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 α for 6 Li/ 7 Li obtained in the present study was 1.021. The light lithium isotope 6 Li and the heavy lithium isotope 7 Li 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   >   LiClO 4   >   LiCl. From the temperature dependence data, the thermodynamic functions values of the lithium isotope exchange reaction were calculated.