Recovery of lithium, nickel and cobalt from mixed lithium-ion batteries in ammonia media

This study investigates the recovery of valuable metals from a mixture of lithium iron phosphate (LFP) and nickel‑manganese‑cobalt (NMC) in an ammoniacal medium. A factorial design of experiments was applied to assess the effects of NH 3 , (NH 4 ) 2 SO 4 , and Na 2 SO 3 concentrations on the leaching behavior of Ni, Mn, Co, and Li. Ammonia enhanced metal dissolution through complexation, (NH 4 ) 2 SO 4 stabilized the pH via buffering, and Na 2 SO 3 acted as a reducing agent improving the dissolution of Ni, Co, and Li. Optimal conditions (6 mol L −1 NH 3 , 3 mol L −1 (NH 4 ) 2 SO 4 , 1 mol L −1 Na 2 SO 3 , 60 °C, S/L = 50 g L −1 ) yielded recoveries of 68.1% Ni, 25.9% Mn, 79.4% Co, 55.6% Li, and 99.7% Cu. An empirical model accurately predicted these dissolution yields. Subsequent solvent extraction enabled selective recovery of Ni, Mn, and Cu using Acorga® M5640, and Li using Cyanex® 936P diluted in kerosene. The proposed flowsheet demonstrates the efficiency and selectivity of ammoniacal leaching as a sustainable alternative to conventional acid-based recycling of lithium-ion batteries. • Factorial design reveals key effects of NH 3 , (NH 4 ) 2 SO 4 and Na 2 SO 3 on leaching. • Ammoniacal leaching achieves high Ni, Co, Li and near-complete Cu recovery. • Na 2 SO 3 improves dissolution via reduction of transition-metal species. • Empirical model accurately predicts multi-metal dissolution yields. • Flowsheet enables selective Ni, Mn, Cu and Li recovery via solvent extraction.