Cyclic voltammetry and potentiodynamic polarization studies of chalcopyrite concentrate in glycine medium
(1. Department of Mining and Metallurgical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran;
2. Department of Mining Engineering, University of Kashan, Kashan, Iran;
3. Department of Chemical and Metallurgical Engineering (CMET), School of Chemical Engineering, Aalto University, P. O. Box 16200, Espoo, Finland;
4. Sarcheshmeh Copper Complex, National Iranian Copper Industries Company, Rafsanjan, Iran)
2. Department of Mining Engineering, University of Kashan, Kashan, Iran;
3. Department of Chemical and Metallurgical Engineering (CMET), School of Chemical Engineering, Aalto University, P. O. Box 16200, Espoo, Finland;
4. Sarcheshmeh Copper Complex, National Iranian Copper Industries Company, Rafsanjan, Iran)
Abstract: Cyclic voltammetry and potentiodynamic polarization analyses were utilized to investigate the mechanism and kinetics of glycine leaching reactions for chalcopyrite. The effects of pH (9-12), temperature (30-90 °C) and glycine concentration (0-2 mol/L) on corrosion current density, corrosion potential and cyclic voltammograms were investigated using chalcopyrite concentrate-carbon paste electrodes. Results showed that an increase in the glycine concentration from 0 to 2 mol/L led to an increased oxidation peak current density. Under the same conditions, corrosion current density was found to change from approximately 28 to 89 μA/cm2, whereas corrosion potential was decreased from -80 to -130 mV. Elevated temperatures enhanced the measured current densities up to 60 °C; however, above this level, current density was observed to decrease. A similar current density behavior was determined with pH. A pH change from 9 to 10.5 resulted in an increase in current density and pH higher than 10.5 gave rise to a reduced current density. In addition, the thermodynamic stability of copper and iron oxides was found to increase at higher temperatures.
Key words: glycine; corrosion current density; corrosion potential; electrochemical behaior; chalcopyrite concentrate