Application of Annular Centrifugal Contactor on Separating Indium from Iron

Abstract

It is hard to separate indium from iron in sulfuric acid leachate without reducing Fe³⁺ to Fe²⁺ with di(2-ethylhexyl) phosphoric acid (HDEHP) by the equilibrium extraction process. A nonequilibrium extraction process with annular centrifugal contactors is studied through the extraction kinetics difference between In and Fe. The mass transfer velocities of In and Fe were determined. Laboratory- and industry-scale extraction tests with miniature and industry scale annular centrifugal contactors, respectively, were conducted. The results indicate the mass transfer velocity of In is much faster than that of Fe, the contact time between the two phases is very short in the contactor, and the In can be well separated from Fe in the nonequilibrium extraction process with annular centrifugal contactors.