Processing of LCO LIBs Leachates—Part I: Removal of Accompanying Metals and Monitoring Losses of Co and Li

This study investigates the hydrometallurgical purification of the acidic leachate from spent LiCoO2-based lithium batteries, focusing on the selective removal of Cu, Mn, and Ni while monitoring co-precipitation of Fe and Al and minimizing Co and Li losses. Thermodynamic modelling using HSC Chemistry 10 and Hydra/Medusa guided the design of precipitation conditions. The optimal Cu precipitation was achieved using Na2S (Na2S:Cu = 4:1, 20 °C, 5 min, 300 rpm), yielding > 99% removal. Mn was efficiently precipitated as MnO2 using KMnO4 (KMnO4:Mn = 1:1, 20 °C, pH ≈ 2, 10–15 min, ≈97% efficiency). Ni was recovered as [Ni(DMG)2] under DMG:Ni = 5:1, 80 °C, 15 min, pH ≈ 5, achieving ≈99% removal. Sequential 2 L experiments (precipitation order: Cu → Mn → Ni) validated the scalability of the process. Cu and Ni removal remained high (>95%), while Mn efficiency slightly decreased (≈91%) due to kinetic and redox inhomogeneity. No significant precipitation of Co and Li was observed, leaving them in solution and concentrating from 12.9 to 18.8 g·L−1 and 2.71 to 3.50 g·L−1, respectively, with total losses of