Ternary lithium-ion batteries, due to their superior performance, have been widely used in portable electronic devices and new energy vehicles worldwide. As the demand for lithium-ion batteries continues to grow, a large number of these batteries are reaching their “retirement” peak. To achieve the circular utilization of valuable metal resources and reduce the environmental impact of solid waste disposal, the recycling of waste lithium-ion batteries has garnered significant attention.
Calcium and Magnesium Removal Process for Nickel-Cobalt-Manganese Mixed Solution from Recycled Ternary Cathode Materials
The cathode materials in waste ternary lithium-ion batteries contain a substantial amount of valuable metals, typically including:
- Cobalt (Co): 5%–20%
- Nickel (Ni): 5%–10%
- Lithium (Li): 5%–7%
- Other metals (Cu, Al, Fe, etc.): 5%–10%
- Organic compounds: 15%
- Plastic: 7%
These materials hold significant economic value. Current recycling technologies mainly fall into two categories: pyrometallurgy and hydrometallurgy. However, pyrometallurgy faces challenges such as high energy consumption, material losses, and environmental issues, making hydrometallurgy a more favorable approach.
Hydrometallurgy Process
After dissolving the waste ternary cathode materials in acid, multiple impurity removal steps are carried out to obtain a nickel-cobalt-manganese mixed salt solution:
- Removal of Iron and Aluminum
- Removal of Copper and Zinc
- Removal of Calcium and Magnesium
- Removal of Fluoride
The purified mixed salt solution is then used to synthesize ternary precursors:
- The filtered salt solution, alkali solution, and complexing agent are fed into a reactor under controlled stirring speed, slurry temperature, and pH. This allows the salt and alkali to neutralize, forming precursor nuclei.
- The nuclei gradually grow, and when the desired particle size is reached, the slurry is filtered, washed, and dried to obtain the ternary precursor.
For the calcium and magnesium removal stage, Southwind Technology‘s LSC Series Chelating Resin demonstrates excellent performance and is widely applied in the new energy battery recycling field.
Calcium and Magnesium Removal Technology by Southwind Technology
To meet the evolving demands of the new energy battery recycling industry, Southwind Technology developed the LSC Series Chelating Resin, supported by patented production equipment for uniform particle-size chelating resin. It is currently the only company in China with the capability to produce uniform chelating resin, filling a gap in the domestic market.
Working Principle of LSC Series Chelating Resin
During operation, the mixed solution is passed through a resin column where the chelating groups on the resin selectively adsorb calcium and magnesium ions from the solution. Once the resin becomes saturated with calcium and magnesium ions, it is regenerated using a desorbing agent to wash off the adsorbed ions, restoring the resin to its original state for reuse in cyclic adsorption processes.
Selectivity of the Resin
The exchange capacity of the LSC Series Chelating Resin depends on the pH level. It can operate in neutral, acidic, or alkaline media, with its affinity for metal ions varying with pH, ion concentration, and temperature.
— pH Acidic
— pH Alialine
- Chemical Structure: The resin is a macroporous, weakly acidic chelating resin crosslinked with styrene and divinylbenzene, which facilitates the formation of chelates with metal ions.
- High Impact Resistance:
- Excellent resistance to osmotic stress.
- High mechanical strength with a low wear rate (≤5% annual breakage).
- Stable hydraulic performance.
- High Chelating Capacity: Superior adsorption performance.
- Uniform Particle Size:
- Outstanding regeneration kinetics with low pressure drop.
- Exceptional Metal Removal Capability:
- Stable secondary brine indices.
- High precision in removing calcium, magnesium, strontium, barium, and nickel.
- When primary brine quality is ensured, calcium and magnesium levels meet battery-grade standards.
Southwind Technology’s LSC Series Chelating Resin provides an efficient and stable solution for calcium and magnesium removal in battery recycling processes, supporting the industry’s goals of resource circularity and sustainable development.