Recovery of critical metals from residues of eletric and eletronic equipment using liquid-liquid extraction with ionic liquids

Abstract

Residues from obsolete electrical and electronic equipment, such as LED lamps and Li-ion batteries are potential sources of critical metals, such as cobalt and rare earths. The recovery of these elements usually involves hydrometallurgical processing, which consists of leaching, separation and purification steps, until obtaining a final product with added value. In the liquid-liquid separation steps, toxic, volatile and flammable organic solvents are used. In view of the need of developing cleaner industrial processes, non-conventional extractants, such as ionic liquids, have been proposed as alternatives to conventional ones. This project aims to evaluate the use of commercial ionic liquids to replace conventional organic extractants in liquid-liquid extraction steps, aiming the recovery of critical metals from leaching liquors of WEEE residues. As main results, it is expected to increase the selectivity of recovery of critical metals when compared to other elements, besides encouraging the use of cleaner alternatives.