A method for efficiently recovering cobalt and nickel from spent lithium battery extract.
By using sodium oxalate solution back-extraction and pH-adjusted precipitation, cobalt and nickel can be efficiently recovered from lithium battery extract, solving the problems of low cobalt and nickel recovery efficiency and environmental pollution, and achieving efficient and low-cost cobalt and nickel recovery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- BEIJING UNIV OF TECH
- Filing Date
- 2023-02-20
- Publication Date
- 2026-05-26
AI Technical Summary
In existing technologies, the recycling efficiency of cobalt and nickel in lithium batteries is low, and traditional methods are complex and costly, leading to resource waste and environmental pollution.
Cobalt and nickel were extracted from a nickel-cobalt-containing extract using sodium oxalate solution back-extraction. After pH adjustment and drying, cobalt oxalate and nickel oxalate products were obtained, simplifying the process and reducing equipment corrosion risks and environmental pollution.
It improves the recycling rate of cobalt and nickel, reduces operating costs, and achieves environmentally friendly and efficient recycling. The back-extraction rate of cobalt and nickel reaches over 97%, and the product purity is high.
Smart Images
Figure CN116190842B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of hydrometallurgical technology, and in particular relates to a method for efficiently recovering cobalt and nickel from the extract of waste lithium batteries. Background Technology
[0002] In an era where decarbonizing energy and transportation systems has become one of the most important international challenges, lithium-ion batteries, due to their excellent energy storage capacity, are widely used in electronic devices, electric vehicles, renewable energy storage, and other applications, which can reduce the transportation industry's dependence on fossil fuels. The total market for automotive lithium batteries alone is projected to reach $221 billion by 2024. However, according to global average recycling content (RC) data and their widespread application, transition metals rank first among all recycled elements (especially nickel and cobalt), which will lead to the depletion of natural resources. The increase in lithium-ion battery production will result in severe shortages of lithium, nickel, and cobalt, and the large amount of discarded lithium-ion batteries will also seriously pollute the environment. At the same time, the content and purity of precious metals are higher than in nature. Without recycling, this will result in enormous resource waste, which contradicts the principles of clean energy and resource utilization. Among lithium battery recycling methods, solvent extraction is widely used for metal separation due to its simple operation, high recovery rate, and good adjustability.
[0003] CN112251604A discloses a method for recovering valuable metals from the comprehensive recycling residue of waste lithium cobalt oxide batteries. After extraction and separation, the recovery rate of lithium can reach 98%, but resources such as cobalt and nickel remain in the extract during the extraction process and are not further utilized. CN111206148A discloses a method for preparing ternary cathode materials from waste ternary lithium batteries. Cobalt and nickel ions are extracted into the extract, and cobalt sulfate and nickel sulfate are obtained by sulfuric acid back-extraction. Finally, cobalt and nickel are recovered by adding sodium hydroxide and ammonia for co-precipitation. This recycling process is complex, and the large consumption of acid reagents causes equipment corrosion. CN112095000A discloses a method for recovering cobalt and lithium metals from waste lithium cobalt oxide batteries. Cobalt is extracted into the extract using an organic extractant, and then cobalt sulfate is obtained by adding sulfuric acid solution to the extract. Finally, alkaline solution is added for precipitation. This recycling method is relatively complex, and the residual acidic and alkaline solutions are not environmentally friendly. Therefore, in response to the problems of insufficient recovery of cobalt and nickel and the environmental pollution caused by the use of large amounts of acid and alkali solutions in the recovery process, it is crucial to develop a simple, efficient, low-cost, and environmentally friendly back-extraction process. Summary of the Invention
[0004] To address the aforementioned problems, this invention employs a method for efficiently recovering cobalt and nickel from waste lithium battery extract. Using sodium oxalate solution, the extract containing nickel and cobalt is back-extracted to obtain a back-extract, which is then precipitated by adjusting the pH. After drying, cobalt oxalate and nickel oxalate products are finally obtained. This method is environmentally friendly and has low operating costs. Furthermore, this process not only reduces equipment corrosion but also improves the reuse rate of cobalt and nickel and regenerates the extract.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] (1) Preparation of sodium oxalate solution: Sodium oxalate is added to ultrapure water, then placed in a water bath and heated and stirred continuously, and finally a transparent solution is obtained by ultrasound.
[0007] (2) The sodium oxalate solution obtained in step (1) is added to the nickel-cobalt extract for thorough mixing and back-extraction. After centrifugation and phase separation, the upper layer is the regenerated extract and the lower layer is the back-extraction solution containing nickel and cobalt.
[0008] (3) Continuously add oxalic acid powder to the nickel-cobalt-containing back-extraction solution obtained in step (2) until the pH of the nickel-cobalt-containing back-extraction solution is 1 to 2. After stirring and filtering, a pink filter residue and a nickel-containing back-extraction solution are obtained.
[0009] (4) Wash the pink filter residue obtained in step (3) repeatedly with anhydrous ethanol and ultrapure water, and dry the washed pink filter residue in a constant temperature oven to obtain pink powder.
[0010] (5) Add sodium bicarbonate powder continuously to the nickel-containing back-extraction solution obtained in step (3) until pH = 6.5-75, and obtain light green filter residue after stirring and filtration;
[0011] (6) Wash the light green filter residue obtained in step (5) repeatedly with anhydrous ethanol and ultrapure water.
[0012] The residue was dried in a constant temperature oven to obtain a light green powder.
[0013] Furthermore, the concentration of the sodium oxalate solution prepared in step (1) is 0.15–0.25 mol / L, the water bath temperature is 60°C, and the stirring speed is 120 r / min;
[0014] Further, in step (2), the cobalt content in the nickel-cobalt extract is 5-7 g / L, the nickel content is 13-15 g / L, the volume ratio of the nickel-cobalt extract to the sodium oxalate solution is 1:3-1:5, the extraction temperature is 15-35℃, the extraction stage is 1 stage, the mixing and stirring time is 15-30 min, the mixing and stirring speed is 300-600 r / min, and after the nickel-cobalt extract and sodium oxalate are thoroughly mixed, they are placed in a centrifuge for phase separation. The centrifugation speed is 5000-8000 r / min, and the centrifugation time is 15-30 min. Finally, the upper layer is the regenerated extract, and the lower layer is the nickel-cobalt-containing back-extraction solution.
[0015] Furthermore, in step (3), the pH of the nickel-cobalt back-extraction solution is adjusted to 1-2, and the stirring speed is 100-150 r / min;
[0016] Furthermore, in step (4), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water 3 to 5 times and drying in an oven at 60 to 80°C is cobalt oxalate.
[0017] Furthermore, in step (5), the pH of the nickel-containing back-extraction solution is adjusted to 6.5–7.5, and the stirring speed is 100–150 r / min;
[0018] Furthermore, in step (6), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water 3 to 5 times and drying in an oven at a temperature of 60 to 80°C is nickel oxalate. Attached Figure Description
[0019] Figure 1 The process flow diagram is provided by the present invention for the efficient recovery of cobalt and nickel from waste lithium battery extract.
[0020] The present invention will be further described in detail below with reference to examples. However, the examples below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be determined by the claims. Detailed Implementation
[0021] To better illustrate the present invention and facilitate understanding of its technical solutions, typical but non-limiting embodiments of the present invention are as follows:
[0022] Example 1
[0023] This embodiment provides a method for efficient recovery of cobalt and nickel from waste lithium battery extract, as follows: Figure 1 As shown.
[0024] The components of the waste lithium battery extract in this embodiment are as follows:
[0025] element Ni Co Content (g / L) 13.12 5.03
[0026] The separation and recovery method described in this embodiment is characterized in that the concentration of the sodium oxalate solution prepared in step (1) is 0.15 mol / L, the water bath temperature is 60℃, and the stirring speed is 120 r / min;
[0027] The separation and recovery method described in this embodiment is characterized in that, in step (2), the cobalt content in the nickel-cobalt extract is 5.03 g / L, the nickel content is 13.12 g / L, the volume ratio of the nickel-cobalt extract to the sodium oxalate solution is 1:5, the extraction temperature is 15℃, the extraction stage is 1 stage, the mixing and stirring time is 15 min, and the mixing and stirring speed is 300 r / min.
[0028] The nickel-cobalt extract and sodium oxalate solution were thoroughly mixed and then separated in a centrifuge at a speed of 5000 r / min.
[0029] The centrifugation time was 15 min, and the final upper layer was the regenerated extract, while the lower layer was the nickel-cobalt back-extract.
[0030] The separation and recovery method described in this embodiment is characterized in that oxalic acid powder is continuously added to the nickel-cobalt-containing back-extraction solution obtained in step (2) until the pH of the nickel-cobalt-containing back-extraction solution is 1, and the stirring speed is 100 r / min.
[0031] The separation and recovery method described in this embodiment is characterized in that, in step (4), anhydrous ethanol is used.
[0032] After washing three times with ultrapure water and drying in an oven at 60°C, the resulting pink powder is cobalt oxalate.
[0033] The separation and recovery method described in this embodiment is characterized by the following steps: [The method involves feeding the nickel-containing reaction mixture obtained in step (3) into the reaction mixture...]
[0034] Sodium bicarbonate powder was continuously added to the extract until the pH reached 6.5, and the stirring speed was 100 r / min.
[0035] The separation and recovery method described in this embodiment is characterized in that, in step (6), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water three times and drying in an oven at 60°C is nickel oxalate.
[0036] The results of the back-extraction recovery experiment in Example 1 are as follows:
[0037] element Extract concentration (g / L) Raffinate concentration (g / L) Back-extraction rate Ni 13.12 0.37 97.16％ Co 5.03 0.09 98.21％
[0038] In this embodiment, after single-stage extraction, the back-extraction rates of nickel and cobalt both reached over 97%, and the purity of the recovered cobalt oxalate and nickel oxalate reached 93.47% and 98.01%, respectively, thus achieving effective recovery of cobalt and nickel from waste lithium battery extract.
[0039] Example 2
[0040] This embodiment provides a method for efficient recovery of cobalt and nickel from waste lithium battery extract, as follows: Figure 1 As shown.
[0041] The components of the waste lithium battery extract in this embodiment are as follows:
[0042] element Ni Co Content (g / L) 13.73 5.47
[0043] The separation and recovery method described in this embodiment is characterized in that the concentration of the sodium oxalate solution prepared in step (1) is 0.15 mol / L, the water bath temperature is 60℃, and the stirring speed is 120 r / min;
[0044] The separation and recovery method described in this embodiment is characterized in that, in step (2), the cobalt content in the nickel-cobalt extract is 5.47 g / L, the nickel content is 13.73 g / L, the volume ratio of the nickel-cobalt extract to the sodium oxalate solution is 1:5, the extraction temperature is 20°C, the extraction stage is 1, the mixing and stirring time is 20 min, the mixing and stirring speed is 400 r / min, and after the nickel-cobalt extract and sodium oxalate are thoroughly mixed, they are placed in a centrifuge for phase separation. The centrifugation speed is 6000 r / min, and the centrifugation time is 20 min. Finally, the upper layer is the regenerated extract, and the lower layer is the nickel-cobalt-containing back-extraction solution.
[0045] The separation and recovery method described in this embodiment is characterized in that oxalic acid powder is continuously added to the nickel-cobalt-containing back-extraction solution obtained in step (2) until the pH of the nickel-cobalt-containing back-extraction solution is 1, and the stirring speed is 100 r / min.
[0046] The separation and recovery method described in this embodiment is characterized in that, in step (4), anhydrous ethanol is used.
[0047] After washing three times with ultrapure water and drying in an oven at 60°C, the resulting pink powder is cobalt oxalate.
[0048] The separation and recovery method described in this embodiment is characterized by the following steps: [The method involves feeding the nickel-containing reaction mixture obtained in step (3) into the reaction mixture...]
[0049] Sodium bicarbonate powder was continuously added to the extract until the pH reached 6.5, and the stirring speed was 100 r / min.
[0050] The separation and recovery method described in this embodiment is characterized in that, in step (6), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water three times and drying in an oven at 60°C is nickel oxalate.
[0051] The results of the back-extraction recovery experiment in Example 2 are as follows:
[0052] element Extract concentration (g / L) Raffinate concentration (g / L) Back-extraction rate Ni 13.73 0.43 96.88％ Co 5.47 0.01 98.05％
[0053] In this embodiment, after single-stage extraction, the back-extraction rates of nickel and cobalt both reached over 96%, and the purity of the recovered cobalt oxalate and nickel oxalate reached 93.98% and 97.80%, respectively, thus achieving effective recovery of cobalt and nickel from waste lithium battery extract.
[0054] Example 3
[0055] This embodiment provides a method for efficient recovery of cobalt and nickel from waste lithium battery extract, as follows: Figure 1 As shown.
[0056] The components of the waste lithium battery extract in this embodiment are as follows:
[0057] element Ni Co Content (g / L) 14.11 5.89
[0058] The separation and recovery method described in this embodiment is characterized in that the concentration of the sodium oxalate solution prepared in step (1) is 0.20 mol / L, the water bath temperature is 60℃, and the stirring speed is 120 r / min;
[0059] The separation and recovery method described in this embodiment is characterized in that, in step (2), the cobalt content in the nickel-cobalt extract is 5.89 g / L, the nickel content is 14.11 g / L, the volume ratio of the nickel-cobalt extract to the sodium oxalate solution is 1:4, the extraction temperature is 20℃, the extraction stage is 1, the mixing and stirring time is 20 min, the mixing and stirring speed is 400 r / min, and after the nickel-cobalt extract and sodium oxalate are thoroughly mixed, they are placed in a centrifuge for phase separation. The centrifugation speed is 6000 r / min, and the centrifugation time is 20 min. Finally, the upper layer is the regenerated extract, and the lower layer is the nickel-cobalt-containing back-extraction solution.
[0060] The separation and recovery method described in this embodiment is characterized in that oxalic acid powder is continuously added to the nickel-cobalt-containing back-extraction solution obtained in step (2) until the pH of the nickel-cobalt-containing back-extraction solution is 1, and the stirring speed is 110 r / min.
[0061] The separation and recovery method described in this embodiment is characterized in that, in step (4), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water four times and drying in an oven at 70°C is cobalt oxalate.
[0062] The separation and recovery method described in this embodiment is characterized in that sodium bicarbonate powder is continuously added to the nickel-containing back-extraction solution obtained in step (3) until pH = 7.0, and the stirring speed is 110 r / min;
[0063] The separation and recovery method described in this embodiment is characterized in that, in step (6), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water four times and drying in an oven at 70°C is nickel oxalate.
[0064] The results of the back-extraction recovery experiment in Example 3 are as follows:
[0065] element Extract concentration (g / L) Raffinate concentration (g / L) Back-extraction rate Ni 14.11 0.48 96.59％ Co 5.89 0.11 98.08％
[0066] In this embodiment, after single-stage extraction, the back-extraction rates of nickel and cobalt both reached over 96%, and the purity of the recovered cobalt oxalate and nickel oxalate reached 92.81% and 97.55%, respectively, thus achieving effective recovery of cobalt and nickel from waste lithium battery extract.
[0067] Example 4
[0068] This embodiment provides a method for efficient recovery of cobalt and nickel from waste lithium battery extract, as follows: Figure 1 As shown.
[0069] The components of the waste lithium battery extract in this embodiment are as follows:
[0070] element Ni Co Content (g / L) 14.62 6.53
[0071] The separation and recovery method described in this embodiment is characterized in that the concentration of the sodium oxalate solution prepared in step (1) is 0.20 mol / L, the water bath temperature is 60℃, and the stirring speed is 120 r / min;
[0072] The separation and recovery method described in this embodiment is characterized in that, in step (2), the cobalt content in the nickel-cobalt extract is 6.53 g / L, the nickel content is 14.62 g / L, the volume ratio of the nickel-cobalt extract to the sodium oxalate solution is 1:3, the extraction temperature is 35℃, the extraction stage is 1, the mixing and stirring time is 25 min, the mixing and stirring speed is 500 r / min, and after the nickel-cobalt extract and sodium oxalate are thoroughly mixed, they are placed in a centrifuge for phase separation. The centrifugation speed is 7000 r / min, and the centrifugation time is 25 min. Finally, the upper layer is the regenerated extract, and the lower layer is the nickel-cobalt-containing back-extraction solution.
[0073] The separation and recovery method described in this embodiment is characterized in that oxalic acid powder is continuously added to the nickel-cobalt-containing back-extraction solution obtained in step (2) until the pH of the nickel-cobalt-containing back-extraction solution is 2, and the stirring speed is 140 r / min.
[0074] The separation and recovery method described in this embodiment is characterized in that, in step (4), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water four times and drying in an oven at 70°C is cobalt oxalate.
[0075] The separation and recovery method described in this embodiment is characterized in that sodium bicarbonate powder is continuously added to the nickel-containing back-extraction solution obtained in step (3) until pH = 7.0, and the stirring speed is 140 r / min;
[0076] The separation and recovery method described in this embodiment is characterized in that, in step (6), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water four times and drying in an oven at 70°C is nickel oxalate.
[0077] The results of the back-extraction recovery experiment in Example 4 are as follows:
[0078] element Extract concentration (g / L) Raffinate concentration (g / L) Back-extraction rate Ni 14.62 0.49 96.65％ Co 6.53 0.12 98.20％
[0079] In this embodiment, after single-stage extraction, the back-extraction rates of nickel and cobalt both reached over 96%, and the purity of the recovered cobalt oxalate and nickel oxalate reached 93.15% and 98.27%, respectively, thus achieving effective recovery of cobalt and nickel from waste lithium battery extract.
[0080] Example 5
[0081] This embodiment provides a method for efficient recovery of cobalt and nickel from waste lithium battery extract, as follows: Figure 1 As shown.
[0082] The components of the waste lithium battery extract in this embodiment are as follows:
[0083] element Ni Co Content (g / L) 14.95 6.88
[0084] The separation and recovery method described in this embodiment is characterized in that the concentration of the sodium oxalate solution prepared in step (1) is 0.25 mol / L, the water bath temperature is 60℃, and the stirring speed is 120 r / min;
[0085] The separation and recovery method described in this embodiment is characterized in that, in step (2), the cobalt content in the nickel-cobalt extract is 6.88 g / L, the nickel content is 14.95 g / L, the volume ratio of the nickel-cobalt extract to the sodium oxalate solution is 1:3, the extraction temperature is 25°C, the extraction stage is 1, the mixing and stirring time is 30 min, the mixing and stirring speed is 600 r / min, and after the nickel-cobalt extract and sodium oxalate are thoroughly mixed, they are placed in a centrifuge for phase separation. The centrifugation speed is 8000 r / min, and the centrifugation time is 30 min. Finally, the upper layer is the regenerated extract, and the lower layer is the nickel-cobalt-containing back-extraction solution.
[0086] The separation and recovery method described in this embodiment is characterized in that oxalic acid powder is continuously added to the nickel-cobalt-containing back-extraction solution obtained in step (2) until the pH of the nickel-cobalt-containing back-extraction solution is 2, and the stirring speed is 150 r / min.
[0087] The separation and recovery method described in this embodiment is characterized in that, in step (4), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water five times and drying in an oven at 80°C is cobalt oxalate.
[0088] The separation and recovery method described in this embodiment is characterized in that sodium bicarbonate powder is continuously added to the nickel-containing back-extraction solution obtained in step (3) until pH = 7.5, and the stirring speed is 150 r / min;
[0089] The separation and recovery method described in this embodiment is characterized in that, in step (6), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water five times and drying in an oven at 80°C is nickel oxalate.
[0090] The results of the back-extraction recovery experiment in Example 5 are as follows:
[0091] element Extract concentration (g / L) Raffinate concentration (g / L) Back-extraction rate Ni 14.95 0.48 96.78％ Co 6.88 0.08 98.84％
[0092] In this embodiment, after single-stage extraction, the back-extraction rates of nickel and cobalt both reached over 96%, and the purity of the recovered cobalt oxalate and nickel oxalate reached 94.92% and 98.51%, respectively, thus achieving effective recovery of cobalt and nickel from waste lithium battery extract.
Claims
1. A method for efficiently recovering nickel and cobalt from waste lithium battery extract, characterized in that, Includes the following steps: (1) Preparation of sodium oxalate solution: Add sodium oxalate solid to ultrapure water, then place it in a water bath and heat and stir continuously at a stirring speed of 120 r / min. Finally, obtain a transparent solution by ultrasound. The water bath temperature is 60℃ and the sodium oxalate solution concentration is 0.15~0.25mol / L. (2) The sodium oxalate solution obtained in step (1) is added to the nickel-cobalt extract for thorough mixing and back-extraction. The mixing speed is 300~600 r / min. The mixture is then centrifuged and separated into phases at a speed of 5000~8000 r / min for 15~30 min. The upper layer is the regenerated extract and the lower layer is the back-extraction liquid containing nickel and cobalt. The nickel-cobalt extract contains 5~7 g / L of cobalt and 13~15 g / L of nickel. The volume ratio of the nickel-cobalt extract to the sodium oxalate solution is 1:3~1:
5. The extraction temperature is 15~35℃. The extraction stage is 1 stage. The mixing time is 15~30 min. (3) Continuously add oxalic acid powder to the nickel-cobalt-containing back-extraction solution obtained in step (2) until the pH of the nickel-cobalt-containing back-extraction solution is 1~2. After stirring and filtering, a pink filter residue and a nickel-containing back-extraction solution are obtained. (4) Wash the pink filter residue obtained in step (3) repeatedly with anhydrous ethanol and ultrapure water, and dry the washed pink filter residue in a constant temperature oven to obtain pink powder. (5) Add sodium bicarbonate powder continuously to the nickel-containing back-extraction solution obtained in step (3) until the pH = 6.5~7.5, and after stirring and filtering, a light green filter residue is obtained; (6) Wash the light green filter residue obtained in step (5) repeatedly with anhydrous ethanol and ultrapure water. Place the washed light green filter residue in a constant temperature oven to dry and obtain light green powder. The obtained light green powder is nickel oxalate.
2. The method for efficiently recovering nickel and cobalt from waste lithium battery extract according to claim 1, characterized in that, In step (3), the stirring speed is 100~150 r / min.
3. The method for efficiently recovering nickel and cobalt from waste lithium battery extract according to claim 1, characterized in that, In step (4), the powder obtained by repeatedly washing with anhydrous ethanol and ultrapure water 3 to 5 times and drying in an oven at 60 to 80°C is cobalt oxalate.
4. The method for efficiently recovering nickel and cobalt from waste lithium battery extract according to claim 1, characterized in that, In step (5), the stirring speed is 100~150 r / min.
5. The method for efficiently recovering nickel and cobalt from waste lithium battery extract according to claim 1, characterized in that, In step (6), the washing is repeated 3 to 5 times with anhydrous ethanol and ultrapure water, and the oven temperature is 60 to 80°C.