Motivation

The EU identified PGMs and REEs as critical materials due to their economic relevance and supply insecurity. The EU demand for PGMs is driven by their use in CCs, with global sales increasing exponentially due to the growth in car sales and more stringent environmental legislations, inducing a corresponding increase in the quantities of SACCs. The growing number of SACCs presents a serious waste-management challenge for recyclers and a potential secondary access to strategic metals, such as PGMs and REE, if adequately exploited. Despite this, the circularity of PGMs material flow in the EU is suboptimal, whilst REEs are not currently recovered. In this new context of global environmental remediation, sustainable, effective, and affordable metallurgy can address both issues. Of the various metallurgical options, aqueous-based metallurgy, also known as hydrometallurgy, appears as an environmentally friendly alternative to pyrometallurgy. However, many of these unit operations rely on hazardous chemicals and produce significant effluents requiring treatment. Therefore, developing greener and more integrated process alternatives capable of replacing the hazardous chemicals in hydrometallurgy while maintaining or improving the process efficiency and selectivity is of the utmost importance.