A Novel Mechanism for the Extraction of Metals from Water to Ionic Liquids

作者：Janssen Camiel H C; Sanchez Antonio; Witkamp Geert Jan; Kobrak Mark N^*

来源：ChemPhysChem, 2013, 14(16): 3806-3813.

DOI：10.1002/cphc.201300686

• crown compounds
• ion chromatography
• ion exchange
• ionic liquids
• thermodynamics

We present a novel mechanism for the extraction of metals from aqueous phases to room-temperature ionic liquids (ILs) by use of a high-temperature salt as an extraction agent. The mechanism capitalizes on the fact that charged metal complexes are soluble in ILs; this allows for extraction of charged complexes rather than the neutral species, which are formed by conventional approaches. The use of a well-chosen extraction agent also suppresses the competing ion-exchange mechanism, thus preventing degradation of the ionic liquid. The approach permits the use of excess extractant to drive the recovery of metals in high yield. This work presents both a thermodynamic framework for understanding the approach and experimental verification of the process in a range of different ILs. The method has great potential value in the recovery of metals, water purification and nuclear materials processing.

• 出版日期2013-11-11