Solvent extraction of cobalt from spent lithium-ion batteries: Dynamic optimization of the number of extraction stages using factorial design of experiments and response surface methodology

The optimization of lithium-ion batteries (LiBs) recycling is crucial not only from a waste management perspective but also to decrease the dependence on imports critical raw materials. In addition, diversification technologies very important for better flexibility market. This study aims at investigating recovery Co spent LiBs using solvent extraction real chloride-based solution obtained after removal Mn, which rarely reported. Cyanex 272 was used as extractant and effect several variables efficiency considered model optimize separation Ni. number stages directly affects process its cost. Thus, in this work, novel approach developed assist selection dynamic method based factorial design experiments response surface methodology combined with Kremseŕs Equation. can design, overall cost operation, Ni reduced stages. concentration feed solutions ∼ 8.3 g/L 1.9 g/L, respectively. Based results, 98% be achieved 1 2 low co-extraction (<5%) when 0.6–0.8 M 272, O:A ratio below pH 5, combinations conditions could provide similar results.