Extraction of Lanthanides from Aqueous Solution by Using Room-Temperature Ionic Liquid and Supercritical Carbon Dioxide in Conjunction

Soufiane Mekki (1, 2, 3) , Chien M. Wai (4) , Isabelle Billard (1) , Gilles Moutiers (3) , James Burt (4) , Byunghoon Yoon (4) , Joanna S. Wang (4) , Clotilde Gaillard (1) , Ali Ouadi (1) , Peter Hesemann (5)

1 IReS - Institut de Recherches Subatomiques
2 INSTN - Institut National des Sciences et Techniques Nucléaires
3 SCP - Service de Chimie Physique
4 University of Idaho [Moscow, USA]
5 UMR 5076 - Hétérochimie Moléculaire et Macromoléculaire

For the first time, the study of a three-step extraction system of water/ionic liquid/supercritical CO2 has been performed. Extraction of trivalent lanthanum and europium from an aqueous nitric acid solution to a supercritical CO2 phase via an imidazolium-based ionic liquid phase is demonstrated, and extraction efficiencies higher than 87 % were achieved. The quantitative extraction is obtained by using different fluorinated -diketones with and without the addition of tri(n-butyl)phosphate. The complexation phenomenon occurring in the room-temperature ionic-liquid (RTIL) phase was evidenced by using luminescence spectroscopy.

Mots clés: carbon dioxide; ionic liquids; lanthanides; metal extraction; supercritical fluids

Domaines: Chimie de coordination; Génie chimique

Soufiane Mekki, Chien M. Wai, Isabelle Billard, Gilles Moutiers, James Burt, et al.. Extraction of Lanthanides from Aqueous Solution by Using Room-Temperature Ionic Liquid and Supercritical Carbon Dioxide in Conjunction. Chemistry - A European Journal, 2005, 12 (6), pp.1760-1766. ⟨10.1002/chem.200500559⟩. ⟨hal-00177988⟩