Dépouillements

On the role of cavitation in particle collection in flotation – A critical review. II / Z.A. Zhou in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 419–433 Titre : On the role of cavitation in particle collection in flotation – A critical review. II Type de document : texte imprimé Auteurs : Z.A. Zhou, Auteur ; Zhenghe Xu, Auteur ; J.A. Finch, Auteur Année de publication : 2009 Article en page(s) : pp. 419–433 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Bubbles  Hydrodynamic  cavitation  Flotation  Coal  Oil  sands Résumé : Research in applying hydrodynamic cavitation to recovery of natural resources during the last decade is reviewed. The existence and formation of tiny bubbles or gas nuclei (with diameter from microns down to nano sizes) in natural water were verified from both direct and in-direct measurements, thus providing a foundation for applying hydrodynamic cavitation to flotation systems. The interactions between tiny bubbles and fine particles in aqueous slurry were analysed based on particle surface properties and types of gas nuclei present in water. Tiny bubbles generated by hydrodynamic cavitation were found to increase contact angle of solids and hence attachment force, bridge fine particles to form aggregates, minimize slime coating, remove oxidation layers on particle surfaces, and in consequence reduce reagents consumption. Experiments on generating tiny bubbles by hydrodynamic cavitation revealed that the energy dissipation levels for cavity formation in a flowing liquid could be much lower than predicted, depending on the content of dissolved gases, presence of free gas nuclei and design of cavitation tubes. Application of hydrodynamic cavitation to fine and coarse particle flotation, high intensity conditioning, oil agglomeration of fine coal, and oil sands processing has confirmed the role of tiny bubbles formed by cavitation in improving recovery efficiency. Based on the characteristics of vapor cavity bubbles, increased flotation kinetics by hydrodynamic cavitation could be attributed to a dual role: some collapsing cavity bubbles serving to break interfacial layers on particle surfaces, while other cavity bubbles attaching to those freshly exposed mineral surfaces. The role of water vapor and other gases within cavity bubbles in particle–bubble attachment remains to be explored, as does the action of frothers. Incorporating hydrodynamic cavitation into flotation systems to take advantage of its unique features is expected to develop the next generation of flotation machines. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002847 [article] On the role of cavitation in particle collection in flotation – A critical review. II [texte imprimé] / Z.A. Zhou, Auteur ; Zhenghe Xu, Auteur ; J.A. Finch, Auteur . - 2009 . - pp. 419–433. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 419–433 Mots-clés : Bubbles  Hydrodynamic  cavitation  Flotation  Coal  Oil  sands Résumé : Research in applying hydrodynamic cavitation to recovery of natural resources during the last decade is reviewed. The existence and formation of tiny bubbles or gas nuclei (with diameter from microns down to nano sizes) in natural water were verified from both direct and in-direct measurements, thus providing a foundation for applying hydrodynamic cavitation to flotation systems. The interactions between tiny bubbles and fine particles in aqueous slurry were analysed based on particle surface properties and types of gas nuclei present in water. Tiny bubbles generated by hydrodynamic cavitation were found to increase contact angle of solids and hence attachment force, bridge fine particles to form aggregates, minimize slime coating, remove oxidation layers on particle surfaces, and in consequence reduce reagents consumption. Experiments on generating tiny bubbles by hydrodynamic cavitation revealed that the energy dissipation levels for cavity formation in a flowing liquid could be much lower than predicted, depending on the content of dissolved gases, presence of free gas nuclei and design of cavitation tubes. Application of hydrodynamic cavitation to fine and coarse particle flotation, high intensity conditioning, oil agglomeration of fine coal, and oil sands processing has confirmed the role of tiny bubbles formed by cavitation in improving recovery efficiency. Based on the characteristics of vapor cavity bubbles, increased flotation kinetics by hydrodynamic cavitation could be attributed to a dual role: some collapsing cavity bubbles serving to break interfacial layers on particle surfaces, while other cavity bubbles attaching to those freshly exposed mineral surfaces. The role of water vapor and other gases within cavity bubbles in particle–bubble attachment remains to be explored, as does the action of frothers. Incorporating hydrodynamic cavitation into flotation systems to take advantage of its unique features is expected to develop the next generation of flotation machines. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002847

Automated analysis of aluminium bath electrolytes by the Rietveld method / Karsten Knorr in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 434–439 Titre : Automated analysis of aluminium bath electrolytes by the Rietveld method Type de document : texte imprimé Auteurs : Karsten Knorr, Auteur ; Chris Kelaart, Auteur Année de publication : 2009 Article en page(s) : pp. 434–439 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Non-ferrous  metallic  ores  Electrometallurgy  Process  control Résumé : Rietveld analysis emerged as a routine tool in quantitative phase analysis of crystalline powder samples. Here, XRD data from solidified aluminium electrolytes were rapidly obtained with a 1-dimensional silicon strip detector and analysed with the TOPAS software. It is shown how to calculate well established process control measures such as Bath ratio and excess AlF3 from the Rietveld results. These measures are widely used in aluminium production and are readily calculated with very high precision. The excellent agreement with Alcan reference data demonstrates the outstanding accuracy of the method. Furthermore, it is shown how to improve conventional Potflux analysis by the Rietveld method. Finally, the automated investigation of aluminium bath samples in AXSLAB is outlined. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002720 [article] Automated analysis of aluminium bath electrolytes by the Rietveld method [texte imprimé] / Karsten Knorr, Auteur ; Chris Kelaart, Auteur . - 2009 . - pp. 434–439. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 434–439 Mots-clés : Non-ferrous  metallic  ores  Electrometallurgy  Process  control Résumé : Rietveld analysis emerged as a routine tool in quantitative phase analysis of crystalline powder samples. Here, XRD data from solidified aluminium electrolytes were rapidly obtained with a 1-dimensional silicon strip detector and analysed with the TOPAS software. It is shown how to calculate well established process control measures such as Bath ratio and excess AlF3 from the Rietveld results. These measures are widely used in aluminium production and are readily calculated with very high precision. The excellent agreement with Alcan reference data demonstrates the outstanding accuracy of the method. Furthermore, it is shown how to improve conventional Potflux analysis by the Rietveld method. Finally, the automated investigation of aluminium bath samples in AXSLAB is outlined. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002720

The recovery of silver from mining wastewaters using hybrid cyanidation and high-pressure membrane process / H. Koseoglu in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 440–444 Titre : The recovery of silver from mining wastewaters using hybrid cyanidation and high-pressure membrane process Type de document : texte imprimé Auteurs : H. Koseoglu, Auteur ; M. Kitis, Auteur Année de publication : 2009 Article en page(s) : pp. 440–444 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Cyanidation  Environmental  Filtration  Precious  metal  ores  Waste  processing Résumé : The main objective of this work was to investigate the recovery of silver from mining wastewaters using a hybrid cyanidation and high-pressure membrane process. The tested hybrid process in lab-scale experiments includes the concentration and recovery of silver by nanofiltration (NF) or reverse osmosis (RO) after the silver is taken into solution as AgCN employing re-cyanidation and subsequent sedimentation and/or pre-filtration of wastewaters. Synthetic water experiments were conducted in this work. In synthetic water experiments (in distilled and deionized water), the soluble AgCN complex was formed after cyanidation of low-soluble AgCl particles which were added to the leach tank. Two different NF membranes and one RO membrane were tested in a lab-scale flat-sheet configuration test unit. The results indicated that although a significant amount of silver was lost on the RO membrane due to irreversible sorption, RO membrane performed better than NF membranes based on higher silver rejections, thus higher mass recoveries. Therefore, RO membrane was found to be more effective in terms of precious metal recovery and production of high quality permeate that can be reused in the leaching process. The tested hybrid cyanidation (leaching) and high-pressure membrane process in this work may be an effective approach in recovering precious metals and producing reusable water from wastes or wastewaters of mining industry. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002768 [article] The recovery of silver from mining wastewaters using hybrid cyanidation and high-pressure membrane process [texte imprimé] / H. Koseoglu, Auteur ; M. Kitis, Auteur . - 2009 . - pp. 440–444. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 440–444 Mots-clés : Cyanidation  Environmental  Filtration  Precious  metal  ores  Waste  processing Résumé : The main objective of this work was to investigate the recovery of silver from mining wastewaters using a hybrid cyanidation and high-pressure membrane process. The tested hybrid process in lab-scale experiments includes the concentration and recovery of silver by nanofiltration (NF) or reverse osmosis (RO) after the silver is taken into solution as AgCN employing re-cyanidation and subsequent sedimentation and/or pre-filtration of wastewaters. Synthetic water experiments were conducted in this work. In synthetic water experiments (in distilled and deionized water), the soluble AgCN complex was formed after cyanidation of low-soluble AgCl particles which were added to the leach tank. Two different NF membranes and one RO membrane were tested in a lab-scale flat-sheet configuration test unit. The results indicated that although a significant amount of silver was lost on the RO membrane due to irreversible sorption, RO membrane performed better than NF membranes based on higher silver rejections, thus higher mass recoveries. Therefore, RO membrane was found to be more effective in terms of precious metal recovery and production of high quality permeate that can be reused in the leaching process. The tested hybrid cyanidation (leaching) and high-pressure membrane process in this work may be an effective approach in recovering precious metals and producing reusable water from wastes or wastewaters of mining industry. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002768

The adsorption of sulfur dispersing agents on sulfur and nickel sulfide concentrate surfaces / Libin Tong in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 445–450 Titre : The adsorption of sulfur dispersing agents on sulfur and nickel sulfide concentrate surfaces Type de document : texte imprimé Auteurs : Libin Tong, Auteur ; David Dreisinger, Auteur Année de publication : 2009 Article en page(s) : pp. 445–450 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulfide  ores  Hydrometallurgy  Leaching  Pressure  oxidation  Liquid  sulfur Résumé : The adsorption behavior of sulfur dispersing agents, including lignosulfonate, Quebracho, o-phenylenediamine (OPD), and humic acid on elemental sulfur and nickel sulfide concentrate was investigated. The charge changes on elemental sulfur surface were characterized by the measurement of the electrokinetic sonic amplitude (ESA) signal. The adsorption behavior of OPD was investigated by measuring the interfacial tension between liquid sulfur and nickel sulfate solution at 140 °C. The adsorption of lignosulfonate on the molten sulfur surface was calculated by the Gibbs Equation. The adsorption of lignosulfonate, Quebracho, and humic acid on the nickel concentrate was studied at ambient temperature. The adsorption mechanism of sulfur dispersing agents on both elemental sulfur and nickel concentrate were discussed. The stability of OPD in the nickel concentrate slurry was discussed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002781 [article] The adsorption of sulfur dispersing agents on sulfur and nickel sulfide concentrate surfaces [texte imprimé] / Libin Tong, Auteur ; David Dreisinger, Auteur . - 2009 . - pp. 445–450. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 445–450 Mots-clés : Sulfide  ores  Hydrometallurgy  Leaching  Pressure  oxidation  Liquid  sulfur Résumé : The adsorption behavior of sulfur dispersing agents, including lignosulfonate, Quebracho, o-phenylenediamine (OPD), and humic acid on elemental sulfur and nickel sulfide concentrate was investigated. The charge changes on elemental sulfur surface were characterized by the measurement of the electrokinetic sonic amplitude (ESA) signal. The adsorption behavior of OPD was investigated by measuring the interfacial tension between liquid sulfur and nickel sulfate solution at 140 °C. The adsorption of lignosulfonate on the molten sulfur surface was calculated by the Gibbs Equation. The adsorption of lignosulfonate, Quebracho, and humic acid on the nickel concentrate was studied at ambient temperature. The adsorption mechanism of sulfur dispersing agents on both elemental sulfur and nickel concentrate were discussed. The stability of OPD in the nickel concentrate slurry was discussed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002781

The relationship between the peak in air recovery and flotation bank performance / K. Hadler in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 451–455 Titre : The relationship between the peak in air recovery and flotation bank performance Type de document : texte imprimé Auteurs : K. Hadler, Auteur ; J. J. Cilliers, Auteur Année de publication : 2009 Article en page(s) : pp. 451–455 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Flotation  bubbles  Flotation  froths  Air  recovery  Air  profiling Résumé : Air recovery, or the fraction of air entering a cell that overflows the cell lip as unburst bubbles, is an important measure of froth stability as it affects the flow of bubble surface to the concentrate. An experimental campaign was carried out over the first four cells of the rougher bank at a South African platinum mine in order to find the relationship between froth stability and flotation performance as a function of air flowrate. The results showed that a peak in air recovery was observed as the air rate increased. Furthermore, this corresponded to the air flowrate at which the highest overall recovery was obtained. This can be explained by understanding the resulting changes in the structural features of the froth such as bubble loading and the flow of bubble surface and suggests that improved flotation performance can be achieved by operating a bank under conditions that result in a maximum in froth stability. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800280X [article] The relationship between the peak in air recovery and flotation bank performance [texte imprimé] / K. Hadler, Auteur ; J. J. Cilliers, Auteur . - 2009 . - pp. 451–455. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 451–455 Mots-clés : Froth  flotation  Flotation  bubbles  Flotation  froths  Air  recovery  Air  profiling Résumé : Air recovery, or the fraction of air entering a cell that overflows the cell lip as unburst bubbles, is an important measure of froth stability as it affects the flow of bubble surface to the concentrate. An experimental campaign was carried out over the first four cells of the rougher bank at a South African platinum mine in order to find the relationship between froth stability and flotation performance as a function of air flowrate. The results showed that a peak in air recovery was observed as the air rate increased. Furthermore, this corresponded to the air flowrate at which the highest overall recovery was obtained. This can be explained by understanding the resulting changes in the structural features of the froth such as bubble loading and the flow of bubble surface and suggests that improved flotation performance can be achieved by operating a bank under conditions that result in a maximum in froth stability. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800280X

Interfacial properties of liquid sulfur in the pressure leaching of nickel concentrate / Libin Tong in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 456–461 Titre : Interfacial properties of liquid sulfur in the pressure leaching of nickel concentrate Type de document : texte imprimé Auteurs : Libin Tong, Auteur ; David Dreisinger, Auteur Année de publication : 2009 Article en page(s) : pp. 456–461 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulfide  ores  Hydrometallurgy  Leaching  Pressure  oxidation  Liquid  sulfur  Interfa Résumé : The effects of sulfur dispersing agents in the oxygen pressure leaching of nickel concentrate at medium temperature were investigated by interfacial studies. Liquid sulfur–aqueous solution interfacial tensions and liquid sulfur–sulfide mineral contact angles were measured at 140 °C, 690 kPa overpressure by nitrogen. The effects of sulfur dispersing agents including lignosulfonate, Quebracho, o-phenylenediamine (OPD), and humic acid were evaluated by the calculation of the work of adhesion in the liquid sulfur–sulfide mineral–aqueous solution systems. It was found that the sulfide mineral surface is sulfophobic at pH from 4.1 to 4.5 due to the hydrolysis of nickel (II) ions to nickel hydroxide and the deposition of nickel hydroxide on the mineral surface. These findings apply to four different sulfide mineral systems, including pentlandite, nickeliferous pyrrhotite, pyrrhotite, and chalcopyrite. Lignosulfonate, Quebracho, and humic acid were found to significantly reduce the work of adhesion indicating they should be effective sulfur dispersing agents. OPD is ineffective in changing the work of adhesion of sulfur on the mineral sulfides indicating that it is not a good candidate for sulfur dispersion. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002811 [article] Interfacial properties of liquid sulfur in the pressure leaching of nickel concentrate [texte imprimé] / Libin Tong, Auteur ; David Dreisinger, Auteur . - 2009 . - pp. 456–461. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 456–461 Mots-clés : Sulfide  ores  Hydrometallurgy  Leaching  Pressure  oxidation  Liquid  sulfur  Interfa Résumé : The effects of sulfur dispersing agents in the oxygen pressure leaching of nickel concentrate at medium temperature were investigated by interfacial studies. Liquid sulfur–aqueous solution interfacial tensions and liquid sulfur–sulfide mineral contact angles were measured at 140 °C, 690 kPa overpressure by nitrogen. The effects of sulfur dispersing agents including lignosulfonate, Quebracho, o-phenylenediamine (OPD), and humic acid were evaluated by the calculation of the work of adhesion in the liquid sulfur–sulfide mineral–aqueous solution systems. It was found that the sulfide mineral surface is sulfophobic at pH from 4.1 to 4.5 due to the hydrolysis of nickel (II) ions to nickel hydroxide and the deposition of nickel hydroxide on the mineral surface. These findings apply to four different sulfide mineral systems, including pentlandite, nickeliferous pyrrhotite, pyrrhotite, and chalcopyrite. Lignosulfonate, Quebracho, and humic acid were found to significantly reduce the work of adhesion indicating they should be effective sulfur dispersing agents. OPD is ineffective in changing the work of adhesion of sulfur on the mineral sulfides indicating that it is not a good candidate for sulfur dispersion. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002811

Effect of Leptospirillum ferrooxidans on the flotation kinetics of sulphide ores / E.T. Pecina in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 462–468 Titre : Effect of Leptospirillum ferrooxidans on the flotation kinetics of sulphide ores Type de document : texte imprimé Auteurs : E.T. Pecina, Auteur ; M. Rodríguez, Auteur ; P. Castillo, Auteur Année de publication : 2009 Article en page(s) : pp. 462–468 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulphide  ores  Biotechnology  Froth  flotation  Flotation  kinetics Résumé : The objective of this work was to determine the effect of Leptospirillum ferrooxidans on the floatability of chalcopyrite, sphalerite, and pyrrhotite by using xanthate as a collector. The tests were carried out in the absence and presence of bacteria in relation to the type of ore and contact time with bacteria. The results indicate that the chalcopyrite flotation rate significantly increased in the presence of L. ferrooxidans due to the formation of hydrophobic species. The bacteria function as a weak depressant for pyrrhotite after a conditioning time ⩾60 min. The behaviour of sphalerite remains without changes due to its low susceptibility to oxidation. It was concluded that L. ferrooxidans brings about superficial changes mainly due to the oxidation of minerals. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002859 [article] Effect of Leptospirillum ferrooxidans on the flotation kinetics of sulphide ores [texte imprimé] / E.T. Pecina, Auteur ; M. Rodríguez, Auteur ; P. Castillo, Auteur . - 2009 . - pp. 462–468. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 462–468 Mots-clés : Sulphide  ores  Biotechnology  Froth  flotation  Flotation  kinetics Résumé : The objective of this work was to determine the effect of Leptospirillum ferrooxidans on the floatability of chalcopyrite, sphalerite, and pyrrhotite by using xanthate as a collector. The tests were carried out in the absence and presence of bacteria in relation to the type of ore and contact time with bacteria. The results indicate that the chalcopyrite flotation rate significantly increased in the presence of L. ferrooxidans due to the formation of hydrophobic species. The bacteria function as a weak depressant for pyrrhotite after a conditioning time ⩾60 min. The behaviour of sphalerite remains without changes due to its low susceptibility to oxidation. It was concluded that L. ferrooxidans brings about superficial changes mainly due to the oxidation of minerals. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002859

Cyanide and copper cyanide recovery by activated carbon / X. Dai in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 469–476 Titre : Cyanide and copper cyanide recovery by activated carbon Type de document : texte imprimé Auteurs : X. Dai, Auteur ; P. L. Breuer, Auteur Année de publication : 2009 Article en page(s) : pp. 469–476 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  ores  Activated  carbon  Cyanidation  Hydrometallurgy Résumé : A process is proposed to recover the cyanide and copper cyanides following the leaching and recovery of gold from copper-containing gold ores. Metallic copper is dissolved into the tailings stream to convert the residual free cyanide to copper cyanides and to concurrently reduce the overall cyanide-to-copper ratio to facilitate copper and cyanide recovery by activated carbon. Metallic copper readily dissolves in both free cyanide and View the MathML source solutions to achieve a final cyanide-to-copper ratio below 3. The theoretical critical CN− and View the MathML source concentration for copper dissolution in air saturated solutions are 2.9 and 2.7 mM, respectively, matching well with the measured values of 3 mM. The copper dissolution rate decreases proportionately with concentration below these critical concentrations. The increase in pH due to oxygen reduction during copper dissolution may cause copper to precipitate as Cu(OH)2. The pH of precipitation decreases with increasing copper concentration and with decreasing cyanide-to-copper ratio. However, precipitation is not observed in the presence of carbon due to the simultaneous adsorption of copper onto carbon, which reduces the solution copper concentration. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002860 [article] Cyanide and copper cyanide recovery by activated carbon [texte imprimé] / X. Dai, Auteur ; P. L. Breuer, Auteur . - 2009 . - pp. 469–476. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 469–476 Mots-clés : Gold  ores  Activated  carbon  Cyanidation  Hydrometallurgy Résumé : A process is proposed to recover the cyanide and copper cyanides following the leaching and recovery of gold from copper-containing gold ores. Metallic copper is dissolved into the tailings stream to convert the residual free cyanide to copper cyanides and to concurrently reduce the overall cyanide-to-copper ratio to facilitate copper and cyanide recovery by activated carbon. Metallic copper readily dissolves in both free cyanide and View the MathML source solutions to achieve a final cyanide-to-copper ratio below 3. The theoretical critical CN− and View the MathML source concentration for copper dissolution in air saturated solutions are 2.9 and 2.7 mM, respectively, matching well with the measured values of 3 mM. The copper dissolution rate decreases proportionately with concentration below these critical concentrations. The increase in pH due to oxygen reduction during copper dissolution may cause copper to precipitate as Cu(OH)2. The pH of precipitation decreases with increasing copper concentration and with decreasing cyanide-to-copper ratio. However, precipitation is not observed in the presence of carbon due to the simultaneous adsorption of copper onto carbon, which reduces the solution copper concentration. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002860

Geochemical evaluation of heap rinsing of the Gold Acres Heap, Cortez joint venture, Nevada / R. J. Bowell in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 477–489 Titre : Geochemical evaluation of heap rinsing of the Gold Acres Heap, Cortez joint venture, Nevada Type de document : texte imprimé Auteurs : R. J. Bowell, Auteur ; J.V. Parshley, Auteur ; G. McClelland, Auteur Année de publication : 2009 Article en page(s) : pp. 477–489 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Geochemistry  Heap  leach  Closure  Rinsing Résumé : This paper presents a summary of field and laboratory studies conducted to determine the need and extent of rinsing requirements for a spent oxide gold heap. The testwork utilized the Gold Acres Heap in Nevada. Monitoring data was reviewed to examine the geochemical processes occurring within the heap and predict the chemistry of future heap solutions for the Gold Acres Heap as well as the other heap facilities. In conjunction with this field study, column rinsing tests involving freshwater and recycled process water were conducted using representative spent oxide ore from the Gold Acres Heap in order to simulate heap conditions observed during field rinsing. A comparison between the column test results and the monitoring data collected during field scale recirculation indicates rinsing oxide ore recirculated barren solution does not decrease solute loadings. The column test indicates applying multiple freshwater rinses to the heap will only exacerbate the release of constituents by changing the pH-redox conditions of the heap. Consequently, this study indicates rinsing heap material with recirculation barren solution will produce no significant change (i.e., improvement) in the heap solution chemistry with respect to environmental release. Rinsing with freshwater will result in a higher risk for potential environmental degradation than not rinsing at all. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002872 [article] Geochemical evaluation of heap rinsing of the Gold Acres Heap, Cortez joint venture, Nevada [texte imprimé] / R. J. Bowell, Auteur ; J.V. Parshley, Auteur ; G. McClelland, Auteur . - 2009 . - pp. 477–489. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 477–489 Mots-clés : Geochemistry  Heap  leach  Closure  Rinsing Résumé : This paper presents a summary of field and laboratory studies conducted to determine the need and extent of rinsing requirements for a spent oxide gold heap. The testwork utilized the Gold Acres Heap in Nevada. Monitoring data was reviewed to examine the geochemical processes occurring within the heap and predict the chemistry of future heap solutions for the Gold Acres Heap as well as the other heap facilities. In conjunction with this field study, column rinsing tests involving freshwater and recycled process water were conducted using representative spent oxide ore from the Gold Acres Heap in order to simulate heap conditions observed during field rinsing. A comparison between the column test results and the monitoring data collected during field scale recirculation indicates rinsing oxide ore recirculated barren solution does not decrease solute loadings. The column test indicates applying multiple freshwater rinses to the heap will only exacerbate the release of constituents by changing the pH-redox conditions of the heap. Consequently, this study indicates rinsing heap material with recirculation barren solution will produce no significant change (i.e., improvement) in the heap solution chemistry with respect to environmental release. Rinsing with freshwater will result in a higher risk for potential environmental degradation than not rinsing at all. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002872

Rapid gangue mineral concentration measurement over conveyors by NIR reflectance spectroscopy / Alexander F.H. Goetz in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 490–499 Titre : Rapid gangue mineral concentration measurement over conveyors by NIR reflectance spectroscopy Type de document : texte imprimé Auteurs : Alexander F.H. Goetz, Auteur ; Brian Curtiss, Auteur ; Daniel A. Shiley, Auteur Année de publication : 2009 Article en page(s) : pp. 490–499 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : On-line  analysis  Ore  mineralogy  Process  control  Process  instrumentation  Sorting  methods Résumé : Near-infrared (NIR) reflectance spectroscopy is being used increasingly as a laboratory technique to supplement XRD analysis and other measurements of blast-hole cuttings for metallurgical processing decision making. The advantage of the technique is the speed of measurement and the lack of need for sample preparation. NIR is a surface measurement that responds to transition element, electronic transitions and molecular, vibrational transitions in crystal lattices. The constituents of a sample are quantified by creating predictive models by regression against primary sample analyses through XRD, XRF and CEC. We have developed predictive models for concentrations of swelling clays, kaolinite, muscovite and biotite from conveyor samples of copper ore using a QS 8000 over-the-conveyor system. The results are precise enough to be used for real-time, process decision making. In addition, prediction models have also been developed for seven oxides in limestone conveyed to stockpiles in cement plants. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002884 [article] Rapid gangue mineral concentration measurement over conveyors by NIR reflectance spectroscopy [texte imprimé] / Alexander F.H. Goetz, Auteur ; Brian Curtiss, Auteur ; Daniel A. Shiley, Auteur . - 2009 . - pp. 490–499. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 490–499 Mots-clés : On-line  analysis  Ore  mineralogy  Process  control  Process  instrumentation  Sorting  methods Résumé : Near-infrared (NIR) reflectance spectroscopy is being used increasingly as a laboratory technique to supplement XRD analysis and other measurements of blast-hole cuttings for metallurgical processing decision making. The advantage of the technique is the speed of measurement and the lack of need for sample preparation. NIR is a surface measurement that responds to transition element, electronic transitions and molecular, vibrational transitions in crystal lattices. The constituents of a sample are quantified by creating predictive models by regression against primary sample analyses through XRD, XRF and CEC. We have developed predictive models for concentrations of swelling clays, kaolinite, muscovite and biotite from conveyor samples of copper ore using a QS 8000 over-the-conveyor system. The results are precise enough to be used for real-time, process decision making. In addition, prediction models have also been developed for seven oxides in limestone conveyed to stockpiles in cement plants. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002884

Solvent extraction separation and recovery of cobalt and nickel from sulphate medium using mixtures of TOPS 99 and TIBPS extractants / B. Ramachandra Reddy in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 500–505 Titre : Solvent extraction separation and recovery of cobalt and nickel from sulphate medium using mixtures of TOPS 99 and TIBPS extractants Type de document : texte imprimé Auteurs : B. Ramachandra Reddy, Auteur ; S. Venkateswara Rao, Auteur ; Kyung Ho Park, Auteur Année de publication : 2009 Article en page(s) : pp. 500–505 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Solvent  extraction  Separation  Cobalt  Nickel  TOPS  99  TIBPS Résumé : We report in this paper the solvent extraction separation of cobalt and nickel from synthetic sulphate solutions using TOPS 99 and TIBPS mixtures diluted in kerosene. The feed contains 1.061 g/L Co and 1.187 g/L Ni. Extraction experiments with synergistic mixture of extractants showed highest separation factor of 12,245 with 0.1 M TOPS 99 and 0.05 M TIBPS at pH 1.1. McCabe–Thiele plot for Co extraction with 0.1 M TOPS 99 and 0.05 M TIBPS extractants mixture indicated the necessity of three theoretical stages for >99% Co extraction at an aqueous to organic phase (A/O) ratio of 2. A three stage counter current extraction simulation test conducted at pH 1.1 with 0.1 M TOPS 99 and 0.05 M TIBPS mixture, confirmed Co extraction of 99.5% with Ni co-extraction of 0.02%. The results demonstrated that the addition of TIBPS–TOPS 99 acts as a synergist for Co extraction and antagonist for Ni. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000028 [article] Solvent extraction separation and recovery of cobalt and nickel from sulphate medium using mixtures of TOPS 99 and TIBPS extractants [texte imprimé] / B. Ramachandra Reddy, Auteur ; S. Venkateswara Rao, Auteur ; Kyung Ho Park, Auteur . - 2009 . - pp. 500–505. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 500–505 Mots-clés : Solvent  extraction  Separation  Cobalt  Nickel  TOPS  99  TIBPS Résumé : We report in this paper the solvent extraction separation of cobalt and nickel from synthetic sulphate solutions using TOPS 99 and TIBPS mixtures diluted in kerosene. The feed contains 1.061 g/L Co and 1.187 g/L Ni. Extraction experiments with synergistic mixture of extractants showed highest separation factor of 12,245 with 0.1 M TOPS 99 and 0.05 M TIBPS at pH 1.1. McCabe–Thiele plot for Co extraction with 0.1 M TOPS 99 and 0.05 M TIBPS extractants mixture indicated the necessity of three theoretical stages for >99% Co extraction at an aqueous to organic phase (A/O) ratio of 2. A three stage counter current extraction simulation test conducted at pH 1.1 with 0.1 M TOPS 99 and 0.05 M TIBPS mixture, confirmed Co extraction of 99.5% with Ni co-extraction of 0.02%. The results demonstrated that the addition of TIBPS–TOPS 99 acts as a synergist for Co extraction and antagonist for Ni. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000028

Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability / I. Demers in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 506–512 Titre : Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability Type de document : texte imprimé Auteurs : I. Demers, Auteur ; J. Finch, Auteur ; E. El-Ammouri, Auteur Année de publication : 2009 Article en page(s) : pp. 506–512 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Acid  rock  drainage  Flocculation  Leaching  Environmental Résumé : The most common treatment for acidic drainage is lime neutralization. The process involves neutralization and precipitation of a metal hydroxide-gypsum sludge using a flocculant, generally Percol. In the short term, the sludge is stable, but in the long term, any tendency of pH to drop can re-dissolve metal hydroxides and contaminate the surrounding area and groundwater. The use of activated silica sol, an inorganic silicate polymer used in municipal water treatment, as a replacement to Percol is investigated to improve long term stability of sludge. Silica sol is an effective flocculant, has neutralization potential, and forms metal–silica bonds more resistant to pH variation than metal hydroxides. Various mine effluents and simulated solutions were treated with lime and silica sol or Percol to pH 9–10. Results show that settling characteristics with low dosages of silica sol and Percol are similar. Leachability tests showed that the stability of the sludge improved when silica sol was used for one cycle, and after 4 cycles results were similar to Percol. Activated silica sol, therefore, has the potential to increase sludge stability in a single stage lime treatment process. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000065 [article] Use of activated silica sol as a flocculant in the treatment of acid mine drainage to promote sludge stability [texte imprimé] / I. Demers, Auteur ; J. Finch, Auteur ; E. El-Ammouri, Auteur . - 2009 . - pp. 506–512. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 506–512 Mots-clés : Acid  rock  drainage  Flocculation  Leaching  Environmental Résumé : The most common treatment for acidic drainage is lime neutralization. The process involves neutralization and precipitation of a metal hydroxide-gypsum sludge using a flocculant, generally Percol. In the short term, the sludge is stable, but in the long term, any tendency of pH to drop can re-dissolve metal hydroxides and contaminate the surrounding area and groundwater. The use of activated silica sol, an inorganic silicate polymer used in municipal water treatment, as a replacement to Percol is investigated to improve long term stability of sludge. Silica sol is an effective flocculant, has neutralization potential, and forms metal–silica bonds more resistant to pH variation than metal hydroxides. Various mine effluents and simulated solutions were treated with lime and silica sol or Percol to pH 9–10. Results show that settling characteristics with low dosages of silica sol and Percol are similar. Leachability tests showed that the stability of the sludge improved when silica sol was used for one cycle, and after 4 cycles results were similar to Percol. Activated silica sol, therefore, has the potential to increase sludge stability in a single stage lime treatment process. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000065

Use of frother with sampling-for-imaging bubble sizing technique / W. Zhang in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 513–515 Titre : Use of frother with sampling-for-imaging bubble sizing technique Type de document : texte imprimé Auteurs : W. Zhang, Auteur ; M. Kolahdoozan, Auteur ; J.E. Nesset, Auteur Année de publication : 2009 Article en page(s) : pp. 513–515 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Flotation  frothers  Flotation  bubbles  Flotation  machines Résumé : Measurement of bubble size in industrial flotation cells is now often accomplished using the sampling-for-imaging technique. Operation calls for frother in the viewing chamber. In this communication the impact of frother concentration in the chamber is examined. A concentration in excess of the system CCC (critical coalescence concentration) is recommended for field work. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002732 [article] Use of frother with sampling-for-imaging bubble sizing technique [texte imprimé] / W. Zhang, Auteur ; M. Kolahdoozan, Auteur ; J.E. Nesset, Auteur . - 2009 . - pp. 513–515. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 513–515 Mots-clés : Flotation  frothers  Flotation  bubbles  Flotation  machines Résumé : Measurement of bubble size in industrial flotation cells is now often accomplished using the sampling-for-imaging technique. Operation calls for frother in the viewing chamber. In this communication the impact of frother concentration in the chamber is examined. A concentration in excess of the system CCC (critical coalescence concentration) is recommended for field work. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002732

A simple heatsink for planetary mills / R.A. Kleiv in Minerals engineering, Vol. 22 N° 5 (Avril 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 516–518 Titre : A simple heatsink for planetary mills Type de document : texte imprimé Auteurs : R.A. Kleiv, Auteur Année de publication : 2009 Article en page(s) : pp. 516–518 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Comminution  Grinding  Surface  modification Résumé : This paper proposes the use of a copper disk as a simple heatsink for planetary mills in order to limit or slow down the temperature increase during prolonged grinding. A series of grinding experiments have been performed in which the surface temperature of different parts of the grinding bowl has been determined as a function of grinding time. Three different experimental series were conducted: a reference series without the heatsink, and two series where the heatsink had been given the respective initial temperatures of 25 °C and −25 °C. As demonstrated in this paper, the proposed concept represents a cheap but effective way of limiting or slowing down the temperature increase occurring in the grinding bowl. The effect is of a magnitude that can be of considerable practical importance, and the concept can be employed on most planetary mills where the grinding bowl holder is designed to accommodate different bowl sizes. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000041 [article] A simple heatsink for planetary mills [texte imprimé] / R.A. Kleiv, Auteur . - 2009 . - pp. 516–518. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 5 (Avril 2009) . - pp. 516–518 Mots-clés : Comminution  Grinding  Surface  modification Résumé : This paper proposes the use of a copper disk as a simple heatsink for planetary mills in order to limit or slow down the temperature increase during prolonged grinding. A series of grinding experiments have been performed in which the surface temperature of different parts of the grinding bowl has been determined as a function of grinding time. Three different experimental series were conducted: a reference series without the heatsink, and two series where the heatsink had been given the respective initial temperatures of 25 °C and −25 °C. As demonstrated in this paper, the proposed concept represents a cheap but effective way of limiting or slowing down the temperature increase occurring in the grinding bowl. The effect is of a magnitude that can be of considerable practical importance, and the concept can be employed on most planetary mills where the grinding bowl holder is designed to accommodate different bowl sizes. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000041

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