Method for Recovering Valuable Metals from Spent Lithium-Ion Battery Leachate

Selective Copper Extraction Technology from Sulfuric Acid Leachate Using a Cyanex301/TBP Mixed Extractant

This technology utilizes a mixture of the organophosphorus extractants Cyanex301 and TBP to selectively extract and separate copper ions from sulfuric acid leachate of spent lithium-ion batteries, while suppressing the extraction of other valuable metals like cobalt and nickel.

Because sulfuric acid leachate from spent lithium-ion batteries contains a mixture of copper, cobalt, and nickel, it has been technically difficult to separate and recover high-purity cobalt and nickel without first removing the copper. This has historically necessitated additional, complex purification processes.

This technology is designed to selectively extract copper by adding Cyanex301 and TBP to a leachate with a sulfuric acid concentration of 0.01–3.0M, while maintaining a larger aqueous phase volume than the organic phase. The extracted copper is stripped using nitric acid or aqua regia, and residual valuable metals are recovered from the remaining filtrate using D2EHPA. It serves as a copper-removal module that enhances the purity of downstream metals, making it ideal for the front-end of solvent extraction-based battery recycling lines and for the production of nickel and cobalt sulfates where copper impurity management is critical.

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Key Features:

• Preparing a spent lithium-ion battery leachate containing copper ions and multiple other metal ions using sulfuric acid
• Adding an organophosphorus copper extractant containing both Cyanex301 and TBP to the leachate to selectively extract copper ions
• Stripping the extracted copper ions from the copper extractant using an acidic solution containing nitric acid or aqua regia
• Adding saponified D2EHPA to the remaining filtrate after copper extraction to extract divalent metal ions, excluding lithium, at a pH of 4 or higher

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