[en] The countercurrent method of separation is suggested and its efficiency is tested, using as examples alkali element and their isotope ion separation in a separation column with a filler. It is shown experimentally, that the degree of alkali ion separation exponentially depends on the rate of countercurrent and separation coefficient. For systems CsOH, NaOH and RbOH, CsOH practically complete separation of elements is achieved. At that, the degree of rubidium (⁸⁵Rb, ⁸⁷Rb) isotope separation reached 1.1, and that of lithium (⁶Li, ⁷Li) isotopes -2.5

[en] Cesium and sodium ion separation during electrodialysis through synthetic cation-exchange membranes (SM) MRF-26, MK-40, as well as through membranes of inorganic exchangers (IE) of ammonium phosphoromolybdate and antimonius acid cationite, is investigated. For SM single separation factor constitutes 1.9±0.05 and it does not depend on solution composition and current density in the studied range of 5-50 μA/cm². For IE α_Cs/Na = 1.45± 0.05 for both sorbents. Characteristics of the MK-40 membrane in counterflow dialysis operation mode are determined and ion separation efficiency using ultrafine porous inert membranes is considered. 2 figs.; 1 tab

[en] A model is proposed of fractional vaporization of lithium iodide in mass spectrometer ion source. The vaporization of even heavy lithium compounds (LiI) is accompanied by abnormal fractionation at the first step. Therefore, to provide reliable measurements of ⁷Li/⁶Li isotope ratios, it is necessary to dehydrate the lithium salt in the ion source that is achieved after heating for 1-1.5 hrs

[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 influence of geometric parameters of a porous membrane on Cs and Na ion separation in their acetate solutions by counterflow electromigration method using membranes on the basis of cellulose esters with 79% porosity has been studied. It is ascertained that membranes with homogeneous pores ≤ 0.45 μm in diameter proved to be ideal medium for electromigration separation of the above - mentioned ion. 5 refs

[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

No abstract available

[en] Possibility to separate ions of alkali metals by a new inconsistent self-adjusting electromigration method is considered. The suggested electromigration method is based on the idea of carrying out the process of separation under the galvanostatic condition providing the balance between the mass of a substance transferred by an electric current and solution countercurrent. Main attention is paid to the search for optimal conditions of electromigration cleaning of rubidium ions from cesium and sodium accompanying ions in sampling. It is suggested to use thin porous membranes with a uniform structure of pores as a stabilizer of a solution flux instead of the columns with a filler. Increase of the membrane diameter from 8 to 32 mm is shown not to lead practically to decrease of efficiency of the separation process

[en] Parameters of electromigration separation of cesium and sodium ions by means of nuclear membranes are experimentally determined. Separation was carried out in aqueous solutions of acetates of these metals (counter-current was carried out by the acetic acid solution) and it was controlled radiometrically using radioactive tracers ¹³⁷Cs,²²Na. Possibility in principle to realise the effect of counterflow electromigration separation of cesium and sodium ions at the 10μm height of a separation layer is shown. The structure of nuclear mambranes provides the homogeneity of the solution flow along the whole cross section of a separation cell, and, as a result, HETP approximates practically to a theoretically possible value