Method for reducing magnesium ions in electrolytic manganese metal solution by using ammonium sulfate and application of method
By reacting ammonium sulfate with manganese sulfate solution to generate magnesium ammonium sulfate double salt crystals, the problem of magnesium ion removal in electrolytic manganese production is solved, achieving efficient, low-cost, and environmentally friendly magnesium ion purification, which is suitable for electrolytic manganese production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-26
- Publication Date
- 2026-03-27
AI Technical Summary
In existing electrolytic manganese production, magnesium ions are difficult to remove efficiently, leading to decreased manganese product purity, increased cell voltage, and higher energy consumption. Furthermore, existing methods are costly, pose significant environmental risks, and are complex.
Ammonium sulfate and manganese sulfate solution are reacted to generate magnesium ammonium sulfate double salt crystals. Magnesium ions are then separated by stirring, settling, and filtration to achieve purification.
It efficiently removes magnesium ions, reduces costs, is environmentally friendly with no secondary pollution, has a simple process that is easy to industrialize, and has a low manganese loss rate, meeting the requirements for electrolytic manganese production.
Smart Images
Figure SMS_1 
Figure SMS_2
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of electrolytic manganese production, and particularly relates to a method for reducing magnesium ions in an electrolytic manganese solution by using ammonium sulfate and application thereof. BACKGROUND
[0002] Manganese has a very important strategic position in the national economy, and it can improve the performance of steel and iron, which is an indispensable bulk raw material in the metallurgical industry. However, its role is not limited to this. With the rapid development of new energy and new material fields, manganese, as the main raw material for batteries, has shown explosive growth in demand. At present, manganese is produced by using an electrolysis process. The process of electrolytic manganese generally includes: preparing a manganese sulfate solution by reacting sulfuric acid with manganese carbonate ore, and then preparing an electrolyte through a series of processes such as neutralization, purification, and filtration. The electrolyte is electrolyzed to deposit metal manganese. Among them, the manganese sulfate solution after neutralization (combined neutralization liquid) still contains a high concentration of magnesium ions. Magnesium ions are easily deposited at the cathode during the electrolysis process, which leads to a decrease in the purity of manganese products and a rough surface. At the same time, it increases the cell voltage and increases the energy consumption. Therefore, the combined neutralization liquid needs to be purified before electrolysis to reduce the content of impurity ions, and the purification of magnesium ions is the key. The current commonly used magnesium removal methods in industry mainly include: (1) chemical precipitation method: adding fluoride salt (such as manganese fluoride and sodium fluoride) to generate insoluble fluoride precipitate. However, the cost of fluoride salt is high, and excessive fluoride ions can easily corrode equipment, posing environmental risks; (2) solvent extraction method: using extractant to selectively separate magnesium ions. However, the extractant is expensive and the process is complex, which increases the production cost of the subsequent back extraction process; (3) recrystallization method: separating magnesium ions by manganese sulfate crystallization. However, the energy consumption is high and the yield is low, which is not suitable for large-scale production.
[0003] From the above analysis, it can be seen that the existing methods have problems such as high cost, high environmental risk, and complex process. Therefore, it is urgent to develop a low-cost, environmentally friendly, and efficient magnesium removal technology for manganese sulfate solution. SUMMARY
[0004] The present application provides a method for reducing magnesium ions in an electrolytic manganese solution by using ammonium sulfate and application thereof, which can efficiently remove magnesium ions and has low cost.
[0005] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:
[0006] In one aspect, the present application provides a method for reducing magnesium ions in an electrolytic manganese solution by using ammonium sulfate, which includes the following steps:
[0007] (1) Take a clear manganese sulfate solution containing magnesium ions, heat it to 40-70℃, and add solid ammonium sulfate under stirring conditions until the ammonium sulfate is completely dissolved to obtain a mixed solution;
[0008] (2) Cool the mixed solution to 20-50℃ and let it stand for 24-96 hours until magnesium ions in the mixed solution combine with sulfate ions and ammonium ions to form magnesium ammonium sulfate double salt crystals.
[0009] (3) Take the mixed solution that produces ammonium magnesium sulfate double salt crystals, and separate the solid and liquid. The solid is the filter residue containing ammonium magnesium sulfate double salt crystals, and the liquid is the manganese sulfate purification solution.
[0010] Preferably, in step (1), the concentration of manganese ions in the manganese sulfate solution is controlled to be 30-42 g / L, and the concentration of ammonium sulfate is controlled to be 60-120 g / L.
[0011] Preferably, in step (1), the concentration of magnesium ions in the manganese sulfate solution containing magnesium ions is 25-45 g / L, and the amount of solid ammonium sulfate added is 1%-10% of the mass of the manganese sulfate solution.
[0012] Preferably, in step (1), the magnesium ion concentration in the manganese sulfate solution containing magnesium ions is 25-45 g / L, the ammonium sulfate concentration is 60-120 g / L, and after stirring until the ammonium sulfate is completely dissolved, the concentration of ammonium sulfate in the mixed solution is controlled to be 140-220 g / L.
[0013] Preferably, in step (2), the temperature is kept constant during the standing process.
[0014] Preferably, in step (2), the mixed solution is cooled to 20-30°C.
[0015] Preferably, in step (3), the solid-liquid separation is carried out using a plate and frame filter press.
[0016] Preferably, the purified manganese sulfate solution enters the subsequent electrolytic manganese process, and the filter residue is recovered as a magnesium resource. Before the filter residue is recovered, it can be washed with a small amount of low-temperature deionized water to improve the purity of the dried magnesium ammonium sulfate double salt crystals. The washing liquid after washing the filter residue can be returned to the manganese sulfate leaching process for recycling, replacing the water added in the manganese sulfate leaching process.
[0017] In another aspect, the present invention provides the application of the above-described method for reducing magnesium ions in electrolytic manganese solutions using ammonium sulfate in the production of electrolytic manganese.
[0018] Furthermore, the present invention provides the application of the above-described method of using ammonium sulfate to reduce magnesium ions in electrolytic manganese solution in the purification of chemical neutralization liquid in electrolytic manganese production, wherein the manganese sulfate solution containing magnesium ions is a chemical neutralization liquid in electrolytic manganese production that has been filtered to remove insoluble impurities.
[0019] The method and its application of using ammonium sulfate to reduce magnesium ions in electrolytic manganese solutions, as described above, have the following beneficial effects:
[0020] (1) High magnesium removal efficiency: The magnesium ion removal rate can reach more than 45%, which can reduce the magnesium ion concentration in the manganese sulfate purification solution to a minimum of 18.21 g / L, which can well meet the requirements of electrolytic manganese production.
[0021] (2) Low cost: Ammonium sulfate is inexpensive and widely available, which significantly reduces the cost of magnesium removal compared to fluoride salts, extractants, etc.
[0022] (3) Good environmental performance: No toxic or harmful substances are generated in the whole process. The main component of the filter residue is ammonium magnesium sulfate double salt crystals, which can be recycled. The washing liquid used to wash the filter residue can be recycled without secondary pollution.
[0023] (4) Simple process: No complicated equipment is required. It can be achieved through conventional operations such as heating, stirring, cooling and filtering, and is easy to promote industrially.
[0024] (5) Low manganese loss rate: The manganese ion loss rate can be controlled to below 6.6%, ensuring the efficient utilization of manganese sulfate resources. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0026] This invention provides a method for reducing magnesium ions in electrolytic manganese solutions using ammonium sulfate and its application, which can efficiently remove magnesium ions and is inexpensive.
[0027] To achieve the above objectives, the technical solution of the present invention is as follows:
[0028] This invention provides a method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate, comprising the following steps:
[0029] (1) Take a clear manganese sulfate solution containing magnesium ions, heat it to 40-70℃ (e.g., 40℃, 45℃, 50℃, 55℃ or 70℃), add solid ammonium sulfate under stirring, and stir until the ammonium sulfate is completely dissolved to obtain a mixed solution;
[0030] (2) Cool the mixed solution to 20-50℃ (e.g., 20℃, 25℃, 28℃, 30℃, 35℃, 40℃ or 50℃) (of course, the cooling temperature is lower than the heating temperature of the manganese sulfate solution containing magnesium ions in step (1)), and let it stand for 24-96h (e.g., 24h, 48h, 55h, 60h, 72h or 96h) until the magnesium ions in the mixed solution combine with sulfate ions and ammonium ions to form magnesium ammonium sulfate double salt crystals;
[0031] (3) Take the mixed solution that produces ammonium magnesium sulfate double salt crystals, and separate the solid and liquid. The solid is the filter residue containing ammonium magnesium sulfate double salt crystals, and the liquid is the manganese sulfate purification solution.
[0032] In step (1) above, a clear manganese sulfate solution containing magnesium ions is obtained by pre-filtering insoluble impurities.
[0033] Preferably, in step (1), the concentration of manganese ions in the manganese sulfate solution is controlled to be 30-42 g / L (e.g., 30 g / L, 36 g / L, 38 g / L, 40 g / L or 42 g / L), and the concentration of ammonium sulfate is 60-120 g / L (e.g., 60 g / L, 80 g / L, 100 g / L, 110 g / L or 120 g / L).
[0034] Preferably, in step (1), the magnesium ion concentration in the manganese sulfate solution containing magnesium ions is 25-45 g / L (e.g., 25 g / L, 28 g / L, 30 g / L, 35 g / L or 45 g / L), and the amount of solid ammonium sulfate added is 1%-10% of the mass of the manganese sulfate solution (e.g., 1%, 2%, 5%, 8% or 10%).
[0035] Preferably, in step (1), the magnesium ion concentration in the manganese sulfate solution containing magnesium ions is 25-45 g / L (e.g., 25 g / L, 28 g / L, 30 g / L, 35 g / L or 45 g / L), and the ammonium sulfate concentration is 60-120 g / L (e.g., 60 g / L, 80 g / L, 100 g / L, 110 g / L or 120 g / L). After stirring until the ammonium sulfate is completely dissolved, the concentration of ammonium sulfate in the mixed solution is controlled to be 140-220 g / L (e.g., 140 g / L, 160 g / L, 180 g / L, 200 g / L or 220 g / L).
[0036] Preferably, in step (2), the temperature is kept constant during the standing process.
[0037] Preferably, in step (2), the mixed solution is cooled to 20-30°C (e.g., 20°C, 25°C, 26°C, 28°C, 29°C or 30°C).
[0038] Preferably, in step (3), solid-liquid separation is carried out using a plate and frame filter press, which has a faster filtration speed and helps to speed up the entire process.
[0039] Preferably, the purified manganese sulfate solution enters the subsequent electrolytic manganese process. Of course, if other impurities are present, they must undergo a treatment process before entering the electrolytic manganese process. The filter residue mainly consists of ammonium magnesium sulfate double salt crystals, which can be used for magnesium resource recovery and as a chemical raw material. Before recycling the filter residue, it can be washed with a small amount of low-temperature deionized water to improve the purity of the dried ammonium magnesium sulfate double salt crystals. The washing liquid after washing the filter residue can be returned to the manganese sulfate leaching process for recycling, replacing the water added in the manganese sulfate leaching process.
[0040] In another aspect, the present invention provides the application of the above-described method for reducing magnesium ions in electrolytic manganese solutions using ammonium sulfate in the production of electrolytic manganese.
[0041] Furthermore, the present invention provides the application of the above-described method of using ammonium sulfate to reduce magnesium ions in electrolytic manganese solution in the purification of chemical neutralization liquid in electrolytic manganese production, wherein the manganese sulfate solution containing magnesium ions is a chemical neutralization liquid in electrolytic manganese production that has been filtered to remove insoluble impurities.
[0042] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments.
[0043] This embodiment describes the treatment of a chemical neutralization solution used in the production of electrolytic manganese metal. The main components of the neutralization solution, as shown in Table 1, were analyzed.
[0044] Table 1. Main components of the compound neutralization solution
[0045]
[0046] Example 1
[0047] (1) Take the chemical neutralization liquid from the electrolytic production of manganese metal, filter to remove insoluble impurities, and obtain a clear manganese sulfate solution. Take the clear manganese sulfate solution containing magnesium ions, heat it to 45°C, and slowly add solid ammonium sulfate under stirring. Stir until the ammonium sulfate is completely dissolved to obtain a mixed solution. The concentration of ammonium sulfate in the mixed solution is 200 g / L.
[0048] (2) Take the mixed solution and slowly cool it to 25°C. Let it stand for 24 hours to allow the magnesium ions in the mixed solution to combine with sulfate ions and ammonium ions to form magnesium ammonium sulfate double salt crystals.
[0049] (3) A mixed solution of ammonium magnesium sulfate double salt crystals is generated by filtration through a plate and frame filter press. The solid and liquid are separated. The solid is the filter residue containing ammonium magnesium sulfate double salt crystals, and the liquid is the manganese sulfate purification solution. The filter residue containing ammonium magnesium sulfate double salt crystals is washed with a small amount of low-temperature deionized water 1-3 times. The washing liquid is returned to the manganese sulfate leaching process for recycling. The filter residue can be used as a magnesium resource for recovery.
[0050] Example 2
[0051] Example 2 is basically the same as Example 1, but in step (2), the standing time is 48h.
[0052] Example 3
[0053] Example 3 is basically the same as Example 1, but in step (2), the standing time is 72h.
[0054] Example 4
[0055] Example 4 is basically the same as Example 1, but in step (2), the standing time is 96h.
[0056] Example 5
[0057] Example 5 is basically the same as Example 1, but in step (1), the concentration of ammonium sulfate in the mixed solution is 180 g / L.
[0058] Example 6
[0059] Example 6 is basically the same as Example 5, but in step (2), the standing time is 48h.
[0060] Example 7
[0061] Example 7 is basically the same as Example 1, but in step (2), the mixed solution is slowly cooled to 30°C.
[0062] Example 8
[0063] Example 8 is basically the same as Example 7, but in step (2), the standing time is 48h.
[0064] Example 9
[0065] Example 9 is basically the same as Example 7, but in step (2), the standing time is 72h.
[0066] Example 10
[0067] Example 10 is basically the same as Example 7, but in step (2), the standing time is 96h.
[0068] Example 11
[0069] Example 11 is basically the same as Example 1, but in step (2), the mixed solution is slowly cooled to 35°C.
[0070] Example 12
[0071] Example 12 is basically the same as Example 11, but in step (2), the standing time is 72h.
[0072] Example 13
[0073] Example 13 is basically the same as Example 1, but in step (1), the concentration of ammonium sulfate in the mixed solution is 160 g / L.
[0074] Example 14
[0075] Example 14 is basically the same as Example 13, but in step (2), the standing time is 72h.
[0076] Example 15
[0077] Example 15 is basically the same as Example 1, except that in step (1), the clarified manganese sulfate solution containing magnesium ions is heated to 50°C.
[0078] Example 16
[0079] Example 16 is basically the same as Example 15, but in step (1), the concentration of ammonium sulfate in the mixed solution is 220 g / L.
[0080] Example 17
[0081] Example 17 is basically the same as Example 1, but in step (2), the mixed solution is slowly cooled to 20°C.
[0082] Example 18
[0083] Example 18 is basically the same as Example 17, but in step (2), the standing time is 72h.
[0084] Example 19
[0085] Example 19 is basically the same as Example 2, but in step (1), the concentration of ammonium sulfate in the mixed solution is 150 g / L.
[0086] Example 20
[0087] Example 20 is basically the same as Example 2, but in step (1), the concentration of ammonium sulfate in the mixed solution is 140 g / L.
[0088] The main component contents of the manganese sulfate purification solutions in Examples 1-18 were determined, and the Mg content was calculated. 2+ The removal rates are shown in Table 2:
[0089] Table 2 Test Results
[0090]
[0091] Based on the above test results, it can be seen that, using the solid ammonium sulfate precipitation method, the magnesium ion concentration in the purified manganese sulfate solution obtained in Examples 1-3, 8-10, and 15-18 was reduced to below 20 g / L. The magnesium ion concentration in the purified manganese sulfate solution obtained in other examples could also be controlled to not exceed 25 g / L, and the manganese ion loss rate was low, which meets the requirements for electrolytic manganese metal production.
Claims
1. A method for reducing magnesium ions in an electrolyzed manganese solution using ammonium sulfate, characterized in that... Includes the following steps: (1) Take a clear manganese sulfate solution containing magnesium ions, heat it to 40-70℃, add solid ammonium sulfate under stirring, and stir until the ammonium sulfate is completely dissolved to obtain a mixed solution; (2) Cool the mixed solution to 20-50℃ and let it stand for 24-96 h to allow the magnesium ions in the mixed solution to combine with sulfate ions and ammonium ions to form magnesium ammonium sulfate double salt crystals. (3) Take the mixed solution that produces ammonium magnesium sulfate double salt crystals, and separate the solid and liquid. The solid is the filter residue containing ammonium magnesium sulfate double salt crystals, and the liquid is the manganese sulfate purification solution.
2. The method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate according to claim 1, characterized in that: In step (1), the concentration of manganese ions in the manganese sulfate solution is controlled to be 30-42 g / L, and the concentration of ammonium sulfate is controlled to be 60-120 g / L.
3. The method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate according to claim 1, characterized in that: In step (1), the magnesium ion concentration in the manganese sulfate solution containing magnesium ions is 25-45 g / L, so the amount of solid ammonium sulfate added is 1%-10% of the mass of the manganese sulfate solution.
4. The method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate according to claim 1, characterized in that: In step (1), the magnesium ion concentration in the manganese sulfate solution containing magnesium ions is 25-45 g / L, and the ammonium sulfate concentration is 60-120 g / L. After stirring until the ammonium sulfate is completely dissolved, the concentration of ammonium sulfate in the mixed solution is controlled to be 140-220 g / L.
5. The method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate according to claim 1, characterized in that: In step (2), the temperature is kept constant during the standing process.
6. The method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate according to claim 1, characterized in that: In step (2), the mixed solution is cooled to 20-30°C.
7. The method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate according to claim 1, characterized in that: In step (3), solid-liquid separation is performed using a plate and frame filter press.
8. The method for reducing magnesium ions in an electrolytic manganese solution using ammonium sulfate according to claim 1, characterized in that: The purified manganese sulfate solution is then used in the subsequent electrolytic manganese process, while the filter residue is recovered as a magnesium resource.
9. The application of the method for reducing magnesium ions in electrolytic manganese solution using ammonium sulfate as described in claims 1-8 in the production of electrolytic manganese.
10. The application of the method for reducing magnesium ions in electrolytic manganese solution using ammonium sulfate as described in claims 1-8 in the purification of the chemical neutralization solution in the production of electrolytic manganese, characterized in that: The manganese sulfate solution containing magnesium ions is a chemical neutralization solution used in the production of electrolytic manganese metal after filtering out insoluble impurities.