Dépouillements

Separation of silica from bauxite via froth flotation / C.P. Massola in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 315–318 Titre : Separation of silica from bauxite via froth flotation Type de document : texte imprimé Auteurs : C.P. Massola, Auteur ; A. P. Chaves, Auteur ; J.R.B. Lima, Auteur Année de publication : 2009 Article en page(s) : pp. 315–318 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Non-ferrous  metallic  ores  Tailings Index. décimale : 622 Industrie minière Résumé : This paper reports an innovative development: concentrating gibbsite via reverse froth flotation in order to obtain a metallurgical-grade bauxite concentrate. Tailings from an industrial plant have undergone attrition scrubbing and desliming; the quartz silica contained in the tailings has undergone flotation. Starch was used as a depressant, and ether-amine as the cationic collector. Optimum pH is around 10.0. In pilot plant scale, a metallurgical-grade concentrate was obtained by assaying 42.3% available alumina with an alumina/insoluble silica mass ratio of 11.1. It contained the gibbsite and the iron and titanium bearing minerals. The concentrate was further upgraded by magnetic separation, leading to 54.0% available alumina, with an alumina/insoluble silica mass ratio of 12.6 at an overall available alumina recovery of 69.3% in the final concentrate (non-magnetic product). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002264 [article] Separation of silica from bauxite via froth flotation [texte imprimé] / C.P. Massola, Auteur ; A. P. Chaves, Auteur ; J.R.B. Lima, Auteur . - 2009 . - pp. 315–318. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 315–318 Mots-clés : Froth  flotation  Non-ferrous  metallic  ores  Tailings Index. décimale : 622 Industrie minière Résumé : This paper reports an innovative development: concentrating gibbsite via reverse froth flotation in order to obtain a metallurgical-grade bauxite concentrate. Tailings from an industrial plant have undergone attrition scrubbing and desliming; the quartz silica contained in the tailings has undergone flotation. Starch was used as a depressant, and ether-amine as the cationic collector. Optimum pH is around 10.0. In pilot plant scale, a metallurgical-grade concentrate was obtained by assaying 42.3% available alumina with an alumina/insoluble silica mass ratio of 11.1. It contained the gibbsite and the iron and titanium bearing minerals. The concentrate was further upgraded by magnetic separation, leading to 54.0% available alumina, with an alumina/insoluble silica mass ratio of 12.6 at an overall available alumina recovery of 69.3% in the final concentrate (non-magnetic product). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002264

Experimental study of flow patterns in deoiling hydrocyclone / Zhi-shan Bai in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 319–323 Titre : Experimental study of flow patterns in deoiling hydrocyclone Type de document : texte imprimé Auteurs : Zhi-shan Bai, Auteur ; Hua-lin Wang, Auteur ; Shan-Tung Tu, Auteur Année de publication : 2009 Article en page(s) : pp. 319–323 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Hydrocyclone  Laser  Doppler  velocimetry  Velocity Index. décimale : 622 Industrie minière Résumé : Using a two-component laser Doppler velocimeter, the axial velocity, tangential velocity and fluctuation velocity were measured in a 35-mm deoiling hydrocyclone. Air core occurs in the hydrocyclone when inlet flow rate is more than 2.00 m3/h. The fluctuation velocities with air core are greater than without air core. The velocity magnitudes are dependent on the inlet flow rate and the flow character is not change by changes in the inlet flow rate in hydrocyclone. The velocity fluctuations are greater near the core and near the wall. The results show that air core in the hydrocyclone will arose turbulence fluctuation. These studies are helpful to understand the separation mechanism of deoiling hydrocyclone. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002288 [article] Experimental study of flow patterns in deoiling hydrocyclone [texte imprimé] / Zhi-shan Bai, Auteur ; Hua-lin Wang, Auteur ; Shan-Tung Tu, Auteur . - 2009 . - pp. 319–323. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 319–323 Mots-clés : Hydrocyclone  Laser  Doppler  velocimetry  Velocity Index. décimale : 622 Industrie minière Résumé : Using a two-component laser Doppler velocimeter, the axial velocity, tangential velocity and fluctuation velocity were measured in a 35-mm deoiling hydrocyclone. Air core occurs in the hydrocyclone when inlet flow rate is more than 2.00 m3/h. The fluctuation velocities with air core are greater than without air core. The velocity magnitudes are dependent on the inlet flow rate and the flow character is not change by changes in the inlet flow rate in hydrocyclone. The velocity fluctuations are greater near the core and near the wall. The results show that air core in the hydrocyclone will arose turbulence fluctuation. These studies are helpful to understand the separation mechanism of deoiling hydrocyclone. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002288

Copper removal from cyanide solutions by acidification / O. Alonso-González in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 324–329 Titre : Copper removal from cyanide solutions by acidification Type de document : texte imprimé Auteurs : O. Alonso-González, Auteur ; F. Nava-Alonso, Auteur ; A. Uribe-Salas, Auteur Année de publication : 2009 Article en page(s) : pp. 324–329 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Cyanidation  Copper–cyanide  complexes  Cyanide  acidification  Hydrogen  cyanide  evolution  Copper  precipitation Index. décimale : 622 Industrie minière Résumé : Cyanidation is the most used method to recover gold and silver from their ores. In this process, other metals besides gold and silver may dissolve under certain circumstances and interfere with the efficiency of extraction. Copper is one of these metals, being able to reach concentrations as high as 1000 mg/L. When the cyanide solution contains a high copper concentration, the extraction of precious metals decreases and the operating costs increase. In addition, the control of the process is more complicated because the free cyanide analysis performed by the operators by titration does not represent the actual cyanide available to dissolve gold and silver. This experimental work has two objectives: to evaluate the amount of copper–cyanide complexes that are measured when titration is used for free cyanide analysis, and to develop and propose a method for copper removal from cyanidation solutions. The method consists in the acidification of the solution with sulfuric acid, and the separation of the precipitated solid (CuCN) by filtration. The thermodynamics of the copper–cyanide system is discussed, and the hydrogen cyanide evolution (HCN) at pH acid is evaluated. One of the main operating variables in cyanidation plants is the “free cyanide” concentration, that is, the amount of cyanide available to dissolve the precious metals. The usual method to estimate free cyanide is titration. When copper is present in the cyanide solution, the titration method not only measures the free cyanide but also part of the cyanide that is forming complexes with copper. It was demonstrated from the tests performed in this work, that for cyanide/copper ratios of 1–10, typically found in cyanidation solutions, around 10% of the free cyanide measured by titration corresponds to copper–cyanide complexes and is not available for gold and silver dissolution. In order to recycle the solution to the process, it is necessary to remove part of the copper. A method of copper removal is proposed, based on the precipitation of CuCN when the copper–cyanide solution is acidified. The precipitated solid is separated from the solution by filtration and finally the clear solution is neutralized. The acidification/filtration/alkalinization of cyanidation solutions containing copper permits the removal of most of the copper present in the solution, thus allowing the recycling of the solution. For synthetic solutions containing 200–730 mg/L Cu at different cyanide/copper ratios, it was found that 93–98% of the copper can be removed as CuCN at pH 2.5, releasing free cyanide to the solution. If a flotation stage is considered to remove the solid formed, the HCN formed by acidification should not represent a problem: the amount of HCN gas stripped at pH 2.5 when using the usual flotation gas flow rates (0.17 cm/s, 0.28 L/min, 1 h for our experimental design) was only 6%, which can be easily controlled with conventional equipment. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800229X [article] Copper removal from cyanide solutions by acidification [texte imprimé] / O. Alonso-González, Auteur ; F. Nava-Alonso, Auteur ; A. Uribe-Salas, Auteur . - 2009 . - pp. 324–329. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 324–329 Mots-clés : Cyanidation  Copper–cyanide  complexes  Cyanide  acidification  Hydrogen  cyanide  evolution  Copper  precipitation Index. décimale : 622 Industrie minière Résumé : Cyanidation is the most used method to recover gold and silver from their ores. In this process, other metals besides gold and silver may dissolve under certain circumstances and interfere with the efficiency of extraction. Copper is one of these metals, being able to reach concentrations as high as 1000 mg/L. When the cyanide solution contains a high copper concentration, the extraction of precious metals decreases and the operating costs increase. In addition, the control of the process is more complicated because the free cyanide analysis performed by the operators by titration does not represent the actual cyanide available to dissolve gold and silver. This experimental work has two objectives: to evaluate the amount of copper–cyanide complexes that are measured when titration is used for free cyanide analysis, and to develop and propose a method for copper removal from cyanidation solutions. The method consists in the acidification of the solution with sulfuric acid, and the separation of the precipitated solid (CuCN) by filtration. The thermodynamics of the copper–cyanide system is discussed, and the hydrogen cyanide evolution (HCN) at pH acid is evaluated. One of the main operating variables in cyanidation plants is the “free cyanide” concentration, that is, the amount of cyanide available to dissolve the precious metals. The usual method to estimate free cyanide is titration. When copper is present in the cyanide solution, the titration method not only measures the free cyanide but also part of the cyanide that is forming complexes with copper. It was demonstrated from the tests performed in this work, that for cyanide/copper ratios of 1–10, typically found in cyanidation solutions, around 10% of the free cyanide measured by titration corresponds to copper–cyanide complexes and is not available for gold and silver dissolution. In order to recycle the solution to the process, it is necessary to remove part of the copper. A method of copper removal is proposed, based on the precipitation of CuCN when the copper–cyanide solution is acidified. The precipitated solid is separated from the solution by filtration and finally the clear solution is neutralized. The acidification/filtration/alkalinization of cyanidation solutions containing copper permits the removal of most of the copper present in the solution, thus allowing the recycling of the solution. For synthetic solutions containing 200–730 mg/L Cu at different cyanide/copper ratios, it was found that 93–98% of the copper can be removed as CuCN at pH 2.5, releasing free cyanide to the solution. If a flotation stage is considered to remove the solid formed, the HCN formed by acidification should not represent a problem: the amount of HCN gas stripped at pH 2.5 when using the usual flotation gas flow rates (0.17 cm/s, 0.28 L/min, 1 h for our experimental design) was only 6%, which can be easily controlled with conventional equipment. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268750800229X

Micro-bubble size distribution measurements by laser diffraction technique / Hudson J. B. Couto in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 330–335 Titre : Micro-bubble size distribution measurements by laser diffraction technique Type de document : texte imprimé Auteurs : Hudson J. B. Couto, Auteur ; Daniel G. Nunes, Auteur ; Reiner Neumann, Auteur Année de publication : 2009 Article en page(s) : pp. 330–335 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Flotation  bubbles  Sizing  Flotation  reagents  Shear  forces  Environmental Index. décimale : 622 Industrie minière Résumé : The size distribution of microbubbles generated for the dissolved air flotation process could be assessed on a fast and reliable way by the application of laser diffraction technique. The bubble generation step could therefore be optimized, in order to decrease the size of the bubbles. Increasing air saturation pressure had a positive effect on bubble size, up to 400 kPa; higher pressures, however, had no effect. Surfactants (Flotigam and sodium oleate) significantly inhibited bubble coalescence, and higher concentrations of the reagents decrease the bubble size distribution, up to the critical micelle concentration. The mode of conditioning also had an important effect on bubble size improvement, by adding the surfactant into the pressure vessel. Overall median bubble size decreased 35% over the size distribution obtained without addition of reagent and conditioning. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002355 [article] Micro-bubble size distribution measurements by laser diffraction technique [texte imprimé] / Hudson J. B. Couto, Auteur ; Daniel G. Nunes, Auteur ; Reiner Neumann, Auteur . - 2009 . - pp. 330–335. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 330–335 Mots-clés : Flotation  bubbles  Sizing  Flotation  reagents  Shear  forces  Environmental Index. décimale : 622 Industrie minière Résumé : The size distribution of microbubbles generated for the dissolved air flotation process could be assessed on a fast and reliable way by the application of laser diffraction technique. The bubble generation step could therefore be optimized, in order to decrease the size of the bubbles. Increasing air saturation pressure had a positive effect on bubble size, up to 400 kPa; higher pressures, however, had no effect. Surfactants (Flotigam and sodium oleate) significantly inhibited bubble coalescence, and higher concentrations of the reagents decrease the bubble size distribution, up to the critical micelle concentration. The mode of conditioning also had an important effect on bubble size improvement, by adding the surfactant into the pressure vessel. Overall median bubble size decreased 35% over the size distribution obtained without addition of reagent and conditioning. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002355

On the removal of Mn2+ ions by adsorption onto natural and activated Chilean zeolites / Silvio Roberto Taffarel in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 336–343 Titre : On the removal of Mn2+ ions by adsorption onto natural and activated Chilean zeolites Type de document : texte imprimé Auteurs : Silvio Roberto Taffarel, Auteur ; Jorge Rubio, Auteur Année de publication : 2009 Article en page(s) : pp. 336–343 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Zeolite  Metal  ions  Ion-exchange  Langmuir  isotherms  Water  treatment Résumé : This paper describes studies of preparation, activation and physical characterization of a Chilean zeolite (Ch-zeolite) employed as adsorbent for manganese ions from aqueous solutions. The zeolite sample, composed mainly of clinoptilolite and mordenite, had a specific surface area of 118 m2 g−1 (N2 adsorption), the particles were negatively charged in a wide pH range and presented a cation-exchange capacity of 1.09 meq View the MathML source. The medium pH influenced significantly the Mn2+ ions adsorption capacity and best results were obtained at pH 6–6.8. The adsorption onto the activated zeolite followed the pseudo-second-order kinetic model and activation of the Ch-zeolite with NaOH resulted in the highest reaction rate. The equilibrium data showed excellent correlation with the Langmuir isotherm model. Ch-zeolite modification by treating it with NaCl (0.77 meq Mn2+ g−1), NaOH (0.76 meq Mn2+ g−1), Na2CO3 (0.72 meq Mn2+ g−1) and NH4Cl (0.67 meq Mn2+ g−1) increased its uptake ability when compared with the natural Ch-zeolite (0.26 meq Mn2+ g−1). These data contribute to the understanding of mechanisms involved in zeolite activation and provide some practical clues to improve the adsorption efficiency (uptake capacity and kinetics) of manganese ions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002379 [article] On the removal of Mn2+ ions by adsorption onto natural and activated Chilean zeolites [texte imprimé] / Silvio Roberto Taffarel, Auteur ; Jorge Rubio, Auteur . - 2009 . - pp. 336–343. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 336–343 Mots-clés : Zeolite  Metal  ions  Ion-exchange  Langmuir  isotherms  Water  treatment Résumé : This paper describes studies of preparation, activation and physical characterization of a Chilean zeolite (Ch-zeolite) employed as adsorbent for manganese ions from aqueous solutions. The zeolite sample, composed mainly of clinoptilolite and mordenite, had a specific surface area of 118 m2 g−1 (N2 adsorption), the particles were negatively charged in a wide pH range and presented a cation-exchange capacity of 1.09 meq View the MathML source. The medium pH influenced significantly the Mn2+ ions adsorption capacity and best results were obtained at pH 6–6.8. The adsorption onto the activated zeolite followed the pseudo-second-order kinetic model and activation of the Ch-zeolite with NaOH resulted in the highest reaction rate. The equilibrium data showed excellent correlation with the Langmuir isotherm model. Ch-zeolite modification by treating it with NaCl (0.77 meq Mn2+ g−1), NaOH (0.76 meq Mn2+ g−1), Na2CO3 (0.72 meq Mn2+ g−1) and NH4Cl (0.67 meq Mn2+ g−1) increased its uptake ability when compared with the natural Ch-zeolite (0.26 meq Mn2+ g−1). These data contribute to the understanding of mechanisms involved in zeolite activation and provide some practical clues to improve the adsorption efficiency (uptake capacity and kinetics) of manganese ions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002379

Kinetic comparison of biological and conventional flotation of coal / E. Amini in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 344–347 Titre : Kinetic comparison of biological and conventional flotation of coal Type de document : texte imprimé Auteurs : E. Amini, Auteur ; M. Oliazadeh, Auteur ; M. Kolahdoozan, Auteur Année de publication : 2009 Article en page(s) : pp. 344–347 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Flotation  Kinetics  Bioflotation  Selectivity  Separation  Tabas  coal Résumé : Froth flotation is commonly used in coal processing to selectively recover the organic material (coal) from inorganic waste material. Tabas coal, located in east Iran, contains fine disseminated pyrite which is floated with coal during flotation, and hence decreasing the quality of the final concentrate. Reagents, such as sodium cyanide, are typically added to depress pyrite. Due to the toxicity of cyanide, alternative strategies for depressing pyrite flotation are being investigated. In this paper the metallurgical performance of Tabas coal treated with sodium cyanide is compared to that of Tabas coal which has undergone bacterial treatment using Acidithiobacillus ferrooxidans. Results indicate that bacterial treatment decreases the flotation rate of pyrite and improves the selectivity between coal and gangue. The possibility of using bacteria in place of toxic chemicals such as cyanide has significant environmental benefit. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002380 [article] Kinetic comparison of biological and conventional flotation of coal [texte imprimé] / E. Amini, Auteur ; M. Oliazadeh, Auteur ; M. Kolahdoozan, Auteur . - 2009 . - pp. 344–347. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 344–347 Mots-clés : Flotation  Kinetics  Bioflotation  Selectivity  Separation  Tabas  coal Résumé : Froth flotation is commonly used in coal processing to selectively recover the organic material (coal) from inorganic waste material. Tabas coal, located in east Iran, contains fine disseminated pyrite which is floated with coal during flotation, and hence decreasing the quality of the final concentrate. Reagents, such as sodium cyanide, are typically added to depress pyrite. Due to the toxicity of cyanide, alternative strategies for depressing pyrite flotation are being investigated. In this paper the metallurgical performance of Tabas coal treated with sodium cyanide is compared to that of Tabas coal which has undergone bacterial treatment using Acidithiobacillus ferrooxidans. Results indicate that bacterial treatment decreases the flotation rate of pyrite and improves the selectivity between coal and gangue. The possibility of using bacteria in place of toxic chemicals such as cyanide has significant environmental benefit. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002380

A gel sample preparation method for the analysis of zinc concentrates by WD-XRF / Gai Zhang in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 348–351 Titre : A gel sample preparation method for the analysis of zinc concentrates by WD-XRF Type de document : texte imprimé Auteurs : Gai Zhang, Auteur ; Xudong Hu, Auteur ; Hairui Ma, Auteur Année de publication : 2009 Article en page(s) : pp. 348–351 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : X-ray  fluorescence  Gel  Sample  preparation  Zinc  concentrates  Zinc Résumé : This article describes a methodology for analyzing zinc in zinc concentrates materials by wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometry with gel for sample preparation. The sample was decomposed with aqua regia. The sample solution mixed with agaron gel was heated to boiling. The mixture became quasi-solid gel under normal temperature. The elements dispersed in gel medium were detected by WD-XRF spectrometry. The method has both advantages of the solution preparation method and the solid preparation method. In addition, this method was adapted in detecting high content ores, because it avoided the risking of using platinum crucible. The method has been applied to the determination of lead, zinc and iron in zinc concentrates successfully. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002392 [article] A gel sample preparation method for the analysis of zinc concentrates by WD-XRF [texte imprimé] / Gai Zhang, Auteur ; Xudong Hu, Auteur ; Hairui Ma, Auteur . - 2009 . - pp. 348–351. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 348–351 Mots-clés : X-ray  fluorescence  Gel  Sample  preparation  Zinc  concentrates  Zinc Résumé : This article describes a methodology for analyzing zinc in zinc concentrates materials by wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometry with gel for sample preparation. The sample was decomposed with aqua regia. The sample solution mixed with agaron gel was heated to boiling. The mixture became quasi-solid gel under normal temperature. The elements dispersed in gel medium were detected by WD-XRF spectrometry. The method has both advantages of the solution preparation method and the solid preparation method. In addition, this method was adapted in detecting high content ores, because it avoided the risking of using platinum crucible. The method has been applied to the determination of lead, zinc and iron in zinc concentrates successfully. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002392

A method for the prediction of the primary flow on large diameter spiral troughs / A.B. Holland-Batt in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 352–356 Titre : A method for the prediction of the primary flow on large diameter spiral troughs Type de document : texte imprimé Auteurs : A.B. Holland-Batt, Auteur Année de publication : 2009 Article en page(s) : pp. 352–356 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Large  spirals  Fluid  flow  Prediction Résumé : In previous work an analysis of the primary flow and secondary circulation on a spiral was developed, based on the use of the Manning equation to describe the flow on the inner part of the spiral and the free vortex equation to characterise the flow on the outer section. More recent studies have advocated the use of the Laminar equation or a new relationship based on the Bagnold shear force. The theoretical basis is modified in the present contribution to permit the estimation of the primary flow on large diameter spiral troughs where the whole of the free surface is part of the vortex flow. Flow predictions for two different large diameter spirals are presented. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002409 [article] A method for the prediction of the primary flow on large diameter spiral troughs [texte imprimé] / A.B. Holland-Batt, Auteur . - 2009 . - pp. 352–356. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 352–356 Mots-clés : Large  spirals  Fluid  flow  Prediction Résumé : In previous work an analysis of the primary flow and secondary circulation on a spiral was developed, based on the use of the Manning equation to describe the flow on the inner part of the spiral and the free vortex equation to characterise the flow on the outer section. More recent studies have advocated the use of the Laminar equation or a new relationship based on the Bagnold shear force. The theoretical basis is modified in the present contribution to permit the estimation of the primary flow on large diameter spiral troughs where the whole of the free surface is part of the vortex flow. Flow predictions for two different large diameter spirals are presented. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002409

Hydrodynamic and kinetic characterization of industrial columns in rougher circuit / M. Massinaei in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 357–365 Titre : Hydrodynamic and kinetic characterization of industrial columns 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. 357–365 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Flotation  kinetics  Flotation  bubbles  Flotation  machines Résumé : In the present investigation the relationship between collection zone rate constant (kc) and gas dispersion parameters, viz. bubble size (db), superficial gas velocity (Jg), gas hold-up (εg) and bubble surface area flux (Sb) was evaluated. Experiments were conducted in an industrial (4 m in diameter and 12 m high) and a pilot (0.1 m in diameter and 4 m high) flotation column in rougher circuit at Miduk copper concentrator in Iran. Gas hold-up was measured using pressure difference technique and mean bubble sizes were estimated from a drift flux analysis. It was found that the collection zone rate constant was not correlated with db and Jg solely but was linearly dependent on εg and Sb for the range of interest. Collection efficiency (Ek) and floatability factor (P) in the industrial columns were quantified (Ek = 3.1%; P = 7.7 × 10−3). The influence of operating parameters comprising superficial gas velocity, slurry solids% and frother dosage/type on Sb and flotation kinetics was discussed. Analysis of available industrial data suggested that Sb and εg were related by Sb = 4.46εg over the range 30 < Sb < 60 s−1 and 7% < εg < 14%. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002422 [article] Hydrodynamic and kinetic characterization of industrial columns in rougher circuit [texte imprimé] / M. Massinaei, Auteur ; M. Kolahdoozan, Auteur ; M. Noaparast, Auteur . - 2009 . - pp. 357–365. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 357–365 Mots-clés : Froth  flotation  Flotation  kinetics  Flotation  bubbles  Flotation  machines Résumé : In the present investigation the relationship between collection zone rate constant (kc) and gas dispersion parameters, viz. bubble size (db), superficial gas velocity (Jg), gas hold-up (εg) and bubble surface area flux (Sb) was evaluated. Experiments were conducted in an industrial (4 m in diameter and 12 m high) and a pilot (0.1 m in diameter and 4 m high) flotation column in rougher circuit at Miduk copper concentrator in Iran. Gas hold-up was measured using pressure difference technique and mean bubble sizes were estimated from a drift flux analysis. It was found that the collection zone rate constant was not correlated with db and Jg solely but was linearly dependent on εg and Sb for the range of interest. Collection efficiency (Ek) and floatability factor (P) in the industrial columns were quantified (Ek = 3.1%; P = 7.7 × 10−3). The influence of operating parameters comprising superficial gas velocity, slurry solids% and frother dosage/type on Sb and flotation kinetics was discussed. Analysis of available industrial data suggested that Sb and εg were related by Sb = 4.46εg over the range 30 < Sb < 60 s−1 and 7% < εg < 14%. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002422

Visual information model based predictor for froth speed control in flotation process / Felipe Núñez in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 366–371 Titre : Visual information model based predictor for froth speed control in flotation process Type de document : texte imprimé Auteurs : Felipe Núñez, Auteur ; Aldo Cipriano, Auteur Année de publication : 2009 Article en page(s) : pp. 366–371 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Dynamic  textures  Froth  flotation  Expert  systems  Modelling Résumé : Image processing sensors are emerging as an important measurement option in mineral processing, mainly due to their non-intrusive characteristics. Their principal application areas have been the determination of ore size distributions in grinding and froth features in flotation. The incorporation of visual information in control loops is the logical step. However, the excessive processing required brings a new problem that must be solve: to count with a strategy able to provide a measured value for each visual sensor in the plant. A first approach is to assign one computer to each sensor yielding a distributed architecture, but this means the implementation of a huge computer network. A more efficient alternative is alternated sampling, but the succeed of this option is limited to the existence of virtual sensors capable of give accurate values that must be use during the unsampled period. In this paper we begin by reviewing classical image processing algorithms used in flotation froth feature extraction. Then a new method is introduced for the characterization and recognition of visual information using dynamic texture techniques. Finally we developed a dynamic texture based virtual sensor for the prediction of froth speed in the unsampled period, tested with industrial data. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002434 [article] Visual information model based predictor for froth speed control in flotation process [texte imprimé] / Felipe Núñez, Auteur ; Aldo Cipriano, Auteur . - 2009 . - pp. 366–371. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 366–371 Mots-clés : Dynamic  textures  Froth  flotation  Expert  systems  Modelling Résumé : Image processing sensors are emerging as an important measurement option in mineral processing, mainly due to their non-intrusive characteristics. Their principal application areas have been the determination of ore size distributions in grinding and froth features in flotation. The incorporation of visual information in control loops is the logical step. However, the excessive processing required brings a new problem that must be solve: to count with a strategy able to provide a measured value for each visual sensor in the plant. A first approach is to assign one computer to each sensor yielding a distributed architecture, but this means the implementation of a huge computer network. A more efficient alternative is alternated sampling, but the succeed of this option is limited to the existence of virtual sensors capable of give accurate values that must be use during the unsampled period. In this paper we begin by reviewing classical image processing algorithms used in flotation froth feature extraction. Then a new method is introduced for the characterization and recognition of visual information using dynamic texture techniques. Finally we developed a dynamic texture based virtual sensor for the prediction of froth speed in the unsampled period, tested with industrial data. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002434

Biosorption of Cr(VI) from aqueous solutions by nonliving green algae Cladophora albida / Liping Deng in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 372–377 Titre : Biosorption of Cr(VI) from aqueous solutions by nonliving green algae Cladophora albida Type de document : texte imprimé Auteurs : Liping Deng, Auteur ; Yang Zhang, Auteur ; Qin, Jie, Auteur Année de publication : 2009 Article en page(s) : pp. 372–377 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Biosorption  Chromium(VI)  Cladophora  albida  Mechanism  Wastewater Résumé : Biosorption of Cr(VI) from aqueous solutions by nonliving green algae Cladophora albida was investigated in batch experiments. The influence of pH, algal dosage, initial Cr(VI) concentration, temperature and co-existing anions on removal efficiencies of C. albida was studied. Cr(VI) removal process was influenced significantly by the variation of pH, and the optimum pH was chosen at a range of 1.0–3.0. The optimum algal dosage 2 g/L was used in the experiment. The removal rate of Cr(VI) was relatively rapid in the first 60 min, but then the rate decreased gradually. Removal mechanism was studied by analyzing Cr(VI) and total Cr in the solution. Biosorption and bioreduction were involved in the Cr(VI) removal. Biosorption of Cr(VI) was the first step, followed by Cr(VI) bioreduction and Cr(III) biosorption on the algal biomass. Actual industrial wastewater was used to evaluate the practicality of the biomass C. albida. From a practical viewpoint, the abundant and economic biomass C. albida could be used for removal of Cr(VI) from wastewater by the reduction of toxic Cr(VI) to less toxic Cr(III). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002525 [article] Biosorption of Cr(VI) from aqueous solutions by nonliving green algae Cladophora albida [texte imprimé] / Liping Deng, Auteur ; Yang Zhang, Auteur ; Qin, Jie, Auteur . - 2009 . - pp. 372–377. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 372–377 Mots-clés : Biosorption  Chromium(VI)  Cladophora  albida  Mechanism  Wastewater Résumé : Biosorption of Cr(VI) from aqueous solutions by nonliving green algae Cladophora albida was investigated in batch experiments. The influence of pH, algal dosage, initial Cr(VI) concentration, temperature and co-existing anions on removal efficiencies of C. albida was studied. Cr(VI) removal process was influenced significantly by the variation of pH, and the optimum pH was chosen at a range of 1.0–3.0. The optimum algal dosage 2 g/L was used in the experiment. The removal rate of Cr(VI) was relatively rapid in the first 60 min, but then the rate decreased gradually. Removal mechanism was studied by analyzing Cr(VI) and total Cr in the solution. Biosorption and bioreduction were involved in the Cr(VI) removal. Biosorption of Cr(VI) was the first step, followed by Cr(VI) bioreduction and Cr(III) biosorption on the algal biomass. Actual industrial wastewater was used to evaluate the practicality of the biomass C. albida. From a practical viewpoint, the abundant and economic biomass C. albida could be used for removal of Cr(VI) from wastewater by the reduction of toxic Cr(VI) to less toxic Cr(III). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002525

Investigation of froth flotation for beneficiation of printed circuit board comminution fines / I.O. Ogunniyi in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 378–385 Titre : Investigation of froth flotation for beneficiation of printed circuit board comminution fines Type de document : texte imprimé Auteurs : I.O. Ogunniyi, Auteur ; M.K.G. Vermaak, Auteur Année de publication : 2009 Article en page(s) : pp. 378–385 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Recycling  Froth  flotation  Printed  circuit  boards Résumé : Froth flotation for beneficiation of printed circuit board comminution fines was investigated in this work, via reverse flotation under a scheme described as natural hydrophobic response. With no reagents, the scheme employed variation of kinetic parameters of airflow rate and impeller speed to optimize metallic enrichment of the sink. The impeller energy and aeration rate required to keep the pulp in suspension and avoid excessive turbulence were found to be much lower compared with conventional mineral flotation. The natural hydrophobic response was found to exist, and stable froth was observed even without the use of any frother. It was submitted that the dynamic froth stability observed is due to fine particle stabilization. Mass pulls obtained were high and cumulative mass pull under the varying kinetic regimes were found to fit very well to the general first order kinetics. The extents of fit, the sink enrichment and the recovery in respect of metallic values were assessed to evaluate the beneficiation performance. Many of the metallic elements were found to concentrate into the sink, while some prefer the froth phase. Notably, gold and palladium were among the best recovered to the sink; with about 64% recovery at enrichment ratio of 3.1 (676 ppm actual assay) for Au. The flotation scheme proved effective for PCB comminution fines, and performance improvement also looks very feasible. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002537 [article] Investigation of froth flotation for beneficiation of printed circuit board comminution fines [texte imprimé] / I.O. Ogunniyi, Auteur ; M.K.G. Vermaak, Auteur . - 2009 . - pp. 378–385. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 378–385 Mots-clés : Recycling  Froth  flotation  Printed  circuit  boards Résumé : Froth flotation for beneficiation of printed circuit board comminution fines was investigated in this work, via reverse flotation under a scheme described as natural hydrophobic response. With no reagents, the scheme employed variation of kinetic parameters of airflow rate and impeller speed to optimize metallic enrichment of the sink. The impeller energy and aeration rate required to keep the pulp in suspension and avoid excessive turbulence were found to be much lower compared with conventional mineral flotation. The natural hydrophobic response was found to exist, and stable froth was observed even without the use of any frother. It was submitted that the dynamic froth stability observed is due to fine particle stabilization. Mass pulls obtained were high and cumulative mass pull under the varying kinetic regimes were found to fit very well to the general first order kinetics. The extents of fit, the sink enrichment and the recovery in respect of metallic values were assessed to evaluate the beneficiation performance. Many of the metallic elements were found to concentrate into the sink, while some prefer the froth phase. Notably, gold and palladium were among the best recovered to the sink; with about 64% recovery at enrichment ratio of 3.1 (676 ppm actual assay) for Au. The flotation scheme proved effective for PCB comminution fines, and performance improvement also looks very feasible. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002537

The critical importance of the grinding environment on fine particle recovery in flotation / Stephen Grano in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 386–394 Titre : The critical importance of the grinding environment on fine particle recovery in flotation Type de document : texte imprimé Auteurs : Stephen Grano, Auteur Année de publication : 2009 Article en page(s) : pp. 386–394 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Grinding  environment  Grinding  media  Fine  particle  flotation Résumé : This paper examines published and new experimental evidence on the effect of the grinding environment on fine (−10 μm) value mineral recovery in flotation. Reasons for increases in fine value mineral recovery from ores with fully electrochemically inert grinding media are discussed in relation to reduced surface contamination by iron hydroxide emanating from the grinding media. The application of stirred milling technology, which allows the use of fully inert grinding media, to primary grinding applications may lead to increased fine value mineral recovery in flotation rougher applications. It is suggested that the effect of the grinding media, which is important for fine particles and progressively becomes more important as the grind size becomes finer, is principally due to the abrasion mechanism of the minerals with the grinding media in the production of fine particles. Opportunities for research and industry application are discussed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002549 [article] The critical importance of the grinding environment on fine particle recovery in flotation [texte imprimé] / Stephen Grano, Auteur . - 2009 . - pp. 386–394. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 386–394 Mots-clés : Grinding  environment  Grinding  media  Fine  particle  flotation Résumé : This paper examines published and new experimental evidence on the effect of the grinding environment on fine (−10 μm) value mineral recovery in flotation. Reasons for increases in fine value mineral recovery from ores with fully electrochemically inert grinding media are discussed in relation to reduced surface contamination by iron hydroxide emanating from the grinding media. The application of stirred milling technology, which allows the use of fully inert grinding media, to primary grinding applications may lead to increased fine value mineral recovery in flotation rougher applications. It is suggested that the effect of the grinding media, which is important for fine particles and progressively becomes more important as the grind size becomes finer, is principally due to the abrasion mechanism of the minerals with the grinding media in the production of fine particles. Opportunities for research and industry application are discussed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002549

Flotation of mixed copper oxide and sulphide minerals with xanthate and hydroxamate collectors / K. Lee in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 395–401 Titre : Flotation of mixed copper oxide and sulphide minerals with xanthate and hydroxamate collectors Type de document : texte imprimé Auteurs : K. Lee, Auteur ; D. Archibald, Auteur ; J. McLean, Auteur Année de publication : 2009 Article en page(s) : pp. 395–401 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Copper  oxide  ores  Copper  sulphide  ores  Flotation  collectors  Mineral  processing  Alkyl  hydroxamates Résumé : Sherwood Copper’s Minto Mine processes a high grade copper–gold deposit in Yukon, Canada. The ore mined is from a primary copper sulphide deposit with separate additional deposits of copper oxides. In conjunction with Ausmelt Chemicals, Minto is currently investigating options to recover copper oxide and sulphide minerals using flotation by blending their primary sulphide ore with oxide ores. The blend used in this laboratory scale investigation was 70% sulphide ore and 30% oxide ore on a weight basis. The copper sulphides present in the blend were bornite and chalcopyrite, while the oxides were malachite and minor azurite. From previous flotation investigations of mixed copper oxide and sulphide minerals using xanthate and hydroxamate collectors it was hard to distinguish the impact of the alkyl hydroxamate collector on sulphide recovery as the sulphide and oxide minerals occurred naturally together. In the case of the Minto operation the copper oxide and sulphide minerals occur in separate ore deposits and can be treated separately or blended together. This investigation has shown that using n-octyl hydroxamates (AM28 made by Ausmelt Limited) in conjunction with traditional sulphide collectors can successfully simultaneously recover copper sulphides and oxides by flotation from blended ore minerals. The copper sulphide recovery did not decrease when processing the blended ore compared to treating the sulphide ore independently. At a blend of 70% sulphide ore and 30% oxide ore, the rougher scavenger copper recovery was as high as 95.5%. The copper recovery from the blended ore using a mixture of collectors was shown to be superior to the recovery obtained using only xanthate after controlled potential sulphidisation. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002690 [article] Flotation of mixed copper oxide and sulphide minerals with xanthate and hydroxamate collectors [texte imprimé] / K. Lee, Auteur ; D. Archibald, Auteur ; J. McLean, Auteur . - 2009 . - pp. 395–401. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 395–401 Mots-clés : Copper  oxide  ores  Copper  sulphide  ores  Flotation  collectors  Mineral  processing  Alkyl  hydroxamates Résumé : Sherwood Copper’s Minto Mine processes a high grade copper–gold deposit in Yukon, Canada. The ore mined is from a primary copper sulphide deposit with separate additional deposits of copper oxides. In conjunction with Ausmelt Chemicals, Minto is currently investigating options to recover copper oxide and sulphide minerals using flotation by blending their primary sulphide ore with oxide ores. The blend used in this laboratory scale investigation was 70% sulphide ore and 30% oxide ore on a weight basis. The copper sulphides present in the blend were bornite and chalcopyrite, while the oxides were malachite and minor azurite. From previous flotation investigations of mixed copper oxide and sulphide minerals using xanthate and hydroxamate collectors it was hard to distinguish the impact of the alkyl hydroxamate collector on sulphide recovery as the sulphide and oxide minerals occurred naturally together. In the case of the Minto operation the copper oxide and sulphide minerals occur in separate ore deposits and can be treated separately or blended together. This investigation has shown that using n-octyl hydroxamates (AM28 made by Ausmelt Limited) in conjunction with traditional sulphide collectors can successfully simultaneously recover copper sulphides and oxides by flotation from blended ore minerals. The copper sulphide recovery did not decrease when processing the blended ore compared to treating the sulphide ore independently. At a blend of 70% sulphide ore and 30% oxide ore, the rougher scavenger copper recovery was as high as 95.5%. The copper recovery from the blended ore using a mixture of collectors was shown to be superior to the recovery obtained using only xanthate after controlled potential sulphidisation. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002690

Research in quantitative mineralogy / K.O. Hoal in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 402–408 Titre : Research in quantitative mineralogy : Examples from diverse applications Type de document : texte imprimé Auteurs : K.O. Hoal, Auteur ; J.G. Stammer, Auteur ; S. K. Appleby, Auteur Année de publication : 2009 Article en page(s) : pp. 402–408 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Quantitative  mineralogy  Research  Geology  Geomet  Ores Résumé : Developed for the mining industry and applied to oil and gas projects, quantitative mineralogy also has enormous potential as a research tool. The Advanced Mineralogy Research Center at Colorado School of Mines was developed for this purpose, and several representative ongoing research projects using QEMSCAN® techniques are described herein. Geomet applications relate mineralogy and geology to potential processing attributes such as hardness and grind characteristics. For kimberlite exploration and development, and diamond petrogenesis, quantitative mineralogy reveals the complex secondary silicate mineralogy in volcanic and mantle materials, and provides a means of viewing garnets from exploration samples. In Carlin-type gold deposits, the distribution of arsenian-pyrite can serve as a proxy for the distribution of gold. Monzonites from porphyry copper deposits reveal pervasive potassic alteration and quartz veining, which may impact the behavior of the materials during processing. A new view of feldspar zoning in granites not only has broad implications for understanding the petrogenetic evolution of magmatic systems, but is of relevance in processing feldspar-bearing materials. Environmental and biological applications include soil mineralogy, the effect of soil chemistry on vegetation, and studies of mammalian tissues. These examples illustrate how automated mineralogy allows researchers a means of quantifying mineralogical relationships in a wide variety of materials. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002719 [article] Research in quantitative mineralogy : Examples from diverse applications [texte imprimé] / K.O. Hoal, Auteur ; J.G. Stammer, Auteur ; S. K. Appleby, Auteur . - 2009 . - pp. 402–408. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 402–408 Mots-clés : Quantitative  mineralogy  Research  Geology  Geomet  Ores Résumé : Developed for the mining industry and applied to oil and gas projects, quantitative mineralogy also has enormous potential as a research tool. The Advanced Mineralogy Research Center at Colorado School of Mines was developed for this purpose, and several representative ongoing research projects using QEMSCAN® techniques are described herein. Geomet applications relate mineralogy and geology to potential processing attributes such as hardness and grind characteristics. For kimberlite exploration and development, and diamond petrogenesis, quantitative mineralogy reveals the complex secondary silicate mineralogy in volcanic and mantle materials, and provides a means of viewing garnets from exploration samples. In Carlin-type gold deposits, the distribution of arsenian-pyrite can serve as a proxy for the distribution of gold. Monzonites from porphyry copper deposits reveal pervasive potassic alteration and quartz veining, which may impact the behavior of the materials during processing. A new view of feldspar zoning in granites not only has broad implications for understanding the petrogenetic evolution of magmatic systems, but is of relevance in processing feldspar-bearing materials. Environmental and biological applications include soil mineralogy, the effect of soil chemistry on vegetation, and studies of mammalian tissues. These examples illustrate how automated mineralogy allows researchers a means of quantifying mineralogical relationships in a wide variety of materials. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002719

Gold extraction by chlorination using a pyrometallurgical process / M.W. Ojeda in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 409–411 Titre : Gold extraction by chlorination using a pyrometallurgical process Type de document : texte imprimé Auteurs : M.W. Ojeda, Auteur ; E. Perino, Auteur Année de publication : 2009 Article en page(s) : pp. 409–411 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  ores  Pyrometallurgy  Extractive  metallurgy Résumé : The feasibility to recover the gold present in alluvial material, by means of a chlorination process, using chlorine as a reactive agent, has been studied. The influence of temperature and reaction time was studied through changes in the reactant solid. The techniques used to characterize the mineral samples and the reaction residues were stereomicroscopy, X-ray diffraction, X-ray fluorescence and scanning electronic microscopy. Results indicate that gold extraction is favored by increasing, both, the temperature and the reaction time. The best recovery values were of 98.23% at 873 K and 3600 s and of 98.73% at 873 K and 5400 s, with very low attack of the matrix containing the metal. The powder of pure gold was not chlorinated at this temperature level. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002276 [article] Gold extraction by chlorination using a pyrometallurgical process [texte imprimé] / M.W. Ojeda, Auteur ; E. Perino, Auteur . - 2009 . - pp. 409–411. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 409–411 Mots-clés : Gold  ores  Pyrometallurgy  Extractive  metallurgy Résumé : The feasibility to recover the gold present in alluvial material, by means of a chlorination process, using chlorine as a reactive agent, has been studied. The influence of temperature and reaction time was studied through changes in the reactant solid. The techniques used to characterize the mineral samples and the reaction residues were stereomicroscopy, X-ray diffraction, X-ray fluorescence and scanning electronic microscopy. Results indicate that gold extraction is favored by increasing, both, the temperature and the reaction time. The best recovery values were of 98.23% at 873 K and 3600 s and of 98.73% at 873 K and 5400 s, with very low attack of the matrix containing the metal. The powder of pure gold was not chlorinated at this temperature level. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002276

Hydraulic and sediment removal performance of a modified hydrocyclone / H.P. Pandit in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 412–414 Titre : Hydraulic and sediment removal performance of a modified hydrocyclone Type de document : texte imprimé Auteurs : H.P. Pandit, Auteur ; N.M. Shakya, Auteur ; H. Stole, Auteur Année de publication : 2009 Article en page(s) : pp. 412–414 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sediment  Particles  separation  Removal  efficiency  Hydrocyclones Résumé : Traditionally, settling basins have been used to exclude suspended sediment in hydropower plants. However, due to the inability of such basins to exclude fine sediment (predominantly hard minerals such as quartz and feldspar) and the excessive sediment loads in Himalayan Rivers, hydro-mechanical equipment and accessories in these plants have been severely damaged. Not only does this involve huge maintenance costs, but there is also a substantial revenue loss due to reduced equipment efficiencies. Thus, more efficient devices such as hydrocyclones are required to remove sediment particles. However, the geometry of a hydrocyclone plays an important role in hydraulic and sediment removal efficiency, and this paper analyses the experimental results of a test rig consisting of a hydrocyclone, 0.38 m in diameter, with a modified geometry. The results were compared with those of other investigators, and show that the modified hydrocyclone gives better hydraulic and sediment removal. The implications for suspended sediment exclusion in hydropower plants of Himalayan region are pointed out. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002367 [article] Hydraulic and sediment removal performance of a modified hydrocyclone [texte imprimé] / H.P. Pandit, Auteur ; N.M. Shakya, Auteur ; H. Stole, Auteur . - 2009 . - pp. 412–414. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 412–414 Mots-clés : Sediment  Particles  separation  Removal  efficiency  Hydrocyclones Résumé : Traditionally, settling basins have been used to exclude suspended sediment in hydropower plants. However, due to the inability of such basins to exclude fine sediment (predominantly hard minerals such as quartz and feldspar) and the excessive sediment loads in Himalayan Rivers, hydro-mechanical equipment and accessories in these plants have been severely damaged. Not only does this involve huge maintenance costs, but there is also a substantial revenue loss due to reduced equipment efficiencies. Thus, more efficient devices such as hydrocyclones are required to remove sediment particles. However, the geometry of a hydrocyclone plays an important role in hydraulic and sediment removal efficiency, and this paper analyses the experimental results of a test rig consisting of a hydrocyclone, 0.38 m in diameter, with a modified geometry. The results were compared with those of other investigators, and show that the modified hydrocyclone gives better hydraulic and sediment removal. The implications for suspended sediment exclusion in hydropower plants of Himalayan region are pointed out. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002367

Mechanical activation of MoS2 + Na2O2 mixtures / J. Temuujin in Minerals engineering, Vol. 22 N° 4 (Mars 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 415–418 Titre : Mechanical activation of MoS2 + Na2O2 mixtures Type de document : texte imprimé Auteurs : J. Temuujin, Auteur ; K.J.D. MacKenzie, Auteur ; G. Burmaa, Auteur Année de publication : 2009 Article en page(s) : pp. 415–418 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Sulphide  ores  Grinding  Leaching  Mineral  processing Résumé : A study of the mechanochemical activation of molybdenum ore concentrate (MoS2) with sodium peroxide (Na2O2) shows that sodium molybdate dihydrate (Na2MoO4 · 2H2O) is the final crystalline product. The mechanochemical formation of sodium molybdate dihydrate is evidenced by XRD, 23Na MAS NMR and the increasing solubility of the molybdenum in water as the oxidative reaction proceeds. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002410 [article] Mechanical activation of MoS2 + Na2O2 mixtures [texte imprimé] / J. Temuujin, Auteur ; K.J.D. MacKenzie, Auteur ; G. Burmaa, Auteur . - 2009 . - pp. 415–418. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 4 (Mars 2009) . - pp. 415–418 Mots-clés : Sulphide  ores  Grinding  Leaching  Mineral  processing Résumé : A study of the mechanochemical activation of molybdenum ore concentrate (MoS2) with sodium peroxide (Na2O2) shows that sodium molybdate dihydrate (Na2MoO4 · 2H2O) is the final crystalline product. The mechanochemical formation of sodium molybdate dihydrate is evidenced by XRD, 23Na MAS NMR and the increasing solubility of the molybdenum in water as the oxidative reaction proceeds. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687508002410

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