摘要 |
<p>Uranium and thorium are separated from each other by subjecting an aqueous feed of their nitrates to an extraction by a solution of tributyl phosphate in an organic medium, controlling the respective volume of the solution and the aqueous feed such that the concentration of uranium in the organic phase thus obtained is close to its theoretical saturation, scrubbing the organic phase with an aqueous solution of nitric acid or of uranyl nitrate acidified by nitric acid, which aqueous solution contains complexing ions for thorium in an amount sufficiently small to keep the organic phase saturated with uranium, and recovering the uranium from the scrubbed organic phase. The organic phase can be kerosene. The complexing ions for thorium are selected from phosphates, sulphates, fluorides, oxalates and mixtures thereof.</p> |