Solvent extraction studies on Th(IV), Pa(V) and U(VI) from nitric acid medium using di-2-ethyl hexyl isobutyramide (D2EHIBA)

Distribution behaviour of Pa has been studied in the presence of varying am ounts of Th (up to 250 g/L) and U (20 g/L) from aqueous nitric acid (1-6 M) employing 1 M solution of di-2-ethyl hexyl isobutyramide (D2EHIBA) in n-do decane at 25 degrees C. A significant decrease in the extraction of Pa as c ompared to that of U with increase in aqueous Th(NO3)(4) concentration resu lts in large separation factor of U over Pa (710 at 1 M HNO3 in presence of 250 gn of Th). Empirical formulae of the extracted species of Th(IV) and P a(V) conform to Th(NO3)(4). 3A and Pa(OH)(2)(NO3)(3). A respectively (where A = D2EHIBA). The distribution ratio values of uranium decrease from 1.19 (for tracer) to 0.49 (at 118.26 g/L of uranium) at 2 M HNO3. No third phase is seen even up to 200 g/L of initial uranium in the aqueous phase.