METHOD FOR EXTRACTING AND SEPARATING HIGH-MELTING AND RARE-EARTH ELEMENTS FROM NITRIC SOLUTIONS Russian patent published in 1998 - IPC

FIELD: recovery of spent fuel of nuclear power stations by separating high-melting and rare-earth fractions from highly active wastes. SUBSTANCE: for extracting and separating high-melting and rare earth elements from nitric solutions, zirconium salt solution in organophosphorous acid, primarily dibutyl phosphorous acid in neutral organophosphorous chemical, is used. Organic chemical is usually tributyl phosphate of 5-46 vol.% concentration in inert thinner. During extraction, molar ratio of zirconium to dibutyl phosphate acid is 1/50 to 1/4. Extracting agent is compatible with the Pyrex-process extraction technology. High-melting and rare-earth elements are separated by rinsing extraction agent with nitric acid solution of 3-12 mol/1 concentration followed by re-extraction of rare-earth elements. Circulating extraction agent is regenerated by removing zirconium salt of organophosphorous acid by rinsing in carbonate-alkali solution. Method is compatible with circulating extraction agent of first recovery cycle of spent fuel. EFFECT: enlarged functional capabilities. 6 cl, 1 dwg, 2 tbl