Documents disponibles écrits par cet auteur

Effect of grinding media on the activation of pyrite flotation / Yongjun Peng in Minerals engineering, Vol. 23 N° 8 (Juillet 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 8 (Juillet 2010) . - pp. 600–605 Titre : Effect of grinding media on the activation of pyrite flotation Type de document : texte imprimé Auteurs : Yongjun Peng, Auteur ; Stephen Grano, Auteur Année de publication : 2011 Article en page(s) : pp. 600–605 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Grinding  media  Pyrite  flotation  Activation  Copper  Lead Résumé : In previous study, it has been found that the grinding conditions have a great effect on the flotation of chalcopyrite and galena as well as their separation from pyrite ( [Peng et al., 2003a] and [Peng et al., 2003b]). In this study, the effect of the grinding conditions on the activation of pyrite by Cu2+ and Pb2+ were investigated. Based on flotation behaviour, EDTA (ethylene diamine-tetra acid) extraction, pulp potential measurement and electrokinetic study, it is found that the activation of pyrite flotation by Cu2+ and Pb2+ involves different mechanisms. Reduction of copper(II) to copper(I) and the formation of new copper sulphide phases are responsible for the activation of pyrite flotation by Cu2+. This is an electrochemical process. However, adsorption of lead hydroxide on pyrite surface is principally responsible for the activation of pyrite flotation by Pb2+. The effect of grinding media on the flotation of pyrite activated by Cu2+ or Pb2+ is through the change of pulp potential and iron oxidation species emanating from the media. The iron oxidation species from grinding media is electrostatically repulsive with respect to copper-activated pyrite and therefore, reducing conditions produced by mild steel medium promotes pyrite flotation in the presence of Cu2+. However, iron oxidation species from grinding media is electrostatically attractive with respect to lead-activated pyrite and therefore inert grinding medium favours pyrite flotation in the presence of Pb2+. This study provides a clear picture of how to increase or decrease pyrite flotation through a smart selection of grinding media. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000397 [article] Effect of grinding media on the activation of pyrite flotation [texte imprimé] / Yongjun Peng, Auteur ; Stephen Grano, Auteur . - 2011 . - pp. 600–605. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 8 (Juillet 2010) . - pp. 600–605 Mots-clés : Grinding  media  Pyrite  flotation  Activation  Copper  Lead Résumé : In previous study, it has been found that the grinding conditions have a great effect on the flotation of chalcopyrite and galena as well as their separation from pyrite ( [Peng et al., 2003a] and [Peng et al., 2003b]). In this study, the effect of the grinding conditions on the activation of pyrite by Cu2+ and Pb2+ were investigated. Based on flotation behaviour, EDTA (ethylene diamine-tetra acid) extraction, pulp potential measurement and electrokinetic study, it is found that the activation of pyrite flotation by Cu2+ and Pb2+ involves different mechanisms. Reduction of copper(II) to copper(I) and the formation of new copper sulphide phases are responsible for the activation of pyrite flotation by Cu2+. This is an electrochemical process. However, adsorption of lead hydroxide on pyrite surface is principally responsible for the activation of pyrite flotation by Pb2+. The effect of grinding media on the flotation of pyrite activated by Cu2+ or Pb2+ is through the change of pulp potential and iron oxidation species emanating from the media. The iron oxidation species from grinding media is electrostatically repulsive with respect to copper-activated pyrite and therefore, reducing conditions produced by mild steel medium promotes pyrite flotation in the presence of Cu2+. However, iron oxidation species from grinding media is electrostatically attractive with respect to lead-activated pyrite and therefore inert grinding medium favours pyrite flotation in the presence of Pb2+. This study provides a clear picture of how to increase or decrease pyrite flotation through a smart selection of grinding media. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000397

The critical importance of the grinding environment on fine particle recovery in flotation / Stephen Grano in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 386–394 Titre : The critical importance of the grinding environment on fine particle recovery in flotation Type de document : texte imprimé Auteurs : Stephen Grano, Auteur Année de publication : 2009 Article en page(s) : pp. 386–394 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Grinding  environment  Grinding  media  Fine  particle  flotation Résumé : This paper examines published and new experimental evidence on the effect of the grinding environment on fine (−10 μm) value mineral recovery in flotation. Reasons for increases in fine value mineral recovery from ores with fully electrochemically inert grinding media are discussed in relation to reduced surface contamination by iron hydroxide emanating from the grinding media. The application of stirred milling technology, which allows the use of fully inert grinding media, to primary grinding applications may lead to increased fine value mineral recovery in flotation rougher applications. It is suggested that the effect of the grinding media, which is important for fine particles and progressively becomes more important as the grind size becomes finer, is principally due to the abrasion mechanism of the minerals with the grinding media in the production of fine particles. Opportunities for research and industry application are discussed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002549 [article] The critical importance of the grinding environment on fine particle recovery in flotation [texte imprimé] / Stephen Grano, Auteur . - 2009 . - pp. 386–394. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 386–394 Mots-clés : Grinding  environment  Grinding  media  Fine  particle  flotation Résumé : This paper examines published and new experimental evidence on the effect of the grinding environment on fine (−10 μm) value mineral recovery in flotation. Reasons for increases in fine value mineral recovery from ores with fully electrochemically inert grinding media are discussed in relation to reduced surface contamination by iron hydroxide emanating from the grinding media. The application of stirred milling technology, which allows the use of fully inert grinding media, to primary grinding applications may lead to increased fine value mineral recovery in flotation rougher applications. It is suggested that the effect of the grinding media, which is important for fine particles and progressively becomes more important as the grind size becomes finer, is principally due to the abrasion mechanism of the minerals with the grinding media in the production of fine particles. Opportunities for research and industry application are discussed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002549