Solvometallurgy: An Emerging Branch of Extractive Metallurgy

This position paper introduces the reader to the concept of solvometallurgy, the term used to describe the extraction of metals from ores, industrial process residues, production scrap, and urban waste using non-aqueous solutions. The paper discusses the key unit operations involved in solvometallurgy, including solvent leaching, residue separation, leach solution purification using non-aqueous methods, and metal recovery through precipitation or electrolysis. Unlike traditional hydrometallurgical processes, solvometallurgy utilizes low temperatures and avoids a discrete water phase, leading to reduced consumption of water and wastewater generation. The sustainability of solvometallurgy relies on utilizing green solvents, thus avoiding toxic or environmentally harmful substances. The paper highlights several advantages of solvometallurgy over conventional methods, such as better selectivity in leaching, reduced acid consumption, and fewer purification steps. Additionally, solvometallurgy shows potential in the treatment of ores rich in soluble silica without forming silica gel. Despite its Technology Readiness Level being classified as low (TRL = 3–4), this emerging field presents significant opportunities for innovation and research in developing near-zero-waste metallurgical processes with lower energy consumption than high-temperature methods.