Removal of iron, aluminium, manganese and copper from leach solutions of lithium-ion battery waste using ion exchange

Abstract

The shift to electric mobility necessitates recycling the metals from lithium ion battery waste. Ion exchange was studied for use in the removal of impurities from synthetic lithium ion battery waste leachate in laboratory-scale batch and column experiments. Aminomethylphosphonic acid functional chelating resin (Lewatit TP260) was capable of removing Fe, Al, Mn, and Cu from the leachate, while leaving valuable Co, Ni, and Li as a pure mixture in the raffinate. Increasing the pH up to 3 and the temperature to 60 °C improved the purity and productivity. Iron and aluminium could not be eluted efficiently by mineral acids, but an oxalate solution was found feasible. A two-step elution procedure, in which Cu and Mn are first removed with sulfuric acid, followed by Fe and Al removal with potassium oxalate, was successfully demonstrated. The suggested process produced a > 99.6% pure Li + Co + Ni solution (battery grade), along with a Mn and Cu rich sulfuric acid solution with Co as an impurity and an oxalate solution of Fe + Al as by-products. The productivities for these solutions were 0.39, 0.16, and 0.38 BV/h, respectively. The Co loss was very low (1.1%) as compared to previously suggested impurity removal processes using precipitation and solvent extraction. Moreover, Co can be easily recycled back to the ion exchange column feed after Mn and Cu are recovered as pure by-products.