A method for recovering manganese from electrolytic manganese anode slime by using ammonium sulfate composite flux

Abstract

This invention discloses a method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux. The recovery is carried out according to the following steps: (1) The manganese anode mud is dried, crushed, dry-ground, and sieved to obtain an electrolytic manganese anode mud sample; (2) The electrolytic manganese anode mud sample is mixed evenly with ammonium sulfate composite flux, spread in a crucible, placed in the middle of a quartz tube in a tube furnace, inert gas is introduced to drive out the air, and gas is supplied throughout the roasting process for protection. The power is turned on, and the furnace temperature is raised to 150°C. Then, constant temperature roasting is started, and the furnace temperature is raised to 320°C for constant temperature roasting. The furnace temperature is raised to 550°C for constant temperature roasting. After roasting, the furnace is naturally cooled to room temperature. The roasting residue sample is carefully removed, and deionized water is added to leach manganese sulfate at room temperature. The residue is filtered and separated to obtain crude manganese sulfate solution and leaching residue. This method significantly reduces the roasting temperature and roasting time, realizing rapid extraction of leached manganese from electrolytic manganese anode mud at a lower cost.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive utilization of solid waste resources, and specifically relates to a method for recovering manganese by treating electrolytic manganese anode mud using ammonium sulfate composite flux. Background Technology

[0002] Electrolytic manganese anode slime is a byproduct rich in manganese, lead, and other metals generated during the electrolytic manganese production process. Its treatment and resource utilization have always been a focus of industry attention. Electrolytic manganese anode slime has a high manganese content, typically 20%–50%, mainly in the form of MnO2 (manganese dioxide), with some Mn3O4 (manganese tetroxide) or low-valent manganese oxides (such as MnO). Simultaneously, the lead content is approximately 10%–30%, primarily from associated lead in manganese ore or corrosion of the anode plate (lead alloy) during electrolysis, existing in the form of PbO2 (lead dioxide), PbSO4 (lead sulfate), or PbO (lead oxide). It also contains 1%–10% iron and other trace metals such as tin, copper, and nickel. Industrially, it is generally used as a raw material for pyrolusite, employing methods such as iron powder reduction, ferrous sulfate reduction leaching, two-ore roasting and water leaching, or a one-step two-ore process to produce manganese sulfate. However, regardless of the method used, the high valence state of manganese in electrolytic manganese anode mud is stable, and the low reduction efficiency leads to a low manganese recovery rate. The simultaneous dissolution and separation of lead is difficult, and the purification process conditions are harsh, making the purification of the leachate difficult. Landfilling electrolytic manganese anode mud not only wastes resources but also easily pollutes the environment. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux. This significantly reduces the roasting temperature and time, enabling rapid extraction and leaching of manganese from electrolytic manganese anode mud at a lower cost.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux, characterized by the following steps:

[0005] (1) The manganese anode mud was dried, crushed, dry-ground and screened to obtain an electrolytic manganese anode mud sample;

[0006] (2) Mix the electrolytic manganese anode mud sample with ammonium sulfate composite flux evenly, spread it in a crucible, place it in the middle of the quartz tube in a tube furnace, introduce inert gas to purge the air and supply gas throughout the roasting process for protection, start the power supply, raise the furnace temperature to 150℃ at a heating rate of 10-15℃ / min, then start constant temperature roasting for 5-10 min, continue to raise the furnace temperature to 320℃ at a heating rate of 10-15℃ / min, maintain constant temperature roasting for 5-10 min, and continue... The furnace temperature was raised to 550℃ at a heating rate of 20-25℃ / min, and calcined at a constant temperature for 15-20 minutes. After calcination, the sample was allowed to cool naturally to room temperature. The calcined residue sample was then removed, and deionized water was added to leach manganese sulfate at room temperature. The residue was filtered and separated to obtain crude manganese sulfate solution and leaching residue. The mass ratio of electrolytic manganese anode mud sample to ammonium sulfate composite flux was 1.5-2.5:1. The ammonium sulfate composite flux was composed of 88%-92% ammonium sulfate and 8%-12% urea.

[0007] (3) Add metallic manganese powder to the crude manganese sulfate solution, react at room temperature, and filter; add ammonium sulfide to the filtrate, react at room temperature, and filter; add flocculant to the filtrate, precipitate, and filter; add ammonia water to the filtrate to adjust the pH to 6-7, add citric acid to react at room temperature, and filter to separate and obtain purified solution.

[0008] (4) Add ammonium bicarbonate to the purified liquid, react at 40-60℃, filter to obtain manganese carbonate and ammonium sulfate solution, and evaporate the ammonium sulfate solution for recycling.

[0009] In the above scheme: manganese carbonate is washed with deionized water 3 to 5 times and then calcined at a high temperature of 830 to 1000°C to obtain solid manganese tetroxide. After being crushed or sand-milled, the solid manganese tetroxide is washed with deionized water and dried to obtain battery-grade manganese tetroxide.

[0010] In the above scheme: the electrolytic manganese anode mud is dried at 100-110℃.

[0011] In the above scheme: the electrolytic manganese anode mud is crushed into particles with a diameter ≤80μm and sieved through a 200-mesh sieve.

[0012] In the above scheme: the inert gas is nitrogen, and the flow rate is 2.0 to 3.0 L / min.

[0013] In the above scheme: during leaching, the amount of deionized water added is 8 to 12 times the mass of the electrolytic manganese anode mud, and the leaching time is 50 to 70 minutes.

[0014] In the above scheme: the amount of metallic manganese powder added is 2‰ to 3‰ of the electrolytic manganese anode mud; the amount of ammonium sulfide added is 1‰ to 2‰ of the mass of the electrolytic furnace manganese iron slag.

[0015] In the above scheme: the flocculant is polyacrylamide, and the amount added is 1‰ to 2‰ of the mass of electrolytic manganese anode mud.

[0016] In the above scheme, the amount of citric acid added is 1.5‰ to 2‰.

[0017] In electrolytic manganese anode mud, manganese mainly exists in the form of MnO2. Without the protection of an inert gas, due to the effect of oxygen in the air, using ammonium sulfate as a single flux cannot completely sulfate MnO2 to MnSO4. Regardless of whether acid leaching or alkali leaching is subsequently used, the large presence of MnO2 leads to a low manganese leaching rate. Usually, the amount of ammonium sulfate is increased to generate a large amount of ammonia through the decomposition of ammonium sulfate to isolate the oxidation of oxygen in the air and enhance the sulfation process of MnO2. However, the effect is still limited. Even when using a composite flux of ammonium sulfate (with the addition of a reducing agent), it is still necessary to increase the amount of composite flux to compensate for the ammonium sulfate. At the same time, it is also necessary to use the atmosphere generated by the reducing agent to prevent the oxidation of oxygen in the air. This invention utilizes inert gas-protected roasting. Because it is free from interference from atmospheric oxygen, the amount of ammonium sulfate consumed is significantly reduced, resulting in a near 100% sulfation utilization rate. Sulfation is achieved within a very short roasting time. Adding a small amount of urea to the ammonium sulfate creates a eutectic point between urea and ammonium sulfate, lowering the flow temperature of the composite flux. Furthermore, the early formation of a large amount of gas (ammonia and carbon dioxide) in the mixed sample accelerates heat transfer, further improving heat utilization efficiency. The generation of a large amount of reducing ammonia reduces high-valence manganese in the electrolytic manganese anode mud to low-valence manganese, promoting manganese sulfate formation and accelerating the reaction process. To remove iron impurities during roasting, the final roasting temperature is increased to 550℃. At this high temperature, manganese sulfate does not decompose, while ferric sulfate decomposes into iron oxide in a short time, and some other metallic impurities (sulfates) also partially decompose. During sulfation, impurities such as lead, calcium, and barium form insoluble sulfates, thus achieving the removal of the main metallic impurities during roasting.

[0018] In the subsequent wet purification process, metallic manganese powder is added to the crude manganese sulfate solution. The trace metal ions such as lead, iron, cobalt, nickel, copper, and zinc remaining in the crude manganese sulfate solution are reduced to metals and separated by filtration. Ammonium sulfide is added to the filtrate to further remove the residual trace metal ions. Polyacrylamide is added to the filtrate to remove the residual aluminum and silicon. Citric acid is added to the filtrate so that the residual magnesium ions in the solution can combine with the citric acid and be removed in the subsequent ammonium bicarbonate precipitation process.

[0019] Beneficial effects:

[0020] (1) By adopting the above technical solution, the roasting temperature and roasting time are greatly reduced, and the leaching manganese can be rapidly extracted from the electrolytic manganese anode mud at a lower cost.

[0021] (2) Using the above technical solution, the recovery rate of leached manganese extracted from electrolytic manganese anode mud is high and stable at over 98%, which is much higher than the 85% recovery rate of the existing ammonium sulfate roasting technology.

[0022] (3) By adopting the above technical solution, the low-temperature roasting and water immersion, as well as the shortening of the process flow, the dual goals of energy conservation at the source and emission reduction are achieved, which is a key path to promote the green and low-carbon transformation of industry.

[0023] (4) By adopting the above technical solution, a large number of impurities are removed during the roasting process, which reduces the pressure of subsequent wet impurity removal. The high-purity manganese tetroxide obtained can meet the requirements of high-end applications. Detailed Implementation

[0024] The present invention will be further described below with reference to embodiments.

[0025] Example 1

[0026] Electrolytic manganese anode mud with a manganese content of 28.5% was dried at 100–110℃, crushed into particles with a diameter ≤80μm, dry-ground, and sieved (through a 200-mesh sieve) to obtain an electrolytic manganese anode mud sample. 100g of the electrolytic manganese anode mud sample was mixed evenly with 40g of ammonium sulfate composite flux. The ammonium sulfate composite flux was composed of 92% ammonium sulfate and 8% urea. The sample was spread evenly in a square corundum crucible and placed in the middle of the quartz tube in a tube furnace. Nitrogen gas was introduced to purge the air, and then nitrogen was supplied throughout the roasting process for protection. The inert gas was nitrogen, with a flow rate of 2.0–3.0 L / min. The power was turned on, and the furnace temperature was raised to 150°C at a rate of 15°C / min. Then, constant temperature roasting was started for 8 minutes. The furnace temperature was raised to 320°C at a rate of 10°C / min and constant temperature roasting was started for 10 minutes. The furnace temperature was raised to 550°C at a rate of 25°C / min and constant temperature roasting was started for 15 minutes. After roasting, the sample was allowed to cool naturally to room temperature. The roasted residue sample was carefully removed, and 1000 g of deionized water was added and leached at room temperature for 60 minutes. The residue was filtered and separated to obtain crude manganese sulfate solution and leaching residue. 0.2 g of metallic manganese powder was added to the crude manganese sulfate solution, and the reaction was carried out at room temperature for 30 min. After filtration and separation, 0.1 g of ammonium sulfide was added to the filtrate, and the reaction was carried out at room temperature for 15 min. After filtration and separation, 0.2 g of polyacrylamide was added to the filtrate, and the reaction was carried out for 30 min. After precipitation and filtration and separation, ammonia water was added to adjust the pH to 6.8, and 0.2 g of citric acid was added. The reaction was carried out at room temperature for 15 min. After filtration and separation, 60 g of ammonium bicarbonate was added to the filtrate to obtain a manganese carbonate and ammonium sulfate solution. The ammonium sulfate solution was evaporated to recover ammonium sulfate. The manganese carbonate was washed three times with deionized water and then calcined at 920℃ to obtain solid manganese tetroxide. The solid manganese tetroxide was crushed or sand-milled, washed with deionized water, and dried to obtain high-purity manganese tetroxide. The recovery rate of manganese in the manganese anode mud was 98.78%, and the purity of manganese tetroxide was 99.85%.

[0027] Example 2

[0028] Electrolytic manganese anode mud with a manganese content of 31.1% was dried at 100–110℃, crushed into particles with a diameter ≤80μm, dry-ground, and sieved (through a 200-mesh sieve) to obtain an electrolytic manganese anode mud sample. 100g of the electrolytic manganese anode mud sample was mixed evenly with 50g of ammonium sulfate composite flux, which was composed of 88% ammonium sulfate and 12% urea. The sample was spread evenly in a square corundum crucible and placed in the middle of the quartz tube in a tube furnace. Nitrogen gas was introduced to purge the air, and then nitrogen was supplied throughout the roasting process for protection. The inert gas was nitrogen, with a flow rate of 2.0–3.0 L / min. The power was turned on, and the furnace temperature was raised to 150°C at a rate of 10°C / min. Then, constant temperature roasting was started for 10 min. The furnace temperature was raised to 320°C at a rate of 10°C / min and constant temperature roasting was started for 6 min. The furnace temperature was raised to 550°C at a rate of 20°C / min and constant temperature roasting was started for 18 min. After roasting, the sample was allowed to cool naturally to room temperature. The roasted residue sample was carefully removed, and 1200 g of deionized water was added and leached at room temperature for 70 min. The residue was filtered and separated to obtain crude manganese sulfate solution and leaching residue. 0.25 g of metallic manganese powder was added to the crude manganese sulfate solution, and the reaction was carried out at room temperature for 30 min. After filtration, 0.16 g of ammonium sulfide was added to the filtrate, and the reaction was carried out at room temperature for 15 min. After filtration, 0.18 g of polyacrylamide was added to the filtrate, and the reaction was carried out for 30 min. After precipitation and filtration, the pH was adjusted to 6.6 with ammonia water, and 0.15 g of citric acid was added. The reaction was carried out at room temperature for 15 min, and the reaction was carried out. After filtration, 65 g of ammonium bicarbonate was added to the filtrate to obtain a manganese carbonate and ammonium sulfate solution. The ammonium sulfate solution was evaporated to recover ammonium sulfate. The manganese carbonate was washed five times with deionized water and then calcined at 920℃ to obtain solid manganese tetroxide. The solid manganese tetroxide was crushed or sand-milled, washed with deionized water, and dried to obtain high-purity manganese tetroxide. The recovery rate of manganese in the manganese anode mud was 98.56%, and the purity of manganese tetroxide was 99.81%.

[0029] Example 3

[0030] Electrolytic manganese anode mud with a manganese content of 40.3% was dried at 100–110°C, crushed into particles with a diameter ≤80μm, dry-ground, and sieved (through a 200-mesh sieve) to obtain an electrolytic manganese anode mud sample. 100g of the electrolytic manganese anode mud sample was mixed evenly with 66g of ammonium sulfate composite flux, which was composed of 90% ammonium sulfate and 10% urea. The sample was spread evenly in a square corundum crucible and placed in the middle of the quartz tube in a tube furnace. Nitrogen gas was introduced to purge the air, and then nitrogen was supplied throughout the roasting process for protection. The inert gas was nitrogen, with a flow rate of 2.0–3.0 L / min. The power was turned on, and the furnace temperature was raised to 150°C at a rate of 12°C / min. Then, it was roasted at a constant temperature for 5 minutes. The furnace temperature was then raised to 320°C at a rate of 10°C / min and roasted at a constant temperature for 5 minutes. The furnace temperature was then raised to 550°C at a rate of 25°C / min and roasted at a constant temperature for 15 minutes. After roasting, the sample was allowed to cool naturally to room temperature. The roasted residue sample was carefully removed, and 800 g of deionized water was added and leached at room temperature for 70 minutes. The residue was then filtered and separated to obtain crude manganese sulfate solution and leaching residue. 0.3 g of metallic manganese powder was added to the crude manganese sulfate solution, and the reaction was carried out at room temperature for 30 min. After filtration, 0.2 g of ammonium sulfide was added to the filtrate, and the reaction was carried out at room temperature for 15 min. After filtration, 0.1 g of polyacrylamide was added to the filtrate, and the reaction was carried out for 30 min. After precipitation and filtration, ammonia water was added to adjust the pH to 6.3, and 0.18 g of citric acid was added. The reaction was carried out at room temperature for 15 min, and the reaction was carried out at room temperature. After filtration, 85 g of ammonium bicarbonate was added to the filtrate to obtain a manganese carbonate and ammonium sulfate solution. The ammonium sulfate solution was evaporated to recover ammonium sulfate. The manganese carbonate was washed five times with deionized water and then calcined at 920℃ to obtain solid manganese tetroxide. The solid manganese tetroxide was crushed or sand-milled, washed with deionized water, and dried to obtain high-purity manganese tetroxide. The recovery rate of manganese in the manganese anode mud was 99.30%, and the purity of manganese tetroxide was 99.87%.

[0031] Example 4

[0032] Electrolytic manganese anode mud with a manganese content of 28.5% was dried at 100–110℃, crushed into particles with a diameter ≤80μm, dry-ground, and passed through a 200-mesh sieve to obtain an electrolytic manganese anode mud sample. 100g of the electrolytic manganese anode mud sample was mixed evenly with 200g of ammonium sulfate composite flux. The ammonium sulfate composite flux was composed of 92% ammonium sulfate and 8% urea. The sample was spread evenly in a square corundum crucible and placed in the middle of the quartz tube in a tube furnace. The furnace temperature was increased to 150°C at a heating rate of 15°C / min, and then constant-temperature roasting was started for 8 minutes. The furnace temperature was then increased to 320°C at a heating rate of 10°C / min and constant-temperature roasting was started for 10 minutes. The furnace temperature was then increased to 550°C at a heating rate of 25°C / min and constant-temperature roasting was started for 15 minutes. After roasting, the sample was allowed to cool naturally to room temperature. The roasted residue sample was carefully removed, and 1000g of deionized water was added and leached at room temperature for 60 minutes. The residue was then filtered and separated to obtain crude manganese sulfate solution and leaching residue. 0.2 g of metallic manganese powder was added to the crude manganese sulfate solution, and the reaction was carried out at room temperature for 30 min. After filtration and separation, 0.1 g of ammonium sulfide was added to the filtrate, and the reaction was carried out at room temperature for 15 min. After filtration and separation, 0.2 g of polyacrylamide was added to the filtrate, and the reaction was carried out for 30 min. After precipitation and filtration and separation, ammonia water was added to adjust the pH to 6.8, and 0.2 g of citric acid was added. The reaction was carried out at room temperature for 15 min. After filtration and separation, 60 g of ammonium bicarbonate was added to the filtrate to obtain a manganese carbonate and ammonium sulfate solution. The ammonium sulfate solution was evaporated to recover ammonium sulfate. The manganese carbonate was washed three times with deionized water and then calcined at 920℃ to obtain solid manganese tetroxide. The solid manganese tetroxide was crushed or sand-milled, washed with deionized water, and dried to obtain high-purity manganese tetroxide. The recovery rate of manganese in the manganese anode mud was 80.76%, and the purity of manganese tetroxide was 99.84%.

[0033] Example 5

[0034] Electrolytic manganese anode mud with a manganese content of 31.1% was dried at 100–110°C, crushed into particles with a diameter ≤80 μm, dry-ground, and passed through a 200-mesh sieve to obtain an electrolytic manganese anode mud sample. 100 g of the electrolytic manganese anode mud sample was mixed evenly with 50 g of ammonium sulfate composite flux. The ammonium sulfate composite flux was composed of 92% ammonium sulfate and 8% urea. The sample was spread evenly in a square corundum crucible and placed in the middle of the quartz tube in a tube furnace. The furnace temperature was increased to 150°C at a heating rate of 15°C / min, and then constant-temperature roasting was started for 8 minutes. The furnace temperature was then increased to 320°C at a heating rate of 10°C / min and constant-temperature roasting was started for 10 minutes. The furnace temperature was then increased to 550°C at a heating rate of 25°C / min and constant-temperature roasting was started for 15 minutes. After roasting, the sample was allowed to cool naturally to room temperature. The roasted residue sample was carefully removed, and 1000g of deionized water was added and leached at room temperature for 60 minutes. The residue was then filtered and separated to obtain crude manganese sulfate solution and leaching residue. 0.25 g of metallic manganese powder was added to the crude manganese sulfate solution, and the reaction was carried out at room temperature for 30 min. After filtration and separation, 0.16 g of ammonium sulfide was added to the filtrate, and the reaction was carried out at room temperature for 15 min. After filtration and separation, 0.2 g of polyacrylamide was added to the filtrate, and the reaction was carried out for 30 min. After precipitation and filtration and separation, ammonia water was added to adjust the pH to 6.6, and 0.15 g of citric acid was added. The reaction was carried out at room temperature for 15 min. After filtration and separation, 65 g of ammonium bicarbonate was added to the filtrate to obtain a manganese carbonate and ammonium sulfate solution. The ammonium sulfate solution was evaporated to recover ammonium sulfate. The manganese carbonate was washed three times with deionized water and then calcined at 920℃ to obtain solid manganese tetroxide. The solid manganese tetroxide was crushed or sand-milled, washed with deionized water, and dried to obtain high-purity manganese tetroxide. The recovery rate of manganese in the manganese anode mud was 76.90%, and the purity of manganese tetroxide was 99.72%.

[0035] This invention is not limited to the above embodiments. Those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this invention. The scope of this invention is defined by the claims and their equivalents.

Claims

1. A method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux, characterized in that, Follow these steps to recycle: (1) The manganese anode mud was dried, crushed, dry-ground and sieved to obtain electrolytic manganese anode mud samples; (2) Mix the electrolytic manganese anode mud sample with ammonium sulfate composite flux evenly, spread it in a crucible, place it in the middle of the quartz tube in a tube furnace, introduce inert gas to purge the air and supply gas throughout the roasting process for protection, start the power supply, raise the furnace temperature to 150℃ at a heating rate of 10-15℃ / min, then start constant temperature roasting for 5-10 min, continue to raise the furnace temperature to 320℃ at a heating rate of 10-15℃ / min, maintain constant temperature roasting for 5-10 min, continue to raise the furnace temperature to 550℃ at a heating rate of 20-25℃ / min, and maintain constant temperature roasting for 15-20 min. After roasting for min, the residue was naturally cooled to room temperature. The roasted residue sample was then removed, and deionized water was added to leach manganese sulfate at room temperature. The residue was filtered and separated to obtain crude manganese sulfate solution and leaching residue. The mass ratio of electrolytic manganese anode mud sample to ammonium sulfate composite flux was 1.5–2.5:

1. The ammonium sulfate composite flux was composed of 88%–92% ammonium sulfate and 8%–12% urea. (3) Add metallic manganese powder to the crude manganese sulfate solution, react at room temperature, and filter; add ammonium sulfide to the filtrate, react at room temperature, and filter; add flocculant to the filtrate, precipitate, and filter; add ammonia water to the filtrate to adjust the pH to 6-7, add citric acid to react at room temperature, and filter to separate and obtain purified solution. (4) Add ammonium bicarbonate to the purified liquid, react at 40~60℃, filter to obtain manganese carbonate and ammonium sulfate solution, and evaporate the ammonium sulfate solution for recycling.

2. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 1, characterized in that: Manganese carbonate is washed with deionized water 3 to 5 times and then calcined at a high temperature of 830 to 1000°C to obtain solid manganese tetroxide. After being crushed or sand-milled, solid manganese tetroxide is washed with deionized water and dried to obtain battery-grade manganese tetroxide.

3. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 1 or 2, characterized in that: The electrolytic manganese anode mud is dried at 100–110°C.

4. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 3, characterized in that: The electrolytic manganese anode mud is crushed into particles with a diameter ≤80μm and sieved through a 200-mesh sieve.

5. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 4, characterized in that: The inert gas is nitrogen, and the flow rate is 2.0–3.0 L / min.

6. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 5, characterized in that: During leaching, the amount of deionized water added is 8 to 12 times the mass of the electrolytic manganese anode mud, and the leaching time is 50 to 70 minutes.

7. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 6, characterized in that: The amount of metallic manganese powder added is 2‰ to 3‰ of the electrolytic manganese anode mud; the amount of ammonium sulfide added is 1‰ to 2‰ of the mass of the electrolytic manganese anode mud.

8. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 7, characterized in that: The flocculant is polyacrylamide, and the amount added is 1‰ to 2‰ of the mass of electrolytic manganese anode mud.

9. The method for recovering manganese from electrolytic manganese anode mud using ammonium sulfate composite flux according to claim 8, characterized in that: The amount of citric acid added is 1.5‰ to 2‰.