The influence of diluent on the extraction behavior of uranium with N-octanoylpyrrolidine

Extraction of uranium(VI) from nitric acid solutions with N-octanoylpyrrolidine (OPOD) in a series of diluents has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nitric acid, extractant, salting-out agent and the temperature was investigated. The experimental results showed that the extracting capacity of OPOD in different diluents increases in the order: chloroform, carbon tetrachloride, 1,2-dichloroethane, n-dodecane, n-octane, cyclohexane, toluene and benzene. This can not be explained only on the theory of polarity of the diluents. The interaction between extractant and the extracted complex and diluent is discussed.