Iron removal process for high-purity manganese sulfate

Abstract

The invention relates to the technical field of manganese sulfate processing, and discloses a high-purity manganese sulfate iron removal process which comprises the steps of raw material treatment, acid leaching, impurity removal, purification, crystallization and drying. The impurity removal comprises iron removal and heavy metal removal; iron removal: an acid leaching solution usually contains iron ions (Fe < 3 + > and Fe < 2 + >), Fe < 2 + > is oxidized into Fe < 3 + >, a proper amount of manganese dioxide (Mn02) or hydrogen peroxide (H2O2) can be added, and a reaction is carried out: 2FeS04 + Mn02 + 2H2S04 = Fe2 (S04) 3 + MnS04 + 2H20; the pH value of the solution is adjusted to 4.7-6.0, Fe3 <-> is hydrolyzed to generate ferric hydroxide precipitate to be removed, and the reaction formula is Fe < 3 + > + 3H20 = Fe (OH) < 3 + > 3H < + >; it is ensured that Fe < 3 + > and Al < 3 + > are completely precipitated in the forms of Fe (OH) 3 and Al (OH) 3, and meanwhile it is avoided that Zn < 2 + > and other metal ions are precipitated too early. According to the iron removal technology for the high-purity manganese sulfate, it is ensured that Fe < 3 + > and Al < 3 + > are completely precipitated in the forms of Fe (OH) 3 and Al (OH) 3, meanwhile, premature precipitation of other metal ions such as Zn < 2 + > is avoided, impurities in the manganese sulfate can be comprehensively removed, and the quality of the high-purity manganese sulfate is improved.

Description

Technical Field

[0001] The invention relates to the technical field of manganese sulfate processing, in particular to a process for removing iron from high-purity manganese sulfate. Background Art

[0002] Manganese sulfate, an important basic manganese salt, has a wide range of applications in many fields. With the rapid development of the electronic chemicals industry, manganese sulfate, as a basic raw material for numerous manganese products, has attracted increasing attention. Market demand for manganese sulfate continues to grow, and quality requirements are also increasing.

[0003] The crystallization process for manganese sulfate crystals is primarily atmospheric evaporation crystallization. However, during the production process, the iron in the manganese sulfate solution is not thoroughly removed, resulting in excessive impurities in the manganese sulfate, which reduces its quality. Summary of the Invention

[0004] (1) Technical problems solved

[0005] In view of the shortcomings of the existing technology, the present invention provides a high-purity manganese sulfate iron removal process, which has the advantages of improving the quality of manganese sulfate and solving the problem of excessive impurities in manganese sulfate.

[0006] (2) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: a high-purity manganese sulfate iron removal process, comprising the following steps:

[0008] 1. Raw material processing;

[0009] 2. Acid leaching;

[0010] 3. Remove impurities;

[0011] 4. Purification;

[0012] 5. Crystallization;

[0013] 6. Drying;

[0014] Impurity removal includes iron removal and heavy metal removal;

[0015] Iron removal: Pickling solution usually contains iron ions (Fe 3+ 、Fe 2+ ), first Fe 2+ Oxidized to Fe 3+ , add an appropriate amount of manganese dioxide (MnO2) or hydrogen peroxide (H2O2) to react: 2FeS04+MnO2+2H2S04=Fe2(S04)3+MnS04+2H20; then adjust the pH value of the solution to 4.7-6.0 to make Fe 3- Hydrolysis generates ferric hydroxide precipitate and is removed. The reaction formula is: Fe3+ +3H20=Fe(OH)3↓+3H + ; Ensure Fe 3+ and Al 3+ Complete precipitation in the form of Fe(OH)3 and Al(OH)3, while avoiding Zn 2+ etc., causing premature precipitation of other metal ions.

[0016] Preferably, heavy metal removal: sulfide precipitation is used to remove heavy metal ions in the solution, such as lead (Pb 2+ ), cadmium (Cd 2+ ) etc., adding sulfides such as manganese sulfide (MnS) to react such as: Pb 2+ +MnS=PbS↓+Mn 2+ , Cd 2+ +MnS=CdS↓+Mn 2+ , so that heavy metal ions are removed by forming insoluble sulfide precipitates.

[0017] Preferably, the raw material processing is: crushing and grinding the molten manganese ore to increase the reaction contact area and improve the subsequent reaction rate;

[0018] Acid leaching: Use sulfuric acid (H2SO4) to leach the pretreated molten manganese ore, and the reaction occurs: MnCO3+H2SO4=MnS04+H20+CO2. At the same time, add an appropriate amount of catalyst, heat and stir;

[0019] Purification: The solution after impurity removal may still contain a small amount of impurities. Ion exchange resin can be used for further purification to remove the remaining trace impurity ions and obtain a pure manganese sulfate solution;

[0020] Crystallization: The purified manganese sulfate solution is evaporated, concentrated, cooled and crystallized to obtain manganese sulfate crystals (MnSO4·H20).

[0021] Preferably, drying: drying the manganese sulfate crystals obtained by crystallization to remove surface moisture to obtain a high-purity manganese sulfate product.

[0022] Preferably, the solution temperature is maintained at 40-65°C during the iron removal process.

[0023] Preferably, a three-stage countercurrent evaporation system is used in the crystallization process, and the concentration of manganese sulfate is gradually increased through the liquid (density is controlled at 1.35-1.45 g / cm³), and the temperature is gradually increased, and the temperature is finally maintained at 80-90°C.

[0024] Compared with the prior art, the present invention provides a high-purity manganese sulfate iron removal process, which has the following beneficial effects:

[0025] 1. In the process of removing iron from high-purity manganese sulfate, the pH value is adjusted to 4.7-6.0 to make Fe 3- Hydrolysis generates ferric hydroxide precipitate and removes it, while ensuring that Fe 3+ and Al 3+ Complete precipitation in the form of Fe(OH)3 and Al(OH)3, while avoiding Zn 2+ The premature precipitation of other metal ions can completely remove the impurities in manganese sulfate and improve the quality of high-purity manganese sulfate.

[0026] 2. This high-purity manganese sulfate iron removal process increases the concentration of manganese sulfate in the liquid step by step (density controlled at 1.35-1.45 g / cm³) and gradually increases the temperature, ultimately maintaining the temperature at 80-90°C. This significantly reduces steam consumption by 53%, thereby lowering energy consumption during the production of high-purity manganese sulfate. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a process flow chart for the high-purity manganese sulfate of the present invention. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] See also Figure 1 A high-purity manganese sulfate iron removal process comprises the following steps:

[0030] 1. Raw material processing;

[0031] 2. Acid leaching;

[0032] 3. Remove impurities;

[0033] 4. Purification;

[0034] 5. Crystallization;

[0035] 6. Drying;

[0036] Raw material processing: crush and grind the manganese ore to increase the reaction contact area and improve the subsequent reaction rate;

[0037] Acid leaching: Use sulfuric acid (H2SO4) to leach the pretreated molten manganese ore, and the reaction occurs: MnCO3+H2SO4=MnS04+H20+CO2. At the same time, add an appropriate amount of catalyst, heat and stir;

[0038] Impurity removal includes iron removal and heavy metal removal;

[0039] Iron removal: Pickling solution usually contains iron ions (Fe 3+ 、Fe 2+ ), first Fe 2+ Oxidized to Fe 3+ , add an appropriate amount of manganese dioxide (MnO2) or hydrogen peroxide (H2O2) to react: 2FeS04+MnO2+2H2S04=Fe2(S04)3+MnS04+2H20; then adjust the pH value of the solution to 4.7-6.0 to make Fe 3- Hydrolysis generates ferric hydroxide precipitate and is removed. The reaction formula is: Fe 3+ +3H20=Fe(OH)3↓+3H + ; Ensure Fe 3+ and Al 3+ Complete precipitation in the form of Fe(OH)3 and Al(OH)3, while avoiding Zn 2+ Wait for other metal ions to precipitate prematurely; during the iron removal process, the solution temperature is maintained at 40-65℃.

[0040] Heavy metal removal: sulfide precipitation method is used to remove heavy metal ions in the solution, such as lead (Pb 2+ ), cadmium (Cd 2+ ) etc., adding sulfides such as manganese sulfide (MnS) to react such as: Pb 2+ +MnS=PbS↓+Mn 2+ , Cd 2+ +MnS=CdS↓+Mn 2+ , so that heavy metal ions are removed by forming insoluble sulfide precipitates.

[0041] Purification: The solution after impurity removal may still contain a small amount of impurities. Ion exchange resin can be used for further purification to remove the remaining trace impurity ions and obtain a pure manganese sulfate solution;

[0042] Crystallization: The purified manganese sulfate solution is evaporated, concentrated, cooled, and crystallized to obtain manganese sulfate crystals (MnSO4·H20). A three-stage countercurrent evaporation system is used in the crystallization process to gradually increase the concentration of manganese sulfate (density controlled at 1.35-1.45 g / cm³) through the feed liquid, and the temperature is gradually increased to maintain at 80-90°C.

[0043] Drying: The manganese sulfate crystals obtained by crystallization are dried to remove surface moisture to obtain high-purity manganese sulfate products.

[0044] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-purity manganese sulfate iron removal process, characterized in that: The following steps are involved:

1. Raw material processing; 2. Acid leaching; 3. Remove impurities; 4. Purification; 5. Crystallization; 6. Drying; Impurity removal includes iron removal and heavy metal removal; Iron removal: Pickling solution usually contains iron ions (Fe 3+ 、Fe 2+ ), first Fe 2+ Oxidized to Fe 3+ , add an appropriate amount of manganese dioxide (MnO2) or hydrogen peroxide (H2O2) to react: 2FeS04+MnO2+2H2S04=Fe2(S04)3+MnS04+2H20; then adjust the pH value of the solution to 4.7-6.0 to make Fe 3- Hydrolysis generates ferric hydroxide precipitate and is removed. The reaction formula is: Fe 3+ +3H20=Fe(OH)3↓+3H + ; Ensure Fe 3+ and Al 3+ Complete precipitation in the form of Fe(OH)3 and Al(OH)3, while avoiding Zn 2+ etc., causing premature precipitation of other metal ions.

2. A high-purity manganese sulfate iron removal process according to claim 1, characterized in that: Heavy metal removal: sulfide precipitation method is used to remove heavy metal ions in the solution, such as lead (Pb 2+ ), cadmium (Cd 2+ ) etc., adding sulfides such as manganese sulfide (MnS) to react such as: Pb 2+ +MnS=PbS↓+Mn 2+ , Cd 2+ +MnS=CdS↓+Mn 2+ , so that heavy metal ions are removed by forming insoluble sulfide precipitates.

3. A high-purity manganese sulfate iron removal process according to claim 1, characterized in that: Raw material processing: crush and grind the manganese ore to increase the reaction contact area and improve the subsequent reaction rate; Acid leaching: Use sulfuric acid (H2SO4) to leach the pretreated molten manganese ore, and the reaction occurs: MnCO3+H2SO4=MnS04+H20+CO2. At the same time, add an appropriate amount of catalyst, heat and stir; Purification: The solution after impurity removal may still contain a small amount of impurities. Ion exchange resin can be used for further purification to remove the remaining trace impurity ions and obtain a pure manganese sulfate solution; Crystallization: The purified manganese sulfate solution is evaporated, concentrated, cooled and crystallized to obtain manganese sulfate crystals (MnSO4·H20).

4. A high-purity manganese sulfate iron removal process according to claim 1, characterized in that: Drying: The manganese sulfate crystals obtained by crystallization are dried to remove surface moisture to obtain high-purity manganese sulfate products.

5. A high-purity manganese sulfate iron removal process according to claim 1, characterized in that: The solution temperature is maintained at 40-65°C during the iron removal process.

6. A high-purity manganese sulfate iron removal process according to claim 3, characterized in that: During the crystallization process, a three-stage countercurrent evaporation system is used to gradually increase the concentration of manganese sulfate through the liquid (density is controlled at 1.35-1.45 g / cm³) and the temperature is gradually increased, and the temperature is finally maintained at 80-90°C.

Images