[en] The factors influencing the efficiency of the countercurrent electromigrational separation of isotopic ions under self-regulated conditions as defined by various parameters of the process, viz., the temperature, the velocity of the countercurrent, the dimensions of the particles of the packing, and the height of the separatory layer, have been studied. It has been shown experimentally that the efficiency of the separation process decreases as the temperature and the height of the separatory layer are increased. It has been established that under self-regulated countercurrent conditions it is possible to maintain a stable process of electromigrational separation of isotopic ions when the height of the separatory column is ≤ 3 mm and to thereby significantly reduce the influence of the nonuniformity of the distribution of the temperature across the column and to increase the efficiency of the process

[en] The unit protium-tritium separation coefficients α_H/T for transfer through a hydrogen-permeable bipolar electrode in KOH solutions of various concentration at a temperature of 50 degree C have been determined. The values of α_H/T obtained (11.8 ± 0.6 for 10 M KOH and 13.4 ± 1.9 for 2 M KOH at a current density of 0.1 A/cm²) are in good agreement with the conception of the multistep separation of the isotopes of hydrogen in a hydrogen-permeable bipolar electrode

[en] Electrodialytic separation of ions bearing charges of the same sign with the aid of ion-exchange membranes has been examined in the literature in relation to the so-called ideal membranes, which do not exhibit selectivity with respect to one ion type in ion exchange. It has been shown that separation on such membranes is effective only for counterions differing in size of charge. A matter of greater importance from the practical standpoint is the possibility of using electrodialysis for separating ions bearing like charges and having similar properties, including ionic forms of isotopes of the same element. In this paper they report a comparative study of ion separation, with reference to the Cs-Na pair, by electrodialysis through various types of cation-exchange membranes. Changes of the solution concentration in the cathode compartment were monitored by measurement of ²²Na and ¹³⁷Cs activities

[en] The possibility of the use of thin porous membranes with a narrow distribution of the pore diameters as an electromigration medium has been considered. The influence of the geometric parameters of porous membranes of the Millipor type on the separation process has been studied in the example case of a model mixture of cesium and sodium ions. The separation coefficient is exponentially dependent on the velocity of the countercurrent over a broad range of current densities (30-200 mA/cm²). The influence of the diameter of the pores in the membrane on the efficiency of the separation of ions has been evaluated with the aid of the concept of theoretical plates. It has been found that membranes with a pore diameter equal to 0.45 μ or less are practically ideal media for carrying out the countercurrent electromigration separation of ions. For example, in one membrane with a thickness equal to 150 μ and a pore diameter equal to 0.45 μ the separation coefficient of cesium and sodium ions was 130 when the velocity of the countercurrent was 3.5 x 1-^-3 cm/sec