Parametric study of copper electrowinning using a pulsed-bed electrode reactor

Abstract

BACKGROUND: The pulsed bed electrode (PBE) has been used successfully for copper electrodeposition from highly concentrated acidic electrolytes. Advantages of this electrode include high space-time yield (Y) and simple operation and maintenance. In this work, the effects of operational conditions were investigated in an attempt to achieve current efficiencies (CE) higher than 76.7%, which was the maximum value obtained in a previous study. RESULTS:The results showed that use of a high current density and low acid concentration provided the best operational conditions for maximizing CE and Y, and minimizing the energy consumption (EC). Nonetheless, the highest current density was limited to 3000 A cm -2 and the lowest acid concentration was limited to 110 g L -1 , due to limitations such as metal dissolution, dendrite growth, and short circuiting. The highest CE achieved was 77.7%, using 2838 A m -2 . According to a statistical model, the maximum CE value that could be achieved is 82.4%, with application of 3000 A cm -2 . This suggests that further improvement of CE would lead to values of EC lower than those found in electrowinning plants.CONCLUSIONS: Electrowinning using a pulsed-bed electrode is an excellent method for copper production, but additional improvements are required to increase CE.