On a Possible Role of Microemulssons for Achieving the Separation of Ni2+and Co2+from Their Mixtures on a Kinetic Basis

Abstract
Complexation of Ni2+ or Co2+ with extractant molecules is usually a very fast process. A separation of the two metals from their mixtures on a kinetic basis would require a considerable slowing down of the rates of complexation. We show here that this can be achieved with microemulsions of a lipophilic extractant by taking advantage of the electrostatic repulsions between the metal ions and the charged surface of the dispersed particles. The effects of pH, extractant concentration, and purity are examined.