Determining of Diffusion Coefficients in Aqueous Electrolyte Solutions

Abstract

Processes of extractive metallurgy include both heterogeneous and homogeneous reactions. Mass transfer rate to reaction interfaces, for example, an interface between an electrode and an aqueous solution in electrorefining processes, controlled the overall reaction rate of processes. Although the diffusion coefficient of solute is a fundamental parameter for mass transfer, available data are still limited at present. Therefore, it is often necessary to measure the values of diffusion coefficient under the conditions concerned. In this review paper, some techniques for determining diffusion coefficients of electrolytes in aqueous solutions are described with discussion on several points to be careful in the experiments, which includes the methods using a porous diaphragm cell, optical instruments and electrochemical devices.