Abstract
Complex formation behavior of Ce (IV) and Ce (III) with NO3- has been examined. Anion exchange characteristics of Ce (IV) at various nitric acid concentration and temperature were measured. Furthermore, separation behavior of Ce (IV) from other light rare earth elements was investigated by anion exchange column. It was found that Ce (IV) forms anionic nitrato-complexes such as Ce (NO3) 5- and Ce (NO3) 62- at nitric acid concentration above 1 mol⋅dm-3 and the nitrato-complexes show relatively strong adsorption on anion exchanger. On the other hand, the adsorbed Ce (IV) was reduced to non-adsorptive Ce (III) through redox reactions with anion exchanger and eluted into the solution, while the elution rate was significantly promoted by temperature. The distribution coefficient of Ce (IV) at 303K, 6 mol⋅dm-3 HNO3 solution onto AR-01 anion exchanger was as high as 100 dm3⋅kg-1. Ce was separated with high purity from a Ce (IV), La (III) and Nd (III) containing nitric acid solution by anion exchange column.
