Temperature-induced surfactant- mediated pre-concentration of uranium assisted by complexation

Alain Favre-Réguillon (1) , Denis Murat (2) , Gérard Cote (3) , Jacques Foos (2) , Micheline Draye (4)

1 LCO - Laboratoire de chimie organique (UMR 7084)
2 Laboratoire des Sciences nucléaires
3 LECA - Laboratoire d'Electrochimie et de Chimie Analytique
4 LCME - Laboratoire de Chimie Moléculaire et Environnement

Cloud-point extraction (CPE) was used with lipophilic chelating agent to extract uranium(VI) from aqueous solutions. The methodology used is based on the formation of metal complexes soluble in a micellar phase of a non-ionic surfactant, Triton X-114. The metal ions complexes are then extracted into the surfactant-rich phase at a temperature above the cloud-point temperature. The influence of surfactant concentration on extraction efficiency was studied and the advantage of adding 8-hydroxyquinoline (8HQ) as lipophilic chelating agent was evidenced. High extraction efficiency was observed, indicating the feasibility of extracting U(VI) using CPE. This study describes a four-step process—(1) extraction, (2) thermo-induced phase splitting, (3) back-extraction and (4) second phase splitting—for the recovery of uranium from water. In our conditions, the extraction yield is quantitative and the concentration factor obtained is superior to 100. After stripping with a diluted nitric acid solution (pH < 1), the system can be recycled through a new four-step cycle

Mots clés: cloud-point extraction; uranium; 8-hydroxyquinoline; Triton X-114

Domaines: Génie chimique

Alain Favre-Réguillon, Denis Murat, Gérard Cote, Jacques Foos, Micheline Draye. Temperature-induced surfactant- mediated pre-concentration of uranium assisted by complexation. Journal of Chemical Technology and Biotechnology, 2006, 81 (12), pp.1872 - 1876. ⟨10.1002/jctb.1618⟩. ⟨hal-03285976⟩