Abstract
The demand of copper has led to several modifications in the tank house including alternative anodic reactions to reduce the high energy requirement during electrowinning. To reduce the cell voltage, it is necessary to avoid oxygen evolution reaction at the anode which requires a potential in excess of two volts. Alternative anodic reaction such as oxidation of sulphur dioxide (S02) is attractive because the oxidation reaction occurs at much lower potentials and produces H2S04. In the present work, a first attempt has been made to examine the formation of dithionate (Sfi^) and other intermediates using Raman spectroscopy during electrowinning of copper in the presence of S02. The outcome of this work in the formation and buildup of dithionates in the solution affecting the deposition will be significant to the electrochemistry and metallurgy communities. Higher sulphuric acid concentration contributes to the lower dithionate formation.