Advanced Technologies in Bio/Hydrometallurgy for Recovery and Recycling of Metals

Studying innovative and sustainable technologies for the recovery and reuse of raw materials (RMs) from primary and secondary resources is fundamental for economic and industrial development in compliance with environmental protection and in the context of a circular economy. Bio/Hydrometallurgy consists of leaching and recovery unit operations. Leaching is the solubilization of metals from a solid phase using chemicals or biological agents, whereas recovery is the extraction of metals from polymetallic leachate using physicochemical processes, electrowinning, or biological processes. Bio-hydrometallurgical processes are new solutions offering environmentally sustainable practices in the mining and environmental sectors for the extraction of base, precious, and toxic metals and rare earth elements (REE) and for the valorization of secondary resources rich in critical raw materials (CRMs), which are fundamental in modern technological applications. The economic concerns of these processes, which are closely linked to the choice and optimization of the experimental parameters, are of great importance. The articles included in this Special Issue contribute to the improvement of innovative bio- and/or hydrometallurgical processes applied for the recovery of valuable and critical metals.