[en] In this colloquium on solvent extraction are examined extractants, new solvents, counter-current contactors, columns hydrodynamics, practical applications, emulsions, membranes and high pressure processes for metal extraction, wastewater treatment, chemical separation etc. Only 8 papers are related to the nuclear field

[en] Many methods of TOPO synthesis are known in the litterature. Neverthless, the purification methods still unknown or quite known. In this work, we have proposed to develop a new method of purification and we have used the extraction properties of TOPO. This method consist to extracting the molybdene with TOPO in acid medium

[en] Twelve chapters review various aspects of solvent extraction, from fundamental theory to practical aspects. One chapter, on use in the nuclear industry, is included as a separate item. (author)

[en] The aqueous solution is contacted with an aminated compound of low solubility in water, for instance a trialkylamine, and the complex formed is separated. Application is made to the recovery of organic phosphorus compounds in effluent for reuse in uranium or plutonium extraction or for extraction of degradation products of TBP

[en] Published in summary form only

[en] From extraction experiments and γ-activity measurements, the extraction constants corresponding to the general equilibrium M⁺(aq) + 1 · Cs⁺(nb) ↔ 1 · M⁺(nb) + Cs⁺(aq) taking part in the two-phase water-nitrobenzene system (1 = hexaarylbenzene-based receptor; M⁺ = H₃O⁺, NH₄⁺, Ag⁺, K⁺, Rb⁺, Tl⁺; aq = aqueous phase, nb = nitrobenzene phase) were evaluated. Furthermore, the stability constants of the ML⁺ complex species in nitrobenzene saturated with water were calculated; they were found to increase in the series of Rb⁺ < K⁺ < Ag⁺, Tl⁺ < H₃O⁺, NH₄⁺. (author)

[en] Several diamide derivates were synthesized in our laboratory. The extraction of actinides and some fission products by these compounds were studied. N,N,N',N'-tetra-(2-ethylhexyl)-3- oxa-pentanediamide (TEHOPDA) has been proven to be a suitable extractant for actinides removal from nitric acid solution. The actinides can be stripped from the loaded solvent by the dilute nitric acid. TEHOPDA showed a high loading capacity to actinides and lanthanides with a mixture of n-octanol and kerosene as the diluent. Considering the extraction and stripping of actinides, 25 mol/L TEHOPDA - 30% n-octanol + 70% kerosene was selected as the solvent. A cascade extraction experiment was carried out with the simulated dissolution of spend fuel as feed. 99.996% U and 99.999% Am, Pu, and Np were extracted in a 4-stage test.

[en] The dynamics of the Ce distribution in a nonequilibrium extraction process are investigated. Results are presented for the extraction of Ce by tributylphosphate in organic diluents from an aqueous solution in which a Belousov-Zhabotinskii oscillating reaction is occurring. The time dependences of [Ce] in the organic phase of the oscillatory extraction system that are synchronous with the redox-potential dependences are obtained for the first time. The effect of the initial concentrations of Ce, oxidant, and organic substrate on the principal parameters of the oscillatory extraction, such as the frequency, amplitude, etc., is found. A conclusion is made about the ability to control an oscillatory extraction process

No abstract available

[en] From extraction experiments and γ-activity measurements, the exchange extraction constants corresponding to the general equilibrium M²⁺(aq) + SrL²⁺ (nb ↔ ML²⁺(nb) + Sr²⁺ (aq) taking place in the two-phase water-nitrobenzene system (M²⁺ = Ca²⁺, Ba²⁺, Pb²⁺, Cd²⁺; L = hexaethyl calix[6]arene hexaacetate; aq = aqueous phase, nb nitrobenzene phase) were evaluated. Moreover, the stability constants of the ML²⁺ complexes in nitrobenzene saturated with water were calculated; they were found to increase in the following order: Cd²⁺ < Ca²⁺ < Sr²⁺ < Pb²⁺ < Ba²⁺. (author)