Co-extractants based on the Hofmeister effect and the Van ‘t Hoff - LeChatelier effect to increase metal extraction efficiencies

Abstract

This work evaluates the impact of the Hofmeister effect and the Van ‘t Hoff – LeChatelier effect on the extraction efficiency of cobalt and neodymium from aqueous phases to pseudo-protic ionic liquids. These metals are particularly relevant for the urban mining from for example electric vehicles. Cheap and readily available co-extractants were employed to investigate the impact of both effects either individually or in parallel on the extraction efficiency. A high driving force is required from either the Hofmeister effect or from both effects simultaneously to successfully increase the extraction of cobalt (more than tenfold). Lower driving forces are sufficient to successfully increase the extraction of neodymium (up to 100 %).