Preparation method for low-carbon environment-friendly linkage production of high-purity manganese sulfate

Abstract

The invention provides a preparation method for low-carbon environment-friendly linkage production of high-purity manganese sulfate, which comprises the following steps of: mixing mineral powder into pulp, desulfurizing and extracting manganese, adding an impurity removing agent into the obtained manganese sulfate crude liquid, carrying out filter pressing to obtain manganese sulfate fine filtrate, evaporating, concentrating and concentrating to obtain manganese sulfate concentrated liquid, adding concentrated sulfuric acid, and crystallizing twice to obtain high-purity manganese sulfate. Primary crystals, primary crystallization mother liquor, secondary crystals and secondary crystallization mother liquor are obtained respectively; adding water into the crystals, pulping, neutralizing and drying to obtain the high-purity manganese sulfate. According to the method, a manganese sulfate solution is produced through wet reduction of sulfur dioxide, high-purity manganese sulfate is obtained through purification and impurity reduction through acidification and crystallization of concentrated sulfuric acid, primary crystallization mother liquor, secondary crystallization mother liquor and rhodochrosite are chemically combined, and the mixture is directly transferred to a production line for producing EMD, manganese metal, industrial-grade manganese sulfate or feed-grade manganese sulfate to be used for producing manganese-containing compounds.

Description

Technical Field

[0001] The present application belongs to the technical field of chemical raw materials, and in particular relates to a preparation method for low-carbon and environmentally friendly production of high-purity manganese sulfate. Background Art

[0002] At present, high-purity manganese sulfate generally adopts the process of impurity removal and purification of crude manganese sulfate. The mainstream production processes currently being used in the crude manganese sulfate impurity removal and purification industry include sulfide precipitation method, fluoride method, high-temperature crystallization, mechanical vapor recompression technology (hereinafter referred to as MVR) concentration crystallization and other purification methods. The sulfide precipitation method has low requirements for manganese sources, but hydrogen sulfide is toxic and prone to safety accidents. The source of sulfides limits the cost and the technology is difficult to promote; the fluoride method has the best effect of removing calcium and magnesium, but fluoride corrodes equipment, has high equipment requirements, high fluorine slag treatment costs, and the fluoride circulation process is complex and requires large equipment investment; the product obtained by high-temperature crystallization has large crystal particles and the product is not easy to agglomerate, but the equipment investment is large, the energy consumption is large, and the product quality is limited by the quality of the raw materials and the number of crystallizations; the MVR concentration crystallization process is simple and the technology is mature, but the MVR equipment is prone to blocking the pipeline, and the product quality is limited by the quality of the raw materials and the number of crystallizations. The crystal particles are small and the product is easy to agglomerate.

[0003] In summary, the process of removing impurities and purifying crude manganese sulfate faces many problems, such as difficulty in removing impurities, high energy consumption cost, environmental issues, safety issues, and difficulty in balancing purification effect and purity. Summary of the invention

[0004] The present application provides a preparation method for the low-carbon and environmentally friendly production of high-purity manganese sulfate, which aims to solve the problems of high energy consumption cost and environmentally unfriendly production process to a certain extent.

[0005] In the first aspect, the present application provides a method for preparing high-purity manganese sulfate by low-carbon and environmentally friendly linkage production, comprising the following steps:

[0006] S1, after slurrying the pyrolusite powder, desulfurizing and extracting manganese in a multi-stage series countercurrent absorption combined reactor system to obtain a crude manganese sulfate solution;

[0007] S2, adding an impurity remover to the crude manganese sulfate solution, and filtering to obtain a manganese sulfate fine filtrate;

[0008] S3, the manganese sulfate concentrate filtrate is concentrated by evaporation to obtain a manganese sulfate concentrate;

[0009] S4, adding concentrated sulfuric acid to the manganese sulfate concentrate, stirring to precipitate crystals, and performing solid-liquid separation to obtain primary crystals and a primary crystal mother liquor;

[0010] S5, adding water to the primary crystal to prepare a crystallization solution, adding concentrated sulfuric acid again, stirring to precipitate crystals, and performing solid-liquid separation to obtain secondary crystals and secondary crystallization mother liquor;

[0011] S6, adding water to the secondary crystals for slurrying, neutralizing, and drying to obtain high-purity manganese sulfate.

[0012] In one embodiment, the primary crystallization mother liquor and the secondary crystallization mother liquor are combined with rhodochrosite and directly transferred to a production line for producing electrolytic manganese dioxide, metallic manganese, industrial-grade manganese sulfate or feed-grade manganese sulfate for producing manganese-containing compounds.

[0013] In one embodiment, in the chemical reaction kettle system in S1, the number of reaction kettle stages is 3 to 6, and the temperature in the chemical reaction kettle system is 60 to 95°C.

[0014] In one embodiment, the impurity remover in S2 is manganese dioxide and / or calcium carbonate.

[0015] In one embodiment, the concentration of the manganese sulfate concentrate in S3 is 350-430 g / L.

[0016] In one embodiment, the amount of concentrated sulfuric acid added in S4 and S5 is 25-40% of the volume fraction of the manganese sulfate concentrated liquid, and the temperature for stirring and crystallizing is 70-100°C.

[0017] In one embodiment, the crystallization solution in S5 is manganese sulfate with a concentration of 350-430 g / L.

[0018] In one embodiment, the amount of water added in S6 is 25-50 wt % of the amount of water added in the secondary crystallization.

[0019] In one embodiment, the neutralization in S6 is performed by adding one or more combinations of metallic manganese powder, manganese carbonate or manganese hydroxide.

[0020] Compared with the prior art, the beneficial effects of this application are:

[0021] 1. This application adopts sulfur dioxide wet reduction to produce manganese sulfate solution, and concentrated sulfuric acid acid precipitation crystallization to purify and reduce impurities to obtain high-purity manganese sulfate. During purification, the heat of sulfur combustion produces steam for concentration of manganese sulfate filtrate and acid precipitation crystallization and slurry drying. The entire process almost no longer requires additional steam to provide heat energy, solving the problem of high energy consumption. In addition, when concentrated sulfuric acid is added for acid precipitation crystallization, a large amount of concentrated sulfuric acid added to the manganese sulfate solution will release a large amount of heat. This step only requires a small amount of steam to provide heat energy for insulation, further reducing energy consumption. Compared with other recrystallization processes, it has low energy consumption and small equipment investment.

[0022] 2. In the process of the present application, a large amount of concentrated sulfuric acid is added to the manganese sulfate solution during crystallization. Due to the common ion effect, a large amount of manganese sulfate will be precipitated in the system. Due to the difference in solubility, most of the calcium sulfate and magnesium sulfate will remain in the solution, thereby achieving the purpose of purifying and reducing impurities in manganese sulfate, while ensuring a high yield of manganese sulfate. Compared with other methods of purification using chemical reagents, no new impurities are introduced, no fluoride and organic reagents are used, no fluorine slag and waste organic reagents need to be treated, and it is safe and environmentally friendly.

[0023] 3. The process of the present application can use the manganese sulfate mother liquor with a high sulfuric acid content produced by acid precipitation crystallization and rhodochrosite (manganese carbonate ore) for acid leaching to obtain a manganese sulfate solution for the production of electrolytic manganese dioxide (hereinafter referred to as EMD), metallic manganese, feed-grade or industrial-grade manganese sulfate. This is equivalent to using the sulfuric acid that should have been directly used for rhodochrosite synthesis for acid precipitation crystallization and then for synthesis. Compared with other recrystallization methods, the cost of acid precipitation crystallization of the present invention is almost zero. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 It is a schematic diagram of the process provided by the embodiment of the present application;

[0026] Figure 2 It is a schematic flow diagram of the multi-stage series countercurrent absorption chemical combination kettle system of the present application. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] In the present application, "at least one" means one or more, and "plurality" 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 items 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, ab (i.e. a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The technical solution of the present application is illustrated below through specific embodiments and comparative examples.

[0037] A method for preparing high-purity manganese sulfate by low-carbon and environmentally friendly linkage production comprises the following steps:

[0038] S1, after slurrying the pyrolusite powder, desulfurizing and extracting manganese in a multi-stage series countercurrent absorption chemical reactor system to obtain a crude manganese sulfate solution,

[0039] S1 uses this combined process to obtain sulfur combustion steam while leaching manganese sulfate for subsequent concentration and crystallization processes;

[0040] S2, adding an impurity remover to the crude manganese sulfate solution, and filtering to obtain a refined manganese sulfate filtrate,

[0041] The purpose of S2 is to remove iron and heavy metals in the manganese sulfate leaching solution;

[0042] S3, the manganese sulfate concentrate filtrate is concentrated by evaporation to obtain a manganese sulfate concentrate;

[0043] The purpose of S3 is to consider that the manganese sulfate concentration of the refined filtrate is low and not suitable for crystallization. It can only meet the acid precipitation crystallization requirements after concentration.

[0044] S4, adding concentrated sulfuric acid to the manganese sulfate concentrate, stirring to precipitate crystals, and performing solid-liquid separation to obtain primary crystals and a primary crystal mother liquor,

[0045] The purpose of S4 is to separate manganese sulfate crystals with low impurity content through primary crystallization, leaving some impurities such as calcium and magnesium in the primary crystallization mother liquor;

[0046] S5, adding water to the primary crystal to prepare a crystallization solution, adding concentrated sulfuric acid again, stirring to precipitate crystals, and performing solid-liquid separation to obtain secondary crystals and secondary crystallization mother liquor,

[0047] The purpose of S5 is to recrystallize after the primary crystallization and further separate the remaining impurities to obtain secondary crystals;

[0048] S6, adding water to the secondary crystals for slurrying, neutralizing, and drying to obtain high-purity manganese sulfate.

[0049] The purpose of S6 is to add water to the secondary crystals to make pulp, neutralize the sulfuric acid and metallic manganese powder or high-purity manganese carbonate and other neutralizing agents adsorbed on the secondary crystals to increase the pH of the secondary crystals to meet the product requirements of high-purity manganese sulfate, and obtain high-purity manganese sulfate after drying.

[0050] In one embodiment, the primary crystallization mother liquor, the secondary crystallization mother liquor and rhodochrosite are combined and directly transferred to the production line of EMD, metallic manganese, industrial-grade manganese sulfate or feed-grade manganese sulfate for the production of manganese-containing compounds. The primary crystallization mother liquor mainly includes 60-80 g / L manganese sulfate and 500-650 g / L sulfuric acid; the secondary crystallization mother liquor includes 60-80 g / L manganese sulfate and 500-650 g / L sulfuric acid.

[0051] In one embodiment, in the multi-stage series countercurrent absorption chemical reactor system in S1, the number of reaction reactors is 3 to 6, and the temperature in the chemical reactor system is 60 to 95°C.

[0052] In one embodiment, the impurity remover in S2 is manganese dioxide and / or calcium carbonate.

[0053] In one embodiment, the manganese sulfate concentrate in S3 is 350-430 g / L.

[0054] In one embodiment, the amount of concentrated sulfuric acid added in S4 and S5 is 25-40% of the volume fraction of the manganese sulfate concentrated liquid, and the temperature for stirring and crystallizing is 70-100°C.

[0055] In one embodiment, the crystallization solution in S5 is 350-430 g / L manganese sulfate.

[0056] In one embodiment, the amount of water added in S6 is 25-50 wt % of the amount of water added in the secondary crystallization.

[0057] In one embodiment, the neutralization in S6 is performed by adding one or more combinations of metallic manganese powder, manganese carbonate or manganese hydroxide.

[0058] In order to enable the above implementation details and operations of the present application to be clearly understood by those skilled in the art, as well as to demonstrate the significant improvement in performance of the embodiments of the present application, the above technical solutions are illustrated by means of multiple embodiments below.

[0059] Embodiment 1:

[0060] A preparation method for low-carbon and environmentally friendly production of high-purity manganese sulfate:

[0061] The manganese content of pyrolusite powder in a mine in Xiangtan City, Hunan Province is 50.2%. Figure 1 The combined manganese extraction method shown in the figure is to mix 6 kg of pyrolusite with 36 L of water to form a slurry, with an initial sulfur dioxide concentration of 12%, and then undergo multi-stage desulfurization (see the schematic diagram of multi-stage desulfurization). Figure 2 SO2 enters from the bottom of the reactor, and manganese oxide slurry enters from the top of the reactor. The main reaction is SO2+MnO2=Mn 2+ +SO4 2-, gas-solid-liquid three-phase reaction, multi-stage combined desulfurization and manganese extraction efficiency are high) to obtain 34L of 210g / L manganese sulfate crude liquid, 4kg of manganese dioxide was added to 34L of manganese sulfate crude liquid and stirred at 80℃ for 1h, then calcium carbonate was added to adjust the pH of the system to 5.0-6.0, and then 180g of barium sulfide was added and stirred for 0.5h, and the manganese sulfate fine filtrate was separated by filter press. The manganese sulfate fine filtrate was evaporated and concentrated to obtain 400g / L manganese sulfate concentrate.

[0062] Take 3L of concentrated solution, add 950mL of 98% concentrated sulfuric acid, stir at 75℃ for 1h. Filter and separate, collect the mother liquor, add 2.5L of water for primary crystallization to prepare 396g / L manganese sulfate solution, then add 800mL of 98% concentrated sulfuric acid, stir at 75℃ for 1h. Filter and separate, collect the mother liquor, add 300mL of pure water for secondary crystallization, add high-purity manganese carbonate, adjust pH to 5.0-5.5, and directly dry to obtain 744g of high-purity manganese sulfate.

[0063] The mother liquor from the two crystallizations is added with water and manganese carbonate ore, and after removing iron and heavy metals, it is used to produce electrolytic manganese dioxide.

[0064] Embodiment 2:

[0065] A preparation method for low-carbon and environmentally friendly production of high-purity manganese sulfate:

[0066] The preparation of the concentrate is the same as in Example 1.

[0067] Take 3L of concentrated solution, add 950mL of 98% concentrated sulfuric acid, stir at 95℃ for 1h. Filter and separate, collect the mother liquor, add 2.5L of water for primary crystallization to prepare 410g / L manganese sulfate solution, then add 800mL of 98% concentrated sulfuric acid, stir at 95℃ for 1h. Filter and separate, collect the mother liquor, add 300mL of pure water for secondary crystallization, add high-purity metal manganese powder, adjust pH to 4.5-5.0, and directly dry to obtain 889g of high-purity manganese sulfate.

[0068] The mother liquors from the two crystallizations were treated in the same manner as in Example 1.

[0069] Embodiment 3:

[0070] A preparation method for low-carbon and environmentally friendly production of high-purity manganese sulfate:

[0071] Pyrolusite powder from a mine in Jingxi City, Guangxi Zhuang Autonomous Region, with a manganese content of 35.5%, 7kg of pyrolusite and 35L of water were mixed into a pulp, and the initial concentration of sulfur dioxide was 10%. After multi-stage desulfurization, 33L of 193g / L manganese sulfate crude liquid was obtained. 4kg of manganese dioxide was added to 33L of manganese sulfate crude liquid and stirred at 80℃ for 1h, and then calcium carbonate was added to adjust the pH of the system to 5.0-6.0, and then 180g of barium sulfide was added and stirred for 0.5h, and the manganese sulfate concentrate was separated by filtration. The manganese sulfate concentrate was evaporated and concentrated to obtain 400g / L manganese sulfate concentrate.

[0072] After multiple chemical reactions and concentrations, 280L of concentrated solution was obtained. 280L of concentrated solution and 95L of 98% concentrated sulfuric acid were added to the crystallization barrel and stirred at 90°C for 1h. Centrifugal separation was performed, the mother liquor was collected, 220L of water was added to the primary crystallization to prepare a 390g / L manganese sulfate solution, and then 74L of 98% concentrated sulfuric acid was added and stirred at 90°C for 1h. Centrifugal separation was performed, the mother liquor was collected, 25L of pure water was added to the secondary crystallization for pulping, high-purity metallic manganese powder was added, the pH was adjusted to 4.0-4.5, and then directly dried to obtain 81kg of high-purity manganese sulfate.

[0073] The mother liquors from the two crystallizations were treated in the same manner as in Example 1.

[0074] Comparative Example:

[0075] A preparation method for low-carbon and environmentally friendly production of high-purity manganese sulfate:

[0076] The concentrated solution of Example 1 was concentrated and crystallized twice.

[0077] Take 3L of 400g / L manganese sulfate concentrate, evaporate and concentrate to 70%, filter and separate while hot, take the filter cake and re-prepare it into 400g / L manganese sulfate solution, evaporate and concentrate to 70% again, filter and separate while hot, and dry the filter cake to obtain 335g manganese sulfate.

[0078] The manganese sulfates of Examples 1-3 of the present invention and the comparative example were subjected to element detection, and the results are shown in Table 1:

[0079] Table 1 Element detection results of Examples 1-3 and Comparative Examples

[0080]

[0081] As shown in Table 1, Examples 1, 2, and 3 use chemical solutions of manganese oxide ore of different grades, and the manganese sulfate samples obtained after two acid precipitation crystallizations all meet the industry standard for high-purity manganese sulfate, while the comparative example uses the same chemical solution as Example 1, and after two traditional concentration crystallizations, the manganese sulfate sample obtained does not meet the industry standard for high-purity manganese sulfate with a lower yield.

[0082] The main reaction of the combination of the crystallization mother liquor and rhodochrosite is MnCO3+H2SO4=MnSO4+H2O+CO2↑, and the sulfuric acid is recovered for the production of EMD, metallic manganese, industrial-grade manganese sulfate or feed-grade manganese sulfate production line, which is equivalent to the sulfuric acid combined with rhodochrosite first being used for acid precipitation crystallization to produce high-purity manganese sulfate, and then the sulfuric acid is directly combined, concentrated sulfuric acid is added to the manganese sulfate leaching solution, and the manganese sulfate is crystallized through the common ion effect. In this process, only the state of the substance changes, and no reaction occurs between the substances. Compared with other recrystallization methods, the cost of the acid precipitation crystallization of the present invention is almost zero.

[0083] 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.

[0084] 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 producing high-purity manganese sulfate in a low-carbon and environmentally friendly manner, characterized in that: The steps include: S1, after slurrying the pyrolusite powder, desulfurizing and extracting manganese in a multi-stage series countercurrent absorption combined reactor system to obtain a crude manganese sulfate solution; S2, adding an impurity remover to the crude manganese sulfate solution, and filtering to obtain a manganese sulfate fine filtrate; S3, the manganese sulfate concentrate filtrate is concentrated by evaporation to obtain a manganese sulfate concentrate; S4, adding concentrated sulfuric acid to the manganese sulfate concentrate, stirring to precipitate crystals, and performing solid-liquid separation to obtain primary crystals and a primary crystallization mother liquor; S5, adding water to the primary crystal to prepare a crystallization solution, adding concentrated sulfuric acid again, stirring to precipitate crystals, and performing solid-liquid separation to obtain secondary crystals and secondary crystallization mother liquor; S6, adding water to the secondary crystals for slurrying, neutralizing, and drying to obtain high-purity manganese sulfate.

2. The preparation method according to claim 1, characterized in that: The primary crystallization mother liquor and the secondary crystallization mother liquor are combined with rhodochrosite and directly transferred to a production line for producing electrolytic manganese dioxide, metallic manganese, industrial-grade manganese sulfate or feed-grade manganese sulfate for producing manganese-containing compounds.

3. The preparation method according to claim 1, characterized in that: In the chemical combination kettle system described in S1, the number of reaction kettle stages is 3 to 6, and the temperature in the chemical combination kettle system is 60 to 95°C.

4. The preparation method according to claim 1, characterized in that: The impurity remover in S2 is manganese dioxide and / or calcium carbonate.

5. The preparation method according to claim 1, characterized in that: The concentration of the manganese sulfate concentrate in S3 is 350-430 g / L.

6. The preparation method according to claim 1, characterized in that: The amount of concentrated sulfuric acid added in S4 and S5 is 25-40% of the volume fraction of the manganese sulfate concentrated liquid, and the temperature for stirring and crystallizing is 70-100°C.

7. The preparation method according to claim 1, characterized in that: The crystallization solution in S5 is manganese sulfate with a concentration of 350-430 g / L.

8. The preparation method according to claim 1, characterized in that: The amount of water added in S6 is 25 to 50 wt % of the amount of water added in the secondary crystallization.

9. The preparation method according to claim 1, characterized in that: The neutralization in S6 is performed by adding one or more combinations of metallic manganese powder, manganese carbonate or manganese hydroxide for neutralization.

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