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Kinetics of high-sulphur and high-arsenic refractory gold concentrate oxidation by dilute nitric acid under mild conditions / Guolong Gao in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 111–115 Titre : Kinetics of high-sulphur and high-arsenic refractory gold concentrate oxidation by dilute nitric acid under mild conditions Type de document : texte imprimé Auteurs : Guolong Gao, Auteur ; Dengxin Li, Auteur ; Zhou, Yong, Auteur Année de publication : 2009 Article en page(s) : pp. 111–115 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  ores  Reaction  kinetics  Oxidation  Mineral  processing Index. décimale : 622 Industrie minière Résumé : On one hand, high-sulphur and high-arsenic refractory gold concentrate (HGC) leads to regional ecological damage. On the other hand, it contains a lot of valuable elements. So utilization of it can bring social and environmental benefits. In this paper, the kinetics of HGC oxidation by dilute nitric acid under mild conditions was investigated. The effects of particle size (50–335 μm), reaction temperature (25–85 °C), initial acid concentration (10–30 wt.%) and stirring speed (400–800 rpm) on the iron extraction rate (Cr) were determined. It is obvious that Cr increases with the rise of initial nitric acid concentration, reaction time and stirring speed, but decreases with the increase of particle size. Oxidation kinetics indicates that the rate of reaction is diffusion controlled. The activation energies were determined to be 10.70 kJ/mol in the 10% HNO3 and 12.25 kJ/mol in the 25% HNO3. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001246 [article] Kinetics of high-sulphur and high-arsenic refractory gold concentrate oxidation by dilute nitric acid under mild conditions [texte imprimé] / Guolong Gao, Auteur ; Dengxin Li, Auteur ; Zhou, Yong, Auteur . - 2009 . - pp. 111–115. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 111–115 Mots-clés : Gold  ores  Reaction  kinetics  Oxidation  Mineral  processing Index. décimale : 622 Industrie minière Résumé : On one hand, high-sulphur and high-arsenic refractory gold concentrate (HGC) leads to regional ecological damage. On the other hand, it contains a lot of valuable elements. So utilization of it can bring social and environmental benefits. In this paper, the kinetics of HGC oxidation by dilute nitric acid under mild conditions was investigated. The effects of particle size (50–335 μm), reaction temperature (25–85 °C), initial acid concentration (10–30 wt.%) and stirring speed (400–800 rpm) on the iron extraction rate (Cr) were determined. It is obvious that Cr increases with the rise of initial nitric acid concentration, reaction time and stirring speed, but decreases with the increase of particle size. Oxidation kinetics indicates that the rate of reaction is diffusion controlled. The activation energies were determined to be 10.70 kJ/mol in the 10% HNO3 and 12.25 kJ/mol in the 25% HNO3. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001246