Two-Site Equilibrium Model for Ion Exchange between Monovalent Cations and Zeolite-A in a Molten Salt

A two-site model has been derived and tested against experimental data for monovalent species ion exchange in molten chloride salt/zeolite A. This system is of interest for the application of spent nuclear fuel treatment. Fission products and transuranics that accumulate in a molten salt electrorefining process can be preferentially removed and eventually stabilized in a waste form, using zeolite A. An excellent fit of Cs−Rb−Na−Li−K data to the model was found with different selectivity sequences for the two sites. Cesium was found to be the preferred cation in the α-cage sites, while lithium was preferred in the framework sites.