Studies on the phase separation kinetics in solvent extraction for uranium recovery in DNPPA + TOPO/MGA system

A process was developed to recover uranium from wet process phosphoric acid (WPA) as well as merchant grade acid (MGA 12 M) by solvent extraction using 0.6 M di-nonyl phenyl phosphoric acid (DNPPA) + 0.3 M tri octyl phosphine oxide (TOPO). Merchant grade acid (MGA 12 M) is the concentrated form of WPA (6M). Solvent extraction process essentially involves the study of the mass transfer in the mixer compartment and phase separation in settler compartment of the mixer settler cascade. Phase separation kinetics in solvent extraction plays an important role in deciding the settler dimensions and solvent inventry in mixer settler cascades. The effect of experimental variables such as extractant concentration, acid concentration of the aqueous phase, temperature, phase ratio (A/O), stirring speed on phase disengagement kinetics was investigated in the present paper