Dépouillements

Kinetics of high-sulphur and high-arsenic refractory gold concentrate oxidation by dilute nitric acid under mild conditions / Guolong Gao in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 111–115 Titre : Kinetics of high-sulphur and high-arsenic refractory gold concentrate oxidation by dilute nitric acid under mild conditions Type de document : texte imprimé Auteurs : Guolong Gao, Auteur ; Dengxin Li, Auteur ; Zhou, Yong, Auteur Année de publication : 2009 Article en page(s) : pp. 111–115 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  ores  Reaction  kinetics  Oxidation  Mineral  processing Index. décimale : 622 Industrie minière Résumé : On one hand, high-sulphur and high-arsenic refractory gold concentrate (HGC) leads to regional ecological damage. On the other hand, it contains a lot of valuable elements. So utilization of it can bring social and environmental benefits. In this paper, the kinetics of HGC oxidation by dilute nitric acid under mild conditions was investigated. The effects of particle size (50–335 μm), reaction temperature (25–85 °C), initial acid concentration (10–30 wt.%) and stirring speed (400–800 rpm) on the iron extraction rate (Cr) were determined. It is obvious that Cr increases with the rise of initial nitric acid concentration, reaction time and stirring speed, but decreases with the increase of particle size. Oxidation kinetics indicates that the rate of reaction is diffusion controlled. The activation energies were determined to be 10.70 kJ/mol in the 10% HNO3 and 12.25 kJ/mol in the 25% HNO3. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001246 [article] Kinetics of high-sulphur and high-arsenic refractory gold concentrate oxidation by dilute nitric acid under mild conditions [texte imprimé] / Guolong Gao, Auteur ; Dengxin Li, Auteur ; Zhou, Yong, Auteur . - 2009 . - pp. 111–115. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 111–115 Mots-clés : Gold  ores  Reaction  kinetics  Oxidation  Mineral  processing Index. décimale : 622 Industrie minière Résumé : On one hand, high-sulphur and high-arsenic refractory gold concentrate (HGC) leads to regional ecological damage. On the other hand, it contains a lot of valuable elements. So utilization of it can bring social and environmental benefits. In this paper, the kinetics of HGC oxidation by dilute nitric acid under mild conditions was investigated. The effects of particle size (50–335 μm), reaction temperature (25–85 °C), initial acid concentration (10–30 wt.%) and stirring speed (400–800 rpm) on the iron extraction rate (Cr) were determined. It is obvious that Cr increases with the rise of initial nitric acid concentration, reaction time and stirring speed, but decreases with the increase of particle size. Oxidation kinetics indicates that the rate of reaction is diffusion controlled. The activation energies were determined to be 10.70 kJ/mol in the 10% HNO3 and 12.25 kJ/mol in the 25% HNO3. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001246

Extraction of titanium (IV) from acidic media by tri-n-butyl phosphate in kerosene / S. Seyfi in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 116–118 Titre : Extraction of titanium (IV) from acidic media by tri-n-butyl phosphate in kerosene Type de document : texte imprimé Auteurs : S. Seyfi, Auteur ; Abdi, M., Auteur Année de publication : 2009 Article en page(s) : pp. 116–118 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Leaching  Solvent  extraction  Hydrometallurgy  Titanium  Tri-n-butyl  phosphate Index. décimale : 622 Industrie minière Résumé : The extraction of titanium (IV) from sulfate, and nitrate solutions has been studied using tri-n-butyl phosphate (TBP) in kerosene. Extraction of titanium was affected by acid concentration over the range of 0.5–4 mol L−1. The titanium distribution coefficient reached a minimum between 1 and 2 mol L−1 acid for both sulfate and nitrate solutions. Third phase formation was observed in the extraction of titanium from acidic media at all condition tested. At the next stage, the stripping of titanium was studied using H2SO4, H2SO4 + H2O2 and Na2CO3. The kinetics of the stripping were very slow for H2SO4. The use of complex forming stripping agents (H2SO4 + H2O2) and Na2CO3 significantly improved the kinetics of stripping. About 98% recovery was achieved by extracting titanium from an aqueous nitrate solution using TBP and stripping with sodium carbonate. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001374 [article] Extraction of titanium (IV) from acidic media by tri-n-butyl phosphate in kerosene [texte imprimé] / S. Seyfi, Auteur ; Abdi, M., Auteur . - 2009 . - pp. 116–118. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 116–118 Mots-clés : Leaching  Solvent  extraction  Hydrometallurgy  Titanium  Tri-n-butyl  phosphate Index. décimale : 622 Industrie minière Résumé : The extraction of titanium (IV) from sulfate, and nitrate solutions has been studied using tri-n-butyl phosphate (TBP) in kerosene. Extraction of titanium was affected by acid concentration over the range of 0.5–4 mol L−1. The titanium distribution coefficient reached a minimum between 1 and 2 mol L−1 acid for both sulfate and nitrate solutions. Third phase formation was observed in the extraction of titanium from acidic media at all condition tested. At the next stage, the stripping of titanium was studied using H2SO4, H2SO4 + H2O2 and Na2CO3. The kinetics of the stripping were very slow for H2SO4. The use of complex forming stripping agents (H2SO4 + H2O2) and Na2CO3 significantly improved the kinetics of stripping. About 98% recovery was achieved by extracting titanium from an aqueous nitrate solution using TBP and stripping with sodium carbonate. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001374

Fine coal preparation using novel tribo-electrostatic separator / R.K. Dwari in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 119–127 Titre : Fine coal preparation using novel tribo-electrostatic separator Type de document : texte imprimé Auteurs : R.K. Dwari, Auteur ; K. Hanumantha Rao, Auteur Année de publication : 2009 Article en page(s) : pp. 119–127 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Coal  preparation  Electrostatic  separation  Fluidisation  Tribo-electrification  Particle  charging Index. décimale : 622 Industrie minière Résumé : Dry coal beneficiation has been examined by tribo-electrostatic method using Indian thermal coal sample from Ramagundam coal mines. The process of tribo-electric coal/ash cleaning is carried out with a newly built cylindrical fluidised bed tribo-charger with internal baffles, made up of copper metal. The charge transfer in coal maceral and mineral particles after repeated contact with copper plate tribo-charger is measured. Separation of particles in an electrostatic separator according to the polarity of particle charge generated during tribo-electrification is discussed with respect to gas flow rate and residence time in fluidised bed tribo-charger and the applied electric field. The coal and mineral particles charge with positive and negative polarities respectively. The magnitude of particles charge found to be relatively high illustrating greater efficiency of contact electrification in fluidised bed tribo-charger. The separation results with −300 μm size fraction of coal containing 43% ash showed that the ash content can be reduced to 18% and 33% with an yield of about 30% and 67%, respectively. These results are comparable to the maximum separation efficiency curve of washability studies on this coal sample. Since the ash percentage of coal particles collected in the bins close to positive and negative electrodes are about 70% and 20%, a better yield with low ash content can be accomplished on recycling the material. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800143X [article] Fine coal preparation using novel tribo-electrostatic separator [texte imprimé] / R.K. Dwari, Auteur ; K. Hanumantha Rao, Auteur . - 2009 . - pp. 119–127. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 119–127 Mots-clés : Coal  preparation  Electrostatic  separation  Fluidisation  Tribo-electrification  Particle  charging Index. décimale : 622 Industrie minière Résumé : Dry coal beneficiation has been examined by tribo-electrostatic method using Indian thermal coal sample from Ramagundam coal mines. The process of tribo-electric coal/ash cleaning is carried out with a newly built cylindrical fluidised bed tribo-charger with internal baffles, made up of copper metal. The charge transfer in coal maceral and mineral particles after repeated contact with copper plate tribo-charger is measured. Separation of particles in an electrostatic separator according to the polarity of particle charge generated during tribo-electrification is discussed with respect to gas flow rate and residence time in fluidised bed tribo-charger and the applied electric field. The coal and mineral particles charge with positive and negative polarities respectively. The magnitude of particles charge found to be relatively high illustrating greater efficiency of contact electrification in fluidised bed tribo-charger. The separation results with −300 μm size fraction of coal containing 43% ash showed that the ash content can be reduced to 18% and 33% with an yield of about 30% and 67%, respectively. These results are comparable to the maximum separation efficiency curve of washability studies on this coal sample. Since the ash percentage of coal particles collected in the bins close to positive and negative electrodes are about 70% and 20%, a better yield with low ash content can be accomplished on recycling the material. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800143X

Dynamic imaging and modelling of multilayer deposition of gold paste tailings / Julio Henriquez in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 128–139 Titre : Dynamic imaging and modelling of multilayer deposition of gold paste tailings Type de document : texte imprimé Auteurs : Julio Henriquez, Auteur ; Paul Simms, Auteur Année de publication : 2009 Article en page(s) : pp. 128–139 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Tailings  disposal  Computational  fluid  dynamics  Environmental  Reclamation Index. décimale : 622 Industrie minière Résumé : Surface deposition of paste or thickened tailings is increasing contemplated as an alternative to conventional slurry deposition. One important challenge in managing paste is to predict the evolving geometry of the tailings stack during deposition. This study dynamically images multilayer deposition of paste in flows in flume and axisymmetric flows. Each layer is left to self-weight consolidate for a day before the next layer is placed. It is found that both the steady-state profiles and the dynamic flows can be modelled as a Bingham fluid using equations developed from lubrication theory. Yield stress and viscosity were determined using rheometry and slump tests. It is shown that the yield stress obtained from the slump test may overestimate the yield stress of significance to flow deposition; namely that yield stress that characterizes when the tailings stop flowing. The lubrication theory equations show that the overall angle of a tailings deposit at steady-state is dependant on the scale of the flow, which may explain the discrepancy between laboratory flume angles and field angles noted in practice. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001441 [article] Dynamic imaging and modelling of multilayer deposition of gold paste tailings [texte imprimé] / Julio Henriquez, Auteur ; Paul Simms, Auteur . - 2009 . - pp. 128–139. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 128–139 Mots-clés : Tailings  disposal  Computational  fluid  dynamics  Environmental  Reclamation Index. décimale : 622 Industrie minière Résumé : Surface deposition of paste or thickened tailings is increasing contemplated as an alternative to conventional slurry deposition. One important challenge in managing paste is to predict the evolving geometry of the tailings stack during deposition. This study dynamically images multilayer deposition of paste in flows in flume and axisymmetric flows. Each layer is left to self-weight consolidate for a day before the next layer is placed. It is found that both the steady-state profiles and the dynamic flows can be modelled as a Bingham fluid using equations developed from lubrication theory. Yield stress and viscosity were determined using rheometry and slump tests. It is shown that the yield stress obtained from the slump test may overestimate the yield stress of significance to flow deposition; namely that yield stress that characterizes when the tailings stop flowing. The lubrication theory equations show that the overall angle of a tailings deposit at steady-state is dependant on the scale of the flow, which may explain the discrepancy between laboratory flume angles and field angles noted in practice. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001441

Immobilization and ferrous iron bio-oxidation studies of a Leptospirillum sp. mixed-cell culture / Michael A. Ginsburg in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 140–148 Titre : Immobilization and ferrous iron bio-oxidation studies of a Leptospirillum sp. mixed-cell culture Type de document : texte imprimé Auteurs : Michael A. Ginsburg, Auteur ; Kalin Penev, Auteur ; Dimitre Karamanev, Auteur Année de publication : 2009 Article en page(s) : pp. 140–148 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Bacteria  Surface  modification  Activated  carbon  Bio-oxidation Index. décimale : 622 Industrie minière Résumé : Immobilization of a mixed bacterial culture (predominantly Leptospirillum sp.) on mechanically modified graphite surfaces and different types of activated carbon fiber supports (felt and textile; both silicated and non-silicated) was studied experimentally. Maximum cell coverage on graphite samples occurred on a surface roughness of 2.08 μm (3.9 × 104 cells/mm2). In non-silicated samples the activated carbon fiber support with the greatest surface area per gram (felt) lead to the greatest number of immobilized microorganisms over a 10 h period (2.2 × 104 cells/mm2). The silication significantly increased surface area in the fibrous matrix voids and thereby increased the number of immobilized microorganisms on both modified activated carbon felt and fabric. The silicated felt exhibited the greatest number of immobilized Leptospirillum sp. cells of all activated carbon fiber cathodes studied (2.9 × 104 cells/mm2). Physical property and elemental analyses of silicated samples indicated that other methods of augmenting bacterial immobilization should be explored as silication increased electrical resistance of the samples 100 fold. Leptospirillum sp. immobilized on unmodified activated carbon felt yielded the maximum experimentally observed rate of ferrous iron bio-oxidation (∼900 mg/L h). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001490 [article] Immobilization and ferrous iron bio-oxidation studies of a Leptospirillum sp. mixed-cell culture [texte imprimé] / Michael A. Ginsburg, Auteur ; Kalin Penev, Auteur ; Dimitre Karamanev, Auteur . - 2009 . - pp. 140–148. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 140–148 Mots-clés : Bacteria  Surface  modification  Activated  carbon  Bio-oxidation Index. décimale : 622 Industrie minière Résumé : Immobilization of a mixed bacterial culture (predominantly Leptospirillum sp.) on mechanically modified graphite surfaces and different types of activated carbon fiber supports (felt and textile; both silicated and non-silicated) was studied experimentally. Maximum cell coverage on graphite samples occurred on a surface roughness of 2.08 μm (3.9 × 104 cells/mm2). In non-silicated samples the activated carbon fiber support with the greatest surface area per gram (felt) lead to the greatest number of immobilized microorganisms over a 10 h period (2.2 × 104 cells/mm2). The silication significantly increased surface area in the fibrous matrix voids and thereby increased the number of immobilized microorganisms on both modified activated carbon felt and fabric. The silicated felt exhibited the greatest number of immobilized Leptospirillum sp. cells of all activated carbon fiber cathodes studied (2.9 × 104 cells/mm2). Physical property and elemental analyses of silicated samples indicated that other methods of augmenting bacterial immobilization should be explored as silication increased electrical resistance of the samples 100 fold. Leptospirillum sp. immobilized on unmodified activated carbon felt yielded the maximum experimentally observed rate of ferrous iron bio-oxidation (∼900 mg/L h). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001490

Automated mineralogy using finite element analysis and X-ray microtomography / Naomi Tsafnat in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 149–155 Titre : Automated mineralogy using finite element analysis and X-ray microtomography Type de document : texte imprimé Auteurs : Naomi Tsafnat, Auteur ; Guy Tsafnat, Auteur ; Allan S. Jones, Auteur Année de publication : 2009 Article en page(s) : pp. 149–155 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Modelling  Simulation  Classification Index. décimale : 622 Industrie minière Résumé : The three-dimensional microstructure of minerals and materials can be visualised in a non-destructive manner using X-ray microtomography. The digitised nature of the tomographic image allows us to generate finite element models which precisely detail the material’s microstructure. With a high degree of automation, high resolution models can be created quickly and with little user interaction. The geometry is taken from the microtomographic data, and loads and boundary conditions are applied to the model to simulate various conditions. The finite element analysis results show the deformation and stress distribution in the material. The technique allows us to study the relationship between microstructure and bulk properties of porous minerals, to characterise them in terms of their strength and stiffness, and to simulate their behaviour under known loading conditions. In this paper we present an application of micro-finite element analysis in the study of porous minerals. Micro-finite element analysis can be used to study the behaviour of a variety of minerals, and is especially useful when applied to materials that have a distinct microstructure that affects their bulk properties. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001611 [article] Automated mineralogy using finite element analysis and X-ray microtomography [texte imprimé] / Naomi Tsafnat, Auteur ; Guy Tsafnat, Auteur ; Allan S. Jones, Auteur . - 2009 . - pp. 149–155. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 149–155 Mots-clés : Modelling  Simulation  Classification Index. décimale : 622 Industrie minière Résumé : The three-dimensional microstructure of minerals and materials can be visualised in a non-destructive manner using X-ray microtomography. The digitised nature of the tomographic image allows us to generate finite element models which precisely detail the material’s microstructure. With a high degree of automation, high resolution models can be created quickly and with little user interaction. The geometry is taken from the microtomographic data, and loads and boundary conditions are applied to the model to simulate various conditions. The finite element analysis results show the deformation and stress distribution in the material. The technique allows us to study the relationship between microstructure and bulk properties of porous minerals, to characterise them in terms of their strength and stiffness, and to simulate their behaviour under known loading conditions. In this paper we present an application of micro-finite element analysis in the study of porous minerals. Micro-finite element analysis can be used to study the behaviour of a variety of minerals, and is especially useful when applied to materials that have a distinct microstructure that affects their bulk properties. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001611

Fractal evaluation of particle size distributions of chromites in different comminution environments / A. Taşdemir in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 156–167 Titre : Fractal evaluation of particle size distributions of chromites in different comminution environments Type de document : texte imprimé Auteurs : A. Taşdemir, Auteur Année de publication : 2009 Article en page(s) : pp. 156–167 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Fractal  dimension  Particle  size  distribution  Fractal  fragmentation  Comminution  Piecewise  fractal  model Index. décimale : 622 Industrie minière Résumé : Particle size distributions (PSDs) are often rendered as cumulative functions, either as number of particles larger than a certain diameter, or as mass smaller than a certain diameter. The fractional exponent of the number/mass-size power law has been interpreted as the fractal dimension of the distribution. An application of PSD in comminuted chromites by means of the fractal mass distribution is presented. The five types of chromite samples were subjected to four comminution events; jaw, cone, hammer crushing and ball milling. The PSDs generated by different comminution devices has been evaluated by mass-based fractal fragmentation theory and the fractal dimensions of fragmentation (DF), a value quantifying the intensity of fragmentation, have been obtained for each chromite ore. The results of the present study show that the particle size distributions of the comminuted chromites having different mineralogical characteristics are fractal in nature. Single and multifractal methods have been successfully applied to characterize particle size distributions (PSD) of chromite samples comminuted by different comminution devices. In general, depending on the energy events, the chromite ores having different mineralogical characteristics showed a general trend of PSDs, and hence, the ranges of DF for a specific device. It can be concluded that breakage mechanisms have more effective on fractal dimensions of chromite samples although the mineralogical properties and size of the chromite ores broken are also a factor. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001635 [article] Fractal evaluation of particle size distributions of chromites in different comminution environments [texte imprimé] / A. Taşdemir, Auteur . - 2009 . - pp. 156–167. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 156–167 Mots-clés : Fractal  dimension  Particle  size  distribution  Fractal  fragmentation  Comminution  Piecewise  fractal  model Index. décimale : 622 Industrie minière Résumé : Particle size distributions (PSDs) are often rendered as cumulative functions, either as number of particles larger than a certain diameter, or as mass smaller than a certain diameter. The fractional exponent of the number/mass-size power law has been interpreted as the fractal dimension of the distribution. An application of PSD in comminuted chromites by means of the fractal mass distribution is presented. The five types of chromite samples were subjected to four comminution events; jaw, cone, hammer crushing and ball milling. The PSDs generated by different comminution devices has been evaluated by mass-based fractal fragmentation theory and the fractal dimensions of fragmentation (DF), a value quantifying the intensity of fragmentation, have been obtained for each chromite ore. The results of the present study show that the particle size distributions of the comminuted chromites having different mineralogical characteristics are fractal in nature. Single and multifractal methods have been successfully applied to characterize particle size distributions (PSD) of chromite samples comminuted by different comminution devices. In general, depending on the energy events, the chromite ores having different mineralogical characteristics showed a general trend of PSDs, and hence, the ranges of DF for a specific device. It can be concluded that breakage mechanisms have more effective on fractal dimensions of chromite samples although the mineralogical properties and size of the chromite ores broken are also a factor. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001635

Contact angle and bubble attachment studies in the flotation of trona and other soluble carbonate salts / O. Ozdemir in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 168–175 Titre : Contact angle and bubble attachment studies in the flotation of trona and other soluble carbonate salts Type de document : texte imprimé Auteurs : O. Ozdemir, Auteur ; C. Karaguzel, Auteur ; A.V. Nguyen, Auteur Année de publication : 2009 Article en page(s) : pp. 168–175 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Industrial  minerals  Trona  Froth  flotation  Thin-layer  wicking  method  Bubble  attachment  time Index. décimale : 622 Industrie minière Résumé : Trona, Na2CO3 · NaHCO3 · 2H2O, is mined as the primary source for sodium carbonate production in the United States. Recent studies have shown that the flotation method can be used for pre-processing of trona ore to remove insoluble mineral contaminants for the production of soda ash (sodium carbonate). Studies with carbonate salts suggest that certain important factors can affect their flotation response, including viscosity of the brine and interfacial water structure. Flotation studies showed that contrary to the strong flotation of NaHCO3 with both anionic and cationic collectors, Na2CO3 does not float at all. Based on the analysis of interfacial water structure in saturated brines, Na2CO3 was found to act as a strong water structure maker, whereas NaHCO3 acts as a weak water structure maker. Bubble attachment time measurements suggest that collector adsorption at the surface of NaHCO3 induces flotation; this is not the case for Na2CO3. Contact angle measurements indicated that the surface of Na2CO3 is hydrated to a great extent, whereas the NaHCO3 salt surface is less hydrated. These results reveal that there is a strong relationship between the interfacial water structure and the contact angle of these salts. The less stable NaHCO3 surface is ascribed to the interfacial water structure which allows for NaHCO3 flotation with both anionic and cationic collectors. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001647 [article] Contact angle and bubble attachment studies in the flotation of trona and other soluble carbonate salts [texte imprimé] / O. Ozdemir, Auteur ; C. Karaguzel, Auteur ; A.V. Nguyen, Auteur . - 2009 . - pp. 168–175. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 168–175 Mots-clés : Industrial  minerals  Trona  Froth  flotation  Thin-layer  wicking  method  Bubble  attachment  time Index. décimale : 622 Industrie minière Résumé : Trona, Na2CO3 · NaHCO3 · 2H2O, is mined as the primary source for sodium carbonate production in the United States. Recent studies have shown that the flotation method can be used for pre-processing of trona ore to remove insoluble mineral contaminants for the production of soda ash (sodium carbonate). Studies with carbonate salts suggest that certain important factors can affect their flotation response, including viscosity of the brine and interfacial water structure. Flotation studies showed that contrary to the strong flotation of NaHCO3 with both anionic and cationic collectors, Na2CO3 does not float at all. Based on the analysis of interfacial water structure in saturated brines, Na2CO3 was found to act as a strong water structure maker, whereas NaHCO3 acts as a weak water structure maker. Bubble attachment time measurements suggest that collector adsorption at the surface of NaHCO3 induces flotation; this is not the case for Na2CO3. Contact angle measurements indicated that the surface of Na2CO3 is hydrated to a great extent, whereas the NaHCO3 salt surface is less hydrated. These results reveal that there is a strong relationship between the interfacial water structure and the contact angle of these salts. The less stable NaHCO3 surface is ascribed to the interfacial water structure which allows for NaHCO3 flotation with both anionic and cationic collectors. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001647

Validation of the generalised Sutherland equation for bubble–particle encounter efficiency in flotation / Phong T. Nguyen in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 176–181 Titre : Validation of the generalised Sutherland equation for bubble–particle encounter efficiency in flotation : Effect of particle density Type de document : texte imprimé Auteurs : Phong T. Nguyen, Auteur ; Anh V. Nguyen, Auteur Année de publication : 2009 Article en page(s) : pp. 176–181 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Flotation  bubble  Flotation  kinetics  Froth  flotation Index. décimale : 622 Industrie minière Résumé : Bubble–particle encounter interaction is the first step of the particle collection by rising air bubbles in flotation and has been predicted based on the potential flow condition by Sutherland and others, leading to the approximate generalised Sutherland equation (GSE). In this paper, the bubble–particle encounter interaction with the potential flow condition has been analysed by solving the full motion equation for the particle employing a numerical computational approach. Together with other inertial forces, the gravitational forces were fully included in the motion equation. The numerical results were compared with the GSE models for the encounter efficiency. The effect of particle density on the encounter interaction was very significant and could counterbalance the “negative” effect of the inertial forces on the particle interaction with air bubbles with a mobile surface under the potential flow condition. For the typical particle size range used in flotation, significant deviation of the Sutherland approximate models from the numerical results due to the particle density effect and gravitational forces was observed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001660 [article] Validation of the generalised Sutherland equation for bubble–particle encounter efficiency in flotation : Effect of particle density [texte imprimé] / Phong T. Nguyen, Auteur ; Anh V. Nguyen, Auteur . - 2009 . - pp. 176–181. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 176–181 Mots-clés : Flotation  bubble  Flotation  kinetics  Froth  flotation Index. décimale : 622 Industrie minière Résumé : Bubble–particle encounter interaction is the first step of the particle collection by rising air bubbles in flotation and has been predicted based on the potential flow condition by Sutherland and others, leading to the approximate generalised Sutherland equation (GSE). In this paper, the bubble–particle encounter interaction with the potential flow condition has been analysed by solving the full motion equation for the particle employing a numerical computational approach. Together with other inertial forces, the gravitational forces were fully included in the motion equation. The numerical results were compared with the GSE models for the encounter efficiency. The effect of particle density on the encounter interaction was very significant and could counterbalance the “negative” effect of the inertial forces on the particle interaction with air bubbles with a mobile surface under the potential flow condition. For the typical particle size range used in flotation, significant deviation of the Sutherland approximate models from the numerical results due to the particle density effect and gravitational forces was observed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001660

Role of silicate phases during comminution of titania slag / P. Chris Pistorius in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 182–189 Titre : Role of silicate phases during comminution of titania slag Type de document : texte imprimé Auteurs : P. Chris Pistorius, Auteur ; Hanlie Kotzé, Auteur Année de publication : 2009 Article en page(s) : pp. 182–189 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Comminution  Pyrometallurgy  Particle  size  Particle  morphology Index. décimale : 622 Industrie minière Résumé : Titania slag is the primary product of ilmenite smelting, and serves as a feedstock to the TiO2 pigment industry. The fine material (smaller than 106 μm in diameter) which is produced during milling of titania slag is enriched in some impurities, notably SiO2, Al2O3, K2O and CaO. Investigation of microstructures of solidified slags confirmed that these oxides partition to the silicate phases which form during final solidification. The presence of silicates on the surfaces of particles in milled slag supports the suggestion that the silicates contribute to fracture during crushing and milling. No significant macro-segregation was found in the slag ingots. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001787 [article] Role of silicate phases during comminution of titania slag [texte imprimé] / P. Chris Pistorius, Auteur ; Hanlie Kotzé, Auteur . - 2009 . - pp. 182–189. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 182–189 Mots-clés : Comminution  Pyrometallurgy  Particle  size  Particle  morphology Index. décimale : 622 Industrie minière Résumé : Titania slag is the primary product of ilmenite smelting, and serves as a feedstock to the TiO2 pigment industry. The fine material (smaller than 106 μm in diameter) which is produced during milling of titania slag is enriched in some impurities, notably SiO2, Al2O3, K2O and CaO. Investigation of microstructures of solidified slags confirmed that these oxides partition to the silicate phases which form during final solidification. The presence of silicates on the surfaces of particles in milled slag supports the suggestion that the silicates contribute to fracture during crushing and milling. No significant macro-segregation was found in the slag ingots. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001787

Recovery of copper cyanide from waste cyanide solution by LIX 7950 / Feng Xie in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 190–195 Titre : Recovery of copper cyanide from waste cyanide solution by LIX 7950 Type de document : texte imprimé Auteurs : Feng Xie, Auteur ; David Dreisinger, Auteur Année de publication : 2009 Article en page(s) : pp. 190–195 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Copper  Cyanide  effluent  Solvent  extraction  Guanidine Index. décimale : 622 Industrie minière Résumé : The use of the guanidine extractant, LIX 7950, to extract copper cyanide from waste cyanide solution has been investigated. Copper extraction is favorable at low pH while a high cyanide to copper molar ratio tends to suppress copper loading. The extractant also strongly extracted zinc and nickel from cyanide solution, but the extraction of iron was poor. The presence of thiocyanate ion significantly depressed copper extraction, but thiosulfate ion produced negligible impact on copper extraction. The preferential extraction of metal cyanide species to free cyanide has been noticed. The potential application of the recovery technique as a pre-concentration step for the treatment of cyanide effluent has been suggested, by which copper can be extracted and concentrated into a small volume of solution and the barren cyanide solution recycled to the cyanidation process. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001799 [article] Recovery of copper cyanide from waste cyanide solution by LIX 7950 [texte imprimé] / Feng Xie, Auteur ; David Dreisinger, Auteur . - 2009 . - pp. 190–195. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 190–195 Mots-clés : Copper  Cyanide  effluent  Solvent  extraction  Guanidine Index. décimale : 622 Industrie minière Résumé : The use of the guanidine extractant, LIX 7950, to extract copper cyanide from waste cyanide solution has been investigated. Copper extraction is favorable at low pH while a high cyanide to copper molar ratio tends to suppress copper loading. The extractant also strongly extracted zinc and nickel from cyanide solution, but the extraction of iron was poor. The presence of thiocyanate ion significantly depressed copper extraction, but thiosulfate ion produced negligible impact on copper extraction. The preferential extraction of metal cyanide species to free cyanide has been noticed. The potential application of the recovery technique as a pre-concentration step for the treatment of cyanide effluent has been suggested, by which copper can be extracted and concentrated into a small volume of solution and the barren cyanide solution recycled to the cyanidation process. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001799

Synthesis of ferronickel slag-based geopolymers / Ioannis Maragkos in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 196–203 Titre : Synthesis of ferronickel slag-based geopolymers Type de document : texte imprimé Auteurs : Ioannis Maragkos, Auteur ; Ioanna P. Giannopoulou, Auteur ; Dimitrios Panias, Auteur Année de publication : 2009 Article en page(s) : pp. 196–203 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Fine  particle  processing  Pyrometallurgy  Wasteprocessing Index. décimale : 622 Industrie minière Résumé : This paper deals with the synthesis of geopolymers utilizing ferronickel slag as raw material. The utilized slag is produced in the Greek plant LARCO during the pyrometallurgical treatment of laterites for the production of ferronickel, specifically at the step of the reductive smelting in electric arc furnaces. The performed work includes the optimization of the slag-based geopolymeric system through the study of the effect of the synthesis parameters on the mechanical properties of the produced materials. The structure of geopolymers was determined with X-ray diffractometry (XRD), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The obtained results showed that the ferronickel slag is an excellent raw material for the production of inorganic polymers using the geopolymerization technology. The materials produced under the optimum synthesis conditions were compact and rigid and presented high compressive strength (118 MPa), as well as extremely low water absorption (0.7–0.8%). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001817 [article] Synthesis of ferronickel slag-based geopolymers [texte imprimé] / Ioannis Maragkos, Auteur ; Ioanna P. Giannopoulou, Auteur ; Dimitrios Panias, Auteur . - 2009 . - pp. 196–203. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 196–203 Mots-clés : Fine  particle  processing  Pyrometallurgy  Wasteprocessing Index. décimale : 622 Industrie minière Résumé : This paper deals with the synthesis of geopolymers utilizing ferronickel slag as raw material. The utilized slag is produced in the Greek plant LARCO during the pyrometallurgical treatment of laterites for the production of ferronickel, specifically at the step of the reductive smelting in electric arc furnaces. The performed work includes the optimization of the slag-based geopolymeric system through the study of the effect of the synthesis parameters on the mechanical properties of the produced materials. The structure of geopolymers was determined with X-ray diffractometry (XRD), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The obtained results showed that the ferronickel slag is an excellent raw material for the production of inorganic polymers using the geopolymerization technology. The materials produced under the optimum synthesis conditions were compact and rigid and presented high compressive strength (118 MPa), as well as extremely low water absorption (0.7–0.8%). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001817

Recovery of zinc from an industrial zinc leach residue by solvent extraction using D2EHPA / E. Vahidi in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 204–206 Titre : Recovery of zinc from an industrial zinc leach residue by solvent extraction using D2EHPA Type de document : texte imprimé Auteurs : E. Vahidi, Auteur ; F. Rashchi, Auteur ; D. Moradkhani, Auteur Année de publication : 2009 Article en page(s) : pp. 204–206 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Zinc  leach  residue  Solvent  extraction  D2EHPA Index. décimale : 622 Industrie minière Résumé : A hydrometallurgical treatment involving solvent extraction of zinc using di-2-ethylhexyl phosphoric acid (D2EHPA) has been investigated to recover zinc from an industrial leach residue. The residue was leached with sulfuric acid producing leach liquor which was subjected to solvent extraction for enrichment of zinc and removal of impurities. Operating variables, such as pH, D2EHPA concentration, temperature, aqueous/organic (A/O) phase ratio, tri-butyl phosphate (TBP) concentration and sodium sulfate (Na2SO4) concentration in aqueous phase were studied. Practically, all zinc was extracted from the aqueous solution at pH 2.5 with 20% w/w D2EHPA in kerosene. Increasing either TBP concentration up to 5%, or Na2SO4 concentration up to 0.2 M, increased the zinc extraction. Zinc could be extracted at one theoretical stage at A/O of 1/1, as calculated by McCabe–Thiele method. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001258 [article] Recovery of zinc from an industrial zinc leach residue by solvent extraction using D2EHPA [texte imprimé] / E. Vahidi, Auteur ; F. Rashchi, Auteur ; D. Moradkhani, Auteur . - 2009 . - pp. 204–206. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 204–206 Mots-clés : Zinc  leach  residue  Solvent  extraction  D2EHPA Index. décimale : 622 Industrie minière Résumé : A hydrometallurgical treatment involving solvent extraction of zinc using di-2-ethylhexyl phosphoric acid (D2EHPA) has been investigated to recover zinc from an industrial leach residue. The residue was leached with sulfuric acid producing leach liquor which was subjected to solvent extraction for enrichment of zinc and removal of impurities. Operating variables, such as pH, D2EHPA concentration, temperature, aqueous/organic (A/O) phase ratio, tri-butyl phosphate (TBP) concentration and sodium sulfate (Na2SO4) concentration in aqueous phase were studied. Practically, all zinc was extracted from the aqueous solution at pH 2.5 with 20% w/w D2EHPA in kerosene. Increasing either TBP concentration up to 5%, or Na2SO4 concentration up to 0.2 M, increased the zinc extraction. Zinc could be extracted at one theoretical stage at A/O of 1/1, as calculated by McCabe–Thiele method. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001258

Leaching of pyrolusite using molasses alcohol wastewater as a reductant / Haifeng Su in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 207–209 Titre : Leaching of pyrolusite using molasses alcohol wastewater as a reductant Type de document : texte imprimé Auteurs : Haifeng Su, Auteur ; Yanxuan Wen, Auteur ; Fan Wang, Auteur Année de publication : 2009 Article en page(s) : pp. 207–209 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Pyrolusite  Molasses  alcohol  wastewater  Sulfuric  acid  leaching  Reductive  leaching Index. décimale : 622 Industrie minière Résumé : Extraction of manganese from a pyrolusite ore was investigated using molasses alcohol wastewater as a reducing agent in dilute sulfuric acid medium. The effects of molasses alcohol wastewater dosage, concentration of sulfuric acid, leaching temperature and reaction time were studied. High manganese recovery, coupled with relatively low Fe and Al extraction yields, was obtained with this leaching process. The optimal leaching conditions were obtained using 1.9 mol/L H2SO4 and 2.0 mL/g ratio of molasses alcohol wastewater to pyrolusite for 120 min at 90 °C. These conditions resulted in leaching yields of 93% for Mn, with relatively low recoveries of 37% for Fe and 25% for Al. These results demonstrate that molasses alcohol wastewater is a low cost resource, containing renewable and non-hazardous reducing agents (when compared to other available reagents) that can be used for manganese leaching under mild acidic conditions. In short, the method provides a good extraction yield while making an economically productive use of molasses alcohol wastewa DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001398 [article] Leaching of pyrolusite using molasses alcohol wastewater as a reductant [texte imprimé] / Haifeng Su, Auteur ; Yanxuan Wen, Auteur ; Fan Wang, Auteur . - 2009 . - pp. 207–209. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 207–209 Mots-clés : Pyrolusite  Molasses  alcohol  wastewater  Sulfuric  acid  leaching  Reductive  leaching Index. décimale : 622 Industrie minière Résumé : Extraction of manganese from a pyrolusite ore was investigated using molasses alcohol wastewater as a reducing agent in dilute sulfuric acid medium. The effects of molasses alcohol wastewater dosage, concentration of sulfuric acid, leaching temperature and reaction time were studied. High manganese recovery, coupled with relatively low Fe and Al extraction yields, was obtained with this leaching process. The optimal leaching conditions were obtained using 1.9 mol/L H2SO4 and 2.0 mL/g ratio of molasses alcohol wastewater to pyrolusite for 120 min at 90 °C. These conditions resulted in leaching yields of 93% for Mn, with relatively low recoveries of 37% for Fe and 25% for Al. These results demonstrate that molasses alcohol wastewater is a low cost resource, containing renewable and non-hazardous reducing agents (when compared to other available reagents) that can be used for manganese leaching under mild acidic conditions. In short, the method provides a good extraction yield while making an economically productive use of molasses alcohol wastewa DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001398

A simple spectrophotometric method for determination of gold (III) in aqueous samples / Yousef Fazli in Minerals engineering, Vol. 22 N° 2 (Janvier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 210–212 Titre : A simple spectrophotometric method for determination of gold (III) in aqueous samples Type de document : texte imprimé Auteurs : Yousef Fazli, Auteur ; Jalal Hassan, Auteur ; Mohamad-Hadi Karbasi, Auteur Année de publication : 2009 Article en page(s) : pp. 210–212 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  UV–vis  TMBH  Water Index. décimale : 622 Industrie minière Résumé : A simple method for rapid determination of trace Au in natural water was presented by using UV–vis spectrophotometry after reaction of gold (III) with 3,3′, 5,5′-tetramethylbenzidine hydrochloride (TMBH) in acidic solution. Under the optimum conditions, in a concentration range of 100–2000 μg L−1 of Au (III) a good linear calibration graph was obtained (r = 0.9969, n = 7). The percent relative standard deviation (RSD) for determination of 1000 μg L−1 Au was 10% (n = 3) and limit of detection based on a signal-to-noise ratio (S/N) of 3 (3Sbl) was 50 μg L−1. The proposed method has been successfully applied to the determination of gold spiked and real aqueous samples. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001453 [article] A simple spectrophotometric method for determination of gold (III) in aqueous samples [texte imprimé] / Yousef Fazli, Auteur ; Jalal Hassan, Auteur ; Mohamad-Hadi Karbasi, Auteur . - 2009 . - pp. 210–212. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 2 (Janvier 2009) . - pp. 210–212 Mots-clés : Gold  UV–vis  TMBH  Water Index. décimale : 622 Industrie minière Résumé : A simple method for rapid determination of trace Au in natural water was presented by using UV–vis spectrophotometry after reaction of gold (III) with 3,3′, 5,5′-tetramethylbenzidine hydrochloride (TMBH) in acidic solution. Under the optimum conditions, in a concentration range of 100–2000 μg L−1 of Au (III) a good linear calibration graph was obtained (r = 0.9969, n = 7). The percent relative standard deviation (RSD) for determination of 1000 μg L−1 Au was 10% (n = 3) and limit of detection based on a signal-to-noise ratio (S/N) of 3 (3Sbl) was 50 μg L−1. The proposed method has been successfully applied to the determination of gold spiked and real aqueous samples. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001453

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