| Abstract: | A break-through experiment on separation of uranium isotopes was carried out by use of a cation-exchange resin in Ti(III) form. By analyzing the experimental results the apparent equilibrium constants of the order K = 1·00021–1·00034 were determined. The maximum value on the experimental curies of the isotopic ratio versus effluent volume was interpreted by considering two antagonistic isotope effects: one relatively large given by an exchange reaction between U(IV) in resin and U(VI) in solution and another smaller given by the reduction reaction of U(VI) with Ti(III). The difference of the equilibrium constants of the these two isotope effects as a function of temperature was used for the determination of the apparent thermodynamic values of the resultant process, determined experimentally: ΔH0 = 0.8542 cal mol?1 and ΔS0 = 3.33×10?3cal°K?1. |
