The effect of organic substituents and structure of organophosphorus compounds on their extraction abilities for uranium

Abstract

With 12 phosphates, 1 phosphonate, 1 phosphinate and 1 phosphine oxide, the pattern of uranium extraction from nitric acid media was investigated. The extraction was affected by the nature of the organic substituents attached to the phosphoryl group as well as by the solvent structure. Phosphates with aryl groups were not satisfactory extractants. The extraction ability increased as the alkyl group was made larger; phosphates with branching alkyl groups were better than phosphates with normal alkyl groups. Removal of the alkoxyl oxygen enhanced the extracting abilities. The relative order of the extracting abilities were: tri- n-butyl phosphine oxide and tri- n-butyl phosphinate > tricyclohexyl phosphate > diethylbutyl phosphonate > phosphates with branching alkyl groups > phosphates with normal alkyl groups > phosphates with aryl groups.