Lithium isotope separation by liquid-liquid extraction using ionic liquid system containing dibenzo-14-crown-4

In this paper, a novel liquid-liquid extraction system was investigated for the selective separation of lithium isotopes using ionic liquid (IL) and dichloroethane as extraction solvent and dibenzo-14-crown-4 (DB14C4) as extractant. Results showed that the separation performance of DB14C4 has been improved after the ILs were involved in the extraction process. The maximum single stage separation factor alpha for Li-6/Li-7 obtained in the present study was 1.021. The light lithium isotope Li-6 and the heavy lithium isotope Li-7 were concentrated in organic phase and solution phase, respectively. The order of the single stage separation factor obtained in different lithium salts was LiI > LiBr > LiClO4 > LiCl. From the temperature dependence data, the thermodynamic functions values of the lithium isotope exchange reaction were calculated. (C) 2016 Elsevier B.V. All rights reserved.