Aspects of the development of a copper electrowinning cell based on reactive electrodialysis

Abstract

This paper reports work aimed at developing a new copper electrowinning cell based on reactive electrodialysis (RED) which uses Fe 2+→Fe 3++e as anodic reaction. In this lab-scale cell, the anolyte (aqueous FeSO 4+H 2SO 4) and the catholyte (aqueous CuSO 4+H 2SO 4) are kept separate by an anion membrane which prevents cation and water transport between the electrolytes. Both solutions are agitated by recirculation. The kinetics of the anodic reaction have been studied via potentiodynamic experiments on various anode materials (lead, platinum, ruthenium oxide, iridium oxide and graphite). The highest oxidation rate was obtained on platinum and the lowest one on lead, whereas the remaining materials showed satisfactory performance. Results in the lab-scale RED cell show that, depending on experimental conditions, for a cell current density of 400 A/ m 2 , the cell voltage ranges from 1.81 to 1.89 V , the cathodic current efficiency from 97.2% to 98.3% and the specific energy consumption, from 1.53 to 1.59 kWh/ kg of deposited copper.