Studies on Phase Separation Kinetics in Solvent Extraction for Uranium Recovery in DNPPA + TOPO/MGA System

Abstract

The present paper deals with the study on phase separation kinetics of di nonyl phenyl phosphoric acid (DNPPA)–tri octyl phosphine oxide (TOPO)–petrofin–phosphoric acid system. Factorial design of experiment (DOE) has been utilized to illustrate the effect of different process variables such as extractant concentration in the organic phase, phosphoric acid concentration in the aqueous phase, temperature, phase ratio, and stirring speed on phase separation time (tp) and specific settling rates (SSR of organic and aqueous phase). The dependence of individual variables and their mutual interactions on phase separation kinetics was also deduced. A mathematical correlation relating process variables and response (tp and SSR) was developed which allows defining the percent effect of each of the variables on response. The influence of variables on response was found to be significant at 99% confidence level, while the interaction effect among variables aqueous acid concentration, organic concentration, and temperature on tp was significant at 95% confidence level. Dimensionless mathematical correlations were transferred to real variables empirical model to predict the phase separation behavior of DNNPA-TOPO-petrofin-phosphoric acid system and found to be in good agreement with the experimental data.