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Evidence for surface cleaning of sulphide minerals by attritioning in stirred mills / Ye, X. in Minerals engineering, Vol. 23 N° 11-13 (Octobre 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 11-13 (Octobre 2010) . - pp. 937–944 Titre : Evidence for surface cleaning of sulphide minerals by attritioning in stirred mills Type de document : texte imprimé Auteurs : Ye, X., Auteur ; S. Gredelj, Auteur ; W. Skinner, Auteur Année de publication : 2011 Article en page(s) : pp. 937–944 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Attrition  Stirred  milling  Flotation  Surface  oxidation Résumé : Recent developments in large scale stirred milling technology using ceramic media have allowed its application to relatively coarse particle streams. Apart from benefits in grinding finer more efficiently, benefits may also be derived from the surface cleaning action of stirred mills. This paper discusses evidence for the cleaning action of a stirred mill on the surfaces of chalcocite and effects on its subsequent flotation. Single mineral samples of chalcocite were ground with either stainless or mild steel grinding media. The effects of surface contamination by iron hydroxide on chalcocite floatability were studied using ethylene diamine-tetra acetic acid (EDTA) extraction, X-ray photoelectron spectroscopy (XPS) surface analysis and contact angle measurements. Depression of both coarse (+75 μm) and fine (−10 μm) size fractions was attributed to the surface precipitation of iron hydroxide species. Transfer of iron hydroxides from coarse particles to fine particles was observed with XPS analysis. Recovery of coarse particles (+75 μm) was improved by attritioning, while additional collector was needed to fully restore chalcocite recovery in both fine and coarse size fractions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000646 [article] Evidence for surface cleaning of sulphide minerals by attritioning in stirred mills [texte imprimé] / Ye, X., Auteur ; S. Gredelj, Auteur ; W. Skinner, Auteur . - 2011 . - pp. 937–944. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 11-13 (Octobre 2010) . - pp. 937–944 Mots-clés : Attrition  Stirred  milling  Flotation  Surface  oxidation Résumé : Recent developments in large scale stirred milling technology using ceramic media have allowed its application to relatively coarse particle streams. Apart from benefits in grinding finer more efficiently, benefits may also be derived from the surface cleaning action of stirred mills. This paper discusses evidence for the cleaning action of a stirred mill on the surfaces of chalcocite and effects on its subsequent flotation. Single mineral samples of chalcocite were ground with either stainless or mild steel grinding media. The effects of surface contamination by iron hydroxide on chalcocite floatability were studied using ethylene diamine-tetra acetic acid (EDTA) extraction, X-ray photoelectron spectroscopy (XPS) surface analysis and contact angle measurements. Depression of both coarse (+75 μm) and fine (−10 μm) size fractions was attributed to the surface precipitation of iron hydroxide species. Transfer of iron hydroxides from coarse particles to fine particles was observed with XPS analysis. Recovery of coarse particles (+75 μm) was improved by attritioning, while additional collector was needed to fully restore chalcocite recovery in both fine and coarse size fractions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000646

Selective flotation of carbon in the Pb–Zn carbonaceous sulphide ores of Century Mine, Zinifex / S. Gredelj in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 279–288 Titre : Selective flotation of carbon in the Pb–Zn carbonaceous sulphide ores of Century Mine, Zinifex Type de document : texte imprimé Auteurs : S. Gredelj, Auteur ; M. Zanin, Auteur ; S.R. Grano, Auteur Année de publication : 2009 Article en page(s) : pp. 279–288 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Flotation  frothers  Sulphide  ores  Surface  modification Index. décimale : 622 Industrie minière Résumé : Century Mine, operated by Zinifex, is one of the largest zinc and lead deposits in Australia. The ore contains sphalerite and galena as valuable minerals, and carbonaceous material is present among the gangue minerals. The presence of carbonaceous matter is detrimental to the concentration of zinc and lead by flotation. Therefore, preflotation, which is flotation in the absence of collector and prior to galena flotation, is employed to remove some of the organic carbon, some of which is naturally hydrophobic, from the flotation feed. The main issues affecting the effectiveness of preflotation are: (i) low carbon recovery, (ii) low selectivity against zinc, and (iii) very high frother (methyl isobutyl carbinol, MIBC) consumption. The present study revealed that: (a) most of the MIBC added during flotation disappears from solution due to its high adsorption onto ore particles and especially on fine carbon enriched particles which have high surface area, (b) the addition of diesel oil can reduce MIBC consumption by 50% (in laboratory flotation tests) and (c) polypropylene glycol (PPG 192) showed lower affinity for carbon surfaces due to this reagent’s higher hydrophilic/lipophilic balance, producing stable froths at 50% of the current MIBC addition. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002057 [article] Selective flotation of carbon in the Pb–Zn carbonaceous sulphide ores of Century Mine, Zinifex [texte imprimé] / S. Gredelj, Auteur ; M. Zanin, Auteur ; S.R. Grano, Auteur . - 2009 . - pp. 279–288. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 279–288 Mots-clés : Froth  flotation  Flotation  frothers  Sulphide  ores  Surface  modification Index. décimale : 622 Industrie minière Résumé : Century Mine, operated by Zinifex, is one of the largest zinc and lead deposits in Australia. The ore contains sphalerite and galena as valuable minerals, and carbonaceous material is present among the gangue minerals. The presence of carbonaceous matter is detrimental to the concentration of zinc and lead by flotation. Therefore, preflotation, which is flotation in the absence of collector and prior to galena flotation, is employed to remove some of the organic carbon, some of which is naturally hydrophobic, from the flotation feed. The main issues affecting the effectiveness of preflotation are: (i) low carbon recovery, (ii) low selectivity against zinc, and (iii) very high frother (methyl isobutyl carbinol, MIBC) consumption. The present study revealed that: (a) most of the MIBC added during flotation disappears from solution due to its high adsorption onto ore particles and especially on fine carbon enriched particles which have high surface area, (b) the addition of diesel oil can reduce MIBC consumption by 50% (in laboratory flotation tests) and (c) polypropylene glycol (PPG 192) showed lower affinity for carbon surfaces due to this reagent’s higher hydrophilic/lipophilic balance, producing stable froths at 50% of the current MIBC addition. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002057