Dépouillements

A review of techniques for measurement of contact angles and their applicability on mineral surfaces / T. T. Chau in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 213–219 Titre : A review of techniques for measurement of contact angles and their applicability on mineral surfaces Type de document : texte imprimé Auteurs : T. T. Chau, Auteur Année de publication : 2009 Article en page(s) : pp. 213–219 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Contact  angle  Hydrophobicity  Froth  flotation Index. décimale : 622 Industrie minière Résumé : Knowledge of the wetting characteristic of mineral surfaces is paramount in enhancing the efficiency of separation of valuable minerals from gangue using froth flotation. The contact angle value is a useful indicator providing the hydrophobic characteristic of the solid mineral surfaces due to a close relationship between this parameter and the floatability of minerals. In this paper, techniques for contact angle measurements and their applicability on mineral surfaces are reviewed. Two main groups of techniques for contact angle measurements are available; one group is applicable to flat and smooth surfaces while the other one has been especially developed for non-ideal surfaces or particles. Capillary penetration methods have been found to be more applicable than the other methods cited in measuring contact angles on real mineral surfaces. The major challenge with this technique is the modification required to overcome the difficulties in the experimental packing technique needed, and more importantly, to obtain the receding contact angle values. The coupling of accurate contact angle measurements with real (batch) flotation data would seem to be area which has had limited attention. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001878 [article] A review of techniques for measurement of contact angles and their applicability on mineral surfaces [texte imprimé] / T. T. Chau, Auteur . - 2009 . - pp. 213–219. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 213–219 Mots-clés : Contact  angle  Hydrophobicity  Froth  flotation Index. décimale : 622 Industrie minière Résumé : Knowledge of the wetting characteristic of mineral surfaces is paramount in enhancing the efficiency of separation of valuable minerals from gangue using froth flotation. The contact angle value is a useful indicator providing the hydrophobic characteristic of the solid mineral surfaces due to a close relationship between this parameter and the floatability of minerals. In this paper, techniques for contact angle measurements and their applicability on mineral surfaces are reviewed. Two main groups of techniques for contact angle measurements are available; one group is applicable to flat and smooth surfaces while the other one has been especially developed for non-ideal surfaces or particles. Capillary penetration methods have been found to be more applicable than the other methods cited in measuring contact angles on real mineral surfaces. The major challenge with this technique is the modification required to overcome the difficulties in the experimental packing technique needed, and more importantly, to obtain the receding contact angle values. The coupling of accurate contact angle measurements with real (batch) flotation data would seem to be area which has had limited attention. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001878

The influence of particle shape on parameters of impact crushing / G. Unland in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 220–228 Titre : The influence of particle shape on parameters of impact crushing Type de document : texte imprimé Auteurs : G. Unland, Auteur ; Y. Al-Khasawneh, Auteur Année de publication : 2009 Article en page(s) : pp. 220–228 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Crushing  Impact  Particle  shape Index. décimale : 622 Industrie minière Résumé : The influence of the shape of limestone particles on impact crushing parameters has been investigated by testing single particles in a high-resolution impact analyzer. The measurements conducted included the contact time and force, the transferred energy, the fragment size and shape distribution as well as the energy utilization. The particles tested were classified in seven different shape classes that ranged from spheres and cubes to plate-shaped and acicular bodies. The results show that the measured parameters are significantly influenced by the particle shape. These differences are caused by an additional orientation phase of an irregularly shaped particle prior to the main impact. Usually, the impact bar of the crusher hits one of the corners first, accelerates, rotates the particle and disintegrates a part of it occasionally. For spherical and cubical particles the contact forces and transferred energy are the highest and the contact time is the lowest. These results suggest that the mechanical design of impact crushers could be made on the basis of testing spheres or cubes, which would provide a safety factor in the design. Regarding the size distribution of the fragments, both the upper diameter and size modulus of a truncated Rosin–Rammler–Sperling–Bennet distribution are the lowest for spherical particles while no clear trend was found in respect to the distribution modulus. The comparison of the fragment shape distributions shows, except for the coarser fragments, hardly an influence of the initial particle shape on the smaller fragments. The energy utilization is the lowest with spherical and cubical bodies and rises with increased elongation and flatness of the feed particles. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002094 [article] The influence of particle shape on parameters of impact crushing [texte imprimé] / G. Unland, Auteur ; Y. Al-Khasawneh, Auteur . - 2009 . - pp. 220–228. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 220–228 Mots-clés : Crushing  Impact  Particle  shape Index. décimale : 622 Industrie minière Résumé : The influence of the shape of limestone particles on impact crushing parameters has been investigated by testing single particles in a high-resolution impact analyzer. The measurements conducted included the contact time and force, the transferred energy, the fragment size and shape distribution as well as the energy utilization. The particles tested were classified in seven different shape classes that ranged from spheres and cubes to plate-shaped and acicular bodies. The results show that the measured parameters are significantly influenced by the particle shape. These differences are caused by an additional orientation phase of an irregularly shaped particle prior to the main impact. Usually, the impact bar of the crusher hits one of the corners first, accelerates, rotates the particle and disintegrates a part of it occasionally. For spherical and cubical particles the contact forces and transferred energy are the highest and the contact time is the lowest. These results suggest that the mechanical design of impact crushers could be made on the basis of testing spheres or cubes, which would provide a safety factor in the design. Regarding the size distribution of the fragments, both the upper diameter and size modulus of a truncated Rosin–Rammler–Sperling–Bennet distribution are the lowest for spherical particles while no clear trend was found in respect to the distribution modulus. The comparison of the fragment shape distributions shows, except for the coarser fragments, hardly an influence of the initial particle shape on the smaller fragments. The energy utilization is the lowest with spherical and cubical bodies and rises with increased elongation and flatness of the feed particles. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002094

Passivation of chalcopyrite during its chemical leaching with ferric ion at 68 °C / E.M. Córdoba in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 229–235 Titre : Passivation of chalcopyrite during its chemical leaching with ferric ion at 68 °C Type de document : texte imprimé Auteurs : E.M. Córdoba, Auteur ; J.A. Muñoz, Auteur ; M. L. Blázquez, Auteur Année de publication : 2009 Article en page(s) : pp. 229–235 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulphide  ores  Hydrometallurgy  Mineral  processing Index. décimale : 622 Industrie minière Résumé : The passivation of chalcopyrite in the presence of ferric sulphate solutions was investigated at 68 °C. The effect of different variables (pulp density, pH and the presence of oxygen) on both the copper dissolution rate and the formation of solid compounds was studied. The leaching tests were carried out in stirred flasks at 180 rpm with 100 mL of a Fe3+/Fe2+ sulphate solution, varying the pulp density between 0.1 and 5% and the pH between 0.5 and 2.0 and both in aerobic and anaerobic conditions. Ferric ion seems to be responsible for the oxidation of chalcopyrite but also promotes its passivation. Ferrous ion plays a key role in the process by controlling the nucleation and precipitation of jarosites, which finally cause the passivation of chalcopyrite. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001830 [article] Passivation of chalcopyrite during its chemical leaching with ferric ion at 68 °C [texte imprimé] / E.M. Córdoba, Auteur ; J.A. Muñoz, Auteur ; M. L. Blázquez, Auteur . - 2009 . - pp. 229–235. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 229–235 Mots-clés : Sulphide  ores  Hydrometallurgy  Mineral  processing Index. décimale : 622 Industrie minière Résumé : The passivation of chalcopyrite in the presence of ferric sulphate solutions was investigated at 68 °C. The effect of different variables (pulp density, pH and the presence of oxygen) on both the copper dissolution rate and the formation of solid compounds was studied. The leaching tests were carried out in stirred flasks at 180 rpm with 100 mL of a Fe3+/Fe2+ sulphate solution, varying the pulp density between 0.1 and 5% and the pH between 0.5 and 2.0 and both in aerobic and anaerobic conditions. Ferric ion seems to be responsible for the oxidation of chalcopyrite but also promotes its passivation. Ferrous ion plays a key role in the process by controlling the nucleation and precipitation of jarosites, which finally cause the passivation of chalcopyrite. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001830

Quantitative analysis of grain boundary fracture in the breakage of single multiphase particles using X-ray microtomography procedures / D. García in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 236–243 Titre : Quantitative analysis of grain boundary fracture in the breakage of single multiphase particles using X-ray microtomography procedures Type de document : texte imprimé Auteurs : D. García, Auteur ; C.L. Lin, Auteur ; J.D. Miller, Auteur Année de publication : 2009 Article en page(s) : pp. 236–243 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Liberation  Liberation  analysis  Mineral  processing  Ore  mineralogy Index. décimale : 622 Industrie minière Résumé : Direct determination of intergranular fracture during multiphase particle breakage is a difficult task to achieve. Perhaps the only method of analysis is measurement of interphase area before and after comminution. Conservation of interfacial area after crushing is indicative of transgranular random breakage. On the other hand, if interfacial area is diminished after breakage some degree of preferential grain boundary fracture has occurred. For complete liberation of all grains after crushing the interfacial area goes to zero. Thus the interfacial area criterion is an important metric to assess the significance of preferential grain boundary fracture for different breakage conditions. This study describes the development of procedures for detailed analysis to quantify the extent of preferential grain boundary fracture for different breakage conditions using X-ray microtomography (XMT). The breakage of single multiphase copper ore particles (3 mm cubic particles) by slow compression is examined. Procedures developed for interfacial area measurements are discussed and determination of the extent of grain boundary fracture of multiphase particles for different breakage conditions is presented. For the copper ore studied, it is shown that preferential grain boundary fracture occurs at low energy dissipation rates. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001842 [article] Quantitative analysis of grain boundary fracture in the breakage of single multiphase particles using X-ray microtomography procedures [texte imprimé] / D. García, Auteur ; C.L. Lin, Auteur ; J.D. Miller, Auteur . - 2009 . - pp. 236–243. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 236–243 Mots-clés : Froth  flotation  Liberation  Liberation  analysis  Mineral  processing  Ore  mineralogy Index. décimale : 622 Industrie minière Résumé : Direct determination of intergranular fracture during multiphase particle breakage is a difficult task to achieve. Perhaps the only method of analysis is measurement of interphase area before and after comminution. Conservation of interfacial area after crushing is indicative of transgranular random breakage. On the other hand, if interfacial area is diminished after breakage some degree of preferential grain boundary fracture has occurred. For complete liberation of all grains after crushing the interfacial area goes to zero. Thus the interfacial area criterion is an important metric to assess the significance of preferential grain boundary fracture for different breakage conditions. This study describes the development of procedures for detailed analysis to quantify the extent of preferential grain boundary fracture for different breakage conditions using X-ray microtomography (XMT). The breakage of single multiphase copper ore particles (3 mm cubic particles) by slow compression is examined. Procedures developed for interfacial area measurements are discussed and determination of the extent of grain boundary fracture of multiphase particles for different breakage conditions is presented. For the copper ore studied, it is shown that preferential grain boundary fracture occurs at low energy dissipation rates. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001842

Significance of liberation characteristics in the fatty acid flotation of Florida phosphate rock / Mohamed I. Al-Wakeel in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 244–253 Titre : Significance of liberation characteristics in the fatty acid flotation of Florida phosphate rock Type de document : texte imprimé Auteurs : Mohamed I. Al-Wakeel, Auteur ; C.L. Lin, Auteur ; Jan D. Miller, Auteur Année de publication : 2009 Article en page(s) : pp. 244–253 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Liberation  analysis  Mineralogy  Florida  phosphate  rock Index. décimale : 622 Industrie minière Résumé : Phosphate flotation has been used by industry for more than a half century but still faces many technical challenges. Such challenges include not only the selection of the chemical reagents but the characteristics of the feed itself. This paper deals with the investigation of feed characteristics and how these characteristics affect the flotation separation efficiency of feed material from a selected phosphate operation. Specifically why some feed, from the same mine, is efficiently separated with high recovery (good feed) while other feed is more difficult to separate (bad feed). The study was conducted using both traditional analytical techniques and more advanced techniques such as X-ray microtomography. The results reveal that the bad feed was highly porous, coarser in size, and, most significantly, exhibits a lower degree of liberation. Such bad feed was inefficiently separated by fatty acid flotation and improved recovery would require controlled grinding in order to improve the extent of liberation. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800188X [article] Significance of liberation characteristics in the fatty acid flotation of Florida phosphate rock [texte imprimé] / Mohamed I. Al-Wakeel, Auteur ; C.L. Lin, Auteur ; Jan D. Miller, Auteur . - 2009 . - pp. 244–253. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 244–253 Mots-clés : Froth  flotation  Liberation  analysis  Mineralogy  Florida  phosphate  rock Index. décimale : 622 Industrie minière Résumé : Phosphate flotation has been used by industry for more than a half century but still faces many technical challenges. Such challenges include not only the selection of the chemical reagents but the characteristics of the feed itself. This paper deals with the investigation of feed characteristics and how these characteristics affect the flotation separation efficiency of feed material from a selected phosphate operation. Specifically why some feed, from the same mine, is efficiently separated with high recovery (good feed) while other feed is more difficult to separate (bad feed). The study was conducted using both traditional analytical techniques and more advanced techniques such as X-ray microtomography. The results reveal that the bad feed was highly porous, coarser in size, and, most significantly, exhibits a lower degree of liberation. Such bad feed was inefficiently separated by fatty acid flotation and improved recovery would require controlled grinding in order to improve the extent of liberation. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800188X

Utilization of electrochemical impedance spectroscopy for monitoring bornite (Cu5FeS4) oxidation by Acidithiobacillus ferrooxidans / Denise Bevilaqua in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 254–262 Titre : Utilization of electrochemical impedance spectroscopy for monitoring bornite (Cu5FeS4) oxidation by Acidithiobacillus ferrooxidans Type de document : texte imprimé Auteurs : Denise Bevilaqua, Auteur ; Heloisa A. Acciari, Auteur ; Fabiana A. Arena, Auteur Année de publication : 2009 Article en page(s) : pp. 254–262 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Bornite  (Cu5FeS4)  Acidithiobacillus  ferrooxidans  Electrochemical  impedance  spectroscopy  (EIS)  Bioleaching Index. décimale : 622 Industrie minière Résumé : In this work, the monitoring of the bacterial and chemical dissolution of bornite was evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS); the mineral surface was examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The analysis of CV results allowed attributing the different peaks observed in both direct and reverse potential scanning to the oxidation of bornite to a secondary covellite and its reduction via different non stoichiometric copper sulphides intermediaries. EIS data for bornite were obtained in control medium up to 78 h of immersion, when a cellular suspension of A. ferrooxidans was added and the experiments continued up to a 192 h of test. The EIS response was different when bacteria were added in the beginning of the test or after some hours of immersion in acid solution. The experiments were performed in different cell configurations and a model of the electrode/electrolyte interface. The correspondent equivalent electrical circuit was used to fit impedance spectra for all studied conditions. A common equivalent circuit used for corrosion processes where anodic (degradation of the mineral) and cathodic (oxygen reduction) reactions occur in parallel, together film and biofilm formation was proposed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001891 [article] Utilization of electrochemical impedance spectroscopy for monitoring bornite (Cu5FeS4) oxidation by Acidithiobacillus ferrooxidans [texte imprimé] / Denise Bevilaqua, Auteur ; Heloisa A. Acciari, Auteur ; Fabiana A. Arena, Auteur . - 2009 . - pp. 254–262. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 254–262 Mots-clés : Bornite  (Cu5FeS4)  Acidithiobacillus  ferrooxidans  Electrochemical  impedance  spectroscopy  (EIS)  Bioleaching Index. décimale : 622 Industrie minière Résumé : In this work, the monitoring of the bacterial and chemical dissolution of bornite was evaluated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS); the mineral surface was examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The analysis of CV results allowed attributing the different peaks observed in both direct and reverse potential scanning to the oxidation of bornite to a secondary covellite and its reduction via different non stoichiometric copper sulphides intermediaries. EIS data for bornite were obtained in control medium up to 78 h of immersion, when a cellular suspension of A. ferrooxidans was added and the experiments continued up to a 192 h of test. The EIS response was different when bacteria were added in the beginning of the test or after some hours of immersion in acid solution. The experiments were performed in different cell configurations and a model of the electrode/electrolyte interface. The correspondent equivalent electrical circuit was used to fit impedance spectra for all studied conditions. A common equivalent circuit used for corrosion processes where anodic (degradation of the mineral) and cathodic (oxygen reduction) reactions occur in parallel, together film and biofilm formation was proposed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508001891

Adsorption and surface tension analysis of concentrated alkali halide brine solutions / Orhan Ozdemir in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 263–271 Titre : Adsorption and surface tension analysis of concentrated alkali halide brine solutions Type de document : texte imprimé Auteurs : Orhan Ozdemir, Auteur ; Stoyan I. Karakashev, Auteur ; Anh V. Nguyen, Auteur Année de publication : 2009 Article en page(s) : pp. 263–271 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sodium  chloride  and  potassium  chloride  Surface  tension  Water  structure  maker  and  breaker Index. décimale : 622 Industrie minière Résumé : In this study, the equilibrium and dynamic surface tensions of sodium chloride and potassium chloride solutions have been measured as a function of concentration up to saturation (5.2 M for NaCl and 4.1 M for KCl) using sessile bubble tensiometry. The experimental results show that the surface tension of these and other salts significantly increases with increasing concentration due to negative adsorption of ions at the air/brine interface, regardless of their structure maker and breaker nature. Furthermore, the effect of these salts on the surface tension of aqueous solutions of sodium dodecyl sulfate (SDS) and methyl isobutyl carbinol (MIBC) was also studied. These results show that the salts increased the surface activity of SDS and MIBC. In the case of SDS, KCl increased the surface activity of SDS more significantly than NaCl did. In the case of MIBC, the effect of NaCl on MIBC surface activity was more significant than that of KCl. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800201X [article] Adsorption and surface tension analysis of concentrated alkali halide brine solutions [texte imprimé] / Orhan Ozdemir, Auteur ; Stoyan I. Karakashev, Auteur ; Anh V. Nguyen, Auteur . - 2009 . - pp. 263–271. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 263–271 Mots-clés : Sodium  chloride  and  potassium  chloride  Surface  tension  Water  structure  maker  and  breaker Index. décimale : 622 Industrie minière Résumé : In this study, the equilibrium and dynamic surface tensions of sodium chloride and potassium chloride solutions have been measured as a function of concentration up to saturation (5.2 M for NaCl and 4.1 M for KCl) using sessile bubble tensiometry. The experimental results show that the surface tension of these and other salts significantly increases with increasing concentration due to negative adsorption of ions at the air/brine interface, regardless of their structure maker and breaker nature. Furthermore, the effect of these salts on the surface tension of aqueous solutions of sodium dodecyl sulfate (SDS) and methyl isobutyl carbinol (MIBC) was also studied. These results show that the salts increased the surface activity of SDS and MIBC. In the case of SDS, KCl increased the surface activity of SDS more significantly than NaCl did. In the case of MIBC, the effect of NaCl on MIBC surface activity was more significant than that of KCl. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800201X

Froth zone characterization of an industrial flotation column in rougher circuit / M. Massinaei in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 272–278 Titre : Froth zone characterization of an industrial flotation column in rougher circuit Type de document : texte imprimé Auteurs : M. Massinaei, Auteur ; M. Kolahdoozan, Auteur ; M. Noaparast, Auteur Année de publication : 2009 Article en page(s) : pp. 272–278 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Flotation  kinetics  Flotation  bubbles  Flotation  machines  Modeling Index. décimale : 622 Industrie minière Résumé : In this investigation the froth zone of an industrial column (4 m “diameter” × 12 m “height”) in rougher circuit was characterized. Experiments were carried out at Miduk copper concentrator, Iran. Miduk is a unique copper processing plant which utilizes columns in rougher circuit. Cleaning and selectivity actions in the rougher froth were illustrated using solids and grade profiles along with RTD data. The impact of froth depth (FD) on overall rate constant (k) and k–Sb relationship was evaluated. Dependency of overall flotation kinetics on froth depth and gas velocity (Jg) was modeled by k = 4.97(FD)−0.87(Jg)0.80. Froth recovery (Rf) was estimated and modeled in terms of froth residence time of slurry (FRTSlurry) as Rf = Rf,maxexp(−k × FRTSlurry). Finally, the correlation between k, Sb (indicative of the collection zone performance) and FRTSlurry (indicative of the froth zone performance) was modeled by k = 0.02 (FRTSlurry)−0.62(Sb)0.82. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002045 [article] Froth zone characterization of an industrial flotation column in rougher circuit [texte imprimé] / M. Massinaei, Auteur ; M. Kolahdoozan, Auteur ; M. Noaparast, Auteur . - 2009 . - pp. 272–278. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 272–278 Mots-clés : Froth  flotation  Flotation  kinetics  Flotation  bubbles  Flotation  machines  Modeling Index. décimale : 622 Industrie minière Résumé : In this investigation the froth zone of an industrial column (4 m “diameter” × 12 m “height”) in rougher circuit was characterized. Experiments were carried out at Miduk copper concentrator, Iran. Miduk is a unique copper processing plant which utilizes columns in rougher circuit. Cleaning and selectivity actions in the rougher froth were illustrated using solids and grade profiles along with RTD data. The impact of froth depth (FD) on overall rate constant (k) and k–Sb relationship was evaluated. Dependency of overall flotation kinetics on froth depth and gas velocity (Jg) was modeled by k = 4.97(FD)−0.87(Jg)0.80. Froth recovery (Rf) was estimated and modeled in terms of froth residence time of slurry (FRTSlurry) as Rf = Rf,maxexp(−k × FRTSlurry). Finally, the correlation between k, Sb (indicative of the collection zone performance) and FRTSlurry (indicative of the froth zone performance) was modeled by k = 0.02 (FRTSlurry)−0.62(Sb)0.82. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002045

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

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

Precipitation of valuable metals from bioleaching solution by biogenic sulfides / Junya Cao in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 289–295 Titre : Precipitation of valuable metals from bioleaching solution by biogenic sulfides Type de document : texte imprimé Auteurs : Junya Cao, Auteur ; Guangji Zhang, Auteur ; Zaisha Mao, Auteur Année de publication : 2009 Article en page(s) : pp. 289–295 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulfate-reducing  bacteria  Bioleaching  solutions  Precipitation  Biogenic  sulfides Index. décimale : 622 Industrie minière Résumé : The aim of this work was to explore the possibility of using sulfate-reducing bacteria for the retrieval of valuable metals from a bioleaching solution. Tests were conducted to determine whether the bacteria produced hydrogen sulfide that could be used to precipitate valuable metals from a bioleaching solution as sulfides. The approach consisted of continuous culture of sulfate-reducing bacteria to produce hydrogen sulfide in the first reactor and the subsequent metal precipitation in the second reactor. Batch and continuous experiments were carried out to determine the optimum process parameters. The advantage of this process was demonstrated including faster precipitation of valuable metals and the possibility of the metal precipitation in the form of sulfides. A new flow sheet for the separation of Ni and Cu by biogenic sulfide precipitation in the presence of magnesium was proposed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002069 [article] Precipitation of valuable metals from bioleaching solution by biogenic sulfides [texte imprimé] / Junya Cao, Auteur ; Guangji Zhang, Auteur ; Zaisha Mao, Auteur . - 2009 . - pp. 289–295. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 289–295 Mots-clés : Sulfate-reducing  bacteria  Bioleaching  solutions  Precipitation  Biogenic  sulfides Index. décimale : 622 Industrie minière Résumé : The aim of this work was to explore the possibility of using sulfate-reducing bacteria for the retrieval of valuable metals from a bioleaching solution. Tests were conducted to determine whether the bacteria produced hydrogen sulfide that could be used to precipitate valuable metals from a bioleaching solution as sulfides. The approach consisted of continuous culture of sulfate-reducing bacteria to produce hydrogen sulfide in the first reactor and the subsequent metal precipitation in the second reactor. Batch and continuous experiments were carried out to determine the optimum process parameters. The advantage of this process was demonstrated including faster precipitation of valuable metals and the possibility of the metal precipitation in the form of sulfides. A new flow sheet for the separation of Ni and Cu by biogenic sulfide precipitation in the presence of magnesium was proposed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002069

Algorithm for dynamic cone crusher control / Erik Hulthén in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 296–303 Titre : Algorithm for dynamic cone crusher control Type de document : texte imprimé Auteurs : Erik Hulthén, Auteur ; C. Magnus Evertsson, Auteur Année de publication : 2009 Article en page(s) : pp. 296–303 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Crushing  Process  control  Process  optimisation  On-line  analysis  Process  instrumentation Index. décimale : 622 Industrie minière Résumé : Cone crushers are used in the mineral, mining, and aggregate industry for fragmentation of rock materials. Control systems for cone crusher settings are widely used for compensating for wear and protecting the machines from high pressure. However, these systems focus on the crusher and not the crushed products. By applying measurement devices on the process the crusher can be run optimally from the saleable products point of view (unlike most existing systems which only protect the machine) in each time. The measurement devices can be mass flow meters, e.g. conveyor belt scales. To analyze data from the process and convert them to a desired CSS value, an algorithm was developed. The developed algorithm is tested and evolved at a real crushing plant for aggregates. The algorithm was loaded into a computer which could communicate with the crusher control system, read data from three mass flow meters, and also interact with the operators. The computer was reachable over the Internet by the researchers at Chalmers and the algorithm was tuned and improved on-line. The result is an algorithm which was capable of providing CSS set-points to the automatic setting regulation system. The amount of saleable product from the crushing stage improved 3.5%, when not limited by the hydraulic pressure, compared to when a fixed closed side setting is used. The use of the algorithm automatically compensates for changes in the feed material and it also decreases the need for calibration of the underlying system. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002070 [article] Algorithm for dynamic cone crusher control [texte imprimé] / Erik Hulthén, Auteur ; C. Magnus Evertsson, Auteur . - 2009 . - pp. 296–303. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 296–303 Mots-clés : Crushing  Process  control  Process  optimisation  On-line  analysis  Process  instrumentation Index. décimale : 622 Industrie minière Résumé : Cone crushers are used in the mineral, mining, and aggregate industry for fragmentation of rock materials. Control systems for cone crusher settings are widely used for compensating for wear and protecting the machines from high pressure. However, these systems focus on the crusher and not the crushed products. By applying measurement devices on the process the crusher can be run optimally from the saleable products point of view (unlike most existing systems which only protect the machine) in each time. The measurement devices can be mass flow meters, e.g. conveyor belt scales. To analyze data from the process and convert them to a desired CSS value, an algorithm was developed. The developed algorithm is tested and evolved at a real crushing plant for aggregates. The algorithm was loaded into a computer which could communicate with the crusher control system, read data from three mass flow meters, and also interact with the operators. The computer was reachable over the Internet by the researchers at Chalmers and the algorithm was tuned and improved on-line. The result is an algorithm which was capable of providing CSS set-points to the automatic setting regulation system. The amount of saleable product from the crushing stage improved 3.5%, when not limited by the hydraulic pressure, compared to when a fixed closed side setting is used. The use of the algorithm automatically compensates for changes in the feed material and it also decreases the need for calibration of the underlying system. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002070

Quantifying the content of gravity recoverable platinum group minerals in ore samples / Z. Xiao in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 304–310 Titre : Quantifying the content of gravity recoverable platinum group minerals in ore samples Type de document : texte imprimé Auteurs : Z. Xiao, Auteur ; André R. Laplante, Auteur ; James A. Finch, Auteur Année de publication : 2009 Article en page(s) : pp. 304–310 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gravity  recovery  Platinum  group  minerals Index. décimale : 622 Industrie minière Résumé : A protocol for predicting recovery of platinum group minerals (GRPGM) is adapted from the protocol for gravity recoverable gold. This paper introduces the methodology to characterize the content of GRPGM in samples using the 3-in. (7.5 cm) laboratory Knelson concentrator. Results for two ore samples are presented, as well as some mineralogical analysis of the gravity concentrates. The methodology can also be used for sample preconcentration to aid mineralogical analysis. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002082 [article] Quantifying the content of gravity recoverable platinum group minerals in ore samples [texte imprimé] / Z. Xiao, Auteur ; André R. Laplante, Auteur ; James A. Finch, Auteur . - 2009 . - pp. 304–310. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 304–310 Mots-clés : Gravity  recovery  Platinum  group  minerals Index. décimale : 622 Industrie minière Résumé : A protocol for predicting recovery of platinum group minerals (GRPGM) is adapted from the protocol for gravity recoverable gold. This paper introduces the methodology to characterize the content of GRPGM in samples using the 3-in. (7.5 cm) laboratory Knelson concentrator. Results for two ore samples are presented, as well as some mineralogical analysis of the gravity concentrates. The methodology can also be used for sample preconcentration to aid mineralogical analysis. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002082

Recovery of nickel from lateritic nickel ore using Aspergillus niger and optimization of parameters / S. Mohapatra in Minerals engineering, Vol. 22 N° 3 (Fevrier 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 311–313 Titre : Recovery of nickel from lateritic nickel ore using Aspergillus niger and optimization of parameters Type de document : texte imprimé Auteurs : S. Mohapatra, Auteur ; N. Pradhan, Auteur ; S. Mohanty, Auteur Année de publication : 2009 Article en page(s) : pp. 311–313 Note générale : Génie minier Langues : Anglais (eng) Mots-clés : Oxide  ore  Sulphide  ores  Fungal  strain  Aspergillus  niger  Bioleaching Index. décimale : 622 Industrie minière Résumé : The present study deals with the extraction of nickel from lateritic nickel ore of Sukinda mines, Orissa, through microbial leaching using Aspergillus niger. The presence of significant metals in oxidic nickel ores, are potential sources of nickel for the future. Thus, experiments were carried out with ore to optimize the conditions for maximum nickel recovery. Experiments designed as per central composite design technique, were carried out for fitting an empirical reduced second order model. The factors studied were sucrose concentration, pulp density, temperature and duration. In addition to main effects of four factors, sucrose concentration, pulp density and duration had quadratic effect on the percentage extraction and there were interactions between different factors also. There was also significant interaction between temperature and duration as well as sucrose and pulp density. The F-value for the model shows that model is significant at less than a 0.01% level (i.e. at 99.99% confidence level). The predicted maximum nickel extraction was 31.34% with a pulp density of 8.75%, sucrose concentration of 10.04 g/l, temperature 33.8 °C and duration of 37.5 days. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002021 [article] Recovery of nickel from lateritic nickel ore using Aspergillus niger and optimization of parameters [texte imprimé] / S. Mohapatra, Auteur ; N. Pradhan, Auteur ; S. Mohanty, Auteur . - 2009 . - pp. 311–313. Génie minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 3 (Fevrier 2009) . - pp. 311–313 Mots-clés : Oxide  ore  Sulphide  ores  Fungal  strain  Aspergillus  niger  Bioleaching Index. décimale : 622 Industrie minière Résumé : The present study deals with the extraction of nickel from lateritic nickel ore of Sukinda mines, Orissa, through microbial leaching using Aspergillus niger. The presence of significant metals in oxidic nickel ores, are potential sources of nickel for the future. Thus, experiments were carried out with ore to optimize the conditions for maximum nickel recovery. Experiments designed as per central composite design technique, were carried out for fitting an empirical reduced second order model. The factors studied were sucrose concentration, pulp density, temperature and duration. In addition to main effects of four factors, sucrose concentration, pulp density and duration had quadratic effect on the percentage extraction and there were interactions between different factors also. There was also significant interaction between temperature and duration as well as sucrose and pulp density. The F-value for the model shows that model is significant at less than a 0.01% level (i.e. at 99.99% confidence level). The predicted maximum nickel extraction was 31.34% with a pulp density of 8.75%, sucrose concentration of 10.04 g/l, temperature 33.8 °C and duration of 37.5 days. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002021

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