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Cyanide and copper cyanide recovery by activated carbon / X. Dai in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 469–476 Titre : Cyanide and copper cyanide recovery by activated carbon Type de document : texte imprimé Auteurs : X. Dai, Auteur ; P. L. Breuer, Auteur Année de publication : 2009 Article en page(s) : pp. 469–476 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  ores  Activated  carbon  Cyanidation  Hydrometallurgy Résumé : A process is proposed to recover the cyanide and copper cyanides following the leaching and recovery of gold from copper-containing gold ores. Metallic copper is dissolved into the tailings stream to convert the residual free cyanide to copper cyanides and to concurrently reduce the overall cyanide-to-copper ratio to facilitate copper and cyanide recovery by activated carbon. Metallic copper readily dissolves in both free cyanide and View the MathML source solutions to achieve a final cyanide-to-copper ratio below 3. The theoretical critical CN− and View the MathML source concentration for copper dissolution in air saturated solutions are 2.9 and 2.7 mM, respectively, matching well with the measured values of 3 mM. The copper dissolution rate decreases proportionately with concentration below these critical concentrations. The increase in pH due to oxygen reduction during copper dissolution may cause copper to precipitate as Cu(OH)2. The pH of precipitation decreases with increasing copper concentration and with decreasing cyanide-to-copper ratio. However, precipitation is not observed in the presence of carbon due to the simultaneous adsorption of copper onto carbon, which reduces the solution copper concentration. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002860 [article] Cyanide and copper cyanide recovery by activated carbon [texte imprimé] / X. Dai, Auteur ; P. L. Breuer, Auteur . - 2009 . - pp. 469–476. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 469–476 Mots-clés : Gold  ores  Activated  carbon  Cyanidation  Hydrometallurgy Résumé : A process is proposed to recover the cyanide and copper cyanides following the leaching and recovery of gold from copper-containing gold ores. Metallic copper is dissolved into the tailings stream to convert the residual free cyanide to copper cyanides and to concurrently reduce the overall cyanide-to-copper ratio to facilitate copper and cyanide recovery by activated carbon. Metallic copper readily dissolves in both free cyanide and View the MathML source solutions to achieve a final cyanide-to-copper ratio below 3. The theoretical critical CN− and View the MathML source concentration for copper dissolution in air saturated solutions are 2.9 and 2.7 mM, respectively, matching well with the measured values of 3 mM. The copper dissolution rate decreases proportionately with concentration below these critical concentrations. The increase in pH due to oxygen reduction during copper dissolution may cause copper to precipitate as Cu(OH)2. The pH of precipitation decreases with increasing copper concentration and with decreasing cyanide-to-copper ratio. However, precipitation is not observed in the presence of carbon due to the simultaneous adsorption of copper onto carbon, which reduces the solution copper concentration. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002860