Extraction and stripping behaviour of tri-<i>iso</i>-amyl phosphate and tri-<i>n</i>-butylphosphate in <i>n</i>-dodecane with U(VI) in nitric acid media

Abstract

Abstract Batch extraction of U(VI) by 1.1 M solution of tri- iso -amyl phosphate (T i AP) in n -dodecane ( n -DD) from uranyl nitrate solutions in nitric acid media has been investigated as a function of metal loading and equilibrium aqueous phase acidity at 303 K. A method adopted for free acidity determination by using a mixture of potassium oxalate and sodium fluoride for complexing U(VI) has been validated by comparing the data generated in the present study with literature data available for tri- n -butyl phosphate (TBP) under identical conditions. Extraction and stripping behaviour of 1.1 M T i AP/ n -DD-U(VI)/HNO 3 and 1.1 M TBP/ n -DD-U(VI)/HNO 3 systems have been compared by carrying out extraction, scrubbing and a series of stripping in cross-current mode. Stripping behaviour of both the solvents loaded with U(VI) and HNO 3 has also been investigated as a function of time to understand the effects of nitric acid induced degradation on stripping.