Electrochemical generation of stable uranium(IV) fluoride-sulphate solutions
Abstract
The electrolytic reduction of uranium(VI) to uranium(IV) was investigated exhaustively in a mixed fluoride-sulphate medium. Highly efficient reduction can be achieved and the discovery and confirmation of high solubility in the uranium(IV) fluoride-sulphate system has shown this reduction to be both an efficient and economic process. Conditions equivalent to 200 g l–1 UIV, 0.75 M HF and 0.5 M H2SO4(representing molar ratios of SO42– : U = 1.5: 1 and F– : U = 1 : 1) were demonstrated as optimum for both UIV solubility and UVI reduction efficiency. Cell reduction efficiency and membrane ion transport data together with solubility and stability data for the reduced UIV species are presented. The mechanisms and factors governing the observed results are discussed.