Leaching Kinetics\nof Valuable Metals from Calcined\nMaterial of Spent Lithium-Ion Batteries

This study aimed to investigate the leaching kinetics\nof valuable\nmetals contained in the calcined black mass derived from the incineration\nof spent lithium-ion battery (LIB) modules. The effects of sulfuric\nacid (H<sub>2</sub>SO<sub>4</sub>) concentration (0.5–3 M),\nhydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) concentration (0.5–2.0\nvol %), solid/liquid (S/L) ratio (25–75 g/L), leaching time\n(10–120 min), and leaching temperature (30 °C–70\n°C) on metal leaching efficiency from black mass were investigated.\nThe optimal leaching conditions were achieved with 1 M H<sub>2</sub>SO<sub>4</sub>, 1 vol % H<sub>2</sub>O<sub>2</sub>, and a S/L ratio\nof 50 g/L at 60 °C for 60 min. Under these conditions, Li, Ni,\nand Mn had leaching efficiencies of 100%, with Co at 97.17%, respectively.\nAn investigation of the leaching kinetics utilizing H<sub>2</sub>O<sub>2</sub> as an additive revealed that the Avrami model fits the metal\nleaching process. The results of this study suggested that diffusion\nand surface chemical reactions controlled the leaching mechanisms\nof these metals, with activation energies of 7.829, 5.646, and 5.077\nkJ mol<sup>–1</sup> for Li, Ni, and Co, respectively.