Laboratory and Pilot Scale Tests of a New Potential-Controlled Method of Copper Industrial Electrolysis

Abstract

Copper electrorefining and electrowinning industrial processes are carried out on industrial scale as current-controlled processes practically from the beginning of the commercial exploitation. However, it is the electrode potential which is a driving force of electrochemical process. The copper electrodeposition from industrial electrolytes is in fact a very complex multi-ion process. Consequently, the theoretical analysis of the experimental results should take into account that in concentrated and complex matrix electrolytes migration, convection and diffusion are mass transfer modes. However, there is only very limited number of papers where copper electroreduction from concentrated electrolytes is considered and most of the published theoretical and experimental studies are carried out in diluted electrolytes of relatively simple compositions where only diffusion of copper ions is considered in theoretical analysis. In the present paper some basic aspects of potential-controlled electrolysis of copper in concentrated and industrial electrolytes as a new method of copper electrorefining and electrowinning are presented and discussed. The pilot scale tests results of copper potential-controlled electrolysis are published for the first time. Apart from the possible industrial applications, studies of the electrochemical processes in concentrated electrolytes are very important from the basic research point of view.