Dépouillements

Relationship between the bubble surface flux that overflows and the mass flow rate of solids in the concentrate of flotation processes / R. Pérez-Garibay in Minerals engineering, Vol. 23 N° 7 (Juin 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 541–548 Titre : Relationship between the bubble surface flux that overflows and the mass flow rate of solids in the concentrate of flotation processes Type de document : texte imprimé Auteurs : R. Pérez-Garibay, Auteur ; R.H. Estrada-Ruiz, Auteur ; P. M. Gallegos-Acevedo, Auteur Année de publication : 2011 Article en page(s) : pp. 541–548 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Column  flotation  Flotation  froths  Flotation  bubbles  Mass  balancing Résumé : This paper presents the relationship between the bubble surface flux that overflows and the mass flow rate of solids in the concentrate. Even though this study was carried out in a flotation column, the knowledge derived from this paper may be applied to all froth flotation processes. The experimental set up was equipped with an image analysis system to estimate the froth bubble diameter and the air recovery. This study describes the difference between the bubble surface flux entering the froth zone (SbI) and the flux that arrives to the top of the froth (SbT) and then overflows to the concentrate (SbO), the latter being most directly related to the mass flow rate of solids in the concentrate. It was observed that the superficial area of the overflow increased with increasing collector addition and air flow rate, but decreased with increasing froth depth and particle size distribution. Visual evidence and experimental results suggest that, it is common that the superficial area of air that overflows in the concentrate is covered by particles. Only when this condition is almost achieved does overflows occur; otherwise, a high level of coalescence and bubble bursting take place at the froth surface. This was concluded after finding compatible trends between the estimated and predicted mass flow rates of solids in the concentrate, when a tractable geometrical model was used (R2 = 0.8). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509003057 [article] Relationship between the bubble surface flux that overflows and the mass flow rate of solids in the concentrate of flotation processes [texte imprimé] / R. Pérez-Garibay, Auteur ; R.H. Estrada-Ruiz, Auteur ; P. M. Gallegos-Acevedo, Auteur . - 2011 . - pp. 541–548. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 541–548 Mots-clés : Column  flotation  Flotation  froths  Flotation  bubbles  Mass  balancing Résumé : This paper presents the relationship between the bubble surface flux that overflows and the mass flow rate of solids in the concentrate. Even though this study was carried out in a flotation column, the knowledge derived from this paper may be applied to all froth flotation processes. The experimental set up was equipped with an image analysis system to estimate the froth bubble diameter and the air recovery. This study describes the difference between the bubble surface flux entering the froth zone (SbI) and the flux that arrives to the top of the froth (SbT) and then overflows to the concentrate (SbO), the latter being most directly related to the mass flow rate of solids in the concentrate. It was observed that the superficial area of the overflow increased with increasing collector addition and air flow rate, but decreased with increasing froth depth and particle size distribution. Visual evidence and experimental results suggest that, it is common that the superficial area of air that overflows in the concentrate is covered by particles. Only when this condition is almost achieved does overflows occur; otherwise, a high level of coalescence and bubble bursting take place at the froth surface. This was concluded after finding compatible trends between the estimated and predicted mass flow rates of solids in the concentrate, when a tractable geometrical model was used (R2 = 0.8). DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509003057

Influence of throw and compression ratio on particle shape / Magnus Bengtsson in Minerals engineering, Vol. 23 N° 7 (Juin 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 549–557 Titre : Influence of throw and compression ratio on particle shape : A full scale investigation and laboratory tests Type de document : texte imprimé Auteurs : Magnus Bengtsson, Auteur ; Elisabeth Lee, Auteur ; C. Magnus Evertsson, Auteur Année de publication : 2011 Article en page(s) : pp. 549–557 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Rock  material  Breakage  characterization  Size  distribution  Particle  shape  Modelling  Simulation  Crusher Résumé : The machine parameters of throw and eccentric speed affect the particle shape. Their influence on particle shape is however not fully investigated. Preliminary tests on a full-scale crusher had shown certain trends in regard to the flakiness of the product (Fig. 1). These effects were investigated in detail by means of a series of piston-and-die tests, followed by modelling of the laboratory data. An empirical model of a crusher was developed which links the product size distribution and the shape of the particles to operating parameters. The simulator produced trends which were similar to the full-scale data. The throw and eccentric speed affects the utilised compression acting on the rock/rock-bed. This paper presents a method suitable for characterizing the compressive breakage behaviour of rock materials during form conditioned compression. In this method, size reduction is primarily related to geometric compression. The method provides a complete description of the breakage characteristics of the tested rock material when compressive crushing is employed. The results can be used for modelling and simulation purposes in the design of crushing equipment or crushing plants. A novel approach to optimise form conditioned crushing in order to achieve an acceptable particle size and shape is presented. The paper concludes that inter-particle breakage in combination with high compression ratio is beneficial for the particle shape. The full scale tests support this since an increase in throw improves particle shape for particles subjected to inter-particle breakage. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509003069 [article] Influence of throw and compression ratio on particle shape : A full scale investigation and laboratory tests [texte imprimé] / Magnus Bengtsson, Auteur ; Elisabeth Lee, Auteur ; C. Magnus Evertsson, Auteur . - 2011 . - pp. 549–557. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 549–557 Mots-clés : Rock  material  Breakage  characterization  Size  distribution  Particle  shape  Modelling  Simulation  Crusher Résumé : The machine parameters of throw and eccentric speed affect the particle shape. Their influence on particle shape is however not fully investigated. Preliminary tests on a full-scale crusher had shown certain trends in regard to the flakiness of the product (Fig. 1). These effects were investigated in detail by means of a series of piston-and-die tests, followed by modelling of the laboratory data. An empirical model of a crusher was developed which links the product size distribution and the shape of the particles to operating parameters. The simulator produced trends which were similar to the full-scale data. The throw and eccentric speed affects the utilised compression acting on the rock/rock-bed. This paper presents a method suitable for characterizing the compressive breakage behaviour of rock materials during form conditioned compression. In this method, size reduction is primarily related to geometric compression. The method provides a complete description of the breakage characteristics of the tested rock material when compressive crushing is employed. The results can be used for modelling and simulation purposes in the design of crushing equipment or crushing plants. A novel approach to optimise form conditioned crushing in order to achieve an acceptable particle size and shape is presented. The paper concludes that inter-particle breakage in combination with high compression ratio is beneficial for the particle shape. The full scale tests support this since an increase in throw improves particle shape for particles subjected to inter-particle breakage. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509003069

An experimental investigation of the effects of operating parameters on the wear of lifters in tumbling mills / M. Rezaeizadeh in Minerals engineering, Vol. 23 N° 7 (Juin 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 558–562 Titre : An experimental investigation of the effects of operating parameters on the wear of lifters in tumbling mills Type de document : texte imprimé Auteurs : M. Rezaeizadeh, Auteur ; M. Fooladi, Auteur ; M.S. Powell, Auteur Année de publication : 2011 Article en page(s) : pp. 558–562 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Mineral  processing  Comminution  Grinding  Particle  size Résumé : Lifters are usually used with mill liners to extend their life and to enhance the grinding and crushing efficiency. Although the lifters are durable wear parts but they will gradually worn and consequently their dimensions change during the course of operation. These changes in dimensions have a significant influence on the overall economic performance of the mills. Therefore, it is useful to know the relationship between the mill operation and the lifter profile, and the influence of lifter wear on the change in lifter profile. In this work, a laboratory mill which is capable of producing the required impact and abrasion grinding was operated both wet and dry. Many factors were varied such as: velocity, charge, ore size and different material for the lifters. Also the wear rate on the top and face of lifters are compared in the different conditions. It is found that the mill charge and the mill speed significantly affect the wear rate. Also, the results showed how size distribution affects the wear rate. The results can be interpreted in terms of the wear process in industrial scale mills over different operating conditions. The experimental results provide the possibility of including the lifter wear in optimising mill performance. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509003070 [article] An experimental investigation of the effects of operating parameters on the wear of lifters in tumbling mills [texte imprimé] / M. Rezaeizadeh, Auteur ; M. Fooladi, Auteur ; M.S. Powell, Auteur . - 2011 . - pp. 558–562. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 558–562 Mots-clés : Mineral  processing  Comminution  Grinding  Particle  size Résumé : Lifters are usually used with mill liners to extend their life and to enhance the grinding and crushing efficiency. Although the lifters are durable wear parts but they will gradually worn and consequently their dimensions change during the course of operation. These changes in dimensions have a significant influence on the overall economic performance of the mills. Therefore, it is useful to know the relationship between the mill operation and the lifter profile, and the influence of lifter wear on the change in lifter profile. In this work, a laboratory mill which is capable of producing the required impact and abrasion grinding was operated both wet and dry. Many factors were varied such as: velocity, charge, ore size and different material for the lifters. Also the wear rate on the top and face of lifters are compared in the different conditions. It is found that the mill charge and the mill speed significantly affect the wear rate. Also, the results showed how size distribution affects the wear rate. The results can be interpreted in terms of the wear process in industrial scale mills over different operating conditions. The experimental results provide the possibility of including the lifter wear in optimising mill performance. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687509003070

Sulfidation roasting of low grade lead–zinc oxide ore with elemental sulfur / Li Yong in Minerals engineering, Vol. 23 N° 7 (Juin 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 563–566 Titre : Sulfidation roasting of low grade lead–zinc oxide ore with elemental sulfur Type de document : texte imprimé Auteurs : Li Yong, Auteur ; Wang Ji-kun, Auteur ; Wei Chang, Auteur Année de publication : 2011 Article en page(s) : pp. 563–566 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Oxide  ores  Pyrometallurgy  Roasting  Ore  handling  Froth  flotation Résumé : Low-grade complex Pb–Zn oxide ore is an important source, and the reserve is very great in the world. It is very difficult to obtain Pb and Zn from the source by traditional technology. In this work, a new technology characterized by sulfidation of low grade Pb–Zn oxide ore with elemental sulfur was developed. The effects of temperature, time, particle size and sulfur amount on the sulfidation extent of Pb–Zn oxide ore was studied at a laboratory-scale. The experimental results show that the sulfidation extent of Pb and Zn oxide reaches 98% and 95% under the optimum conditions, respectively. A flotation concentrate was obtained with 38.9% Zn and 10.2% Pb from the materials which was treated by sulfidation, and the recovery of Zn and Pb is 88.2% and 79.5%, respectively. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000051 [article] Sulfidation roasting of low grade lead–zinc oxide ore with elemental sulfur [texte imprimé] / Li Yong, Auteur ; Wang Ji-kun, Auteur ; Wei Chang, Auteur . - 2011 . - pp. 563–566. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 563–566 Mots-clés : Oxide  ores  Pyrometallurgy  Roasting  Ore  handling  Froth  flotation Résumé : Low-grade complex Pb–Zn oxide ore is an important source, and the reserve is very great in the world. It is very difficult to obtain Pb and Zn from the source by traditional technology. In this work, a new technology characterized by sulfidation of low grade Pb–Zn oxide ore with elemental sulfur was developed. The effects of temperature, time, particle size and sulfur amount on the sulfidation extent of Pb–Zn oxide ore was studied at a laboratory-scale. The experimental results show that the sulfidation extent of Pb and Zn oxide reaches 98% and 95% under the optimum conditions, respectively. A flotation concentrate was obtained with 38.9% Zn and 10.2% Pb from the materials which was treated by sulfidation, and the recovery of Zn and Pb is 88.2% and 79.5%, respectively. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000051

Design and measurement of small recovery gains / N.O. Lotter in Minerals engineering, Vol. 23 N° 7 (Juin 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 567–577 Titre : Design and measurement of small recovery gains : A case study at Raglan concentrator Type de document : texte imprimé Auteurs : N.O. Lotter, Auteur ; A. Di Feo, Auteur ; L.J. Kormos, Auteur Année de publication : 2011 Article en page(s) : pp. 567–577 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Flotation  Xanthates  Plant  trial  Reference  distributions  Autocorrelation Résumé : The appearance of a significant amount of liberated fine pentlandite in the Raglan tailings, during a campaign to demonstrate future ore behaviour, called attention to a recovery opportunity. This opportunity was identified by a statistical benchmark survey of the operation during that campaign, and QEMSCAN measurement of these survey samples. This development was caused by escalating ore treatment rates and different characteristics in future ore sources. It was thus proposed to change the selection of collector from potassium amyl xanthate (PAX) to potassium isobutyl xanthate (PIBX). Laboratory scale flotation testwork, using high-confidence flotation testing, followed. The PIBX showed much faster flotation than the PAX. Nickel yield to first rougher concentrate was increased from 23.5% to 44.2%. The Raglan flowsheet bypasses this first rougher concentrate directly to final concentrate. Thus there was an expectation that overall performance would improve at plant scale when using PIBX. A designed plant trial was implemented in 2007 to measure and confirm the performance gain. This trial design used on–off switching following a 3-month baseline data block of normal operations using PAX. This layout provided checking of standard PAX performance prior to and during the trial. Thereafter, they were used to evaluate the trial blocks using PIBX. This trial format was deliberately designed so as to overcome the effects of autocorrelation in the operations data. In this way, small but significant metal recovery gains may be measured and proven in a plant trial. The paper describes the case study to show that this approach successfully blocks out autocorrelation in time, which is an obstacle in analysing concentrator operations data. The results showed that the PIBX had produced clear and statistically significant recovery gains for Ni, Cu, Pt and Pd. Adjusted for feed and concentrate grades, these recovery gains were: Ni: 1.04%, Cu: 1.01%, Pt: 2.67% and Pd: 1.79% in absolute terms. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000099 [article] Design and measurement of small recovery gains : A case study at Raglan concentrator [texte imprimé] / N.O. Lotter, Auteur ; A. Di Feo, Auteur ; L.J. Kormos, Auteur . - 2011 . - pp. 567–577. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 567–577 Mots-clés : Flotation  Xanthates  Plant  trial  Reference  distributions  Autocorrelation Résumé : The appearance of a significant amount of liberated fine pentlandite in the Raglan tailings, during a campaign to demonstrate future ore behaviour, called attention to a recovery opportunity. This opportunity was identified by a statistical benchmark survey of the operation during that campaign, and QEMSCAN measurement of these survey samples. This development was caused by escalating ore treatment rates and different characteristics in future ore sources. It was thus proposed to change the selection of collector from potassium amyl xanthate (PAX) to potassium isobutyl xanthate (PIBX). Laboratory scale flotation testwork, using high-confidence flotation testing, followed. The PIBX showed much faster flotation than the PAX. Nickel yield to first rougher concentrate was increased from 23.5% to 44.2%. The Raglan flowsheet bypasses this first rougher concentrate directly to final concentrate. Thus there was an expectation that overall performance would improve at plant scale when using PIBX. A designed plant trial was implemented in 2007 to measure and confirm the performance gain. This trial design used on–off switching following a 3-month baseline data block of normal operations using PAX. This layout provided checking of standard PAX performance prior to and during the trial. Thereafter, they were used to evaluate the trial blocks using PIBX. This trial format was deliberately designed so as to overcome the effects of autocorrelation in the operations data. In this way, small but significant metal recovery gains may be measured and proven in a plant trial. The paper describes the case study to show that this approach successfully blocks out autocorrelation in time, which is an obstacle in analysing concentrator operations data. The results showed that the PIBX had produced clear and statistically significant recovery gains for Ni, Cu, Pt and Pd. Adjusted for feed and concentrate grades, these recovery gains were: Ni: 1.04%, Cu: 1.01%, Pt: 2.67% and Pd: 1.79% in absolute terms. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000099

Study of the electrodeposition conditions of metallic manganese in an electrolytic membrane reactor / Qifeng Wei in Minerals engineering, Vol. 23 N° 7 (Juin 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 578–586 Titre : Study of the electrodeposition conditions of metallic manganese in an electrolytic membrane reactor Type de document : texte imprimé Auteurs : Qifeng Wei, Auteur ; Xiulian Ren, Auteur ; Jie Du, Auteur Année de publication : 2011 Article en page(s) : pp. 578–586 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Electrometallurgy  Electrowinning  Reduction Résumé : This paper reports the optimization of the process parameters for the electrodeposition of manganese in an electrolytic membrane reactor. The manganese(II) and ammonium ion concentrations, pH, temperature and additives to the electrolyte were varied over a relatively broad range to evaluate the changes in the current efficiency and specific energy consumption of manganese electrodeposition. The catholyte was aqueous manganese(II) sulfate containing ammonia sulfate, and the anolyte was a sulfuric acid solution. An anionic membrane separated the anolyte from the catholyte while maintaining a conductive path between the two. A high current efficiency and low specific energy consumption were favored at a pH of 7.5 with additive incorporation. Under the optimized conditions, a maximum current efficiency of 85.86% was attained with an electrolyte composition of 35 g/L Mn and 130 g/L (NH4)2SO4 at a temperature of 40 °C and a pH of 7.5 in the presence of additives and with a cathode current density of 400 A/m2. The electrolysis experiment over time showed that the specific energy consumption was 4779 kW h/t of Mn deposited under the optimum conditions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268751000021X [article] Study of the electrodeposition conditions of metallic manganese in an electrolytic membrane reactor [texte imprimé] / Qifeng Wei, Auteur ; Xiulian Ren, Auteur ; Jie Du, Auteur . - 2011 . - pp. 578–586. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 578–586 Mots-clés : Electrometallurgy  Electrowinning  Reduction Résumé : This paper reports the optimization of the process parameters for the electrodeposition of manganese in an electrolytic membrane reactor. The manganese(II) and ammonium ion concentrations, pH, temperature and additives to the electrolyte were varied over a relatively broad range to evaluate the changes in the current efficiency and specific energy consumption of manganese electrodeposition. The catholyte was aqueous manganese(II) sulfate containing ammonia sulfate, and the anolyte was a sulfuric acid solution. An anionic membrane separated the anolyte from the catholyte while maintaining a conductive path between the two. A high current efficiency and low specific energy consumption were favored at a pH of 7.5 with additive incorporation. Under the optimized conditions, a maximum current efficiency of 85.86% was attained with an electrolyte composition of 35 g/L Mn and 130 g/L (NH4)2SO4 at a temperature of 40 °C and a pH of 7.5 in the presence of additives and with a cathode current density of 400 A/m2. The electrolysis experiment over time showed that the specific energy consumption was 4779 kW h/t of Mn deposited under the optimum conditions. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S089268751000021X

Preparation of nanosized synthetic rutile from ilmenite concentrate / B. N. Akhgar in Minerals engineering, Vol. 23 N° 7 (Juin 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 587–589 Titre : Preparation of nanosized synthetic rutile from ilmenite concentrate Type de document : texte imprimé Auteurs : B. N. Akhgar, Auteur ; M. Pazouki, Auteur ; M. Ranjbar, Auteur Année de publication : 2011 Article en page(s) : pp. 587–589 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Oxide  ores  Industrial  minerals  Mineral  processing  Particle  size  Leaching Résumé : In this paper, the preparation of nanosized synthetic rutile by reductive hydrochloric acid leaching of mechanically activated ilmenite concentrate (FeTiO3) is discussed. X-ray fluorescence analysis of the nanosized rutile which forms by rapid hydrolysis of dissolved titanium indicates that the powder contains 91.1% TiO2, 1.3% Fe2O3, 6.3% SiO2. The presence of the rutile phase is confirmed by X-ray diffractometry and the sizes of particles are measured by transmission electron microscopy to be less than 100 nm. The photocatalytic activity of nanosized rutile is observed by the decomposition of methylene blue. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000087 [article] Preparation of nanosized synthetic rutile from ilmenite concentrate [texte imprimé] / B. N. Akhgar, Auteur ; M. Pazouki, Auteur ; M. Ranjbar, Auteur . - 2011 . - pp. 587–589. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 7 (Juin 2010) . - pp. 587–589 Mots-clés : Oxide  ores  Industrial  minerals  Mineral  processing  Particle  size  Leaching Résumé : In this paper, the preparation of nanosized synthetic rutile by reductive hydrochloric acid leaching of mechanically activated ilmenite concentrate (FeTiO3) is discussed. X-ray fluorescence analysis of the nanosized rutile which forms by rapid hydrolysis of dissolved titanium indicates that the powder contains 91.1% TiO2, 1.3% Fe2O3, 6.3% SiO2. The presence of the rutile phase is confirmed by X-ray diffractometry and the sizes of particles are measured by transmission electron microscopy to be less than 100 nm. The photocatalytic activity of nanosized rutile is observed by the decomposition of methylene blue. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000087

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