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Nigel J Cook - One of the best experts on this subject based on the ideXlab platform.
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indium distribution in Sphalerite from sulfide oxide silicate skarn assemblages a case study of the dulong zn sn in deposit southwest china
Mineralium Deposita, 2021Co-Authors: Nigel J Cook, Cristiana L Ciobanu, Alkiviadis Kontonikascharos, Sarah GilbertAbstract:Economic interest in indium (In) and other critical metals has accelerated efforts to understand how such elements occur in nature and the controls on their mineralogy. In this contribution, the distribution of In and other trace elements in the Dulong Zn–Sn–In deposit, China, is described, using a holistic approach which targets not only sulfides but also the potential for In and Sn within co-existing oxides and skarn silicates. Sphalerite is the most significant In carrier. Four distinct types of Sphalerite are identified, which differ with respect to ore texture and the concentration of In (0.74–4572 ppm). Subordinate amounts of In also occur within chalcopyrite and within andradite garnet, an abundant mineral in the skarn at Dulong and possibly accounting for a significant proportion of total In. Tin is not especially concentrated in either Sphalerite or chalcopyrite, occurring instead as cassiterite but with measurable concentrations also in magnetite and skarn silicates. The study confirms that the dominant substitution for In in Sphalerite is 2Zn2+ ↔ Cu+ + In3+ but that Ag and Sn may also play a subordinate role in some Sphalerite sub-types via the substitution: 3Zn2+ ↔ Ag+ + Sn2+ + In3+. The study highlights that concentrations of In in Sphalerite are likely to be heterogeneous at scales from single mineral grains to that of the deposit. The observed partitioning of both In and Sn into skarn silicates, and to a lesser extent, oxides, is a critical factor that may significantly compromise estimations of by-product elements that would be economically recoverable during exploitation of sulfide ores.
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gold behavior in intermediate sulfidation epithermal systems a case study from the zhengguang gold deposit heilongjiang province ne china
Ore Geology Reviews, 2019Co-Authors: Guoxue Song, Kezhang Qin, Le Wang, Nigel J Cook, Cristiana L CiobanuAbstract:Abstract The Zhengguang gold deposit, a typical intermediate-sulfidation epithermal deposit, is located in the southeastern part of the Duobaoshan orefield, west of the Hegenshan-Heihe suture zone, in the eastern part of the Central Asian Orogenic Belt. The deposit comprises five ore zones with total Au reserves exceeding 35 tonnes, with potential additional resources at depth. All vein-type orebodies are hosted by Paleozoic volcanic rocks and comprise multiple vein sets 1–100 cm in thickness. Although gold generally occurs in native form, or as electrum in epithermal deposits like Zhengguang, both pyrite and Sphalerite are known to accommodate modest concentrations of invisible gold. This study employs a combination of petrography and sulfide chemistry to determine the role of invisible gold in the Zhengguang ores and the mechanisms of gold incorporation into epithermal sulfides. Three sulfide stages are identified: an early quartz + pyrite (Py1a, Py1b) ± chalcopyrite (Ccp1) stage; a subsequent quartz + Sphalerite (Sph2a, Sph2b) + pyrite (Py2a, Py2b, Py2c, Py2d) + chalcopyrite (Ccp2a, Ccp2b) ± galena ± calcite stage; and a late stage containing deformed quartz + pyrite (Py3a, Py3b) ± Sphalerite. Petrography and sulfide chemistry allow three groups of pyrite (Au-poor, Au-rich, and a distinct Sb-rich group) to be distinguished, alongside three groups of chalcopyrite (Bi-rich, intermediate-Bi, and Bi-poor), and two groups of Sphalerite (Au-poor, Au-rich). A potential porphyry system is indicated beneath the epithermal system by the appearance of Au-poor pyrite and Bi-poor chalcopyrite. After precipitation of early Au-poor sulfides, inflow of relatively low temperature epithermal fluids led to alteration and replacement of early porphyry-related sulfides, and to precipitation of Au-rich pyrite, Bi-rich and intermediate-Bi chalcopyrite, and Sphalerite. Gold-rich pyrite contains up to 140 ppm Au, interpreted as both as lattice-scale substitution (Au1+) and as included particles of native gold (Au0). Epithermal chalcopyrite is an important silver carrier but, although Au is measurable, it is a not a good carrier for gold. A strong positive correlation between Au and Cu in pyrite from the first two stages indicate that gold and other metals were likely sourced from magma-derived hydrothermal fluids. The deposit was formed in the Early Paleozoic but some gold ores appear deformed and partially destroyed by a later metamorphic event during which a distinct Sb-rich pyrite crystallized. This study should catalyze exploration in the orefield as it provides further support for an as-yet undiscovered porphyry system close to the Zhengguang deposit.
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distribution and substitution mechanism of ge in a ge fe bearing Sphalerite
Minerals, 2015Co-Authors: Nigel J Cook, Cristiana L Ciobanu, Allan Pring, Barbara Etschmann, Kalotina Geraki, Daryl L Howard, Tim Williams, Nicholas A Rae, Guorong Chen, Bernt JohannessenAbstract:The distribution and substitution mechanism of Ge in the Ge-rich Sphalerite from the Tres Marias Zn deposit, Mexico, was studied using a combination of techniques at μm- to atomic scales. Trace element mapping by Laser Ablation Inductively Coupled Mass Spectrometry shows that Ge is enriched in the same bands as Fe, and that Ge-rich Sphalerite also contains measurable levels of several other minor elements, including As, Pb and Tl. Micron- to nanoscale heterogeneity in the sample, both textural and compositional, is revealed by investigation using Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) combined with Synchrotron X-ray Fluorescence mapping and High-Resolution Transmission Electron Microscopy imaging of FIB-prepared samples. Results show that Ge is preferentially incorporated within Fe-rich Sphalerite with textural complexity finer than that of the microbeam used for the X-ray Absorption Near Edge Structure (XANES) measurements. Such heterogeneity, expressed as intergrowths between 3C Sphalerite and 2H wurtzite on zones, could be the result of either a primary growth process, or alternatively, polystage crystallization, in which early Fe-Ge-rich Sphalerite is partially replaced by Fe-Ge-poor wurtzite. FIB-SEM imaging shows evidence for replacement supporting the latter. Transformation of Sphalerite into wurtzite is promoted by (111)* twinning or lattice-scale defects, leading to a heterogeneous ZnS sample, in which the dominant component, Sphalerite, can host up to ~20% wurtzite. Ge K-edge XANES spectra for this Sphalerite are identical to those of the germanite and argyrodite standards and the synthetic chalcogenide glasses GeS2 and GeSe2, indicating the Ge formally exists in the tetravalent form in this Sphalerite. Fe K-edge XANES spectra for the same sample indicate that Fe is present mainly as Fe2+, and Cu K-edge XANES spectra are characteristic for Cu+. Since there is no evidence for coupled substitution involving a monovalent element, we propose that Ge4+ substitutes for (Zn2+, Fe2+) with vacancies in the structure to compensate for charge balance. This study shows the utility of synchrotron radiation combined with electron beam micro-analysis in investigating low-level concentrations of minor metals in common sulfides.
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trace and minor elements in Sphalerite from metamorphosed sulphide deposits
Mineralogy and Petrology, 2014Co-Authors: Julian A Lockington, Nigel J Cook, Cristiana L CiobanuAbstract:Sphalerite is a common sulphide and is the domi- nant ore mineral in Zn-Pb sulphide deposits. Precise determi- nation of minor and trace element concentrations in sulphides, including Sphalerite, by Laser-Ablation Inductively-Coupled- Plasma Mass-Spectrometry (LA-ICP-MS) is a potentially valuable petrogenetic tool. In this study, LA-ICP-MS is used to analyse 19 Sphalerite samples from metamorphosed, Sphalerite-bearing volcanic-associated and sedimentary exhalative massive sulphide deposits in Norway and Austra- lia. The distributions of Mn, Fe, Co, Cu, Ga, Se, Ag, Cd, In, Sn,Sb,Hg, Tl, Pb and Bi are addressed withemphasisonhow concentrations of these elements vary with metamorphic grade of the deposit and the extent of sulphide recrystalliza- tion. Results show that the concentrations of a group of trace elements which are believed to be present in Sphalerite as micro- to nano-scale inclusions (Pb, Bi, and to some degree Cu and Ag) diminish with increasing metamorphic grade. This is interpreted as due to release of these elements during Sphalerite recrystallization and subsequent remobilization to form discrete minerals elsewhere. The concentrations of lattice-bound elements (Mn, Fe, Cd, In and Hg) show no correlation with metamorphic grade. Primary metal sources, physico-chemical conditions during initial deposition, and element partitioning between Sphalerite and co-existing sul- phides are dominant in defining the concentrations of these elements and they appear to be readily re-incorporated into recrystallized Sphalerite, offering potential insights into ore genesis. Giventhat Sphalerite accommodates a variety of trace elements that can be precisely determined by contemporary microanalytical techniques, the mineral has considerable po- tential as a geothermometer, providing that element partitioning between Sphalerite and coexisting minerals (gale- na, chalcopyrite etc.) can be quantified in samples for which the crystallization temperature can be independently
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trace and minor elements in Sphalerite from base metal deposits in south china a la icpms study
Ore Geology Reviews, 2011Co-Authors: Nigel J Cook, Cristiana L Ciobanu, Liu Yuping, Zhang Qian, Liu Tiegeng, Gao Wei, Yang Yulong, Leonid DanyushevskiyAbstract:Laser-ablation ICP mass-spectroscopy has been used to investigate the geochemistry of Sphalerite in a range of nine Zn–Pb deposits in South China. The deposits, which are of different ages and belong to different metallogenic provinces, have been assigned to the following genetic types: skarn (Hetaoping, Luziyuan), syngenetic massive sulphide (Dabaoshan, Laochang and Bainiuchang) and Mississippi-Valley-type (Huize, Mengxing, Niujiaotang) based on the features of the ore, even though their origin is heavily debated based on other criteria. The giant Jinding deposit is considered separately. Sphalerite from each genetic class of deposit shows a distinct chemical signature. Sphalerite from the skarn deposits is characterised by elevated, lattice-bound concentrations of Co and Mn. The distal character of these skarn systems is reflected by the low In content of Sphalerite. The three syngenetic massive sulphide deposits feature Sphalerite strongly enriched in In, Sn and Ga, whereas the deposits of MVT-type are typically enriched in Ge, Cd, Tl and As. These divergent characters are reflected in absolute element abundances as well as in element ratios. Time-resolved depth profiles for Sphalerite from the Chinese deposits confirm the presence of elements such as Co, In, Ge, Ga, and Cd in solid solution, but the dataset expands the understanding of Sphalerite mineral chemistry by also indicating that other elements, whose ability to enter the crystal structure of Sphalerite has been previously debated (Ag, Sn, Tl, Sb), may also be in solid solution. Sphalerite is a refractory mineral and trace element analysis of Sphalerite shows promise as a tracer of ore genesis even in overprinted ores. Systematic work on larger sample suites may help define the geochemical signature of different metallogenic epochs in regions as geologically complex as South China and help resolve the mechanism by which many of the debated ore deposits were formed.
Cristiana L Ciobanu - One of the best experts on this subject based on the ideXlab platform.
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indium distribution in Sphalerite from sulfide oxide silicate skarn assemblages a case study of the dulong zn sn in deposit southwest china
Mineralium Deposita, 2021Co-Authors: Nigel J Cook, Cristiana L Ciobanu, Alkiviadis Kontonikascharos, Sarah GilbertAbstract:Economic interest in indium (In) and other critical metals has accelerated efforts to understand how such elements occur in nature and the controls on their mineralogy. In this contribution, the distribution of In and other trace elements in the Dulong Zn–Sn–In deposit, China, is described, using a holistic approach which targets not only sulfides but also the potential for In and Sn within co-existing oxides and skarn silicates. Sphalerite is the most significant In carrier. Four distinct types of Sphalerite are identified, which differ with respect to ore texture and the concentration of In (0.74–4572 ppm). Subordinate amounts of In also occur within chalcopyrite and within andradite garnet, an abundant mineral in the skarn at Dulong and possibly accounting for a significant proportion of total In. Tin is not especially concentrated in either Sphalerite or chalcopyrite, occurring instead as cassiterite but with measurable concentrations also in magnetite and skarn silicates. The study confirms that the dominant substitution for In in Sphalerite is 2Zn2+ ↔ Cu+ + In3+ but that Ag and Sn may also play a subordinate role in some Sphalerite sub-types via the substitution: 3Zn2+ ↔ Ag+ + Sn2+ + In3+. The study highlights that concentrations of In in Sphalerite are likely to be heterogeneous at scales from single mineral grains to that of the deposit. The observed partitioning of both In and Sn into skarn silicates, and to a lesser extent, oxides, is a critical factor that may significantly compromise estimations of by-product elements that would be economically recoverable during exploitation of sulfide ores.
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gold behavior in intermediate sulfidation epithermal systems a case study from the zhengguang gold deposit heilongjiang province ne china
Ore Geology Reviews, 2019Co-Authors: Guoxue Song, Kezhang Qin, Le Wang, Nigel J Cook, Cristiana L CiobanuAbstract:Abstract The Zhengguang gold deposit, a typical intermediate-sulfidation epithermal deposit, is located in the southeastern part of the Duobaoshan orefield, west of the Hegenshan-Heihe suture zone, in the eastern part of the Central Asian Orogenic Belt. The deposit comprises five ore zones with total Au reserves exceeding 35 tonnes, with potential additional resources at depth. All vein-type orebodies are hosted by Paleozoic volcanic rocks and comprise multiple vein sets 1–100 cm in thickness. Although gold generally occurs in native form, or as electrum in epithermal deposits like Zhengguang, both pyrite and Sphalerite are known to accommodate modest concentrations of invisible gold. This study employs a combination of petrography and sulfide chemistry to determine the role of invisible gold in the Zhengguang ores and the mechanisms of gold incorporation into epithermal sulfides. Three sulfide stages are identified: an early quartz + pyrite (Py1a, Py1b) ± chalcopyrite (Ccp1) stage; a subsequent quartz + Sphalerite (Sph2a, Sph2b) + pyrite (Py2a, Py2b, Py2c, Py2d) + chalcopyrite (Ccp2a, Ccp2b) ± galena ± calcite stage; and a late stage containing deformed quartz + pyrite (Py3a, Py3b) ± Sphalerite. Petrography and sulfide chemistry allow three groups of pyrite (Au-poor, Au-rich, and a distinct Sb-rich group) to be distinguished, alongside three groups of chalcopyrite (Bi-rich, intermediate-Bi, and Bi-poor), and two groups of Sphalerite (Au-poor, Au-rich). A potential porphyry system is indicated beneath the epithermal system by the appearance of Au-poor pyrite and Bi-poor chalcopyrite. After precipitation of early Au-poor sulfides, inflow of relatively low temperature epithermal fluids led to alteration and replacement of early porphyry-related sulfides, and to precipitation of Au-rich pyrite, Bi-rich and intermediate-Bi chalcopyrite, and Sphalerite. Gold-rich pyrite contains up to 140 ppm Au, interpreted as both as lattice-scale substitution (Au1+) and as included particles of native gold (Au0). Epithermal chalcopyrite is an important silver carrier but, although Au is measurable, it is a not a good carrier for gold. A strong positive correlation between Au and Cu in pyrite from the first two stages indicate that gold and other metals were likely sourced from magma-derived hydrothermal fluids. The deposit was formed in the Early Paleozoic but some gold ores appear deformed and partially destroyed by a later metamorphic event during which a distinct Sb-rich pyrite crystallized. This study should catalyze exploration in the orefield as it provides further support for an as-yet undiscovered porphyry system close to the Zhengguang deposit.
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distribution and substitution mechanism of ge in a ge fe bearing Sphalerite
Minerals, 2015Co-Authors: Nigel J Cook, Cristiana L Ciobanu, Allan Pring, Barbara Etschmann, Kalotina Geraki, Daryl L Howard, Tim Williams, Nicholas A Rae, Guorong Chen, Bernt JohannessenAbstract:The distribution and substitution mechanism of Ge in the Ge-rich Sphalerite from the Tres Marias Zn deposit, Mexico, was studied using a combination of techniques at μm- to atomic scales. Trace element mapping by Laser Ablation Inductively Coupled Mass Spectrometry shows that Ge is enriched in the same bands as Fe, and that Ge-rich Sphalerite also contains measurable levels of several other minor elements, including As, Pb and Tl. Micron- to nanoscale heterogeneity in the sample, both textural and compositional, is revealed by investigation using Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) combined with Synchrotron X-ray Fluorescence mapping and High-Resolution Transmission Electron Microscopy imaging of FIB-prepared samples. Results show that Ge is preferentially incorporated within Fe-rich Sphalerite with textural complexity finer than that of the microbeam used for the X-ray Absorption Near Edge Structure (XANES) measurements. Such heterogeneity, expressed as intergrowths between 3C Sphalerite and 2H wurtzite on zones, could be the result of either a primary growth process, or alternatively, polystage crystallization, in which early Fe-Ge-rich Sphalerite is partially replaced by Fe-Ge-poor wurtzite. FIB-SEM imaging shows evidence for replacement supporting the latter. Transformation of Sphalerite into wurtzite is promoted by (111)* twinning or lattice-scale defects, leading to a heterogeneous ZnS sample, in which the dominant component, Sphalerite, can host up to ~20% wurtzite. Ge K-edge XANES spectra for this Sphalerite are identical to those of the germanite and argyrodite standards and the synthetic chalcogenide glasses GeS2 and GeSe2, indicating the Ge formally exists in the tetravalent form in this Sphalerite. Fe K-edge XANES spectra for the same sample indicate that Fe is present mainly as Fe2+, and Cu K-edge XANES spectra are characteristic for Cu+. Since there is no evidence for coupled substitution involving a monovalent element, we propose that Ge4+ substitutes for (Zn2+, Fe2+) with vacancies in the structure to compensate for charge balance. This study shows the utility of synchrotron radiation combined with electron beam micro-analysis in investigating low-level concentrations of minor metals in common sulfides.
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trace and minor elements in Sphalerite from metamorphosed sulphide deposits
Mineralogy and Petrology, 2014Co-Authors: Julian A Lockington, Nigel J Cook, Cristiana L CiobanuAbstract:Sphalerite is a common sulphide and is the domi- nant ore mineral in Zn-Pb sulphide deposits. Precise determi- nation of minor and trace element concentrations in sulphides, including Sphalerite, by Laser-Ablation Inductively-Coupled- Plasma Mass-Spectrometry (LA-ICP-MS) is a potentially valuable petrogenetic tool. In this study, LA-ICP-MS is used to analyse 19 Sphalerite samples from metamorphosed, Sphalerite-bearing volcanic-associated and sedimentary exhalative massive sulphide deposits in Norway and Austra- lia. The distributions of Mn, Fe, Co, Cu, Ga, Se, Ag, Cd, In, Sn,Sb,Hg, Tl, Pb and Bi are addressed withemphasisonhow concentrations of these elements vary with metamorphic grade of the deposit and the extent of sulphide recrystalliza- tion. Results show that the concentrations of a group of trace elements which are believed to be present in Sphalerite as micro- to nano-scale inclusions (Pb, Bi, and to some degree Cu and Ag) diminish with increasing metamorphic grade. This is interpreted as due to release of these elements during Sphalerite recrystallization and subsequent remobilization to form discrete minerals elsewhere. The concentrations of lattice-bound elements (Mn, Fe, Cd, In and Hg) show no correlation with metamorphic grade. Primary metal sources, physico-chemical conditions during initial deposition, and element partitioning between Sphalerite and co-existing sul- phides are dominant in defining the concentrations of these elements and they appear to be readily re-incorporated into recrystallized Sphalerite, offering potential insights into ore genesis. Giventhat Sphalerite accommodates a variety of trace elements that can be precisely determined by contemporary microanalytical techniques, the mineral has considerable po- tential as a geothermometer, providing that element partitioning between Sphalerite and coexisting minerals (gale- na, chalcopyrite etc.) can be quantified in samples for which the crystallization temperature can be independently
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trace and minor elements in Sphalerite from base metal deposits in south china a la icpms study
Ore Geology Reviews, 2011Co-Authors: Nigel J Cook, Cristiana L Ciobanu, Liu Yuping, Zhang Qian, Liu Tiegeng, Gao Wei, Yang Yulong, Leonid DanyushevskiyAbstract:Laser-ablation ICP mass-spectroscopy has been used to investigate the geochemistry of Sphalerite in a range of nine Zn–Pb deposits in South China. The deposits, which are of different ages and belong to different metallogenic provinces, have been assigned to the following genetic types: skarn (Hetaoping, Luziyuan), syngenetic massive sulphide (Dabaoshan, Laochang and Bainiuchang) and Mississippi-Valley-type (Huize, Mengxing, Niujiaotang) based on the features of the ore, even though their origin is heavily debated based on other criteria. The giant Jinding deposit is considered separately. Sphalerite from each genetic class of deposit shows a distinct chemical signature. Sphalerite from the skarn deposits is characterised by elevated, lattice-bound concentrations of Co and Mn. The distal character of these skarn systems is reflected by the low In content of Sphalerite. The three syngenetic massive sulphide deposits feature Sphalerite strongly enriched in In, Sn and Ga, whereas the deposits of MVT-type are typically enriched in Ge, Cd, Tl and As. These divergent characters are reflected in absolute element abundances as well as in element ratios. Time-resolved depth profiles for Sphalerite from the Chinese deposits confirm the presence of elements such as Co, In, Ge, Ga, and Cd in solid solution, but the dataset expands the understanding of Sphalerite mineral chemistry by also indicating that other elements, whose ability to enter the crystal structure of Sphalerite has been previously debated (Ag, Sn, Tl, Sb), may also be in solid solution. Sphalerite is a refractory mineral and trace element analysis of Sphalerite shows promise as a tracer of ore genesis even in overprinted ores. Systematic work on larger sample suites may help define the geochemical signature of different metallogenic epochs in regions as geologically complex as South China and help resolve the mechanism by which many of the debated ore deposits were formed.
Hongbo Zeng - One of the best experts on this subject based on the ideXlab platform.
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mapping the nanoscale heterogeneity of surface hydrophobicity on the Sphalerite mineral
Journal of Physical Chemistry C, 2017Co-Authors: Lei Xie, Qingxia Liu, Qi Liu, Jingyi Wang, Chen Shi, Xin Cui, Jun Huang, Hao Zhang, Hongbo ZengAbstract:Hydrophobic effect plays an important role in a wide range of natural phenomena and engineering applications, such as mineral froth flotation. In this work, atomic force microscope (AFM) force mapping was employed, for the first time, to probe the nanoscale heterogeneity of surface hydrophobicity and surface interactions on the Sphalerite mineral surface before/after conditioning treatment (activated by copper sulfate and then treated by amyl xantahte). The AFM force mapping demonstrates that adhesion on Sphalerite falls in a narrow range with a peak centered at 16.4 mN/m and adhesion on conditioned Sphalerite falls in a wide range with a small peak centered at 15.5 mN/m and a large peak centered at 58.1 mN/m. It is evident that the Sphalerite surface is hydrophilic with homogeneous surface hydrophobicity whereas conditioned Sphalerite exhibits a heterogeneous distribution of surface hydrophobicity due to the nonuniform adsorption of xanthate. The significantly enhanced adhesion after conditioning treatme...
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effects of salinity on xanthate adsorption on Sphalerite and bubble Sphalerite interactions
Minerals Engineering, 2015Co-Authors: Jingyi Wang, Qingxia Liu, Lei Xie, Hongbo ZengAbstract:Abstract The adsorption of amyl xanthate on Sphalerite in NaCl solutions of different concentrations and in saline water (viz. simulated sea water) and the surface properties of treated minerals were investigated. The interactions between xanthate treated Sphalerite particles and air bubbles were examined using induction time measurement, which revealed that the salt ions could inhibit the adsorption of xanthate on Sphalerite due to the competitive adsorption, but also could compress the electrical double layer at mineral/water interface. The induction time of Sphalerite treated in potassium amyl xanthate (PAX) with saline water was shorter than that of Sphalerite treated in PAX with NaCl of the same ion concentration, which implies that the water composition (e.g. Ca 2+ , Mg 2+ ) could play an important role in the bubble–particle interaction. The hydrophobicity, chemical composition, and charge property of PAX treated Sphalerite surfaces were characterized using contact angle measurement, Cryo-X-ray photoelectron spectroscopy (Cryo-XPS) and zeta potential determination, respectively, which support the inhibition effect of salt ions on the xanthate adsorption on Sphalerite. In the case of saline water, the xanthate decomposition products were confirmed by XPS, which could further lower the hydrophobicity of the treated Sphalerite. Our results provide insights into the basic understanding of the salinity effects on the xanthate adsorption on Sphalerite and the bubble–mineral interactions in flotation.
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probing the interaction between air bubble and Sphalerite mineral surface using atomic force microscope
Langmuir, 2015Co-Authors: Lei Xie, Qingxia Liu, Jingyi Wang, Chen Shi, Jun Huang, Hongbo ZengAbstract:The interaction between air bubbles and solid surfaces plays important roles in many engineering processes, such as mineral froth flotation. In this work, an atomic force microscope (AFM) bubble probe technique was employed, for the first time, to directly measure the interaction forces between an air bubble and Sphalerite mineral surfaces of different hydrophobicity (i.e., Sphalerite before/after conditioning treatment) under various hydrodynamic conditions. The direct force measurements demonstrate the critical role of the hydrodynamic force and surface forces in bubble–mineral interaction and attachment, which agree well with the theoretical calculations based on Reynolds lubrication theory and augmented Young–Laplace equation by including the effect of disjoining pressure. The hydrophobic disjoining pressure was found to be stronger for the bubble–water–conditioned Sphalerite interaction with a larger hydrophobic decay length, which enables the bubble attachment on conditioned Sphalerite at relatively...
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understanding copper activation and xanthate adsorption on Sphalerite by time of flight secondary ion mass spectrometry x ray photoelectron spectroscopy and in situ scanning electrochemical microscopy
Journal of Physical Chemistry C, 2013Co-Authors: Jingyi Wang, Qingxia Liu, Hongbo ZengAbstract:In situ scanning electrochemical microscopy (SECM) was applied for the first time to study the copper activation and subsequent xanthate adsorption on Sphalerite. The corresponding surface compositions were analyzed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). The probe approach curve (PAC) using SECM shows that unactivated and activated Sphalerite surfaces have negative current feedback and partially positive current feedback, respectively, suggesting that CuxS is formed on the Sphalerite after copper activation. The copper activation of Sphalerite strongly depends on the surface heterogeneity (e.g., presence of polishing defects, chemical composition), impacting the subsequent xanthate adsorption process. The SECM, ToF-SIMS, and XPS analyses show that during the copper activation the polishing defects, which have high excess surface energy, tend to consume more copper ions, resulting in Cu-rich regions by forming CuS-like species, while Fe oxid...
K. A. Natarajan - One of the best experts on this subject based on the ideXlab platform.
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surface chemical studies on Sphalerite and galena using extracellular polysaccharides isolated from bacillus polymyxa
Journal of Colloid and Interface Science, 2002Co-Authors: Deenan Santhiya, S Subramanian, K. A. NatarajanAbstract:Adsorption, electrokinetic, microflotation, and flocculation studies have been carried out on Sphalerite and galena minerals using extracellular polysaccharides (ECP) isolated from Bacillus polymyxa. The adsorption density of ECP onto galena is found to be higher than that onto Sphalerite. The adsorption of ECP onto Sphalerite is found to increase from pH 3 to about pH 7, where a maximum is attained, and thereafter continuously decreases. With respect to galena, the adsorption density of ECP steadily increases with increased pH. The addition of ECP correspondingly reduces the negative electrophoretic mobilities of Sphalerite and galena in absolute magnitude without shifting their isoelectric points. However, the magnitude of the reduction in the electrophoretic mobility values is found to be greater for galena compared to that for Sphalerite. Microflotation tests show that galena is depressed while Sphalerite is floated using ECP in the entire pH range investigated. Selective flotation tests on a synthetic mixture of galena and Sphalerite corroborate that Sphalerite could be floated from galena at pH 9-9.5 using ECP as a depressant for galena. Flocculation tests reveal that in the pH range 9-11, Sphalerite is dispersed and galena is flocculated in the presence of ECP. Dissolution tests indicate release of the lattice metal ions from galena and Sphalerite, while co-precipitation tests confirm chemical interaction between lead or zinc ions and ECP. Fourier transform infrared spectroscopic studies provide evidence in support of hydrogen bonding and chemical interaction for the adsorption of ECP onto galena/Sphalerite surfaces.
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bio modulation of galena and Sphalerite surfaces using thiobacillus thiooxidans
International Journal of Mineral Processing, 2001Co-Authors: Deenan Santhiya, K. A. Natarajan, S Subramanian, K.s. Eric ForssbergAbstract:The interaction of Thiobacillus thiooxidans (T. thiooxidans) with Sphalerite and galena has been investigated through adsorption, electrokinetic, and flotation studies. The amount of T. thiooxidans cells adsorbed onto galena and Sphalerite is found to be almost independent of pH. However, a greater amount of cells is adsorbed onto galena compared to Sphalerite. The adsorption isotherms of T. thiooxidans onto both galena and Sphalerite exhibit Langmuirian behaviour. Electrokinetic measurements reveal that the isoelectric points (iep) of galena and Sphalerite are located around pH 2, while that of T. thiooxidans is around pH 3. The isoelectric points of the minerals are shifted to higher pH values after interaction, consequent to bacterial cell attachment, indicating specific adsorption. Additionally, the electrophoretic mobilities are found to become less negative as a function of time after bacterial interaction. Such a trend is also followed in the case of the cells after interaction with the minerals for different time intervals. On a comparative basis, the cells after interaction with Sphalerite are less negative vis-a-vis those after interaction with galena. The flotation recovery of Sphalerite, beyond 1 h of interaction with T. thiooxidans cells is not affected but galena is totally depressed in the presence of T. thiooxidans cells, in the pH range 5–11. The differential flotation tests on a synthetic mixture of galena and Sphalerite reveal that Sphalerite can be selectively floated from galena in the presence of T. thiooxidans.
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surface chemical studies on Sphalerite and galena using bacillus polymyxa
Joint International Conference on Information Sciences, 2001Co-Authors: Deenan Santhiya, S V Subramanian, K. A. NatarajanAbstract:The interaction of Sphalerite and galena with cells of Bacillus polymyxa was investigated through adsorption, electrokinetic, flotation, and flocculation studies. Adsorption experiments indicated that a higher amount of the cells was adsorbed onto galena compared to Sphalerite. The adsorption density of the cells onto galena was almost independent of pH while that onto Sphalerite was found to continuously decrease with increasing pH. The adsorption isotherms of the bacterial cells on galena and Sphalerite exhibited Langmuirian behavior. Electrokinetic measurements showed that the negative electrophoretic mobilities of the cells were reduced in magnitude in proportion to the time of interaction with either Sphalerite or galena. Similar trends were observed in the cases of Sphalerite and galena after interaction with the cells. However, the magnitude of the reduction in the electrophoretic mobilities was found to be greater for galena than for Sphalerite. Flotation tests revealed that galena was almost completely depressed after interaction with the cells both in the absence and in the presence of the collector. In contrast, the addition of collector and activator to Sphalerite, which was initially interacted with the cells, restored the floatability at and beyond pH 8.5. Selective flotation tests on a synthetic mixture of galena and Sphalerite confirmed that Sphalerite could be preferentially floated from galena, which was depressed by the bacterial cells. Selective flocculation tests further demonstrated that galena could be flocculated from Sphalerite, which was dispersed in the presence of cells of B. polymyxa at pH 9–9.5.
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surface chemical studies on Sphalerite and galena using bacillus polymyxa ii mechanisms of microbe mineral interactions
Journal of Colloid and Interface Science, 2001Co-Authors: Deenan Santhiya, S V Subramanian, K. A. NatarajanAbstract:Biodissolution tests reveal the release of lead/zinc species from galena/Sphalerite, respectively, while biosorption experiments confirm interaction of cells of Bacillus polymyxa (B. polymyxa) with the metal ions of interest. The amount of exo-polysaccharides is found to be the highest in the case of galena-interacted cells, followed by the Bromfield medium-grown cells while the Sphalerite-interacted cells have the least, based on ruthenium red adsorption studies. In contrast, the Sphalerite-interacted cells assay the highest amount of protein while the galena-interacted cells have the lowest amount, on a comparative basis. The adsorption of xanthate onto galena is found to be diminished in the presence of the cells whereas the xanthate adsorption density for activated Sphalerite is unaffected in the pH range 9–11. Additionally, the cell surface hydrophobicity tests confirm that the Sphalerite-interacted cells are more hydrophobic relative to the galena-interacted cells. FTIR spectroscopic data lend support to the higher adsorption density of the cells onto galena vis-a-vis Sphalerite. The higher exo-polysaccharide and lower protein contents together with the hydrophilic nature of the galena-interacted cells could be the contributing factors to the selective flocculation and depression of galena. In a similar manner, the higher protein and lower exo-polysaccharide contents as well as the greater hydrophobicity of the Sphalerite-interacted cells favor its floatability and dispersion.
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surface chemical studies on galena and Sphalerite in the presence of thiobacillus thiooxidans with reference to mineral beneficiation
Minerals Engineering, 2000Co-Authors: Deenan Santhiya, S Subramanian, K. A. NatarajanAbstract:Adsorption and electrokinetic studies were carried out to examine the surface chemical changes on galena and Sphalerite before and after interaction with Thiobacillus thiooxidans (T. thiooxidans). The adsorption density of bacterial cells onto the two sulphide minerals was found to be independent of pH, although an increased number of cells was adsorbed onto galena compared to Sphalerite. The adsorption isotherms of the cells with respect to the two minerals conform to the Langmuir equation. Zeta potential measurements revealed that the isoelectric points of the sulphide minerals were shifted to higher pH values after bacterial interaction, suggestive of specific adsorption. Both the sulphide minerals as well as the cells became less electronegative as a function of time after interaction with each other. Selective flotation and flocculation studies highlighted that galena could be separated from Sphalerite after bacterial interaction. These tests confirmed that galena was depressed while Sphalerite was made hydrophobic after interaction with the cells. Fourier transform infrared spectroscopic studies provided evidence in support of hydrogen bonding for the mineral-cell adsorption process. Possible mechanisms of interaction between galena/Sphalerite and the cells of T. thiooxidans are discussed.
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mapping the nanoscale heterogeneity of surface hydrophobicity on the Sphalerite mineral
Journal of Physical Chemistry C, 2017Co-Authors: Lei Xie, Qingxia Liu, Qi Liu, Jingyi Wang, Chen Shi, Xin Cui, Jun Huang, Hao Zhang, Hongbo ZengAbstract:Hydrophobic effect plays an important role in a wide range of natural phenomena and engineering applications, such as mineral froth flotation. In this work, atomic force microscope (AFM) force mapping was employed, for the first time, to probe the nanoscale heterogeneity of surface hydrophobicity and surface interactions on the Sphalerite mineral surface before/after conditioning treatment (activated by copper sulfate and then treated by amyl xantahte). The AFM force mapping demonstrates that adhesion on Sphalerite falls in a narrow range with a peak centered at 16.4 mN/m and adhesion on conditioned Sphalerite falls in a wide range with a small peak centered at 15.5 mN/m and a large peak centered at 58.1 mN/m. It is evident that the Sphalerite surface is hydrophilic with homogeneous surface hydrophobicity whereas conditioned Sphalerite exhibits a heterogeneous distribution of surface hydrophobicity due to the nonuniform adsorption of xanthate. The significantly enhanced adhesion after conditioning treatme...
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effects of salinity on xanthate adsorption on Sphalerite and bubble Sphalerite interactions
Minerals Engineering, 2015Co-Authors: Jingyi Wang, Qingxia Liu, Lei Xie, Hongbo ZengAbstract:Abstract The adsorption of amyl xanthate on Sphalerite in NaCl solutions of different concentrations and in saline water (viz. simulated sea water) and the surface properties of treated minerals were investigated. The interactions between xanthate treated Sphalerite particles and air bubbles were examined using induction time measurement, which revealed that the salt ions could inhibit the adsorption of xanthate on Sphalerite due to the competitive adsorption, but also could compress the electrical double layer at mineral/water interface. The induction time of Sphalerite treated in potassium amyl xanthate (PAX) with saline water was shorter than that of Sphalerite treated in PAX with NaCl of the same ion concentration, which implies that the water composition (e.g. Ca 2+ , Mg 2+ ) could play an important role in the bubble–particle interaction. The hydrophobicity, chemical composition, and charge property of PAX treated Sphalerite surfaces were characterized using contact angle measurement, Cryo-X-ray photoelectron spectroscopy (Cryo-XPS) and zeta potential determination, respectively, which support the inhibition effect of salt ions on the xanthate adsorption on Sphalerite. In the case of saline water, the xanthate decomposition products were confirmed by XPS, which could further lower the hydrophobicity of the treated Sphalerite. Our results provide insights into the basic understanding of the salinity effects on the xanthate adsorption on Sphalerite and the bubble–mineral interactions in flotation.
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probing the interaction between air bubble and Sphalerite mineral surface using atomic force microscope
Langmuir, 2015Co-Authors: Lei Xie, Qingxia Liu, Jingyi Wang, Chen Shi, Jun Huang, Hongbo ZengAbstract:The interaction between air bubbles and solid surfaces plays important roles in many engineering processes, such as mineral froth flotation. In this work, an atomic force microscope (AFM) bubble probe technique was employed, for the first time, to directly measure the interaction forces between an air bubble and Sphalerite mineral surfaces of different hydrophobicity (i.e., Sphalerite before/after conditioning treatment) under various hydrodynamic conditions. The direct force measurements demonstrate the critical role of the hydrodynamic force and surface forces in bubble–mineral interaction and attachment, which agree well with the theoretical calculations based on Reynolds lubrication theory and augmented Young–Laplace equation by including the effect of disjoining pressure. The hydrophobic disjoining pressure was found to be stronger for the bubble–water–conditioned Sphalerite interaction with a larger hydrophobic decay length, which enables the bubble attachment on conditioned Sphalerite at relatively...
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understanding copper activation and xanthate adsorption on Sphalerite by time of flight secondary ion mass spectrometry x ray photoelectron spectroscopy and in situ scanning electrochemical microscopy
Journal of Physical Chemistry C, 2013Co-Authors: Jingyi Wang, Qingxia Liu, Hongbo ZengAbstract:In situ scanning electrochemical microscopy (SECM) was applied for the first time to study the copper activation and subsequent xanthate adsorption on Sphalerite. The corresponding surface compositions were analyzed by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). The probe approach curve (PAC) using SECM shows that unactivated and activated Sphalerite surfaces have negative current feedback and partially positive current feedback, respectively, suggesting that CuxS is formed on the Sphalerite after copper activation. The copper activation of Sphalerite strongly depends on the surface heterogeneity (e.g., presence of polishing defects, chemical composition), impacting the subsequent xanthate adsorption process. The SECM, ToF-SIMS, and XPS analyses show that during the copper activation the polishing defects, which have high excess surface energy, tend to consume more copper ions, resulting in Cu-rich regions by forming CuS-like species, while Fe oxid...
