Most industrial processes for the separation of f-elements and their isotopes are carried out under steady-state conditions. The growing importance of separating and recovering lanthanides and isotopes of elements with closely similar physicochemical properties necessitates the search for new, more efficient separation approaches. In recent years, redox reactions have been increasingly investigated as a means of separating such closely related elements in heterogeneous systems. The authors have suggested [1–2] that separation efficiency can be significantly enhanced under non-equilibrium, non-stationary conditions.