Process for the preparation of electrolyte for electrolytic manganese metal

Abstract

This invention provides a method for preparing an electrolyte for electrolytic manganese metal, relating to the technical field of manganese electrolyte preparation methods. The method involves first reacting manganese ore powder and sulfuric acid to obtain crude manganese sulfate solution; then pretreating the crude manganese sulfate solution with a protective agent to generate a mixed complex solution; adding a precipitant to the mixed complex solution to generate ferric hydroxide precipitate, resulting in a primary impurity removal solution and a secondary impurity removal solution; adding H₂O₂ to the secondary impurity removal solution to obtain a solution containing manganese ions; and then adding ammonium fluoride to the solution containing manganese ions to obtain a manganese sulfate solution. Therefore, by protecting manganese in the form of a complex before the impurity removal process, oxidation, precipitation, or co-precipitation are avoided during subsequent impurity removal. After heavy metal impurities are removed, manganese ions are released, reducing manganese loss during the impurity removal process, avoiding raw material waste, and minimizing the adsorption of impurities, equipment blockage, and interference with electrolysis caused by manganese ions in solid phases such as MnO₂ / Mn(OH)₂ / MnS.

Description

Technical Field

[0001] This invention belongs to the technical field of manganese electrolyte preparation methods, specifically relating to a method for preparing an electrolyte for electrolyzing metallic manganese. Background Technology

[0002] Electrolytic manganese metal (EMM) and electrolytic manganese dioxide (EMD) are key basic materials for the electronics, new energy batteries, and special alloy industries. The core of their production lies in preparing high-purity manganese sulfate electrolytic feedstock—the Mn²⁺ concentration, impurity content, and acidity of this feedstock directly determine the current efficiency and product purity during the electrolysis process. With the increasing purity requirements for power batteries and high-end electronic-grade manganese materials (e.g., battery-grade manganese sulfate requires heavy metal impurities to be below 1 ppm, and the content of alkali / alkaline earth metals such as calcium and magnesium also needs strict control), the demand for high-purity manganese is growing.

[0003] Currently, the industrial preparation of manganese sulfate electrolytic solution mainly uses manganese carbonate ore or manganese oxide ore as raw materials, which are then leached with sulfuric acid to obtain Mn-containing solutions. 2+ Fe 2+ / Fe 3+ Ni 2+ Co²⁺, Cu 2+ Zn 2+ Cd 2+ Pb 2+ Ca 2+ Mg 2+ K + A mixed solution of various ions. The purification of sulfuric acid leachate usually involves the following steps: oxidation and neutralization to remove iron, precipitation of heavy metals with sulfides or organic chelating agents, and precipitation of calcium and magnesium with fluorides.

[0004] For example, barium sulfide or sodium sulfide is used to remove heavy metals, and magnesium fluoride or ammonium fluoride is used to remove calcium and magnesium; and, as in the prior art, Chinese invention patent application number 201310396688.5 discloses a method for preparing liquid for electrolytic manganese, which includes: (1) adding manganese ore powder to a return anolyte and adding sulfuric acid for leaching reaction; (2) performing a first-stage pressure filtration of the leaching reaction slurry to separate the solid and liquid and obtain the leaching filtrate; (3) neutralizing the separated leaching filtrate and adding air or H2O2 for oxidation to remove iron; (4) adjusting the pH value and then performing sulfidation to remove heavy metals; (5) performing a second-stage pressure filtration; (6) performing static separation; (7) performing a third-stage pressure filtration to complete the liquid preparation process. Although this invention effectively reduces the impurity content in the liquid, reduces the consumption of sulfiding agent SDD, and reduces the production cost of electrolytic manganese, in this patent, multiple steps of acid and alkali adjustment are required during the removal of iron and heavy metals, and Mn 2+ It is highly susceptible to hydrolysis due to increased pH, forming Mn(OH)2 precipitate, and can also be precipitated by localized oxidative environments (such as during iron removal by air or H2O2 oxidation).2+ Oxidized to Mn 4+ (MnO2) enters the slag phase, or during the heavy metal removal stage of sulfidation, high concentrations of Mn 2+ It will compete with heavy metal ions for precipitants, forming MnS co-precipitates, etc. These manganese losses not only reduce the raw material recovery rate (the manganese loss rate in traditional processes is usually 3%~5%), but also further increase the pressure on solid waste disposal due to the generation of manganese slag. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing an electrolyte for electrolytic manganese metal that reduces manganese loss during the impurity removal process, thereby improving the raw material recovery rate and reducing the pressure of solid waste treatment.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] A method for preparing an electrolyte for electrolyzing metallic manganese includes the following steps:

[0008] S1 leaching: Manganese ore powder and sulfuric acid are reacted and filtered to obtain crude manganese sulfate solution;

[0009] S2 Pretreatment: The crude manganese sulfate solution is pretreated with a protective agent to generate a mixed complex solution for Mn. 2+ Protect it;

[0010] S3 Iron Ion Removal: Manganese oxide and calcium carbonate are added to the mixed complex solution to react and generate iron hydroxide precipitate. The solution is then filtered to obtain a primary removal solution.

[0011] S4 Heavy Metal Removal: A removal agent is added to the primary removal solution to remove Ni. 2+ Co 2+ Cu 2+ Zn 2+ Cd 2+ Pb 2+ Filter to obtain a secondary purified solution;

[0012] S5 Manganese ion reduction: Add H2O2 to the secondary impurity removal solution to release manganese ions and obtain a solution containing manganese ions;

[0013] S6 Calcium and Magnesium Ion Removal: Add ammonium fluoride to a solution containing manganese ions, filter to remove calcium and magnesium ions, and then filter again to obtain a manganese sulfate solution.

[0014] Preferably, in step S2, the protective agent is tartaric acid or ascorbic acid.

[0015] Preferably, in step S5, the pH of the added H2O2 is 2.0-3.0, the mass concentration of the H2O2 is 30%, and the amount of added H2O2 is 1.5-2 times the amount of added tartaric acid.

[0016] Preferably, in step S5, the reaction time is 0.5h-1h and the reaction temperature is 55℃-70℃.

[0017] Preferably, "adding H2O2 to the secondary impurity removal solution" specifically means that H2O2 is added in multiple portions as the reaction proceeds, with a predetermined amount added every 15-20 minutes.

[0018] Preferably, the H2O2 is added in three stages. The H2O2 is added for the first time when the temperature of the secondary impurity removal solution reaches 50-55°C, and the H2O2 is added for the second and third times when the temperature of the secondary impurity removal solution reaches the reaction temperature.

[0019] Preferably, in step S2, the tartaric acid reacts with the Mn in the crude manganese sulfate solution. 2+ The mass ratio is 1:40-50, and the mass ratio of tartaric acid to ascorbic acid is 9-10:1.

[0020] Preferably, in step S2, the reaction temperature is 55-65℃ and the reaction time is 10-30 min.

[0021] Preferably, in step S4, the impurity removal agent is sodium thiram or manganese sulfide;

[0022] Adding a purification agent to the primary purification solution specifically includes: pre-purification and fine purification.

[0023] The pre-removal process involves adding manganese sulfide to the primary removal solution and filtering to pre-remove Ni. 2+ Co 2+ Cu 2+ Cd 2 + A pre-purified solution was obtained;

[0024] The fine purification process involves adding sodium fumarate to the pre-purification solution, filtering, and removing residual heavy metals to the ppm level to obtain a secondary purification solution.

[0025] Preferably, in the pre-purification process, the reaction temperature is 65℃-75℃ and the reaction time is 1h-1.5h, and in the fine purification process, the reaction temperature is 53℃-65℃ and the reaction time is 0.5h-1h.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention provides a method for preparing an electrolyte for electrolyzing metallic manganese. The method involves first reacting and filtering manganese ore powder and sulfuric acid to obtain crude manganese sulfate solution; then pretreating the crude manganese sulfate solution with a protective agent to generate a mixed complex solution for the electrolysis of Mn. 2+ Protect it to prevent damage to Mn during subsequent impurity removal processes. 2+ The loss is then reduced; manganese oxide and calcium carbonate are added to the mixed complex solution to react and generate ferric hydroxide precipitate, which is then filtered to obtain a primary impurity removal solution. Iron ions are first removed from this solution, and then an impurity removal agent is added to further remove impurities, specifically Ni. 2+ Co 2+ Cu 2+ Zn 2+ Cd 2+ Pb 2+ The process involves filtration to obtain a secondary impurity-removed solution. H₂O₂ is added to this solution to release manganese ions, resulting in a solution containing manganese ions. Ammonium fluoride is then added to this manganese-containing solution, followed by filtration to remove calcium and magnesium ions, yielding a manganese sulfate solution. Therefore, by protecting manganese in the form of a complex before the impurity removal process, oxidation, precipitation, or co-precipitation are prevented during subsequent impurity removal. After heavy metal impurities are removed, manganese ions are released, reducing manganese loss during the impurity removal process, avoiding raw material waste, improving raw material recovery rate, and reducing solid waste treatment pressure. Simultaneously, it reduces the risk of impurities being adsorbed by manganese ions in solid phases such as MnO₂ / Mn(OH)₂ / MnS, which can clog equipment and interfere with electrolysis.

[0028] On the other hand, the above steps avoid the introduction of other impurities, and the resulting manganese sulfate solution has a low content of heavy metal impurities, which is beneficial for the production of electrolytic manganese. Detailed Implementation

[0029] To facilitate understanding of this application, a more comprehensive description is provided below, along with preferred embodiments. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] This application provides a method for preparing an electrolyte for electrolyzing metallic manganese, comprising the following steps:

[0032] S1 leaching: Manganese ore powder and sulfuric acid are reacted and filtered to obtain crude manganese sulfate solution;

[0033] S2 Pretreatment: The crude manganese sulfate solution is pretreated with a protective agent to generate a mixed complex solution for Mn. 2+ Protect it;

[0034] S3 Iron Ion Removal: Manganese oxide and calcium carbonate are added to the mixed complex solution to react and generate iron hydroxide precipitate. The solution is then filtered to obtain a primary removal solution.

[0035] S4 Heavy Metal Removal: A removal agent is added to the primary removal solution to remove Ni. 2+ Co 2+ Cu 2+ Zn 2+ Cd 2+ Pb 2+ Filter to obtain a secondary purified solution;

[0036] S5 Manganese ion reduction: Add H2O2 to the secondary impurity removal solution to release manganese ions and obtain a solution containing manganese ions;

[0037] S6 Calcium and Magnesium Ion Removal: Add ammonium fluoride to a solution containing manganese ions, filter to remove calcium and magnesium ions, and then filter again to obtain a manganese sulfate solution.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] This invention provides a method for preparing an electrolyte for electrolyzing metallic manganese. The method involves first reacting and filtering manganese ore powder and sulfuric acid to obtain crude manganese sulfate solution; then pretreating the crude manganese sulfate solution with a protective agent to generate a mixed complex solution for the electrolysis of Mn. 2+ Protect it to prevent damage to Mn during subsequent impurity removal processes. 2+ The loss is then reduced; manganese oxide and calcium carbonate are added to the mixed complex solution to react and generate ferric hydroxide precipitate, which is then filtered to obtain a primary impurity removal solution. Iron ions are first removed from this solution, and then an impurity removal agent is added to further remove impurities, specifically Ni. 2+ Co 2+ Cu 2+ Zn 2+ Cd 2+ Pb 2+The solution is filtered to obtain a secondary impurity removal solution. H2O2 is added to the secondary impurity removal solution to release manganese ions, resulting in a solution containing manganese ions. Ammonium fluoride is then added to the solution containing manganese ions, and the solution is filtered to remove calcium and magnesium ions. After filtration, a manganese sulfate solution is obtained. Therefore, by protecting manganese in the form of a complex before the impurity removal process, it is possible to avoid oxidation, precipitation, or co-precipitation during the subsequent impurity removal process. After the heavy metal impurities are removed, the manganese ions are released to reduce manganese loss during the impurity removal process, avoid raw material waste, and reduce the risk of impurities being adsorbed, equipment being blocked, and electrolysis being interfered with by manganese ions in the form of solid phases such as MnO2 / Mn(OH)2 / MnS.

[0040] On the other hand, the above steps avoid the introduction of other impurities, and the resulting manganese sulfate solution has a low content of heavy metal impurities, which is beneficial for the production of electrolytic manganese.

[0041] Each step will now be explained in detail:

[0042] S1 leaching: Manganese ore powder and sulfuric acid are reacted and filtered to obtain crude manganese sulfate solution;

[0043] Specifically, manganese ore powder with a mass ratio of 1:0.5-1 is mixed with sulfuric acid and leached at 80-90℃ under acidic conditions for 2-3.5 hours. After filtration, crude manganese sulfate solution is obtained.

[0044] S2 Pretreatment: The crude manganese sulfate solution is pretreated with a protective agent to generate a mixed complex solution for Mn. 2+ Protect it;

[0045] In one embodiment, the protective agent is tartaric acid or ascorbic acid.

[0046] Furthermore, the tartaric acid and the Mn in the crude manganese sulfate solution... 2+ The mass ratio is 1:40-50 to make the free Mn 2+ Concentration much less than 10 -4 The mass ratio of tartaric acid to ascorbic acid is 9-10:1.

[0047] Furthermore, the reaction system pH was 5-6, the reaction temperature was 55-65℃, and the reaction time was 10-30 min.

[0048] Before impurity removal, tartaric acid is used to complex manganese ions to form stable and soluble Mn(C4H4O6) and [Mn(H2O)6]. 2+ A mixed complex solution is used to mask manganese ions, allowing other ions to preferentially react and be removed during subsequent impurity removal, thus reducing manganese ion loss. Simultaneously, ascorbic acid is added to maintain a reducing atmosphere and prevent Mn from being lost. 2+ Oxidized to Mn4+ This also provides a basis for the subsequent release of manganese ions, avoiding Mn 2+ Oxidized to Mn 4+ (MnO2 precipitation).

[0049] S3 Iron Ion Removal: Manganese oxide and calcium carbonate are added to the mixed complex solution to react and generate iron hydroxide precipitate. The solution is then filtered to obtain a primary removal solution.

[0050] Specifically, the reaction temperature is 80℃-90℃. At this temperature, the complex formed by tartaric acid and K ions in the crude manganese sulfate solution is destroyed. Then, manganese oxide is added, which causes Fe... 2+ Converted to Fe 3+ It also adsorbs potassium ions and Fe. 3+ It reacts with calcium carbonate to form ferric hydroxide precipitate, thereby removing iron and potassium ions. At the same time, impurities are removed by manganese oxide, without introducing other impurities.

[0051] S4 Heavy Metal Removal: A removal agent is added to the primary removal solution to remove Ni. 2+ Co 2+ Cu 2+ Zn 2+ Cd 2+ Pb 2+ Filter to obtain a secondary purified solution;

[0052] Furthermore, the impurity removal agent is sodium thiram or manganese sulfide.

[0053] Specifically, in step S4, adding a purification agent to the primary purification solution includes: pre-purification and fine purification.

[0054] The pre-removal process involves adding manganese sulfide to the primary removal solution and filtering to pre-remove Ni. 2+ Co 2+ Cu 2+ Cd 2 + This yields a pre-purified solution, avoiding the introduction of sodium ions;

[0055] The reaction temperature is 65℃-75℃, the reaction time is 1h-1.5h, and the pH is 5.5-6.8, preferably 55℃, 0.5h, and pH 6.5. The amount of manganese sulfide used is 1.5 times the total amount of heavy metals (molar ratio). The reaction is carried out under nitrogen protection, and the system is filtered after the reaction. Ni is present in the system. 2+ Co 2+ Cu 2+ Cd 2+ The removal rate reaches over 95%.

[0056] The fine purification process involves adding sodium fumarate to the pre-purification solution, filtering, and removing residual heavy metals to the ppm level to obtain a secondary purification solution.

[0057] The reaction temperature is 53℃-65℃, the reaction time is 0.5h-1h, preferably 55℃ and 0.5h. The amount of sodium thime is 1.2 times the total amount of heavy metals (molar ratio). The pH is 6.3. During the reaction, when no red color is detected in the dimethylglyoxime, it indicates that the nickel and other metals have been completely removed. The reaction ends, and the solution is filtered to obtain a secondary impurity removal solution. The total amount of heavy metals in the secondary impurity removal solution is reduced to below 0.5ppm.

[0058] By combining pre-removal and fine removal, most heavy metals are first removed with manganese sulfide, and then residual trace heavy metals are treated with SDD, which can significantly reduce SDD consumption while ensuring ppm accuracy.

[0059] S5 Manganese ion reduction: Add H2O2 to the secondary impurity removal solution to release manganese ions and obtain a solution containing manganese ions;

[0060] When H2O2 is added, the pH of the reaction system is 2.0-3.0, the mass concentration of H2O2 is 30%, and the amount of H2O2 added is 1.5-2 times the amount of tartaric acid added. Preferably, the pH is 2, and the amount of H2O2 added is twice the amount of tartaric acid added.

[0061] The reaction time is 0.5-1 hour, and the reaction temperature is 55-70°C. Preferably, the reaction time is 50 minutes. During the oxidation and destruction of the complex by H2O2, the presence of ascorbic acid in the system, along with the control of the system's pH and temperature, prevents the release of Mn. 2+ Oxidized to Mn 4+ (MnO2 precipitation) At the same time, after the reaction is completed, the excess H2O2 in the system is reduced by ascorbic acid, eliminating the remaining H2O2, avoiding the continuous decomposition of H2O2 and reducing the current efficiency.

[0062] Furthermore, to avoid H2O2 decomposing into oxygen and water, which would reduce utilization and cause violent local bubble reactions, "adding H2O2 to the secondary impurity removal solution" specifically means that H2O2 is added in multiple portions as the reaction proceeds, with a predetermined amount added every 15-20 minutes.

[0063] Specifically, the H2O2 is added evenly in three parts. When the temperature of the secondary impurity removal solution reaches 50-55℃, the H2O2 is added for the first time. When the temperature of the secondary impurity removal solution reaches the reaction temperature, the H2O2 is added for the second and third times, with a time interval between the second and third additions.

[0064] Specifically, you can add them as shown in Table 1:

[0065] Table 1

[0066]

[0067] The initial addition of H2O2 initiates a gentle decomposition at low temperature, creating an oxidizing environment with low reactive oxygen concentration. This breaks down the complex, allowing tartaric acid to be partially decomposed and free Mn to be released. 2+ After re-establishing equilibrium, heating and adding H2O2 further decompose the complex, significantly reducing the risk of manganese oxidation. Simultaneously, adding the H2O2 in batches avoids localized high-concentration zones, thus minimizing the oxidation of Mn. 2+ Exponential growth.

[0068] S6 Calcium and magnesium ion removal: Add ammonium fluoride (NH4F) to the solution containing manganese ions, filter to remove calcium and magnesium ions, filter again, let stand for 24 hours, filter again to obtain manganese sulfate solution.

[0069] The reaction temperature is 70℃, F - With Ca 2+ The molar ratio of the components is 2:1, and the reaction is carried out to remove magnesium ions and calcium ions. The magnesium ion content in the system is less than 3 ppm, and the calcium ion content is less than 5 ppm.

[0070] The manganese ion loss rate in the final manganese sulfate solution is reduced by 3-4.5% compared to the existing technology without manganese ion protection, and the heavy metal content in the manganese sulfate solution is much lower than 2 ppma.

[0071] This invention first allows tartaric acid to preferentially react with Mn. 2+ Complexation reduces its reactivity without affecting subsequent electrolysis, while citric acid maintains a reducing atmosphere throughout the process, preventing Mn from being absorbed. 2+ Oxidized to Mn 4+ Most heavy metals are then removed using inexpensive MnS that does not introduce sodium ions, followed by SDD to further remove heavy metals, bringing the heavy metal content down to the ppm level and reducing heavy metal impurities. After impurity removal, H2O2 is used to break down the complexes and restore Mn. 2+ Electrochemical activity is used to ensure electrolysis efficiency, and finally, the difference in ionic radii is utilized to repel Mn during CaF2 / MgF2 crystallization. 2+ This allows for selective separation, reducing manganese loss from the traditional 3-5% to below 0.5%, while ensuring that heavy metal impurities are stably controlled below 0.2 ppm.

[0072] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the invention. Those skilled in the art will understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A method for preparing an electrolyte for electrolytic manganese metal, characterized by, Includes the following steps: S1 leaching: Manganese ore powder and sulfuric acid are reacted and filtered to obtain crude manganese sulfate solution; S2 pretreatment: the manganese sulfate crude liquid is pretreated by a protective agent to generate a mixed complex solution to protect Mn 2+ from being oxidized S3 Iron Ion Removal: Manganese oxide and calcium carbonate are added to the mixed complex solution to react and generate iron hydroxide precipitate. The solution is then filtered to obtain a primary impurity removal solution. S4 heavy metal impurity removal: impurities are removed by adding an impurity removal agent to the primary impurity removal solution to remove Ni 2+ , Co 2+ , Cu 2+ , Zn 2+ , Cd 2+ , Pb 2+ , and filtered to obtain a secondary impurity removal solution; S5 Manganese ion reduction: Add H2O2 to the secondary impurity removal solution to release manganese ions and obtain a solution containing manganese ions; S6 Calcium and Magnesium Ion Removal: Add ammonium fluoride to a solution containing manganese ions, filter to remove calcium and magnesium ions, and then filter again to obtain a manganese sulfate solution.

2. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 1, characterized by, In S2, the protective agent is tartaric acid or ascorbic acid.

3. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 2, characterized by, In step S5, the pH of the added H2O2 is 2.0-3.0, the mass concentration of the H2O2 is 30%, and the amount of H2O2 added is 1.5-2 times the amount of tartaric acid added.

4. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 3, characterized by, In S5, the reaction time is 0.5h-1h and the reaction temperature is 55℃-70℃.

5. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 4, characterized in that, "Adding H2O2 to the secondary impurity removal solution" specifically means that H2O2 is added in multiple portions as the reaction proceeds, with a predetermined amount added every 15-20 minutes.

6. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 5, characterized in that, The H2O2 is added in three stages. The H2O2 is added for the first time when the temperature of the secondary impurity removal solution reaches 50-55℃, and the H2O2 is added for the second and third times when the temperature of the secondary impurity removal solution reaches the reaction temperature.

7. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 2, characterized in that, In step S2, the tartaric acid reacts with the Mn in the crude manganese sulfate solution. 2+ The mass ratio is 1:40-50, and the mass ratio of tartaric acid to ascorbic acid is 9-10:

1.

8. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 6, characterized in that, In S2, the reaction temperature is 55-65℃ and the reaction time is 10min-30min.

9. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 1, characterized in that, In step S4, the impurity removal agent is sodium thiram or manganese sulfide; Adding a purification agent to the primary purification solution specifically includes: pre-purification and fine purification. The pre-removal process involves adding manganese sulfide to the primary removal solution and filtering to pre-remove Ni. 2+ Co 2+ Cu 2+ Cd 2+ A pre-purified solution was obtained; The fine purification process involves adding sodium fumarate to the pre-purification solution, filtering, and removing residual heavy metals to the ppm level to obtain a secondary purification solution.

10. The method for preparing an electrolyte solution for electrolytic manganese metal according to claim 9, characterized in that, characterized in that, In the pre-purification process, the reaction temperature is 65℃-75℃ and the reaction time is 1h-1.5h. In the fine purification process, the reaction temperature is 53℃-65℃ and the reaction time is 0.5h-1h.

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