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Effect of mechano-chemical activation on bioleaching of Indian Ocean nodules by a fungus / K.D. Mehta in Minerals engineering, Vol. 23 N° 15 (Décembre 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 15 (Décembre 2010) . - pp. 1207–1212 Titre : Effect of mechano-chemical activation on bioleaching of Indian Ocean nodules by a fungus Type de document : texte imprimé Auteurs : K.D. Mehta, Auteur ; Chitrangada Das, Auteur ; Kumar, Rakesh, Auteur Année de publication : 2011 Article en page(s) : pp. 1207–1212 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Mechano-chemical  activation  Ocean  nodules  Bioleaching  Aspergillus  niger Résumé : The effect of mechano-chemical activation of Indian sea nodules, while recording the zeta potential, particle size distribution and surface area, on the bio-dissolution of metals by Aspergillus niger has been investigated. Activation is a term used to indicate what takes place when increasing grinding time does not result in significant change in particle size but rather results in the accumulation of energy that may lead to the development of lattice defects within the particles that can aid biological attack. It was observed that the mechano-chemical activation improved the bio-dissolution of metals such as copper, nickel and cobalt from the sea nodules at initial pH in the range 4.0–5.0. With 10 min milling of particles of ⩽75 μm size, 86% material was reduced to ⩽10 μm size with a change in zeta potential from −18 to −34 mV. Above 95% copper, nickel and cobalt each was leached out in 15 days time from the nodules activated for 10 min at 5% (w/v) PD and 35 °C temperature with initial pH of 4.5; the biorecovery being almost similar when the material was activated for 30 min. In the case of nodules without activation, ⩾89% metal bioleaching was achieved in 25 days time at an initial pH of 4.5 under this condition. The mechano-chemical activation of sea nodules has thus influenced the bio-dissolution process, while providing a wider pH range available for processing of nodules with the involvement of organic acids such as oxalic and citric generated from the fungus. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510002074 [article] Effect of mechano-chemical activation on bioleaching of Indian Ocean nodules by a fungus [texte imprimé] / K.D. Mehta, Auteur ; Chitrangada Das, Auteur ; Kumar, Rakesh, Auteur . - 2011 . - pp. 1207–1212. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 15 (Décembre 2010) . - pp. 1207–1212 Mots-clés : Mechano-chemical  activation  Ocean  nodules  Bioleaching  Aspergillus  niger Résumé : The effect of mechano-chemical activation of Indian sea nodules, while recording the zeta potential, particle size distribution and surface area, on the bio-dissolution of metals by Aspergillus niger has been investigated. Activation is a term used to indicate what takes place when increasing grinding time does not result in significant change in particle size but rather results in the accumulation of energy that may lead to the development of lattice defects within the particles that can aid biological attack. It was observed that the mechano-chemical activation improved the bio-dissolution of metals such as copper, nickel and cobalt from the sea nodules at initial pH in the range 4.0–5.0. With 10 min milling of particles of ⩽75 μm size, 86% material was reduced to ⩽10 μm size with a change in zeta potential from −18 to −34 mV. Above 95% copper, nickel and cobalt each was leached out in 15 days time from the nodules activated for 10 min at 5% (w/v) PD and 35 °C temperature with initial pH of 4.5; the biorecovery being almost similar when the material was activated for 30 min. In the case of nodules without activation, ⩾89% metal bioleaching was achieved in 25 days time at an initial pH of 4.5 under this condition. The mechano-chemical activation of sea nodules has thus influenced the bio-dissolution process, while providing a wider pH range available for processing of nodules with the involvement of organic acids such as oxalic and citric generated from the fungus. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510002074