Influence of temperature on Pu(IV) extraction from nitric acid solutions into 30% TBP, considered within the framework of A.M. Rozen’s model and of a new (multireaction) model

Published and newly obtained data on the influence of temperature on the extraction of Pu(IV) from nitric acid solutions into 30% TBP are analyzed. The analysis shows that both A.M. Rozen’s model and the new (multireaction) model insufficiently accurately describe the influence of temperature on the Pu(IV) extraction at HNO3 concentrations in the aqueous phase of 1 M and lower, where Pu(IV) can undergo partial hydrolysis, and at HNO3 concentrations of 4 M and higher. Changes are made in the system of equilibrium constants in both models.