It is accepted worldwide that the dissolution of minerals in some cases, is an electrochemical process where anodic and cathodic reactions take place. There are many parameters, such as agent concentration, that directly affect the dissolution process. The rate of leaching of minerals may differ depending on the oxygen concentration. In this paper, the existence of anodic and cathodic zones on the mineral surface during the dissolution/leaching of minerals and metals has been presented with some different works. It is worth mentioning that a good number of published papers have experimentally demonstrated the existence of anodic and cathodic areas on the mineral surface. (C) 2014 Elsevier B.V. All rights reserved.