Lanthanides Extraction by 8-Quinolinol and by a Mixture of Quinolinol and Trioctylphosphine Oxide

ABSTRACT The solvent extraction of Nd3+ , Sm3+, Eu3+ , Gd3+, Dy3+ , Ho3+ , and Er3+ from a M ionic strength medium (CH3COONa), pH (CH3COOH) by 8-quinolinol (HOx) and by a mixture of HOx and trioctylphosphine oxide (TOPO) in CCl4, CHCl3, C6H6, C6H5—NO2, C6H5—CH3 C6H5Cl and C6H5—Br is studied using titrimetric methods. A synergistic factor of over 10,000 is obtained. The atomic number and diluent effects are evident in the calculated formation constants and the lanthanide separation factors. A combination of the data obtained and that of Th4+ indicates that an excellent separation of thorium from the lanthanides can be obtained with this extraction system.