Ionic‐Liquid‐Based Acidic Aqueous Biphasic Systems for Simultaneous Leaching and Extraction of Metallic Ions

The first instance of an acidic aqueous biphasic system (AcABS) based on tributyltetradecyl phosphonium chloride ([P44414][Cl]) and an acid is here reported. This AcABS exhibits pronounced thermomorphic behavior and is shown to be applicable to the extraction of metal ions from concentrated acidic solutions. Metal ions such as cobalt(II), iron(III), platinum(IV) and nickel(II) are found to partition preferentially to one of the phases of the acidic aqueous biphasic system and it is here shown that it successfully allows the difficult separation of CoII from NiII, here studied at 24 and 50 °C. Metal recovery from acidic solutions: A novel type of acidic aqueous biphasic systems (AcABS) based on an inorganic acid and an ionic liquid is presented. This system has been successfully applied to the extraction of metal ions. The thermotropic behavior and the use of large acid concentrations in the AcABS provide a promising alternative to conventional extracting systems.