Electrolytic manganese metal raw material mixing iron removal process

Abstract

The invention relates to the technical field of iron removal of electrolytic manganese metal raw materials, and discloses an electrolytic manganese metal raw material mixing iron removal process which comprises the following steps: S1, pretreating a manganese metal raw material, S2, detecting the iron content of the manganese metal raw material, S3, calculating the iron content, S4, preparing a solution, S5, adding an iron removal reagent, and S6, generating a precipitate and separating the precipitate: slowly dropwise adding a sodium hydroxide solution to adjust the pH value of the solution, and ferrous ions are separated from the solution in the form of ferrous hydroxide precipitate through filtration. The iron content in each batch of mixed electrolytic manganese metal raw materials is calculated through a titration method, the use amount of the required iron removal agent manganese powder in the reaction of the manganese metal raw materials can be accurately calculated, the situation that the final product quality is affected due to incomplete iron removal caused by insufficient addition of the iron removal agent is effectively avoided, and the effect of accurate iron removal is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of iron removal of electrolytic manganese raw materials, in particular to a mixed iron removal process of electrolytic manganese raw materials. Background Art

[0002] Electrolytic manganese is an indispensable key raw material in many important industrial fields. However, the raw materials used for production usually contain iron impurities, which seriously affects the purity and performance of the product and greatly limits its performance in high-end applications. In order to increase the production of electrolytic manganese, mixed feeding can make full use of each batch of raw materials and avoid the increased cost of separate treatment due to excessively high or low iron content in individual batches. Therefore, it is necessary to calculate the iron content of each batch of raw materials through measurement to improve the iron removal effect.

[0003] However, most of the metallic manganese is mixed in the process of iron removal, and it is difficult to measure the iron content of different batches of raw materials separately. Production decisions will become blind, and it is impossible to accurately judge when the amount of iron removal reagent needs to be adjusted, resulting in reduced iron removal effect and waste of resources. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a mixed iron removal process for electrolytic manganese raw materials, which solves the problem of being unable to accurately judge when the amount of iron removal reagent needs to be adjusted, resulting in reduced iron removal effect and waste of resources.

[0005] To achieve the above objectives, the present invention is implemented by the following technical scheme: a process for removing iron from electrolytic manganese raw materials by mixing, comprising the following method steps:

[0006] S1: Pretreatment of manganese metal raw materials

[0007] The manganese ore mined in different batches is crushed into particles, placed separately, and the mass of each batch of manganese ore is calculated;

[0008] S2: Detection of iron content in manganese metal raw materials

[0009] Take each batch of manganese ore samples and put them in a conical flask, then add hydrochloric acid, heat to completely dissolve them, then add stannous chloride solution to reduce trivalent iron to divalent iron, and remove the unreacted stannous chloride by oxidation with mercuric chloride to obtain a sample solution, add sulfuric acid and phosphoric acid mixed acid, which is prepared by mixing sulfuric acid and phosphoric acid in proportion, adjust the acidity of the solution, then add sodium diphenylamine sulfonate indicator, and titrate with potassium dichromate standard solution until the solution presents a stable purple-red color as the end point;

[0010] S3: Calculate iron content

[0011]

[0012] in:

[0013] C is the concentration of potassium dichromate standard solution (mol / L)

[0014] V is the volume of potassium dichromate standard solution consumed (mL)

[0015] 56 is the molar mass of iron (g / mol)

[0016] m is the mass of the electrolytic manganese raw material sample (g)

[0017] ω(Fe) is the iron content (%)

[0018] Then through

[0019] ω 平均 (Fe) is the average iron content of different batches of metallic manganese raw materials;

[0020] S4: Solution Preparation

[0021] The manganese ore raw material obtained in S1 is mixed into an acid-resistant reaction container, the temperature is controlled, sulfuric acid solution and ammonium chloride are added for acid leaching, and then stirred and mixed;

[0022] S5: Add iron removal reagent

[0023] The manganese metal solution obtained in S4 is added with an iron removal agent and stirred. The iron removal agent is composed of manganese powder. 3+ +Mn=2Fe 2+ +Mn 2+ The stoichiometric relationship is that the molar ratio of iron to manganese is 2:1, so the mass calculation formula of manganese powder to be added is obtained.

[0024] Where m 总 is the total mass of the electrolytic manganese raw material sample

[0025] 55 is the molar mass of manganese (g / mol);

[0026] S6: Precipitation Generation and Separation

[0027] Sodium hydroxide solution is slowly added dropwise to adjust the pH value of the solution, and the divalent iron ions are separated from the solution by filtration in the form of ferrous hydroxide precipitation.

[0028] Preferably, different batches of manganese ore in S1 are crushed and ground into particles between 100 mesh and 200 mesh, and impurities larger than 200 mesh are filtered out.

[0029] Preferably, 0.5-1.0 g of each batch of manganese ore particles is taken from S2, the conical flask has a capacity of 250 mL, the heating temperature is (40-70° C.), 20-30 ml of the hydrochloric acid solution is added, the volume ratio of hydrochloric acid to water is 1:1, the concentration of the stannous chloride solution is 50-60 g / L, 10-20 drops are added to the conical flask through a 20 drop / mL dropper, and the mixture is placed at a temperature of 20-25° C. for 2-3 minutes to react, the concentration of the mercuric chloride is about 7.4 g / 100 ml, and a sample solution is obtained after reacting with stannous chloride.

[0030] Preferably, the sulfur-phosphorus mixed acid in S2 is obtained by mixing 100-150mL sulfuric acid with 600-700mL and cooling it, then adding 100-150mL phosphoric acid and stirring it, and 3-4 drops of sodium diphenylamine sulfonate are added to the sample solution as a color developer, and the potassium dichromate standard solution is composed of potassium dichromate and water, and its concentration is 0.05mol / L.

[0031] Preferably, in S3, the iron content in each batch of metallic manganese raw material samples is calculated by titrating the volume V of the potassium dichromate standard solution, and then the average iron content of the metallic manganese raw materials in different batches is calculated.

[0032] Preferably, the acid-resistant reaction container in S4 is made of polytetrafluoroethylene, the temperature of which is controlled to 80-90°C, and a stirring device is provided inside the container. The concentration of the sulfuric acid solution is 2-4 mol / L, and the concentration of the ammonium chloride solution is 1-3 mol / L.

[0033] Preferably, in S5, a quantitative amount of manganese powder is added into the acid-resistant reaction container according to a calculation formula, and the manganese powder reduces trivalent iron ions to divalent iron ions.

[0034] Preferably, the sodium hydroxide solution in S6 is 1-5 mol / L, and the pH value in the acid-resistant reaction container is controlled to be maintained between 7-9.

[0035] The present invention provides a process for removing iron from electrolytic manganese raw materials by mixing them. It has the following beneficial effects:

[0036] 1. The present invention calculates the iron content in each batch of electrolytic manganese raw materials in the mixed feed by titration, and can accurately calculate the amount of iron removal agent manganese powder required for the reaction of the manganese raw materials, effectively avoiding incomplete iron removal due to insufficient addition of iron removal agent, affecting the quality of the final product, and achieving the effect of accurate iron removal.

[0037] 2. After clarifying the iron content in the raw materials, the present invention can accurately calculate the appropriate amount of the required iron removal agent based on it. If the iron content is low, the amount of iron removal agent can be reduced accordingly to avoid waste caused by excessive use of the iron removal agent, thereby achieving the effect of optimizing the iron removal process to the greatest extent and improving the utilization efficiency of resources.

[0038] 3. The present invention has concluded through experimental research that when measuring the iron content in the raw material, at 40°C, the dissolution rate of hydrochloric acid is relatively stable, which is convenient for the operator to better control the reaction process, and can more accurately observe and judge the changes in the reaction stage, and can reduce unnecessary oxidation of manganese elements and the formation of certain complex compounds, thereby improving the accuracy and reliability of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The present invention is a process flow chart of the mixed iron removal process of electrolytic manganese raw materials. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. 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 creative work are within the scope of protection of the present invention.

[0041] Please refer to the attached Figure 1 The embodiment of the present invention provides a process for removing iron from electrolytic manganese raw materials by mixing them, including the following method steps:

[0042] S1: Pretreatment of manganese metal raw materials

[0043] The manganese ore mined in different batches is crushed into particles, placed separately, and the mass of each batch of manganese ore is calculated;

[0044] S2: Detection of iron content in manganese metal raw materials

[0045] Take each batch of manganese ore samples and put them in a conical flask, then add hydrochloric acid, heat to completely dissolve them, then add stannous chloride solution to reduce trivalent iron to divalent iron, and remove the unreacted stannous chloride by oxidation with mercuric chloride to obtain a sample solution, add sulfuric acid and phosphoric acid mixed acid, which is prepared by mixing sulfuric acid and phosphoric acid in proportion, adjust the acidity of the solution, then add sodium diphenylamine sulfonate indicator, and titrate with potassium dichromate standard solution until the solution presents a stable purple-red color as the end point;

[0046] S3: Calculate iron content

[0047]

[0048] in:

[0049] C is the concentration of potassium dichromate standard solution (mol / L)

[0050] V is the volume of potassium dichromate standard solution consumed (mL)

[0051] 56 is the molar mass of iron (g / mol)

[0052] m is the mass of the electrolytic manganese raw material sample (g)

[0053] ω(Fe) is the iron content (%)

[0054] Then through

[0055] ω 平均 (Fe) is the average iron content of different batches of metallic manganese raw materials;

[0056] S4: Solution Preparation

[0057] The manganese ore raw material obtained in S1 is mixed into an acid-resistant reaction container, the temperature is controlled, sulfuric acid solution and ammonium chloride are added for acid leaching, and then stirred and mixed;

[0058] S5: Add iron removal reagent

[0059] The manganese metal solution obtained in S4 is added with an iron removal agent and stirred. The iron removal agent is composed of manganese powder. 3+ +Mn=2Fe 2+ +Mn 2+ The stoichiometric relationship is that the molar ratio of iron to manganese is 2:1, so the mass calculation formula of manganese powder to be added is obtained.

[0060] Where m 总 is the total mass of the electrolytic manganese raw material sample

[0061] 55 is the molar mass of manganese (g / mol);

[0062] S6: Precipitation Generation and Separation

[0063] Sodium hydroxide solution is slowly added dropwise to adjust the pH value of the solution, and the divalent iron ions are separated from the solution by filtration in the form of ferrous hydroxide precipitation.

[0064] Different batches of manganese ore in S1 are crushed and ground into particles between 100 mesh and 200 mesh, and impurities larger than 200 mesh are filtered out.

[0065] Specifically, different batches of manganese ore are crushed and ground into particles of uniform size, which effectively increases the subsequent reaction area of ​​manganese ore particles, and is beneficial to the consistency of subsequent processing and chemical reactions.

[0066] Take 0.5-1.0 g of each batch of manganese ore particles from S2, the conical flask has a capacity of 250 mL, the heating temperature is (40-70 ° C), 20-30 ml of hydrochloric acid solution is added, the volume ratio of hydrochloric acid to water is 1:1, the concentration of stannous chloride solution is 50-60 g / L, 10-20 drops are added to the conical flask through a 20 drop / mL dropper, and the reaction is allowed to stand at a temperature of 20-25 degrees for 2-3 minutes. The concentration of mercuric chloride is about 7.4 g / 100 ml, and the sample solution is obtained after reacting with stannous chloride.

[0067] Specifically, if the content of iron in each batch of manganese ore needs to be determined, 0.5-1.0 gram of manganese ore particles can be taken for testing, and the change in the volume of the solution can be visually seen through the conical flask, which is helpful for judging and controlling the reaction process. Hydrochloric acid can react chemically with the metallic manganese raw material sample. It has strong acidity, so that the iron and other components in the sample are converted into ionic state and enter the solution. Stannous chloride can reduce the trivalent iron ions in the solution to divalent iron ions. By placing it at a temperature of 20-25 degrees for 2-3 minutes for reaction, it can be ensured that the reduction reaction is fully carried out. After that, the excess stannous chloride can be reacted with mercuric chloride, thereby eliminating its interference with the subsequent sample solution titration determination, thereby ensuring the accuracy of the titration result.

[0068] The sulfur-phosphorus mixed acid in S2 is obtained by mixing 100-150 mL of sulfuric acid with 600-700 mL of sulfuric acid and cooling it, then adding 100-150 mL of phosphoric acid and stirring it, and 3-4 drops of sodium diphenylamine sulfonate are added to the sample solution as a color developer. The potassium dichromate standard solution is composed of potassium dichromate and water, and its concentration is 0.05 mol / L.

[0069] Specifically, the sulfur-phosphorus mixed acid can adjust the acidity of the solution, improve the oxidizing ability of potassium dichromate and ensure the smooth oxidation reaction of iron, while sodium diphenylamine sulfonate is an indicator in the titration process. With the addition of potassium dichromate standard solution, divalent iron ions can be gradually oxidized to trivalent iron ions. When approaching the titration endpoint, the excess potassium dichromate in the solution will oxidize the sodium diphenylamine sulfonate, turning it purple-red, thereby indicating that the titration has reached the endpoint.

[0070] In S3, the iron content in each batch of metallic manganese raw material samples is calculated by titrating the volume V of the potassium dichromate standard solution, and then the average iron content of the metallic manganese raw materials in different batches is calculated.

[0071] Specifically, when the indicated titration reaches the endpoint, the volume V of the potassium dichromate standard solution can be determined by observing the change in the scale in the conical flask before and after the potassium dichromate titration to measure the average iron content of different batches of metallic manganese raw materials, thereby selecting the manganese powder required for the quantitative and mixed manganese ore particles to react and avoiding excessive or insufficient placement of manganese powder.

[0072] The acid-resistant reaction vessel in S4 is made of polytetrafluoroethylene, and its temperature is controlled to 80-90°C. It is also equipped with a stirring device. The concentration of the sulfuric acid solution is 2-4 mol / L, and the concentration of the ammonium chloride solution is 1-3 mol / L.

[0073] Specifically, the acid-resistant reaction container made of polytetrafluoroethylene has excellent corrosion resistance, ensuring that the container will not be corroded and damaged during chemical reactions and high temperature processes. The sulfuric acid solution can react chemically with the manganese oxide in the manganese ore and convert it into soluble manganese ions. The ammonium chloride solution and sulfuric acid act synergistically to enhance the solubility of manganese ore and improve the leaching effect. At the same time, the temperature of 80-90°C and stirring can increase the thermal motion of molecules, accelerate the chemical reaction, and improve the leaching efficiency of manganese in the manganese ore.

[0074] In S5, a quantitative amount of manganese powder is added into the acid-resistant reaction container according to a calculation formula, and the manganese powder reduces the trivalent iron ions to divalent iron ions.

[0075] Specifically, a certain amount of manganese powder is added according to the average iron content of each batch of metallic manganese raw materials, so as to avoid waste caused by excessive manganese powder and incomplete iron removal caused by too little manganese powder. The trivalent iron ions with strong oxidizing property of manganese powder are converted into divalent iron ions with weaker oxidizing property, thereby changing the chemical properties of iron ions in the solution.

[0076] The sodium hydroxide solution in S6 is 1-5 mol / L, and the pH value in the acid-resistant reaction container is controlled to be maintained between 7 and 9.

[0077] Specifically, sodium hydroxide solution is added dropwise to adjust the pH value of the solution, so that the divalent iron ions form ferrous hydroxide precipitates, thereby separating the iron ions from the solution, thereby facilitating the purity of the subsequent electrolysis of metallic manganese.

[0078] The following is an introduction in conjunction with specific embodiments:

[0079] Embodiment 1

[0080] In S1: taking manganese ore mined in different batches and crushing them into particles of 100 mesh, placing them separately, and calculating the mass of each batch of manganese ore;

[0081] In S2: Take 0.5g of each batch of manganese ore particles and place them in a conical flask for measurement. Add 20ml of hydrochloric acid solution with a volume ratio of 1:1 into the conical flask, heat it at 40℃ to completely dissolve the sample, then add 50g / L stannous chloride solution again until the yellow color caused by the trivalent iron ions in the solution is completely faded, continue to add 2 drops, stand at 20℃ for 2 minutes to determine that the color of the solution does not change again, make it excessive, and then continue to add 10ml of saturated mercuric chloride solution and shake it. If the white filamentous precipitate no longer increases, the sample solution is obtained.

[0082] In S2: then add 20 ml of sulfuric acid and phosphoric acid and shake well, then add 3 drops of sodium diphenylamine sulfonate indicator, and then immediately titrate with potassium dichromate standard solution while shaking the conical flask until the solution shows a stable purple-red color as the end point, and record the volume of potassium dichromate solution consumed.

[0083] In S3: formula

[0084] in:

[0085] C is the concentration of potassium dichromate standard solution (mol / L)

[0086] V is the volume of potassium dichromate standard solution consumed (mL)

[0087] 56 is the molar mass of iron (g / mol)

[0088] m is the mass of the electrolytic manganese raw material sample (g)

[0089] ω(Fe) is the iron content (%)

[0090] Then through

[0091] ω 平均 (Fe) is the average iron content of different batches of metallic manganese raw materials, and the average iron content of the electrolytic metallic manganese raw materials is calculated.

[0092] In S4: all electrolytic manganese metal raw materials are placed in an acid-resistant reaction container, the temperature of which is controlled to 80° C. and stirred. Sulfuric acid solution is added to react chemically with manganese oxides in the manganese ore. The ammonium chloride solution and sulfuric acid act synergistically to enhance the dissolution capacity of the manganese ore and improve the leaching effect.

[0093] S5: Pass The total required mass of manganese powder is calculated to convert the ferric iron ions in the electrolytic manganese metal raw material in the acid-resistant reaction vessel into the less oxidizing ferrous iron ions.

[0094] In S6: the pH value is controlled to be maintained at 7 by adding 5 mol / L sodium hydroxide solution dropwise, so that the divalent iron ions form ferrous hydroxide precipitation, thereby achieving separation of the iron ions from the solution.

[0095] Embodiment 2

[0096] In S1: taking manganese ore mined in different batches and crushing them into particles between 200 meshes, placing them separately, and calculating the mass of each batch of manganese ore;

[0097] In S2: 1 g of manganese ore particles from each batch is taken and placed in a conical flask for measurement, 30 ml of a hydrochloric acid solution with a volume ratio of 1:1 is added to the conical flask, and heated at 70°C to completely dissolve the sample, and then a 60 g / L stannous chloride solution is added dropwise again until the yellow color caused by the trivalent iron ions in the solution is completely faded, and then 2 drops are added dropwise, and the solution is allowed to stand at 25°C for 3 minutes to determine that the color of the solution does not change again, so that it is excessive, and then 10 ml of a saturated mercuric chloride solution is continuously added dropwise and shaken. If the white filamentous precipitate no longer increases, a sample solution is obtained.

[0098] In S2: then add 20 ml of sulfuric acid and phosphoric acid and shake well, then add 3 drops of sodium diphenylamine sulfonate indicator, and then immediately titrate with potassium dichromate standard solution while shaking the conical flask until the solution shows a stable purple-red color as the end point, and record the volume of potassium dichromate solution consumed.

[0099] In S3: formula

[0100] in:

[0101] C is the concentration of potassium dichromate standard solution (mol / L)

[0102] V is the volume of potassium dichromate standard solution consumed (mL)

[0103] 56 is the molar mass of iron (g / mol)

[0104] m is the mass of the electrolytic manganese raw material sample (g)

[0105] ω(Fe) is the iron content (%)

[0106] Then through

[0107] ω 平均 (Fe) is the average iron content of different batches of metallic manganese raw materials, and the average iron content of the electrolytic metallic manganese raw materials is calculated.

[0108] In S4: all electrolytic manganese metal raw materials are placed in an acid-resistant reaction container, the temperature of which is controlled to 90° C. and stirred. Sulfuric acid solution is added to react chemically with manganese oxides in the manganese ore. The ammonium chloride solution and sulfuric acid act synergistically to enhance the dissolution capacity of the manganese ore and improve the leaching effect.

[0109] S5: Pass The total required mass of manganese powder is calculated to convert the ferric iron ions in the electrolytic manganese metal raw material in the acid-resistant reaction vessel into the less oxidizing ferrous iron ions.

[0110] In S6: the pH value is controlled to be maintained at 9 by adding 5 mol / L sodium hydroxide solution dropwise, so that the divalent iron ions form ferrous hydroxide precipitation, thereby achieving separation of the iron ions from the solution.

[0111] Table 1

[0112] Embodiment 1 Embodiment 2 Measurement temperature (℃) 40 degrees Celsius 70 degrees Celsius Iron removal reaction time Slow Longer Iron determination accuracy high middle Remaining amount of manganese powder after iron removal Low Lower Iron content of raw materials after iron removal Low Lower

[0113] At 40°C, the dissolution rate of hydrochloric acid is relatively stable, which can reduce unnecessary oxidation of manganese and the formation of certain complex compounds, thereby improving the accuracy and reliability of the measurement results. At 70°C, certain organic additives or impurities may decompose at high temperatures to produce substances that interfere with the measurement. At the same time, manganese may be oxidized into higher-valent manganese ions, thereby affecting the determination and subsequent treatment of manganese.

[0114] Although 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 the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for removing iron from electrolytic manganese raw materials by mixing, characterized in that: The method comprises the following steps: S1: Pretreatment of manganese metal raw materials The manganese ore mined in different batches is crushed into particles, placed separately, and the mass of each batch of manganese ore is calculated; S2: Detection of iron content in manganese metal raw materials Take each batch of manganese ore samples and place them in a conical flask, then add hydrochloric acid, heat (40-70°C) to completely dissolve them, then add stannous chloride solution to reduce trivalent iron to divalent iron, and remove the unreacted stannous chloride by oxidation with mercuric chloride to obtain a sample solution, add sulfuric acid and phosphoric acid mixed acid, which is prepared by mixing sulfuric acid and phosphoric acid in proportion, adjust the acidity of the solution, then add sodium diphenylamine sulfonate indicator, and titrate with potassium dichromate standard solution until the solution presents a stable purple-red color as the end point; S3: Calculate iron content in: C is the concentration of potassium dichromate standard solution (mol / L) V is the volume of potassium dichromate standard solution consumed (mL) 56 is the molar mass of iron (g / mol) m is the mass of the electrolytic manganese raw material sample (g) ω(Fe) is the iron content (%) Then through ω 平均 (Fe) is the average iron content of different batches of metallic manganese raw materials; S4: Solution Preparation The manganese ore raw material obtained in S1 is mixed into an acid-resistant reaction container, the temperature is controlled, sulfuric acid solution and ammonium chloride are added for acid leaching, and then stirred and mixed; S5: Add iron removal reagent The manganese metal solution obtained in S4 is added with an iron removal agent and stirred. The iron removal agent is composed of manganese powder. 3+ +Mn=2Fe 2+ +Mn 2+ Stoichiometric relationship, the molar ratio of iron to manganese is 2:1, then the mass of manganese powder that needs to be added is obtained. M n Calculation formula Where m 总 The total mass of electrolytic manganese metal raw materials 55 is the molar mass of manganese (g / mol); S6: Precipitation Generation and Separation Sodium hydroxide solution is slowly added dropwise to adjust the pH value of the solution, and the divalent iron ions are separated from the solution by filtration in the form of ferrous hydroxide precipitation.

2. The process for removing iron from electrolytic manganese raw materials by mixing according to claim 1, characterized in that: The different batches of manganese ores in S1 are crushed and ground into particles between 100 mesh and 200 mesh, and impurities larger than 200 mesh are filtered and discharged.

3. The process for removing iron from electrolytic manganese raw materials by mixing according to claim 1, characterized in that: 0.5-1.0 g of manganese ore particles from each batch are taken from S2, the conical flask has a capacity of 250 mL, the heating temperature is (40-70° C.), 20-30 ml of the hydrochloric acid solution is added, the volume ratio of hydrochloric acid to water is 1:1, the concentration of the stannous chloride solution is 50-60 g / L, 10-20 drops are added to the conical flask through a 20 drop / mL dropper, and the solution is placed at a temperature of 20-25 degrees for 2-3 minutes to react. The concentration of mercuric chloride is about 7.4 g / 100 ml, and a sample solution is obtained after reacting with stannous chloride.

4. The process for removing iron from electrolytic manganese raw materials by mixing according to claim 1, characterized in that: The sulfur-phosphorus mixed acid in S2 is obtained by mixing 100-150mL sulfuric acid with 600-700mL and cooling it, then adding 100-150mL phosphoric acid and stirring it, and 3-4 drops of sodium diphenylamine sulfonate are added to the sample solution as a color developer. The potassium dichromate standard solution is composed of potassium dichromate and water, and its concentration is 0.05mol / L.

5. The process for removing iron from electrolytic manganese raw materials by mixing according to claim 1, characterized in that: In S3, the iron content in each batch of metallic manganese raw material samples is calculated by titrating the volume V of the potassium dichromate standard solution, and then the average iron content of the metallic manganese raw materials in different batches is calculated.

6. The process for removing iron from electrolytic manganese raw materials by mixing according to claim 1, characterized in that: The acid-resistant reaction container in S4 is made of polytetrafluoroethylene, and its temperature is controlled to 80-90°C. It is also equipped with a stirring device. The concentration of the sulfuric acid solution is 2-4 mol / L, and the concentration of the ammonium chloride solution is 1-3 mol / L.

7. The process for removing iron from electrolytic manganese raw materials by mixing according to claim 1, characterized in that: In S5, a quantitative amount of manganese powder is added into the acid-resistant reaction container according to a calculation formula, and the manganese powder reduces trivalent iron ions to divalent iron ions.

8. The process for removing iron from electrolytic manganese raw materials by mixing according to claim 1, characterized in that: The sodium hydroxide solution in S6 is 1-5 mol / L, and the pH value in the acid-resistant reaction container is controlled to be maintained between 7-9.

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