Documents disponibles écrits par cet auteur

An evaluation of factors affecting the robustness of colour measurement and its potential to predict the grade of flotation concentrate / J.F. Reddick in Minerals engineering, Vol. 22 N° 1 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 1 (Janvier 2009) . - pp. 64–69 Titre : An evaluation of factors affecting the robustness of colour measurement and its potential to predict the grade of flotation concentrate Type de document : texte imprimé Auteurs : J.F. Reddick, Auteur ; A.H. Hesketh, Auteur ; S.H. Morar, Auteur Année de publication : 2009 Article en page(s) : pp. 64–69 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : On-line  analysis  Process  control  Sulphide  ores  Froth  flotation Index. décimale : 622 Industrie minière Résumé : Recent developments in machine vision, applied to froth flotation, show the potential for the use of the measurement of froth surface descriptors to provide an improvement to the operation of flotation cells and banks. One such descriptor, froth colour, has been traditionally assumed to relate to the grade of the concentrate recovered. This work sets out to test this assumption, and was performed using a machine vision system, SmartFroth. This system included a camera hood with built in LED lighting, a colour calibration patch and a CIE ‘Lab’ colour space conversion algorithm, which all served to reduce the effect of ambient lighting on the colour measurements. The effectiveness of these techniques was evaluated by comparing colour measurements of dry synthetic ore under various lighting conditions. It was found that the influence of ambient lighting had not been completely eliminated. Batch flotation tests were conducted on a sulphide ore, from the Kennecott Utah Copperton Concentrator, and established that froth colour does not account for entrained gangue, which is barely visible on the froth surface. Thus, froth colour alone cannot be used to accurately predict concentrate grade. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508000836 [article] An evaluation of factors affecting the robustness of colour measurement and its potential to predict the grade of flotation concentrate [texte imprimé] / J.F. Reddick, Auteur ; A.H. Hesketh, Auteur ; S.H. Morar, Auteur . - 2009 . - pp. 64–69. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 1 (Janvier 2009) . - pp. 64–69 Mots-clés : On-line  analysis  Process  control  Sulphide  ores  Froth  flotation Index. décimale : 622 Industrie minière Résumé : Recent developments in machine vision, applied to froth flotation, show the potential for the use of the measurement of froth surface descriptors to provide an improvement to the operation of flotation cells and banks. One such descriptor, froth colour, has been traditionally assumed to relate to the grade of the concentrate recovered. This work sets out to test this assumption, and was performed using a machine vision system, SmartFroth. This system included a camera hood with built in LED lighting, a colour calibration patch and a CIE ‘Lab’ colour space conversion algorithm, which all served to reduce the effect of ambient lighting on the colour measurements. The effectiveness of these techniques was evaluated by comparing colour measurements of dry synthetic ore under various lighting conditions. It was found that the influence of ambient lighting had not been completely eliminated. Batch flotation tests were conducted on a sulphide ore, from the Kennecott Utah Copperton Concentrator, and established that froth colour does not account for entrained gangue, which is barely visible on the froth surface. Thus, froth colour alone cannot be used to accurately predict concentrate grade. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508000836

Mitigating the generation of acid mine drainage from copper sulfide tailings impoundments in perpetuity / A.H. Hesketh in Minerals engineering, Vol. 23 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 3 (Fevrier 2010) . - pp. 225–229 Titre : Mitigating the generation of acid mine drainage from copper sulfide tailings impoundments in perpetuity : A case study for an integrated management strategy Type de document : texte imprimé Auteurs : A.H. Hesketh, Auteur ; J. L. Broadhurst, Auteur ; S.T.L. Harrison, Auteur Année de publication : 2011 Article en page(s) : pp. 225–229 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Acid  mine  drainage  Sulfide  ores  Froth  flotation  Tailings  disposal  Waste  processing Résumé : Acid mine drainage (AMD) is one of the most serious and pervasive challenges facing the minerals industry. Current philosophy in sulfide tailings management takes an end-of-pipe approach which is yet to be shown to be sufficient to prevent post-closure impacts from AMD and guarantee “walk-away” status. An improved, integrated approach to tailings management and AMD mitigation is proposed, whereby conventional tailings are separated with the use of flotation into a largely benign tailings stream and a sulfide-rich product. The key features of this conceptual approach are outlined and partly demonstrated for the case of porphyry-type copper sulfide tailings. The significance of this approach is that it provides a basis for the identification of opportunities for the development of new process designs incorporating waste management systems for mitigating AMD in a manner consistent with the principles of cleaner production and sustainable development. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509002453 [article] Mitigating the generation of acid mine drainage from copper sulfide tailings impoundments in perpetuity : A case study for an integrated management strategy [texte imprimé] / A.H. Hesketh, Auteur ; J. L. Broadhurst, Auteur ; S.T.L. Harrison, Auteur . - 2011 . - pp. 225–229. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 3 (Fevrier 2010) . - pp. 225–229 Mots-clés : Acid  mine  drainage  Sulfide  ores  Froth  flotation  Tailings  disposal  Waste  processing Résumé : Acid mine drainage (AMD) is one of the most serious and pervasive challenges facing the minerals industry. Current philosophy in sulfide tailings management takes an end-of-pipe approach which is yet to be shown to be sufficient to prevent post-closure impacts from AMD and guarantee “walk-away” status. An improved, integrated approach to tailings management and AMD mitigation is proposed, whereby conventional tailings are separated with the use of flotation into a largely benign tailings stream and a sulfide-rich product. The key features of this conceptual approach are outlined and partly demonstrated for the case of porphyry-type copper sulfide tailings. The significance of this approach is that it provides a basis for the identification of opportunities for the development of new process designs incorporating waste management systems for mitigating AMD in a manner consistent with the principles of cleaner production and sustainable development. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509002453