Method for recovering nickel and cobalt metals in high-manganese-based black powder

Abstract

The invention belongs to the field of nickel and cobalt metallurgy, and discloses a method for recovering nickel and cobalt metals in high-manganese-based black powder. According to the method disclosed by the invention, nickel and cobalt are completely converted into sulfate by utilizing a sulfating roasting process, and then nickel, cobalt and manganese completely enter an aqueous solution in an ionic state by utilizing a high-temperature water quenching method. In the process, nickel and cobalt are completely converted into high valence states by utilizing the weak oxidizability of the alkaline wastewater, and precipitation is carried out by virtue of the alkaline wastewater added in the process, so that nickel and cobalt and a small amount of manganese enter slag in the form of high-valence hydroxide, and most of manganese exists in the solution in the form of ions. By utilizing the process, the purpose of preferentially separating nickel and cobalt from the high-manganese-based battery black powder is achieved.

Description

Technical Field

[0001] The invention belongs to the field of hydrometallurgy and discloses a method for recovering nickel and cobalt metals in high-manganese-based black powder. Background Art

[0002] At present, with the continuous increase in the number of retired batteries, the nickel and cobalt resources in waste batteries have become a powerful supplement to mine resources. In the future, the nickel and cobalt resources needed in the new energy battery field will mainly rely on the nickel and cobalt in retired batteries for supplementation.

[0003] At present, there are many types of waste batteries in the field of retired battery recycling, including most high-manganese-based retired batteries. The percentage of manganese in the black powder produced by this part of retired batteries can reach about 35%, and the percentage of nickel and cobalt can only reach 3-5%. In terms of conventional recycling processes, this type of retired battery recycling is often carried out by wet full immersion, iron removal, P204 impurity removal, and P507 nickel-cobalt separation. However, for high-manganese-based battery black powder materials, manganese is the main metal element component in battery black powder materials, and the content of manganese and nickel and cobalt in the leachate is very different. In the process of cobalt metal recovery and purification, the separation of manganese, nickel and cobalt mainly adopts the P204 multi-stage countercurrent extraction process. For materials with a relatively large proportion of manganese metal, it is necessary to ensure a longer extraction stage to ensure the nickel-cobalt-manganese separation effect. In high manganese-based battery black powder, the percentage of manganese is 3-4 times that of nickel and cobalt combined. This requires the P204 extraction process to use a larger extraction flow ratio to ensure the extraction of manganese, and rely on a longer extraction stage to ensure the complete separation of nickel, cobalt and manganese. Since the value of manganese metal is not high, this recovery process is not economical.

[0004] The present invention adopts a sulfation roasting process to make sulfuric acid fully react with the ternary battery black powder material, so that the nickel, cobalt and manganese in the ternary battery black powder material are all converted into sulfates. Subsequently, the weakly oxidizing alkaline wastewater produced by the company's existing cobalt metallurgical system is used to react with the roasted material. During the reaction process, the nickel and cobalt metals are converted into trivalent ions under weakly oxidizing conditions and react with the hydroxide in the alkaline wastewater. Finally, the nickel and cobalt are separated from most of the manganese in the solution in the form of precipitation. After the above-mentioned roasting and alkali leaching process, the precipitate produced will contain a large amount of nickel and cobalt and a small amount of manganese metal. The purpose of separating nickel and cobalt from high manganese-based black powder can be achieved through the above-mentioned process. Summary of the invention

[0005] The purpose of the present invention is to preferentially and economically extract nickel and cobalt from high manganese-based battery black powder and provide a method for recovering nickel and cobalt metals from high manganese-based black powder.

[0006] To this end, the present invention provides the following technical solutions: The method for recovering nickel and cobalt metals from high manganese-based black powder of the present invention comprises the following steps: (1) Fully mix the high manganese-based battery black powder with concentrated sulfuric acid, and calcine the mixed material at a high temperature of 450-650°C for 1-3 hours; quickly transfer the calcined material into weak oxidizing alkaline wastewater in an uncooled state, and continue to stir. During the reaction process, the reaction temperature is controlled at 65-75°C, and stirring is continued for 2-3 hours. During the reaction process, weak oxidizing alkaline wastewater is slowly added to control the end point pH to 3.5-4.5; The mass percentage of each element in the high manganese-based black powder is C 30-40%, Mn 25-40%, Ni 3-5%, and Co 3-5%. The solid-liquid ratio of the manganese-based battery black powder to concentrated sulfuric acid is 1:1-2 (g / mL); the weak oxidizing alkaline wastewater is alkaline wastewater with a concentration of 1-2% sodium hypochlorite and a pH of 9-10.

[0007] (2) After the reaction is completed, the filter is washed with water, and the filter residue produced by filtration is slurried and dissolved and leached; the solid-liquid ratio is controlled to be 1:3-5 during slurrying, the pH of the dissolution and leaching process is controlled to be 1.0, and the pH of the dissolution and leaching end point is controlled to be 1.5; after the dissolution is completed, a high-concentration nickel-cobalt leaching solution is obtained. When the cobalt content in the filter residue produced by filtration is less than 0.2% and the nickel content is less than 0.2%, it indicates that nickel and cobalt have been preferentially extracted.

[0008] In the sulfation roasting process of the present invention, nickel, cobalt and manganese in the black powder react with sulfuric acid and are converted into corresponding forms of sulfates. In the oxidation precipitation process, the weakly oxidizing waste alkali reacts with nickel and cobalt first, so that nickel and cobalt are separated from most of the manganese in the form of precipitation. In the nickel-cobalt slag dissolution process, nickel and cobalt enter the solution in the form of ions under acidic leaching conditions, and cooperate with the subsequent conventional nickel-cobalt wet recovery process to achieve the purpose of preparing a nickel-cobalt salt solution.

[0009] Compared with the prior art, the present invention has the following beneficial effects: 1. The weak alkaline oxidation precipitation process is used to achieve the purpose of using the existing system alkaline wastewater to preferentially separate manganese and nickel and cobalt. The alkaline wastewater is reused to effectively reduce the cost of alkaline wastewater treatment.

[0010] 2. The preferential separation of manganese and nickel and cobalt avoids the large amount of liquid alkali consumption caused by the traditional P204 extraction and separation process for separating nickel, cobalt and manganese, and effectively reduces the cost of recovering nickel and cobalt from high-manganese-based battery black powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The figure is a process flow chart for recovering nickel and cobalt metals from high manganese-based black powder of the present invention. DETAILED DESCRIPTION

[0012] Example 1 (1) The elemental composition of the high manganese-based battery black powder used in this example is: Mn 35.26%, Ni 4.6%, Co 4.4%, Cu 2.1%. Weigh 500 g of the high manganese-based battery black powder and 600 mL of concentrated sulfuric acid, mix thoroughly, and transfer to a 2L experimental alumina test boat.

[0013] (2) The experimental boat was placed in a muffle furnace and calcined at 500°C for 2 h. After the calcination, a steel shovel was used to transfer the material in the boat to an iron reaction tank containing 2.1 L of weakly oxidizing alkaline wastewater. The sodium hypochlorite concentration in the weakly oxidizing alkaline wastewater was 1.1% and the pH was 9.

[0014] (3) Start stirring and control the reaction temperature to 70°C during the reaction process to ensure that the solution in the reaction tank reacts continuously for more than 2 hours. During the reaction, slowly add weakly oxidizing alkaline wastewater according to the pH of the solution to ensure that the pH at the reaction endpoint is 3.5.

[0015] (4) Filter the above solution, rinse the filter residue with fresh water, place the filter residue in a beaker and add fresh water to slurry, ensuring that the slurry liquid-to-solid ratio is 3.5:1, then start stirring to dissolve and leach, and raise the temperature to 70°C, then slowly add concentrated sulfuric acid to continue the reaction, control the pH of the dissolution process to 1.0, add an appropriate amount of sodium metabisulfite to the end of the reaction, control the pH of the dissolution end to 1.5, ensure that the dissolved solution is clear and free of black residue, and take samples for analysis.

[0016] According to the analysis results, the obtained leaching solution has a cobalt content of 45.2g / L, a nickel content of 47.5g / L, and a manganese content of 2.5g / L; the obtained leaching residue has a cobalt content of 0.10%, a nickel content of 0.12%, and a manganese content of 38.5%. The above experimental results show that the process of sulfuric acid roasting + alkaline wastewater leaching can achieve the preferential extraction of metal nickel and cobalt from high manganese-based battery black powder.

[0017] Example 2 (1) The elemental composition of the high manganese-based battery black powder used in this example is: Mn 35.26%, Ni 4.6%, Co 4.4%, Cu 2.1%. Weigh 500g of the high iron zinc cobalt sulfide recovery material powder and 500mL of concentrated sulfuric acid, mix them thoroughly, and transfer them to a 2L experimental alumina test boat.

[0018] (2) Place the test boat in a muffle furnace and calcine at 550°C for 2 h. After calcination, use a steel shovel to transfer the material in the boat to an iron reaction tank containing 2.5 L of weakly oxidizing alkaline wastewater, where the sodium hypochlorite concentration is 1.2% and the pH is 10.

[0019] (3) Start stirring and control the reaction temperature to 70°C during the reaction process to ensure that the solution in the reaction tank reacts continuously for more than 2 hours. During the reaction, slowly add weakly oxidizing alkaline wastewater according to the pH of the solution to ensure that the pH at the reaction endpoint is 4.0.

[0020] (4) Filter the above solution, rinse the filter residue with fresh water, place the filter residue in a beaker and add fresh water to slurry, ensuring that the slurry liquid-to-solid ratio is 4:1, then start stirring and increase the temperature to 70°C, then slowly add concentrated sulfuric acid to continue the reaction, control the pH of the dissolution process to 1.0, add an appropriate amount of sodium metabisulfite to the end of the reaction, control the pH of the dissolution end to 1.5, ensure that the dissolved solution is clear and free of black residue, and take samples for analysis.

[0021] According to the analysis results, the obtained leaching solution has a cobalt content of 42.2g / L, a nickel content of 44.5g / L, and a manganese content of 2.6g / L; the obtained leaching residue has a cobalt content of 0.15%, a nickel content of 0.16%, and a manganese content of 39.5%. The above experimental results show that the process of sulfuric acid roasting + alkaline wastewater leaching can achieve the preferential extraction of metal nickel and cobalt from high manganese-based battery black powder.

[0022] In summary, the method of the present invention uses a sulfation roasting process to convert nickel, cobalt and manganese in the mixed acid black powder into sulfates of the corresponding metals, and cooperates with a water quenching process to convert nickel and cobalt ions into high-valent ions under weak oxidizing conditions and react with the alkaline wastewater used for water quenching to produce a corresponding form of hydroxide precipitation. In this process, manganese ions are preferentially oxidized and precipitated due to their higher oxidizing properties than nickel and cobalt ions, and a large amount of manganese exists in the solution. This process achieves the purpose of preferentially separating nickel and cobalt from high-manganese-based black powder, and achieves preferential extraction of nickel and cobalt.

[0023] The above are preferred embodiments of the present invention. Any simple modification, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for recovering nickel and cobalt metals from high manganese-based black powder, characterized in that: The following steps are involved: (1) Fully mix the high manganese-based battery black powder with concentrated sulfuric acid, and calcine the mixed material at a high temperature of 450-650°C; quickly transfer the calcined material into weak oxidizing alkaline wastewater in an uncooled state, and continue to stir. During the reaction process, the reaction temperature is controlled at 65-75°C, and stirring is continued for 2-3 hours. During the reaction process, weak oxidizing alkaline wastewater is slowly added to control the end point pH to 3.5-4.5; (2) After the reaction is completed, the filter is filtered and washed with water, and the filter residue produced by the filtration is slurried and dissolved and leached; the solid-liquid ratio is controlled to be 1:3-5 during the slurrying, the pH of the dissolution and leaching process is controlled to be 1.0, and the pH of the dissolution and leaching end point is controlled to be 1.5; after the dissolution and leaching are completed, a nickel-cobalt leaching solution is obtained.

2. The method for recovering nickel and cobalt metals from high manganese-based black powder according to claim 1, characterized in that: In step (1), the mass percentage of each element in the high manganese-based black powder is C 30-40%, Mn 25-40%, Ni 3-5%, and Co 3-5%.

3. The method for recovering nickel and cobalt metals in high manganese-based black powder according to claim 1, characterized in that: In step (1), the solid-liquid ratio of manganese-based battery black powder to concentrated sulfuric acid is 1:1-2.

4. The method for recovering nickel and cobalt metals from high manganese-based black powder according to claim 1, characterized in that: In step (1), the high temperature calcination time is 1-3 hours.

5. The method for recovering nickel and cobalt metals from high manganese-based black powder according to claim 1, characterized in that: In step (1), the weakly oxidizing alkaline wastewater is alkaline wastewater with a mass concentration of 1-2% sodium hypochlorite and a pH of 9-10.

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