[en] The distribution coefficients of Th, Pa, U, Np, Pu, Am, and Cf, in addition to Zr-Nb between the cation-exchanger Dowex-50 and HF solutions as a function of [HF] (0.01-1.0 M) and the presence of an oxidizer (PbO₂) on the resin are determined. The basic principles of the behavior of the actinides are found. Suggestions are made about the sorption mechanism from HF solutions of these elements in various oxidation states on the cation exchangers. Simple effective methods are presented for the separation of trivalent TPE from the other actinides (Pa, U, Np, Pu) and for the separation of certain pairs of actinides in higher oxidation states using small cation-exchange columns and 0.01-0.5 M HF as eluents. Continuous generation of isotopically pure ²³⁹Np and ²³³Pa is possible from the parent ²⁴³Am and ²³⁷Np, respectively. A method is developed for isolating and purifying ²³¹Pa and its radioactive decay products ²²⁷Ac and ²²⁷Th on a single cation-exchange column

[en] Coefficients of distribution of Th, Pa, U, Np, Pu, Am, Cf as well as Zr-Nb among Dowex-50 cationite and solutions of hydrofluoric acid are determined depending on HF concentration (0.01-1.0 mol/l) and presence of oxidizer (PbO₂) in the resin phase. Basis regularities of actinoid behaviour are established and assumptions are made as regards the sorption mechanism of these elements in HF solutions. A possibility of a continuous multiple production of isotopically pure ²³⁹Np and ²³³Pa from their mother radionuclides - ²⁴³Am and ²³⁷Np, respectively, is shown. A technique of extracting and purifying ²³¹Pa and products of its radioactive decay - ²³⁷Ac and ²²⁶Th - in same cation-exchange column is developed

No abstract available

[en] Analysis of the nuclear-physical properties of natural and man-made radionuclides shows that analyzed actinides can be contaminatedy during their chemical separation and that the energies of α-emissions can overlap during spectrometric determination of these elements. The behavior of Ac, Th, Pa, U, Np, Pu, Am, Cm, and other elements on ion exchangers in HCl, HNO₃, HClO₄, H₃PO₄, HF, and H₂SO₄ solutions is systematically investigated as a function of acid concentration and type of ion exchanger. Schemes are proposed for the successive separation of the actinides, interfering radionuclides (Ra, Po), and macroscopic inpurities (Fe, Al, etc.) that use cation or anion exchangers and gradient elution by mineral-acid solutions. The advantages of using the developed methods to separate and determine actinides in the environment are discussed

No abstract available

[en] Measurements have been made on cation-exchanger sorption of americium, other actinoids, and certain rare-earth elements from 0.1-2.0 M H₃PO₄ when the elements have been oxidized with ammonium persulfate alone or mixed with silver phosphate. There are considerable differences in behavior between the americium and the other elements on account of its being oxidized to a higher valency state. Measurements have been made on the effects of acid and oxidant concentrations and of the oxidation and elution conditions on the americium yield when the exchanger is treated with H₃PO₄. Optimum oxidation conditions have been chosen, and a rapid method has been devised for separating americium(VI) from other transplutonium elements and REE on Dowex 50 /times/ 8, where the eluent is 0.1-1.0 M H₃PO₄ plus 0.05 M (NH₄)₂S₂O₈

[en] Systematic investigation is fulfilled of the behaviour of Ac, Th, Pa, U, Np, Pu, Am, Cm and other elements on ionites in HCl, HNO₃, HClO₄, H₃PO₄, HF and H₂SO₄ solutions in dependence on the acid concentration and ion exchanger type. Schemes are proposed for successive isolation of actinide elements, and also of interfering radionuclides (Ra, Po) and macrocomponents (Fe, Al and others) with usage of cationite or anionite and gradient elution by inorganic acid solutions. Advantages of developed method application for isolation and determination of actinides in the environment are discussed

[en] Behaviour of europium and other REE, TPE and Sr on cationites in hydrochloric acid solutions depending on acid concentration, cationite nature, DVB content in resin, and also the degree of resin loading by macrocomponent at columns with Zn(Hg) reducer, is studied. On the basis of obtained results method of separation of bivalent europium macroquantities from trivalent RE and TPE at one column, containing Dowex-50·5+Zn(Hg) cationite in 1 mol/l HCl solutions, is developed. Satisfactory separation is shown to be attained even at ∼50% resin loading by macrocomponent

No abstract available

[en] Sorption is studied of Am, Cm, and Cf on anionite Dowax-1X8 from water-metal solutions of a mixture of lactic and mineral acids. The distribution coefficients are determined of the elements under investigation in relation to the content of the different components in the solution. A sharp increase is detected in sorption from water-alcohol solutions of a mixture of lactic and nitric acids. The possibility is shown of using such solutions for separating transplutonium elements on anionites. The separation factors for Am-Cm and Cm-Cf pairs in the optimum conditions are 4 and 3, respectively