Extraction of uranium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A)

The extraction behavior of uranium (VI) from chloride medium with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) in dodecane has been investigated under wide range of conditions. Attempts have been made to establish the extraction mechanism of uranium(VI) with PC-88A. Treatment of the distribution data by slope analysis technique showed the formation of a monomeric complex of the nature [UO2(A(2)H)(2)]. Formation of this species was also confirmed by non-linear least square regression of the distribution data to the mathematical expression correlating percentage extraction and acidity. In this investigation attempts have also been made to develop a mathematical model for the system (UO2Cl2-HCl-H2O-PC-88A-dodecane) using experimental data on the distribution of uranium against initial aqueous acidity at different initial metal concentration. The mathematical model D = 37.547+/-0.223/C(i)(1/2)x[H-i](2) can be used to predict the concentration of uranium in organic as well as in aqueous phases at any initial concentration of uranium [C-i] and initial hydrogen ion concentration [H-i]. The extraction constant (K-ex) has been calculated.