Dépouillements

Microwave roasting of a carbonaceous sulphidic gold concentrate / R. K. Amankwah in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1095–1101 Titre : Microwave roasting of a carbonaceous sulphidic gold concentrate Type de document : texte imprimé Auteurs : R. K. Amankwah, Auteur ; C.A. Pickles, Auteur Année de publication : 2009 Article en page(s) : pp. 1095–1101 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Gold  ores  Oxidation  Roasting  Leaching  Cyanidation Résumé : Gold ores containing carbonaceous matter and sulphidic minerals are generally referred to as double refractory. Extraction of the gold from such ores usually requires an oxidation step to both liberate the ultra-fine gold from the matrix of the sulphides and remove the carbon that preg-robs the dissolved gold. In this investigation, a double refractory flotation concentrate was microwave roasted to oxidize both the sulphides and the carbonaceous matter. The concentrate was characterized by thermogravimetric and infrared analysis and the microwave absorbtion characteristics were quantified by determining the permittivities. The microwave heating behaviour studies showed that the sample temperature increased with increasing incident microwave power, processing time and sample mass. Due to the hyperactive response of the concentrate to the microwaves, a low incident power of 600 W was found to be suitable for roasting, as higher powers resulted in sintering and melting of the concentrate. The gold extraction values after cyanidation were over 96% and these were similar to those obtained by conventional roasting. The main advantages of microwave roasting were that both the total carbon removal rates and the heating rates were higher and the specific energy consumptions were lower than in conventional roasting. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000697 [article] Microwave roasting of a carbonaceous sulphidic gold concentrate [texte imprimé] / R. K. Amankwah, Auteur ; C.A. Pickles, Auteur . - 2009 . - pp. 1095–1101. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1095–1101 Mots-clés : Gold  ores  Oxidation  Roasting  Leaching  Cyanidation Résumé : Gold ores containing carbonaceous matter and sulphidic minerals are generally referred to as double refractory. Extraction of the gold from such ores usually requires an oxidation step to both liberate the ultra-fine gold from the matrix of the sulphides and remove the carbon that preg-robs the dissolved gold. In this investigation, a double refractory flotation concentrate was microwave roasted to oxidize both the sulphides and the carbonaceous matter. The concentrate was characterized by thermogravimetric and infrared analysis and the microwave absorbtion characteristics were quantified by determining the permittivities. The microwave heating behaviour studies showed that the sample temperature increased with increasing incident microwave power, processing time and sample mass. Due to the hyperactive response of the concentrate to the microwaves, a low incident power of 600 W was found to be suitable for roasting, as higher powers resulted in sintering and melting of the concentrate. The gold extraction values after cyanidation were over 96% and these were similar to those obtained by conventional roasting. The main advantages of microwave roasting were that both the total carbon removal rates and the heating rates were higher and the specific energy consumptions were lower than in conventional roasting. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000697

Microwaves in extractive metallurgy / C.A. Pickles in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1102–1111 Titre : Microwaves in extractive metallurgy : Part 1 – Review of fundamentals Type de document : texte imprimé Auteurs : C.A. Pickles, Auteur Année de publication : 2009 Article en page(s) : pp. 1102–1111 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Oxide  ores  Extractive  metallurgy  Pyrometallurgy  Mineral  processing  Reduction Résumé : Microwave radiation is a relatively new energy source, which has considerable potential for various applications in mineral processing and extractive metallurgy. However, the strengths of the interaction of the microwave radiation with the materials of interest are largely unknown. Additionally, in contrast to the aqueous solutions used in hydrometallurgy, the microwave interaction with the heterogeneous solids used in pyrometallurgical processes is difficult to model from fundamentals. Since the microwave heating characteristics of most of the materials cannot be predicted, research is being performed to determine the underlying factors which govern the microwave response of ores, concentrates, reducing agents and other feedstocks used in pyrometallurgical processes. In the present research, the techniques used to measure the microwave coupling characteristics are outlined and the application of these techniques to some relevant pyrometallurgical materials is reviewed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000703 [article] Microwaves in extractive metallurgy : Part 1 – Review of fundamentals [texte imprimé] / C.A. Pickles, Auteur . - 2009 . - pp. 1102–1111. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1102–1111 Mots-clés : Oxide  ores  Extractive  metallurgy  Pyrometallurgy  Mineral  processing  Reduction Résumé : Microwave radiation is a relatively new energy source, which has considerable potential for various applications in mineral processing and extractive metallurgy. However, the strengths of the interaction of the microwave radiation with the materials of interest are largely unknown. Additionally, in contrast to the aqueous solutions used in hydrometallurgy, the microwave interaction with the heterogeneous solids used in pyrometallurgical processes is difficult to model from fundamentals. Since the microwave heating characteristics of most of the materials cannot be predicted, research is being performed to determine the underlying factors which govern the microwave response of ores, concentrates, reducing agents and other feedstocks used in pyrometallurgical processes. In the present research, the techniques used to measure the microwave coupling characteristics are outlined and the application of these techniques to some relevant pyrometallurgical materials is reviewed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000703

Microwaves in extractive metallurgy / C.A. Pickles in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1112–1118 Titre : Microwaves in extractive metallurgy : Part 2 – A review of applications Type de document : texte imprimé Auteurs : C.A. Pickles, Auteur Année de publication : 2009 Article en page(s) : pp. 1112–1118 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Oxide  ores  Dewatering  Pyrometallurgy  Reduction  Extractive  metallurgy Résumé : In metal extraction processes, such as reduction or smelting, a source of energy is required for the endothermic reactions. This energy is often supplied by the combustion of carbonaceous materials or hydrocarbons or by inputting some electrical energy. Typically, large-scale reactors are used and the energy is transported to the reacting materials from the heat source via convective, conductive and radiative processes. Additionally, considerable heat is transferred to the containment vessel, the surroundings and the off-gases and this energy is difficult to recover. On the other hand, microwave heating systems can be designed such that only the material to be processed absorbs the microwaves, since microwave radiation is deposited directly in the material to be heated. Other potential advantages of microwave processing include; high energy densities, selective heating, improved control, environmental benefits and minimal off-gas generation. In the present research, the utilization of microwaves as an energy source in metal extraction and, in particular the pyrometallurgical processing of oxide ores, is reviewed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000715 [article] Microwaves in extractive metallurgy : Part 2 – A review of applications [texte imprimé] / C.A. Pickles, Auteur . - 2009 . - pp. 1112–1118. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1112–1118 Mots-clés : Oxide  ores  Dewatering  Pyrometallurgy  Reduction  Extractive  metallurgy Résumé : In metal extraction processes, such as reduction or smelting, a source of energy is required for the endothermic reactions. This energy is often supplied by the combustion of carbonaceous materials or hydrocarbons or by inputting some electrical energy. Typically, large-scale reactors are used and the energy is transported to the reacting materials from the heat source via convective, conductive and radiative processes. Additionally, considerable heat is transferred to the containment vessel, the surroundings and the off-gases and this energy is difficult to recover. On the other hand, microwave heating systems can be designed such that only the material to be processed absorbs the microwaves, since microwave radiation is deposited directly in the material to be heated. Other potential advantages of microwave processing include; high energy densities, selective heating, improved control, environmental benefits and minimal off-gas generation. In the present research, the utilization of microwaves as an energy source in metal extraction and, in particular the pyrometallurgical processing of oxide ores, is reviewed. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000715

Use of QEMSCAN® for the characterization of Ni-rich and Ni-poor goethite in laterite ores / Jens C.Ø. Andersen in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1119–1129 Titre : Use of QEMSCAN® for the characterization of Ni-rich and Ni-poor goethite in laterite ores Type de document : texte imprimé Auteurs : Jens C.Ø. Andersen, Auteur ; Gavyn K. Rollinson, Auteur ; Ben Snook, Auteur Année de publication : 2009 Article en page(s) : pp. 1119–1129 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Oxide  ores  Ore  mineralogy  Mineral  processing Résumé : Nickel laterites are mineralogically complex, yet increasingly important sources of nickel and cobalt. To be successfully exploited they require accurate characterization of the mineralogy, texture and grade. As spatially resolved mineralogical techniques, automated scanning electron microscopy-based analysis systems (such as QEMSCAN®) offer significant advantages over traditional bulk compositional and mineralogical methods. This project tests how QEMSCAN® can be employed to characterize goethite and potentially interfering mineral compounds in nickel laterites. This involves the development and testing of a Species Identification Protocol (SIP) that discriminates goethite on the basis of nickel, chromium, and manganese content. The SIP is calibrated to quantitative compositional data obtained by electron-probe microanalysis (EPMA). The SIP is tested on ore specimens from Çaldağ (Turkey), Acoje (the Philippines) and Devolli (Albania). The project demonstrates the advantages of increased X-ray acquisition rate for the characterization of low-Ni concentrations and the significance of EPMA analysis for the quantitative validation of mineral identifications in the SIP. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000934 [article] Use of QEMSCAN® for the characterization of Ni-rich and Ni-poor goethite in laterite ores [texte imprimé] / Jens C.Ø. Andersen, Auteur ; Gavyn K. Rollinson, Auteur ; Ben Snook, Auteur . - 2009 . - pp. 1119–1129. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1119–1129 Mots-clés : Oxide  ores  Ore  mineralogy  Mineral  processing Résumé : Nickel laterites are mineralogically complex, yet increasingly important sources of nickel and cobalt. To be successfully exploited they require accurate characterization of the mineralogy, texture and grade. As spatially resolved mineralogical techniques, automated scanning electron microscopy-based analysis systems (such as QEMSCAN®) offer significant advantages over traditional bulk compositional and mineralogical methods. This project tests how QEMSCAN® can be employed to characterize goethite and potentially interfering mineral compounds in nickel laterites. This involves the development and testing of a Species Identification Protocol (SIP) that discriminates goethite on the basis of nickel, chromium, and manganese content. The SIP is calibrated to quantitative compositional data obtained by electron-probe microanalysis (EPMA). The SIP is tested on ore specimens from Çaldağ (Turkey), Acoje (the Philippines) and Devolli (Albania). The project demonstrates the advantages of increased X-ray acquisition rate for the characterization of low-Ni concentrations and the significance of EPMA analysis for the quantitative validation of mineral identifications in the SIP. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509000934

Improving the Bayer Process productivity / Glayson Stopa Gontijo in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1130–1136 Titre : Improving the Bayer Process productivity : An industrial case study Type de document : texte imprimé Auteurs : Glayson Stopa Gontijo, Auteur ; Antonio Carlos Brandão De Araújo, Auteur ; Shiva Prasad, Auteur Année de publication : 2009 Article en page(s) : pp. 1130–1136 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Mineral  processing  Fine  particle  processing  Filtration  Leaching Résumé : Alumina production through Bayer Process is limited by the instability of soluble sodium aluminate in the supersaturated solutions used by the alumina refineries. The precipitation of aluminum hydrate can occur in equipment not designed for this purpose, causing significant loss of production. The stabilization of sodium aluminate in solution results in a decrease of the supersaturation, reducing the driving force for precipitation of aluminum hydrate. The reduction of supersaturation can be achieved by the application of stabilizing substances, known as nucleation inhibitors. This study has the objective of evaluating the effect of the concentration of a polymeric type nucleation inhibitor on the productivity of the Bayer Process. A set of experiments was executed in the laboratory, for the evaluation of the influence of the quantity of inhibitor and of the concentration of solids on the stability of the green liquor that feeds the filtration step. It was generally observed that supersaturation was significantly reduced. The amount of inhibitor used made little difference to the stability, whereas the concentration of solids was shown to have a strong influence. The implementation of the results of this work in an industrial plant resulted in an increase of alumina production of 100,000 ton/year. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001186 [article] Improving the Bayer Process productivity : An industrial case study [texte imprimé] / Glayson Stopa Gontijo, Auteur ; Antonio Carlos Brandão De Araújo, Auteur ; Shiva Prasad, Auteur . - 2009 . - pp. 1130–1136. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1130–1136 Mots-clés : Mineral  processing  Fine  particle  processing  Filtration  Leaching Résumé : Alumina production through Bayer Process is limited by the instability of soluble sodium aluminate in the supersaturated solutions used by the alumina refineries. The precipitation of aluminum hydrate can occur in equipment not designed for this purpose, causing significant loss of production. The stabilization of sodium aluminate in solution results in a decrease of the supersaturation, reducing the driving force for precipitation of aluminum hydrate. The reduction of supersaturation can be achieved by the application of stabilizing substances, known as nucleation inhibitors. This study has the objective of evaluating the effect of the concentration of a polymeric type nucleation inhibitor on the productivity of the Bayer Process. A set of experiments was executed in the laboratory, for the evaluation of the influence of the quantity of inhibitor and of the concentration of solids on the stability of the green liquor that feeds the filtration step. It was generally observed that supersaturation was significantly reduced. The amount of inhibitor used made little difference to the stability, whereas the concentration of solids was shown to have a strong influence. The implementation of the results of this work in an industrial plant resulted in an increase of alumina production of 100,000 ton/year. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001186

A novel approach for the modelling of high-pressure grinding rolls / M. Torres in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1137–1146 Titre : A novel approach for the modelling of high-pressure grinding rolls Type de document : texte imprimé Auteurs : M. Torres, Auteur ; A. Casali, Auteur Année de publication : 2009 Article en page(s) : pp. 1137–1146 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Modelling  Grinding  Sulphide  ores Résumé : The HPGR technology has become more attractive to the copper industry because of its high throughput capacities and its low specific energy consumptions. A HPGR model, able to give enough information based on pilot plant testing, in order to back up HPGR engineering studies, was developed. The model was based on the physical phenomena of the grinding operation. The model parameters were fitted with pilot scale test results, corresponding to a Chilean copper ore, classified in two lithologies (andesitic and porphyrytic ores). Some sets of data were not used in the fitting stage, to test the predictive capability of the model. The pilot scale tests were performed at the facilities of two HPGR manufacturers, changing operating pressure and rolls peripheral velocity (only one of the manufacturers). The simulated specific energy consumptions and particle size distributions, compared with the experimental data, were considered good enough. The model was able to predict adequately throughput capacity, specific energy consumption and particle size distributions of the edge, centre and total products. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001198 [article] A novel approach for the modelling of high-pressure grinding rolls [texte imprimé] / M. Torres, Auteur ; A. Casali, Auteur . - 2009 . - pp. 1137–1146. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1137–1146 Mots-clés : Modelling  Grinding  Sulphide  ores Résumé : The HPGR technology has become more attractive to the copper industry because of its high throughput capacities and its low specific energy consumptions. A HPGR model, able to give enough information based on pilot plant testing, in order to back up HPGR engineering studies, was developed. The model was based on the physical phenomena of the grinding operation. The model parameters were fitted with pilot scale test results, corresponding to a Chilean copper ore, classified in two lithologies (andesitic and porphyrytic ores). Some sets of data were not used in the fitting stage, to test the predictive capability of the model. The pilot scale tests were performed at the facilities of two HPGR manufacturers, changing operating pressure and rolls peripheral velocity (only one of the manufacturers). The simulated specific energy consumptions and particle size distributions, compared with the experimental data, were considered good enough. The model was able to predict adequately throughput capacity, specific energy consumption and particle size distributions of the edge, centre and total products. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001198

A comparison of the critical impeller speed for solids suspension in a bench-scale and a pilot-scale mechanical flotation cell / O.A. Lima in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1147–1153 Titre : A comparison of the critical impeller speed for solids suspension in a bench-scale and a pilot-scale mechanical flotation cell Type de document : texte imprimé Auteurs : O.A. Lima, Auteur ; D.A. Deglon, Auteur ; L.S. Leal Filho, Auteur Année de publication : 2009 Article en page(s) : pp. 1147–1153 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Froth  flotation  Flotation  machines  Solids  suspension Résumé : This paper compares the critical impeller speed results for 6 L Denver and Wemco bench-scale flotation cells with findings from a study by Van der Westhuizen and Deglon [Van der Westhuizen, A.P., Deglon, D.A., 2007. Evaluation of solids suspension in a pilot-scale mechanical flotation cell: the critical impeller speed. Minerals Engineering 20, 233–240; Van der Westhuizen, A.P., Deglon, D.A., 2008. Solids suspension in a pilot scale mechanical flotation cell: a critical impeller speed correlation. Minerals Engineering 21, 621–629] conducted in a 125 L Batequip flotation cell. Understanding solids suspension has become increasingly important due to dramatic increases in flotation cell sizes. The critical impeller speed is commonly used to indicate the effectiveness of solids suspension. The minerals used in this study were apatite, quartz and hematite. The critical impeller speed was found to be strongly dependent on particle size, solids density and air flow rate, with solids concentration having a lesser influence. Liquid viscosity was found to have a negligible effect. The general Zwietering-type critical impeller speed correlation developed by Van der Westhuizen and Deglon [Van der Westhuizen, A.P., Deglon, D.A., 2008. Solids suspension in a pilot scale mechanical flotation cell: a critical impeller speed correlation. Minerals Engineering 21, 621–629] was found to be applicable to all three flotation machines. The exponents for particle size, solids concentration and liquid viscosity were equivalent for all three cells. The exponent for solids density was found to be less significant than that obtained by the previous authors, and to be consistent with values reported in the general literature for stirred tanks. Finally, a new dimensionless critical impeller speed correlation is proposed where the particle size is divided by the impeller diameter. This modified equation generally predicts the experimental measurements well, with most predictions within 10% of the experimental. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001320 [article] A comparison of the critical impeller speed for solids suspension in a bench-scale and a pilot-scale mechanical flotation cell [texte imprimé] / O.A. Lima, Auteur ; D.A. Deglon, Auteur ; L.S. Leal Filho, Auteur . - 2009 . - pp. 1147–1153. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1147–1153 Mots-clés : Froth  flotation  Flotation  machines  Solids  suspension Résumé : This paper compares the critical impeller speed results for 6 L Denver and Wemco bench-scale flotation cells with findings from a study by Van der Westhuizen and Deglon [Van der Westhuizen, A.P., Deglon, D.A., 2007. Evaluation of solids suspension in a pilot-scale mechanical flotation cell: the critical impeller speed. Minerals Engineering 20, 233–240; Van der Westhuizen, A.P., Deglon, D.A., 2008. Solids suspension in a pilot scale mechanical flotation cell: a critical impeller speed correlation. Minerals Engineering 21, 621–629] conducted in a 125 L Batequip flotation cell. Understanding solids suspension has become increasingly important due to dramatic increases in flotation cell sizes. The critical impeller speed is commonly used to indicate the effectiveness of solids suspension. The minerals used in this study were apatite, quartz and hematite. The critical impeller speed was found to be strongly dependent on particle size, solids density and air flow rate, with solids concentration having a lesser influence. Liquid viscosity was found to have a negligible effect. The general Zwietering-type critical impeller speed correlation developed by Van der Westhuizen and Deglon [Van der Westhuizen, A.P., Deglon, D.A., 2008. Solids suspension in a pilot scale mechanical flotation cell: a critical impeller speed correlation. Minerals Engineering 21, 621–629] was found to be applicable to all three flotation machines. The exponents for particle size, solids concentration and liquid viscosity were equivalent for all three cells. The exponent for solids density was found to be less significant than that obtained by the previous authors, and to be consistent with values reported in the general literature for stirred tanks. Finally, a new dimensionless critical impeller speed correlation is proposed where the particle size is divided by the impeller diameter. This modified equation generally predicts the experimental measurements well, with most predictions within 10% of the experimental. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001320

A new practical method to determine the microwave energy absorption ability of materials / S. J. Ma in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1154–1159 Titre : A new practical method to determine the microwave energy absorption ability of materials Type de document : texte imprimé Auteurs : S. J. Ma, Auteur ; X.W. Zhou, Auteur ; X.J. Su, Auteur Année de publication : 2009 Article en page(s) : pp. 1154–1159 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Industrial  minerals  Activated  carbon  Comminution  Roasting  Leaching Résumé : To quantitatively measure and compare the ability of different materials in absorbing microwave energy, a new practical method, only using a home microwave oven with microwave radiation out of the bottom of the cavity as the major apparatus, was developed. During the measuring process, each target material and water, separately contained with two microwave transparent containers, respectively, were simultaneously placed in the oven cavity for microwave irradiation. The water container was above the tested materials container, and the water acted as the medium to absorb the microwave energy surplus to that absorbed by tested materials. By determining the water temperature and then calculating its absorbed microwave energy, the microwave energy absorbed by the target materials could be obtained. According to this method, seven bulk solid materials of reagent grade were tested and the results agree well with previous research reports. In addition, the principle and control of the measuring conditions of the novel method were discussed in this paper. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001332 [article] A new practical method to determine the microwave energy absorption ability of materials [texte imprimé] / S. J. Ma, Auteur ; X.W. Zhou, Auteur ; X.J. Su, Auteur . - 2009 . - pp. 1154–1159. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1154–1159 Mots-clés : Industrial  minerals  Activated  carbon  Comminution  Roasting  Leaching Résumé : To quantitatively measure and compare the ability of different materials in absorbing microwave energy, a new practical method, only using a home microwave oven with microwave radiation out of the bottom of the cavity as the major apparatus, was developed. During the measuring process, each target material and water, separately contained with two microwave transparent containers, respectively, were simultaneously placed in the oven cavity for microwave irradiation. The water container was above the tested materials container, and the water acted as the medium to absorb the microwave energy surplus to that absorbed by tested materials. By determining the water temperature and then calculating its absorbed microwave energy, the microwave energy absorbed by the target materials could be obtained. According to this method, seven bulk solid materials of reagent grade were tested and the results agree well with previous research reports. In addition, the principle and control of the measuring conditions of the novel method were discussed in this paper. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001332

Single particle impact breakage characteristics of clinkers related to mineral composition and grindability / Ö. Genç in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1160–1165 Titre : Single particle impact breakage characteristics of clinkers related to mineral composition and grindability Type de document : texte imprimé Auteurs : Ö. Genç, Auteur ; A. H. Benzer, Auteur Année de publication : 2009 Article en page(s) : pp. 1160–1165 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Comminution  Crushing  Sizing  Particle  size Résumé : Single particle impact breakage characteristics of clinkers from different plants were determined by the drop-weight technique. Impact breakage distribution parameter (t10) defined by Narayanan [Narayanan, S.S., Whiten, W.J., 1983. Breakage characteristics for ores for ball mill modelling. In: Proceeding of the Australasian Institute of Mining and Metallurgy, vol. 286, pp. 31–39.] was used to characterise the breakage distributions of different clinkers based on the specific comminution energy. The single particle impact breakage resistance parameter as represented by A·b [Man, Y.T., 2000. A model based scale-up procedure for wet, overflow ball mills. Ph.D. Thesis, Department of Mining, Minerals and Materials Engineering, The University of Queensland] based on the model parameters of the well known Ecs−t10 relationship given by Leung [Leung, K., 1987. An energy-based ore specific model for autogeneous and semi-autogeneous grinding. Ph.D. Thesis, The University of Queensland, JKMRC] was correlated with the standard bond index number, belite and alite mineral amounts. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001460 [article] Single particle impact breakage characteristics of clinkers related to mineral composition and grindability [texte imprimé] / Ö. Genç, Auteur ; A. H. Benzer, Auteur . - 2009 . - pp. 1160–1165. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1160–1165 Mots-clés : Comminution  Crushing  Sizing  Particle  size Résumé : Single particle impact breakage characteristics of clinkers from different plants were determined by the drop-weight technique. Impact breakage distribution parameter (t10) defined by Narayanan [Narayanan, S.S., Whiten, W.J., 1983. Breakage characteristics for ores for ball mill modelling. In: Proceeding of the Australasian Institute of Mining and Metallurgy, vol. 286, pp. 31–39.] was used to characterise the breakage distributions of different clinkers based on the specific comminution energy. The single particle impact breakage resistance parameter as represented by A·b [Man, Y.T., 2000. A model based scale-up procedure for wet, overflow ball mills. Ph.D. Thesis, Department of Mining, Minerals and Materials Engineering, The University of Queensland] based on the model parameters of the well known Ecs−t10 relationship given by Leung [Leung, K., 1987. An energy-based ore specific model for autogeneous and semi-autogeneous grinding. Ph.D. Thesis, The University of Queensland, JKMRC] was correlated with the standard bond index number, belite and alite mineral amounts. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001460

Mechanisms of sulfide ion oxidation during cyanidation / D.M. Hewitt in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1166–1172 Titre : Mechanisms of sulfide ion oxidation during cyanidation : Part II: Surface catalysis by pyrite Type de document : texte imprimé Auteurs : D.M. Hewitt, Auteur ; P. L. Breuer, Auteur ; M.I. Jeffrey, Auteur Année de publication : 2009 Article en page(s) : pp. 1166–1172 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Cyanidation  Sulfide  ores Résumé : The mechanisms and the reaction products for the oxidation of sulfide ions in the presence of pyrite have been established. When the leach solution contains free sulfide ions, oxidation occurs via electron transfer from the sulfide ion to dissolved oxygen on the pyrite mineral surface, with polysulfides being formed as an intermediate oxidation product. In the absence of cyanide, the polysulfides are further oxidised to thiosulfate, whilst with cyanide present, thiocyanate and sulfite are also formed from the reaction of polysulfides with cyanide and dissolved oxygen. Polysulfide chain length has been shown to affect the final reaction products of polysulfide oxidation by dissolved oxygen. The rate of pyrite catalysed sulfide ion oxidation was found to be slower in cyanide solutions compared to cyanide free solutions. Mixed potential measurements indicated that the reduction of oxygen at the pyrite surface is hindered in the presence of cyanide. The presence of sulfide ions was also found to activate the pyrite surface, increasing its rate of oxidation by oxygen. This effect was particularly evident in the presence of cyanide; in the presence of sulfide the increase in total sulfur from pyrite oxidation was 2.3 mM in 7 h, compared to an increase of <1 mM in the absence of sulfide over 24 h. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001472 [article] Mechanisms of sulfide ion oxidation during cyanidation : Part II: Surface catalysis by pyrite [texte imprimé] / D.M. Hewitt, Auteur ; P. L. Breuer, Auteur ; M.I. Jeffrey, Auteur . - 2009 . - pp. 1166–1172. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1166–1172 Mots-clés : Cyanidation  Sulfide  ores Résumé : The mechanisms and the reaction products for the oxidation of sulfide ions in the presence of pyrite have been established. When the leach solution contains free sulfide ions, oxidation occurs via electron transfer from the sulfide ion to dissolved oxygen on the pyrite mineral surface, with polysulfides being formed as an intermediate oxidation product. In the absence of cyanide, the polysulfides are further oxidised to thiosulfate, whilst with cyanide present, thiocyanate and sulfite are also formed from the reaction of polysulfides with cyanide and dissolved oxygen. Polysulfide chain length has been shown to affect the final reaction products of polysulfide oxidation by dissolved oxygen. The rate of pyrite catalysed sulfide ion oxidation was found to be slower in cyanide solutions compared to cyanide free solutions. Mixed potential measurements indicated that the reduction of oxygen at the pyrite surface is hindered in the presence of cyanide. The presence of sulfide ions was also found to activate the pyrite surface, increasing its rate of oxidation by oxygen. This effect was particularly evident in the presence of cyanide; in the presence of sulfide the increase in total sulfur from pyrite oxidation was 2.3 mM in 7 h, compared to an increase of <1 mM in the absence of sulfide over 24 h. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001472

Total recovery of gold, palladium, and platinum using lignophenol derivative / Durga Parajuli in Minerals engineering, Vol. 22 N° 13 (Octobre 2009) 

Public ISBD [article]  in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1173–1178 Titre : Total recovery of gold, palladium, and platinum using lignophenol derivative Type de document : texte imprimé Auteurs : Durga Parajuli, Auteur ; Kanjana Khunathai, Auteur ; Chaitanya Raj Adhikari, Auteur Année de publication : 2009 Article en page(s) : pp. 1173–1178 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : DMA-CLP  Precious  metals  Ion  exchange  Aqua  regia  sample Résumé : A tertiary amine type adsorption gel was prepared by the immobilization of dimethylamine onto crosslinked lignophenol (CLP) matrix. This novel product was studied for its adsorption behavior for Au(III), Pd(II), Pt(IV), Cu(II), Zn(II), Ni(II), and Fe(III) in 0.5–6 M hydrochloric acid medium. From our previous study, crosslinked lignophenol (CLP) is known to hold solo selectivity for Au(III). After modification to dimethylamine type adsorbent (DMA-CLP), an extended selectivity of Au(III), Pd(II), and Pt(IV) was observed. The maximum loading capacity for these three metal ions was evaluated by isotherm study. For Au(III) an impressive value of 7.2 mol/kg of DMA-CLP was observed. The feasibility of recovery of precious metals from a mixture containing several other metal ions was studied in batch mode by using both model solution and actual industrial solution obtained after aqua regia leaching of metal components in obsolate e-devices. In addition, a number of adsorption–elution cycles were produced so as to know the feasibility of multiple uses. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001484 [article] Total recovery of gold, palladium, and platinum using lignophenol derivative [texte imprimé] / Durga Parajuli, Auteur ; Kanjana Khunathai, Auteur ; Chaitanya Raj Adhikari, Auteur . - 2009 . - pp. 1173–1178. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 22 N° 13 (Octobre 2009) . - pp. 1173–1178 Mots-clés : DMA-CLP  Precious  metals  Ion  exchange  Aqua  regia  sample Résumé : A tertiary amine type adsorption gel was prepared by the immobilization of dimethylamine onto crosslinked lignophenol (CLP) matrix. This novel product was studied for its adsorption behavior for Au(III), Pd(II), Pt(IV), Cu(II), Zn(II), Ni(II), and Fe(III) in 0.5–6 M hydrochloric acid medium. From our previous study, crosslinked lignophenol (CLP) is known to hold solo selectivity for Au(III). After modification to dimethylamine type adsorbent (DMA-CLP), an extended selectivity of Au(III), Pd(II), and Pt(IV) was observed. The maximum loading capacity for these three metal ions was evaluated by isotherm study. For Au(III) an impressive value of 7.2 mol/kg of DMA-CLP was observed. The feasibility of recovery of precious metals from a mixture containing several other metal ions was studied in batch mode by using both model solution and actual industrial solution obtained after aqua regia leaching of metal components in obsolate e-devices. In addition, a number of adsorption–elution cycles were produced so as to know the feasibility of multiple uses. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509001484

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