Ionic Liquids and Deep-Eutectic Solvents in Extractive Metallurgy: Mismatch Between Academic Research and Industrial Applicability

Abstract The past 10–20 years have seen numerous academic papers describing the benefits of ionic liquids (ILs) and deep-eutectic solvents (DESs) for leaching, solvent extraction electrowinning. scientific community—including authors this opinion article—have frequently proclaimed these neoteric as game-changers in extractive metallurgy. Despite this, there been no commercial breakthroughs. In paper we reflect on reasons why ILs DESs seem to failed impact metallurgical industry. These include: (1) issues with high viscosity; (2) limited chemical stability under conditions processes; (3) difficulties recycling reuse; (4) a lack demonstrated unit processes flowsheets pilot scale; (5) insufficient material-property data available engineering purposes; (6) administrative burden obtaining licenses safety permits; (7) very costs large-scale operations; (8) minimal added value compared state-of-the-art hydrometallurgical processes. Our belief is that innovations hydrometallurgy based or are unlikely. Instead, should be aiming deeper understanding at molecular level. This because advances more likely derive from refocused efforts experienced IL/DES researchers investigating speciation thermodynamics solutions, which will then hasten transition linear low-energy-input, circular hydrometallurgy. Graphical