TY - JOUR
T1 - Leaching of chalcopyrite with ferric ion. Part III
T2 - Effect of redox potential on the silver-catalyzed process
AU - Córdoba, E. M.
AU - Muñoz, J. A.
AU - Blázquez, M. L.
AU - González, F.
AU - Ballester, A.
PY - 2008/8
Y1 - 2008/8
N2 - This study examines the effect of redox potential on silver-catalyzed chalcopyrite leaching. Leaching tests were carried out in stirred Erlenmeyer flasks with 0.5 g chalcopyrite mineral, 1 g Ag/kg Cu and 100 mL of a sulphate solution of Fe3+/Fe2+ (with redox potential ranging between 300 and 600 mV Ag/AgCl) at pH 1.8, 180 rpm and 35°C or 68 °C. Unlike uncatalyzed leaching, an increase of the redox potential increased copper dissolution in the presence of silver ions, as the regeneration of Ag+ requires a high concentration of oxidizing agent, Fe3+. Additionally, the high reactivity of the mineral surface when silver was present could have been responsible for inhibiting the nucleation of hydrolysis products of Fe3+ on it. Excessive addition of silver transformed the chalcopyrite surface into copper-rich sulphides such as covellite, CuS, and geerite, Cu8S5, preventing the formation of CuFeS2/Ag2S galvanic couple and the recycling of silver ions.
AB - This study examines the effect of redox potential on silver-catalyzed chalcopyrite leaching. Leaching tests were carried out in stirred Erlenmeyer flasks with 0.5 g chalcopyrite mineral, 1 g Ag/kg Cu and 100 mL of a sulphate solution of Fe3+/Fe2+ (with redox potential ranging between 300 and 600 mV Ag/AgCl) at pH 1.8, 180 rpm and 35°C or 68 °C. Unlike uncatalyzed leaching, an increase of the redox potential increased copper dissolution in the presence of silver ions, as the regeneration of Ag+ requires a high concentration of oxidizing agent, Fe3+. Additionally, the high reactivity of the mineral surface when silver was present could have been responsible for inhibiting the nucleation of hydrolysis products of Fe3+ on it. Excessive addition of silver transformed the chalcopyrite surface into copper-rich sulphides such as covellite, CuS, and geerite, Cu8S5, preventing the formation of CuFeS2/Ag2S galvanic couple and the recycling of silver ions.
UR - http://www.scopus.com/inward/record.url?scp=45049084312&partnerID=8YFLogxK
U2 - 10.1016/j.hydromet.2007.11.006
DO - 10.1016/j.hydromet.2007.11.006
M3 - Artículo en revista científica indexada
AN - SCOPUS:45049084312
SN - 0304-386X
VL - 93
SP - 97
EP - 105
JO - Hydrometallurgy
JF - Hydrometallurgy
IS - 3-4
ER -