are effectively removed, a qualified manganese sulfate product is finally obtained, and the manganese resource is fully utilized; meanwhile, the method is simple and efficient, and impurities such as potassium and sodium can be effectively removed; besides, the method for preparing the manganese sulfate from the manganese source is an economical and environment-friendly method, the manganese source can be effectively recycled, the influence on the environment can be reduced, and sustainable development is promoted.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a method for preparing manganese sulfate. Background Art

[0002] Manganese sulfate, as the most important basic manganese salt, is widely used in industries such as industry, electronics, light industry, animal husbandry and agriculture. It is an important industrial product for the production of other manganese oxides and manganese salts. For example, manganese sulfate is used to produce electrolytic manganese dioxide for battery manufacturing. Manganese sulfate solution is generally obtained by leaching manganese ore, but the solution often contains potassium, sodium, magnesium, calcium and heavy metal impurity elements, which need further treatment. Among them, the removal method of potassium and sodium is the yellow potassium iron alum method, that is, adding iron sulfate to the solution, controlling the reaction pH to 1.5, the temperature to 90°C, the reaction time to 3 to 4 hours, and the removal rate of potassium and sodium is above 90%, but this method has the problems of large slag volume, low iron content, difficult process control, and environmental pollution. Therefore, how to clean and efficiently treat impurities in manganese sulfate solution is also a problem that the industry needs to solve urgently.

[0003] Therefore, it is necessary to improve the method for preparing manganese sulfate from manganese ore. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, one object of the present invention is to provide a method for preparing manganese sulfate, which starts from a manganese source, precipitates, dissolves, removes impurities and concentrates manganese through a series of steps, effectively removes impurities, and finally obtains a manganese sulfate product of qualified quality, thereby making full use of manganese resources.

[0005] To this end, the first aspect of the present invention provides a method for preparing manganese sulfate, comprising the following steps:

[0006] In the presence of a solvent, a manganese source and an alkaline substance are mixed, the pH is adjusted to 7.0-8.0, and a precipitate is obtained; the precipitate is mixed with an acid, the pH is adjusted to 4.5-5.0, and then concentrated to obtain manganese sulfate. Starting from the manganese source, the present invention precipitates, dissolves, removes impurities and concentrates manganese through a series of steps, effectively removes impurities, and finally obtains a manganese sulfate product of qualified quality, making full use of manganese resources; at the same time, the method of the present invention is simple and efficient; in addition, the preparation of manganese sulfate using a manganese source is an economical and environmentally friendly approach, which can not only effectively recover manganese resources, but also reduce the impact on the environment and promote sustainable development.

[0007] In some embodiments of the present invention, the manganese source comprises an industrial manganese source, which comprises industrial solid manganese waste or a manganese-containing solution obtained by leaching industrial solid manganese waste, wherein the concentration of manganese ions in the manganese-containing solution is 120 to 160 g / L.

[0008] In some embodiments of the present invention, the alkaline substance includes at least one of sodium hydroxide, calcium hydroxide, potassium hydroxide, aluminum hydroxide, strontium hydroxide and ammonia water.

[0009] In some embodiments of the present invention, the manganese source and the alkaline substance are mixed at 25°C to 40°C.

[0010] In some embodiments of the present invention, the acid includes at least one of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, phosphoric acid, hydrofluoric acid, citric acid, and oxalic acid.

[0011] The manganese source of the present invention contains a variety of impurities, including but not limited to at least one of heavy metal elements, calcium elements, magnesium elements, zinc elements, iron elements and potassium elements. In some embodiments of the present invention, the precipitate and the acid are mixed to obtain a dissolving solution, which is then subjected to heavy metal removal treatment and calcium and magnesium removal treatment in sequence.

[0012] In some embodiments of the present invention, the heavy metal removal treatment includes: the heavy metal removal treatment includes: under the condition of 30-40°C, mixing the dissolved liquid and the heavy metal removal agent, reacting for 1-2 hours, filtering, and obtaining a heavy metal removal liquid.

[0013] In some embodiments of the present invention, the heavy metal removal agent includes a sulfiding agent; the sulfiding agent includes at least one of manganese sulfide, barium sulfide or H2S.

[0014] In some embodiments of the present invention, the calcium and magnesium removal treatment comprises: mixing a calcium and magnesium removal agent and a heavy metal removal liquid at 70 to 80° C., reacting for 1 to 2 hours, filtering, and obtaining a calcium and magnesium removal liquid.

[0015] In some embodiments of the present invention, the calcium and magnesium removing agent comprises manganese fluoride.

[0016] In some embodiments of the present invention, the concentration specifically comprises: evaporating, concentrating and crystallizing the system at 90-100°C.

[0017] In some embodiments of the present invention, after concentration, the obtained product is dried to obtain manganese sulfate.

[0018] In some embodiments of the present invention, the drying temperature is 100-120° C. and the drying time is 1-2 hours.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0021] Figure 1 A flow chart showing a method for preparing manganese sulfate according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0022] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0023] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more.

[0024] The first aspect of the present invention provides a method for preparing manganese sulfate, comprising the following steps:

[0025] In the presence of a solvent, a manganese source and an alkaline substance are mixed, the pH is adjusted to 7.0-8.0, and a precipitate is obtained; the precipitate is mixed with an acid, the pH is adjusted to 4.5-5.0, and then concentrated to obtain manganese sulfate.

[0026] The present invention starts from a manganese source, precipitates, dissolves, removes impurities and concentrates manganese through a series of steps, effectively removes impurities, and finally obtains a manganese sulfate product of qualified quality, thereby making full use of manganese resources; at the same time, the method of the present invention is simple and efficient; in addition, the present invention uses a manganese source to prepare manganese sulfate, which is an economical and environmentally friendly practice, can not only effectively recover manganese resources, but also reduce the impact on the environment and promote sustainable development.

[0027] As an example, the pH may be adjusted to 4.5, 4.6, 4.7, 4.8, 4.9 or 5.0 by mixing the precipitate with an acid.

[0028] In some embodiments of the invention, the solvent comprises water.

[0029] In some embodiments of the present invention, the manganese source includes an industrial manganese source. The industrial manganese source includes industrial solid manganese waste or a manganese-containing solution obtained by leaching industrial solid manganese waste. The present invention has no special requirements for the manganese source; if the manganese source is a manganese-containing solution, the solvent is a solvent for the manganese-containing solution; if the manganese source is industrial solid manganese waste, the solvent is an acid, and the acid can help the manganese source dissolve in the liquid system to facilitate subsequent treatment. Industrial waste manganese sources are usually waste generated during manganese ore processing or manganese alloy production. By recovering manganese in these wastes, dependence on new manganese ores can be reduced and resources can be saved. If industrial waste manganese sources are directly discharged without treatment, they will cause pollution to water bodies and soil. The present invention converts industrial waste manganese sources into manganese sulfate products through certain treatments, which can reduce harm to the environment and achieve the purpose of waste reduction and resource utilization. The use of industrial waste manganese sources to prepare manganese sulfate can reduce the procurement cost of raw materials and reduce the cost of treating waste; in addition, the use of waste materials for reprocessing can improve the overall economic benefits. By converting industrial waste manganese sources into valuable chemicals, manganese sulfate in solid form is convenient for storage, transportation and further processing.

[0030] In some embodiments of the present invention, the concentration of manganese ions in the manganese-containing solution is 120-160 g / L; in other preferred embodiments of the present invention, the concentration of manganese ions in the manganese-containing solution is 140-150 g / L. The manganese-containing solution with a concentration of 140-150 g / L can not only ensure the efficiency of subsequent reactions, but also save water.

[0031] In some embodiments of the present invention, the pH of the manganese-containing solution is 1.5-2.2.

[0032] The type and concentration of the alkali used in the present invention can also be selected according to actual conditions. In some embodiments of the present invention, the alkaline substance includes at least one of sodium hydroxide, calcium hydroxide, potassium hydroxide, aluminum hydroxide, strontium hydroxide and ammonia water.

[0033] In some embodiments of the present invention, the manganese source and the alkaline substance are mixed at 25° C. to 40° C. For example, the manganese source and the alkaline substance are mixed at 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40° C.

[0034] The type and concentration of the acid used in the present invention can also be selected according to actual conditions. In some embodiments of the present invention, the acid includes at least one of hydrochloric acid, sulfuric acid, nitric acid, acetic acid, phosphoric acid, hydrofluoric acid, citric acid, and oxalic acid.

[0035] The manganese source of the present invention contains a variety of impurities, including but not limited to at least one of heavy metal elements, calcium elements, magnesium elements, zinc elements, iron elements and potassium elements. The presence of impurities will not only reduce the purity of the product, but also cause manganese sulfate to produce toxicity or other adverse effects in subsequent applications (such as battery materials, etc.). The manganese sulfate solution obtained after the impurity removal step has high purity, and the manganese sulfate product finally prepared has better quality.

[0036] In some embodiments of the present invention, after mixing the manganese source and the alkaline substance, the pH is adjusted to 7.0-8.0. For example, the pH is adjusted to 7.0, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9 or 8.0. If the pH of the reaction is too low, the manganese source precipitation will be incomplete or even unable to generate precipitation, resulting in the failure to achieve efficient utilization of the manganese source. If the pH of the reaction is too high, calcium ions and magnesium ions will generate Ca(OH)2 and Mg(OH)2 precipitations, which may cause Ca(OH)2, Mg(OH)2 precipitations and Mn(OH)2 to precipitate simultaneously, and the efficient separation of manganese ions and calcium and magnesium ions cannot be achieved.

[0037] In some embodiments of the present invention, the precipitate and the acid are mixed to obtain a dissolved solution, which is then sequentially treated for heavy metal removal and calcium and magnesium removal.

[0038] In some embodiments of the present invention, the heavy metal includes at least one of lead, zinc, copper, and cadmium, and the heavy metal exists in the solution in the form of ions. In some embodiments of the present invention, the heavy metal removal treatment includes: mixing the dissolved solution and the heavy metal removal agent under the condition of 30 to 40°C, reacting for 1 to 2 hours, filtering, and obtaining a heavy metal removal liquid and a heavy metal filter residue. As an example, the temperature of mixing the dissolved solution and the heavy metal removal agent can be 30, 31, 32, 33, 34, 35, 36, 37, 38, 39 or 40°C. As an example, the time for mixing the dissolved solution and the heavy metal removal agent can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 hours.

[0039] In some embodiments of the present invention, the heavy metal removal agent includes a sulfiding agent; the ratio of the amount of heavy metal ions in the solution to the amount of the sulfiding agent is 1:(1-2); the sulfiding agent includes at least one of manganese sulfide, barium sulfide or H2S. As an example, the ratio of the amount of heavy metal ions in the solution to the amount of the sulfiding agent can be 1:1, 1:1.2, 1:1.5, 1:1.6, 1:1.8, or 1:2.

[0040] In some embodiments of the present invention, the decalcification and magnesium treatment comprises: mixing the decalcification and magnesium agent with the heavy metal removal liquid at 70 to 80° C., reacting for 1 to 2 hours, filtering, and obtaining the decalcification and magnesium liquid and the calcium and magnesium slag. As an example, the temperature at which the decalcification and magnesium agent and the heavy metal removal liquid are mixed can be 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80° C. As an example, the time for mixing the decalcification and magnesium agent and the heavy metal removal liquid can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2 hours.

[0041] In some embodiments of the present invention, the calcium and magnesium removing agent comprises manganese fluoride.

[0042] In some embodiments of the present invention, the ratio of the amount of the substance of calcium ions and magnesium ions in the heavy metal removal solution to the amount of the substance of manganese fluoride is 1:(1-2). As an example, the ratio of the amount of the substance of calcium ions and magnesium ions in the heavy metal removal solution to the amount of the substance of manganese fluoride can be 1:1, 1:1.2, 1:1.5, 1:1.6, 1:1.8, or 1:2.

[0043] In some embodiments of the present invention, the concentration specifically includes: evaporating, concentrating and crystallizing the system at 90-100° C. As an example, the temperature of evaporating, concentrating and crystallizing can be 90, 91, 92, 93, 94, 95, 96, 97, 98, 99 or 100° C.

[0044] In some embodiments of the present invention, after concentration, the obtained product is dried to obtain manganese sulfate. After drying, manganese sulfate with higher purity can be obtained.

[0045] In some embodiments of the present invention, the manganese sulfate solution is evaporated, concentrated and crystallized at 90-100° C., and when the solution is about to be evaporated to dryness, it is filtered while hot to obtain a manganese sulfate mother liquor and manganese sulfate monohydrate crystals, and the manganese sulfate monohydrate crystals are dried to obtain manganese sulfate.

[0046] In some embodiments of the present invention, the drying temperature is 100 to 120° C. and the time is 1 to 2 hours. If the reaction temperature is too low, the reaction will be incomplete, resulting in difficulty in post-processing. If the reaction temperature is too high, the reaction rate cannot be effectively increased, and there is also the disadvantage of excessive energy consumption. As an example, the drying temperature can be 100, 105, 110, 115 or 120° C. As an example, the drying time can be 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2 hours.

[0047] The scheme of the present disclosure will be explained below in conjunction with the examples. Those skilled in the art will understand that the following examples are only used to illustrate the present disclosure and should not be regarded as limiting the scope of the present disclosure. If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or in accordance with the product instructions shall be followed. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially. The manganese-containing solution raw material in the embodiments of the present invention is a manganese-containing solution obtained by reduction leaching and separation of zinc electrolysis anode mud.

[0048] Example 1

[0049] The preparation method of manganese sulfate in this embodiment uses the following composition of the manganese-containing solution raw material, and the flow chart is as follows: Figure 1 shown.

[0050] Composition of manganese-containing solution: pH 2.2, manganese ion concentration 150.1g / L, zinc 1.29g / L, potassium 3.75g / L, calcium 0.65g / L, magnesium 0.16g / L, and iron 0.02g / L.

[0051] The preparation method specifically comprises the following steps:

[0052] (1) Manganese precipitation: adding sodium hydroxide to the above manganese-containing solution at 25° C., adjusting the pH to 8.0, filtering the system to obtain pure white manganese salt and filtrate, which can be recycled;

[0053] (2) Dissolution: Dissolve the manganese salt and dilute sulfuric acid at room temperature, stir until no white precipitate is visible, obtain a solution, and adjust the pH to 4.5;

[0054] (3) Removal of heavy metals: At 40°C, H2S was introduced into the solution, with the molar ratio of heavy metal ions to H2S being 1:1.5. After reacting for 2 hours, the solution was filtered while hot to obtain a filter residue and a heavy metal removal solution.

[0055] (4) Removing calcium and magnesium: adding manganese fluoride to the heavy metal removal liquid at 70°C, wherein the ratio of the amount of calcium ions and magnesium ions in the heavy metal removal liquid to the amount of manganese fluoride is 1:1.7, reacting for 2 hours, filtering, and obtaining calcium and magnesium slag and calcium and magnesium removal liquid;

[0056] (5) Evaporation and crystallization: The solution obtained in step (4) is evaporated and concentrated at 90° C. and filtered while hot when the solution is about to be evaporated to dryness to obtain a manganese sulfate mother liquor and manganese sulfate monohydrate crystals, and the manganese sulfate monohydrate crystals are placed at 105° C. and dried for 2 hours to obtain a manganese sulfate product, the composition of which is shown in Table 1. The standard for qualified manganese products is HG / T 4823-2015. The manganese sulfate product prepared in the embodiment of the present invention meets the national quality standards, meets the market demand for qualified products, and can be widely used in agriculture, metallurgy, battery manufacturing and other fields.

[0057] Table 1 Manganese sulfate composition %

[0058] element Mn Pb Mg Zn Ca K Na Fe Cu Cd Example 1 31.91 0.0012 0.013 0.0011 0.018 0.01 0.01 0.0018 0.0018 0.001 Qualified products 31.80 0.0015 0.02 0.002 0.02 0.01 0.01 0.002 0.002 0.001

[0059] Table 1 shows that, by adopting the method of this embodiment, after the manganese-containing solution is treated as described above, a qualified manganese sulfate product is prepared, and no pollutants are produced during the whole process.

[0060] Example 2

[0061] The preparation method of manganese sulfate in this embodiment uses the following composition of the manganese-containing solution raw material, and the flow chart is as follows: Figure 1 shown.

[0062] Composition of manganese-containing solution: pH 1.5, manganese ion concentration 140.7g / L, zinc 0.33g / L, potassium 3.15g / L, calcium 0.45g / L, magnesium 0.14g / L, and iron 0.022g / L.

[0063] The preparation method specifically comprises the following steps:

[0064] (1) Manganese precipitation: adding alkali to the above manganese-containing solution at 25° C., adjusting the pH to 7.5, filtering the system to obtain pure white manganese salt and filtrate, which can be recycled;

[0065] (2) Dissolution: Dissolve the manganese salt and dilute sulfuric acid at room temperature, stir until no white precipitate is visible, obtain a solution, and adjust the pH to 4.5;

[0066] (3) Removal of heavy metals: H2S was introduced into the solution at 35°C, with the molar ratio of heavy metal ions to H2S being 1:1.2. After reacting for 2 hours, the solution was filtered while hot to obtain a filter residue and a heavy metal removal solution.

[0067] (4) Removing calcium and magnesium: adding manganese fluoride to the heavy metal removal liquid at 80°C, wherein the ratio of the amount of calcium ions and magnesium ions in the heavy metal removal liquid to the amount of manganese fluoride is 1:1.6, reacting for 2 hours, filtering, and obtaining calcium and magnesium slag and calcium and magnesium removal liquid;

[0068] (5) Evaporation and crystallization: The solution obtained in step (4) was evaporated and concentrated at 90° C. to obtain crystals. When the solution was almost evaporated to dryness, it was filtered while hot to obtain manganese sulfate mother liquor and manganese sulfate monohydrate crystals. The manganese sulfate monohydrate crystals were placed at 105° C. and dried for 2 h to obtain a manganese sulfate product, the composition of which is shown in Table 2. The standard for qualified manganese products is HG / T 4823-2015.

[0069] Table 2 Manganese sulfate composition %

[0070] element Mn Pb Mg Zn Ca K Na Fe Cu Cd Example 2 31.85 0.0010 0.016 0.0014 0.011 0.01 0.01 0.0013 0.0008 0.001 Qualified products 31.80 0.0015 0.02 0.002 0.02 0.01 0.01 0.002 0.002 0.001

[0071] Table 2 shows that, by adopting the method of this embodiment, after the manganese-containing solution is treated as described above, a qualified manganese sulfate product is prepared, and no pollutants are produced during the whole process.

[0072] Example 3

[0073] The preparation method of manganese sulfate in this embodiment is as follows: Figure 1 The composition of the manganese-containing solution raw material used is shown below.

[0074] Composition of manganese-containing solution: Composition of manganese-containing solution: pH 2.0, manganese ion concentration 120g / L, zinc 0.43g / L, potassium 3.20g / L, calcium 0.45g / L, magnesium 0.16g / L, iron 0.025g / L.

[0075] The preparation method comprises the following steps:

[0076] (1) Manganese precipitation: adding alkali to the above manganese-containing solution at 40° C., adjusting the pH to 7.0, filtering the system to obtain pure white manganese salt and filtrate, which can be recycled;

[0077] (2) Dissolution: Dissolve the manganese salt and dilute sulfuric acid at room temperature, stir until no white precipitate is visible, obtain a solution, and adjust the pH to 5.0;

[0078] (4) Removal of heavy metals: At 30°C, H2S was introduced into the solution, with the molar ratio of heavy metal ions to H2S being 1:1.3. After reacting for 1 hour, the solution was filtered while hot to obtain a filter residue and a heavy metal removal solution.

[0079] (3) Removing calcium and magnesium: adding manganese fluoride to the heavy metal removal liquid at 75°C, wherein the ratio of the amount of calcium ions and magnesium ions in the heavy metal removal liquid to the amount of manganese fluoride is 1:1.5. After reacting for 1 hour, filtering is performed to obtain calcium and magnesium slag and calcium and magnesium removal liquid;

[0080] (5) Evaporation and crystallization: The solution obtained in step (4) was evaporated and concentrated at 95° C. and filtered while hot when the solution was almost evaporated to dryness to obtain manganese sulfate mother liquor and manganese sulfate monohydrate crystals. The manganese sulfate monohydrate crystals were placed at 100° C. and dried for 2 h to obtain a manganese sulfate product, the composition of which is shown in Table 3. The standard for qualified manganese products is HG / T 4823-2015.

[0081] Table 3 Manganese sulfate composition %

[0082] element Mn Pb Mg Zn Ca K Na Fe Cu Cd Example 3 31.85 0.0011 0.012 0.0012 0.010 0.009 0.008 0.0012 0.0006 0.001 Qualified products 31.80 0.0015 0.02 0.002 0.02 0.01 0.01 0.002 0.002 0.001

[0083] Example 4

[0084] The preparation method of manganese sulfate in this embodiment is as follows: Figure 1 The composition of the manganese-containing solution raw material used is shown below.

[0085] Composition of manganese-containing solution: pH 1.8, manganese ion concentration 160g / L, zinc 0.40g / L, potassium 3.18g / L, calcium 0.40g / L, magnesium 0.14g / L, and iron 0.026g / L.

[0086] The preparation method comprises the following steps:

[0087] (1) Manganese precipitation: adding alkali to the above manganese-containing solution at 30° C., adjusting the pH to 7.5, filtering the system to obtain pure white manganese salt and filtrate, which can be recycled;

[0088] (2) Dissolution: Dissolve the manganese salt and dilute sulfuric acid at room temperature, stir until no white precipitate is visible, obtain a solution, and adjust the pH to 4.5;

[0089] (3) Removal of heavy metals: H2S was introduced into the solution at 35°C, with the molar ratio of heavy metal ions to H2S being 1:1.3. After reacting for 1 hour, the solution was filtered while hot to obtain a filter residue and a heavy metal removal solution.

[0090] (4) Removing calcium and magnesium: adding manganese fluoride to the heavy metal removal liquid at 70°C, wherein the ratio of the amount of calcium ions and magnesium ions in the heavy metal removal liquid to the amount of manganese fluoride is 1:1.6. After reacting for 1 hour, filtering is performed to obtain calcium and magnesium slag and calcium and magnesium removal liquid;

[0091] (5) Evaporation and crystallization: The solution obtained in step (4) was evaporated and concentrated at 100° C., and when the solution was almost evaporated to dryness, it was filtered while hot to obtain manganese sulfate mother liquor and manganese sulfate monohydrate crystals, and the manganese sulfate monohydrate crystals were placed at 110° C. and dried for 2 h to obtain a manganese sulfate product, the composition of which is shown in Table 4. The standard for qualified manganese products is HG / T 4823-2015.

[0092] Table 4 Manganese sulfate composition %

[0093] element Mn Pb Mg Zn Ca K Na Fe Cu Cd Example 4 31.85 0.0012 0.014 0.001 0.01 0.008 0.01 0.0011 0.0008 0.001 Qualified products 31.80 0.0015 0.02 0.002 0.02 0.01 0.01 0.002 0.002 0.001

[0094] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", "some implementation schemes" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0095] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing manganese sulfate, characterized in that: The following steps are involved: In the presence of a solvent, a manganese source and an alkaline substance are mixed, the pH is adjusted to 7.0-8.0, and a precipitate is obtained; the precipitate is mixed with an acid, the pH is adjusted to 4.5-5.0, and then concentrated to obtain manganese sulfate.

2. The method for preparing manganese sulfate according to claim 1, characterized in that: At 25°C to 40°C, a manganese source and an alkaline substance are mixed.

3. The method for preparing manganese sulfate according to claim 1, characterized in that: The precipitate is mixed with an acid to obtain a dissolving solution, which is then sequentially treated for heavy metal removal and calcium and magnesium removal.

4. The method for preparing manganese sulfate according to claim 3, characterized in that: The heavy metal removal treatment comprises: mixing the dissolved liquid and the heavy metal removal agent at 30-40° C., reacting for 1-2 hours, filtering, and obtaining a heavy metal removal liquid.

5. The method for preparing manganese sulfate according to claim 4, characterized in that: The heavy metal removal agent includes a sulfiding agent; the sulfiding agent includes at least one of manganese sulfide, barium sulfide or H2S.

6. The method for preparing manganese sulfate according to claim 4, characterized in that: The calcium and magnesium removal treatment comprises: mixing a calcium and magnesium removal agent and a heavy metal removal liquid at 70 to 80° C., reacting for 1 to 2 hours, filtering, and obtaining a calcium and magnesium removal liquid.

7. The method for preparing manganese sulfate according to claim 6, characterized in that: The calcium and magnesium removing agent includes manganese fluoride.

8. The method for preparing manganese sulfate according to claim 1, characterized in that: The concentration specifically includes: evaporating, concentrating and crystallizing the system at 90-100°C.

9. The method for preparing manganese sulfate according to claim 1, characterized in that: After concentration, the obtained product is dried to obtain manganese sulfate.

10. The method for preparing manganese sulfate according to claim 9, characterized in that: The drying temperature is 100-120° C. and the drying time is 1-2 hours.

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