Absorption Characteristics of Fission Product Elements on Zeolite

In pyrometallugical reprocessing, the spent electrorefiner salt containing fission product (FP) elements may be purified by zeolite and reused. Batch-type absorption tests were conducted using one or two FP chlorides in a LiCl-KCl eutectic electrolyte in order to obtain absorption isotherms to fit to a Langmuir equation model. For the trivalent FP elements in the one-component or two-component systems, the FP-element uptake in the zeolite can be related to its concentration in the salt using a single Langmuir-type equation. In contrast, for monovalent and divalent FP elements, it was necessary to use three different Langmuir-type equations. Using these derived absorption equations and a stage concentration diagram, it was found that only a three-stage process is required to attain a decontamination factor of 50 for trivalent FP elements via a countercurrent multistage process.