Third phase formation in the extraction of Th(NO3)4 by tri-2-methyl butyl phosphate from nitric acid media

Summary Third phase formation in the extraction of Th(IV) by tri-2-methyl butyl phosphate (T2MBP) in various diluents such as n-dodecane, n-tetradecane and n-hexadecane from nitric acid media has been investigated for the first time. The limiting organic concentration (LOC) and maximum organic concentration (MOC) as well as critical aqueous concentration (CAC) and saturated aqueous concentration (SAC) were measured as a function of equilibrium aqueous acidity. Data on LOC and MOC values have been generated with various concentrations of T2MBP (1.1 M, 1.38 M and 1.65 M) in n-dodecane at 303 K. LOC and CAC values have been measured for the extraction of Th(IV) by 1.1 M T2MBP/n-hexadecane at various temperatures (298 K, 303 K and 313 K) as a function of equilibrium aqueous acidity. Effect of temperature on third phase formation has been studied in the extraction of Th(IV) from its solution with near zero free acidity by 1.1 M T2MBP in n-tetradecane and n-hexadecane as diluents. Data on extraction of nitric acid in the absence and presence of Th(IV) by T2MBP/n-dodecane is also reported in this paper.