Determination of 55Fe and 63Ni in Pb–Bi by Radiochemical Separation Method

This paper introduces a simple and rapid separation method for the determination of 55 Fe and 63 Ni in lead–bismuth alloys. This method is based on chemical precipitation and solid-phase extraction chromatography techniques, which can separate and purify individual radionuclides from sample matrix elements and other radionuclides. First, lead, bismuth, and iron are separated by chemical precipitation. On the one hand, nickel is separated on a NI-resin column from the filtered solution. On the other hand, after the precipitation is digested, iron is further separated from lead and bismuth by chemical precipitation. This study explored the effects of solution pH, ammonium citrate concentration, and eluent concentration (acid concentration) on the retention behavior of the NI-resin. The optimal separation efficiency for nickel was achieved under the following conditions: a solution pH of approximately 9, an ammonium citrate concentration of 0.2 mol/L, and an eluent (nitric acid) concentration of 3 mol/L. The recovery rates of Fe and Ni obtained by this method are 88.24% and 81.57%, respectively, and the decontamination factors of Pb and Bi are 6.5 × 10 2 and 1.4 × 10 4 , respectively.