The Effect of the Structure of Trialkyl Phosphates on their Physicochemical Properties and Extraction Behavior

The density of various trialkyl phosphates (TalP) such as tri-n-butyl phosphate (TBP), tri-iso-butyl phosphate (TiBP), tri-sec-butyl phosphate (TsBP), tri-n-amyl phosphate (TAP), tri-2-methylbutyl phosphate (T2MBP), tri-iso-amyl phosphate (tri-3-methylbutyl phosphate, TiAP), tri-sec-amyl phosphate (tri-2-amyl phosphate, TsAP), tri-cyclo-amyl phosphate (TcyAP), tri-n-hexyl phosphate (THP), and 1.1M solutions of some of these phosphates in various diluents, solubility of water in trialkyl phosphates, and the aqueous solubility of trialkyl phosphates have been measured. Extraction of nitric acid, Th(IV), and U(VI) by trialkyl phosphates has also been studied by the batch extraction method. Metal-solvate stoichiometry in the extraction of Th(IV) and U(VI) by some of the phosphates has been evaluated. Data on the extraction of U(VI) by various trialkyl phosphates as a function of equilibrium aqueous-phase nitric acid concentration at 303K are presented in this paper. Data on the extraction of Th(IV) and U(VI) from 1M and 5M HNO3 by trialkyl phosphates as a function of equilibrium aqueous-phase metal concentration at 303K are also presented in this paper. The effects of the structure of trialkyl phosphates on their physicochemical properties and extraction behavior are described in this paper.