Application of Mixed Potential Theory to Leaching of Mineral Phases

Leaching is a central unit operation in the hydrometallurgical processing of minerals, which often occurs by means of electrochemical reactions. The objective of this study is to apply mixed potential theory to elucidate the kinetics involved in oxidative and reductive leaching processes. The methodology involves an examination of electron-conducting phases such as native metals, selected oxides, and most base metal sulfides, analyzing their leaching mechanisms which may include normal corrosion, passivation, or galvanic couple mechanisms. The study enables the calculation of mixed potentials and overall reaction kinetics through the presentation of various examples illustrating the electrochemical nature of selected leaching processes. The results highlight the significance of mixed potentials, geometry, and associated kinetic reactions in influencing leaching efficacy. This research contributes valuable insights into the optimization of hydrometallurgical processes, fostering enhanced metal recovery practices. Scholars and practitioners in the field will find the insights useful for further advancements in mineral processing techniques.