Chemical solubility of alkali metal uranate(VI) species in molten carbonates under basic and acidic conditions / Volkovich VA,Griffiths TR,Fray DJ,Thied RC // PHYSICAL CHEMISTRY CHEMICAL PHYSICS. - 2000. - V. 2, l. 13. - P. 3029-3035.

ISSN/EISSN:

1463-9076 / нет данных

Type:

Article

Abstract:

A detailed investigation of the dissolution of alkali metal uranates in carbonate melts under the influence of CO(2) and O(2) partial pressures has been performed between 450 and 800 degrees C. At low temperatures or high CO(2) pressure an acidic melt is formed. Acidic dissolution of uranates releases oxide ions and the possible dissolution routes of mono- and diuranates are discussed. At high temperatures carbonates begin to decompose, lose CO(2), and become basic melts. Under these conditions, basic dissolution of uranates occurs and again the possible routes and products are discussed. Oxygen partial pressure influences uranate dissolution due to the formation of peroxycarbonate complexes. Under acidic conditions and using pure O(2) under pressure a maximum solubility of K(2)UO(4) of ca. 37 mol ppm in (Li-Na-K)(2)CO(3) eutectic was evaluated. This system, when under CO(2) and below 600 degrees C, did not produce the expected yellow coloured (quenched) melts from the dissolution of uranates, but gave grey melts that became yellow only on heating above 600 degrees C. The reproducible grey colour is due to a minor contribution from intervalence bands resulting from the formation of very low concentrations of oxygen-deficient polyuranates under these conditions.

Author keywords:

FUSED NA2SO4; NIO; MIXTURES; 1200-K; OXIDATION; OXIDES; UO2

DOI:

10.1039/b001936o

Web of Science ID:

ISI:000088087000026

Соавторы в МНС:

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Другие поля

Поле	Значение
Publisher	ROYAL SOC CHEMISTRY
Address	THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND
Language	English
Keywords-Plus	FUSED NA2SO4; NIO; MIXTURES; 1200-K; OXIDATION; OXIDES; UO2
Research-Areas	Chemistry; Physics
Web-of-Science-Categories	Chemistry, Physical; Physics, Atomic, Molecular \& Chemical
ResearcherID-Numbers	Volkovich, Vladimir/K-8339-2012
ORCID-Numbers	Volkovich, Vladimir/0000-0003-4438-1194
Number-of-Cited-References	36
Usage-Count-Since-2013	5
Journal-ISO	Phys. Chem. Chem. Phys.
Doc-Delivery-Number	332RJ