A study of the ion-exchange behavior of Bi as a homolog of element 115 in dilute hydrohalic acid solutions

Abstract

The ion-exchange behavior of Bi, a light homolog of element 115, in dilute HCl and HBr solutions was studied. The distribution coefficients of Bi, Pb, and other elements were determined in relation to the acid concentration and kind of the ion exchanger. From 0.25–0.5 M HCl and HBr, Bi is weakly sorbed by the cation exchanger with the distribution coefficients Kd ≤ 10, but is strongly sorbed (Kd ≥ 104) by the anion exchanger, which proves formation of negatively charged complexes in such solutions. High separation factors (≥105–106) of Bi from actinide and other elements were obtained. The distribution coefficients of Bi and Pb differ considerably, which was used for their separation. The optimum conditions were found for repeated isolation of the short-lived isotopes 211Bi (2.1 min), 212Bi (60.6 min), and 213Bi (45.6 min) and for their separation from the long-lived parent radionuclides (Th, Ac, Ra, Pb) used as the initial elements in various generator systems. The possibility of isolation of element 115 and its decay products in the continuous on-line mode was demonstrated.