Daniel Fornasiero - Academia.edu (original) (raw)
Papers by Daniel Fornasiero
The interaction of particles with bubbles as a function of particle size (0.1-7 micrometers) and ... more The interaction of particles with bubbles as a function of particle size (0.1-7 micrometers) and surface hydrophobicity was investigated using single bubble flotation experiments. A minimum in collection efficiency was observed at particle diameters of 1-2 micrometers. ...
Journal of Colloid and Interface Science, Feb 1, 2010
We have studied the stability and structure of emulsions formed in the presence of colloidal mixt... more We have studied the stability and structure of emulsions formed in the presence of colloidal mixtures of partially hydrophobic titania particles and hydrophilic silica particles. On their own, the titania particles attached strongly to the oil-water interface and stabilised emulsions, while the silica particles did not attach to the interface. Adding silica particles to the titania dispersions enhanced coalescence processes during emulsion formation, except under mixing conditions that favoured particle heteroaggregation. The destabilisation of the emulsions was linked to the presence of silica particles in the particle layers at the interface.
ABSTRACT The objective of this study is to investigate the effects of water quality on mineral fl... more ABSTRACT The objective of this study is to investigate the effects of water quality on mineral floatability. For this, the species commonly found in process water, such as metal and sulphate ions, were investigated for their potential impact on the flotation performance of two valuable sulphide minerals, chalcopyrite and molybdenite. Zeta potential and X-ray photoelectron spectroscopy (XPS) measurements were used to identify the surface species responsible for the flotation of these minerals. Results showed that the flotation of both chalcopyrite and molybdenite was mostly depressed by aluminium and iron ions. Manganese and sulphate ions also depressed the flotation of molybdenite but not that of chalcopyrite. These results and interpretation of the zeta potential of these minerals in the presence of these salts in solution were able to explain the depression of the mineral flotation by metal hydroxide precipitated on the mineral surface. XPS analysis revealed that sulphate ions promoted the oxidation of molybdenite, which had a negative impact the flotation of this mineral.
International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology, 1986
The myocardial imaging agent technetium-99m-hexakis (tertiarybutylisonitrile) (99mTc-TBI) was pre... more The myocardial imaging agent technetium-99m-hexakis (tertiarybutylisonitrile) (99mTc-TBI) was prepared by the reaction of [99mTc]pertechnetate with TBI in 50% ethanol/0.9% saline at 100 degrees C, using stannous chloride as the reducing agent. A study of the reaction parameters enabled the yield to be optimized to better than 90%, although this was reduced to approximately 60% if a purification step was carried out. Chromatographic analysis on ITLC-SG medium showed the final product to be of high radiochemical purity. Biological studies comprising biodistribution in mice over a 2-h period, imaging studies in animals and sub-acute toxicity testing in mice indicated that 99mTc-TBI prepared as here described is a suitable agent for routine clinical use in humans.
Minerals Engineering, 2014
ABSTRACT In the flotation of copper ores, several processing plants report that copper recovery i... more ABSTRACT In the flotation of copper ores, several processing plants report that copper recovery is affected by the proportion and reactivity of pyrite in the ore, with the effect becoming more intense when the feed particles are finer as a result of regrinding. In this work, a mixed model mineral system consisting of chalcopyrite (CuFeS2) and pyrite (FeS2) with varying pyrite content (20–80 wt.%) was used to investigate the effect of pyrite on the pulp chemistry and chalcopyrite recovery. Flotation tests showed that chalcopyrite flotation rate, recovery and grade, as well as the pulp oxidation potential, decreased with increasing pyrite content whilst pyrite recovery increased. Surface analysis (XPS, ToF-SIMS and EDTA) indicated that copper activation of pyrite increased with increasing pyrite content, facilitating pyrite recovery. The decrease in chalcopyrite recovery can be attributed to increased surface oxidation.
International Journal of Mineral Processing, 2015
Surface and Colloid Science, 2004
Minerals Engineering, 2006
Minerals Engineering, 2005
Journal of the Chemical Society, Faraday Transactions, 1995
... 3, ch. 5. 7 R. Crawford and J. Ralston, Znt. J . Miner. Process., 1988,23, 1. 8 L. R. Fisher,... more ... 3, ch. 5. 7 R. Crawford and J. Ralston, Znt. J . Miner. Process., 1988,23, 1. 8 L. R. Fisher, D. Hewitt, EE Mitchell, J. Ralston and J. Wolfe, Adv. Colloid Interface Sci., 1992,39,397. 9 D. Hewitt, D. Fornasiero, J. Ralston and L. R. Fisher, J. Chem. SOC., Faraday Trans., 1993,89,817. ...
Journal of the Chemical Society, Faraday Transactions, 1998
The Journal of Physical Chemistry C, 2011
The wettability of a titania surface, whose surface was partially covered with a strongly based o... more The wettability of a titania surface, whose surface was partially covered with a strongly based octadecyltrihydrosilane, was studied above and below the isoelectric point (or pHiep). The advancing water contact angle is at a maximum at the pH iep, decreasing ...
The Journal of Physical Chemistry C, 2011
Colloid probe atomic force microscopy experiments were carried out between a titania particle and... more Colloid probe atomic force microscopy experiments were carried out between a titania particle and an air bubble in KCl solutions. The surface charges of both the bubble and the particle were controlled by varying the electrolyte concentration and pH of the solution. In ...
The Journal of Physical Chemistry C, 2012
... 6. Ata, S.; Davis, ES; Dupin, D.; Armes, SP; Wanless, EJ Langmuir 2010, 26, 7865 [.
The Journal of Physical Chemistry B, 2003
The Journal of Physical Chemistry B, 2003
... Conclusion. The formation of very small gas bubbles (so-called nanobubbles) at structured s... more ... Conclusion. The formation of very small gas bubbles (so-called nanobubbles) at structured solid−water interfaces has been studied using the tapping mode atomic force microscopy (TMAFM) imaging technique. ... (1) Dai, Z.; Fornasiero, D.; Ralston, J. J. Chem. ...
The interaction of particles with bubbles as a function of particle size (0.1-7 micrometers) and ... more The interaction of particles with bubbles as a function of particle size (0.1-7 micrometers) and surface hydrophobicity was investigated using single bubble flotation experiments. A minimum in collection efficiency was observed at particle diameters of 1-2 micrometers. ...
Journal of Colloid and Interface Science, Feb 1, 2010
We have studied the stability and structure of emulsions formed in the presence of colloidal mixt... more We have studied the stability and structure of emulsions formed in the presence of colloidal mixtures of partially hydrophobic titania particles and hydrophilic silica particles. On their own, the titania particles attached strongly to the oil-water interface and stabilised emulsions, while the silica particles did not attach to the interface. Adding silica particles to the titania dispersions enhanced coalescence processes during emulsion formation, except under mixing conditions that favoured particle heteroaggregation. The destabilisation of the emulsions was linked to the presence of silica particles in the particle layers at the interface.
ABSTRACT The objective of this study is to investigate the effects of water quality on mineral fl... more ABSTRACT The objective of this study is to investigate the effects of water quality on mineral floatability. For this, the species commonly found in process water, such as metal and sulphate ions, were investigated for their potential impact on the flotation performance of two valuable sulphide minerals, chalcopyrite and molybdenite. Zeta potential and X-ray photoelectron spectroscopy (XPS) measurements were used to identify the surface species responsible for the flotation of these minerals. Results showed that the flotation of both chalcopyrite and molybdenite was mostly depressed by aluminium and iron ions. Manganese and sulphate ions also depressed the flotation of molybdenite but not that of chalcopyrite. These results and interpretation of the zeta potential of these minerals in the presence of these salts in solution were able to explain the depression of the mineral flotation by metal hydroxide precipitated on the mineral surface. XPS analysis revealed that sulphate ions promoted the oxidation of molybdenite, which had a negative impact the flotation of this mineral.
International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology, 1986
The myocardial imaging agent technetium-99m-hexakis (tertiarybutylisonitrile) (99mTc-TBI) was pre... more The myocardial imaging agent technetium-99m-hexakis (tertiarybutylisonitrile) (99mTc-TBI) was prepared by the reaction of [99mTc]pertechnetate with TBI in 50% ethanol/0.9% saline at 100 degrees C, using stannous chloride as the reducing agent. A study of the reaction parameters enabled the yield to be optimized to better than 90%, although this was reduced to approximately 60% if a purification step was carried out. Chromatographic analysis on ITLC-SG medium showed the final product to be of high radiochemical purity. Biological studies comprising biodistribution in mice over a 2-h period, imaging studies in animals and sub-acute toxicity testing in mice indicated that 99mTc-TBI prepared as here described is a suitable agent for routine clinical use in humans.
Minerals Engineering, 2014
ABSTRACT In the flotation of copper ores, several processing plants report that copper recovery i... more ABSTRACT In the flotation of copper ores, several processing plants report that copper recovery is affected by the proportion and reactivity of pyrite in the ore, with the effect becoming more intense when the feed particles are finer as a result of regrinding. In this work, a mixed model mineral system consisting of chalcopyrite (CuFeS2) and pyrite (FeS2) with varying pyrite content (20–80 wt.%) was used to investigate the effect of pyrite on the pulp chemistry and chalcopyrite recovery. Flotation tests showed that chalcopyrite flotation rate, recovery and grade, as well as the pulp oxidation potential, decreased with increasing pyrite content whilst pyrite recovery increased. Surface analysis (XPS, ToF-SIMS and EDTA) indicated that copper activation of pyrite increased with increasing pyrite content, facilitating pyrite recovery. The decrease in chalcopyrite recovery can be attributed to increased surface oxidation.
International Journal of Mineral Processing, 2015
Surface and Colloid Science, 2004
Minerals Engineering, 2006
Minerals Engineering, 2005
Journal of the Chemical Society, Faraday Transactions, 1995
... 3, ch. 5. 7 R. Crawford and J. Ralston, Znt. J . Miner. Process., 1988,23, 1. 8 L. R. Fisher,... more ... 3, ch. 5. 7 R. Crawford and J. Ralston, Znt. J . Miner. Process., 1988,23, 1. 8 L. R. Fisher, D. Hewitt, EE Mitchell, J. Ralston and J. Wolfe, Adv. Colloid Interface Sci., 1992,39,397. 9 D. Hewitt, D. Fornasiero, J. Ralston and L. R. Fisher, J. Chem. SOC., Faraday Trans., 1993,89,817. ...
Journal of the Chemical Society, Faraday Transactions, 1998
The Journal of Physical Chemistry C, 2011
The wettability of a titania surface, whose surface was partially covered with a strongly based o... more The wettability of a titania surface, whose surface was partially covered with a strongly based octadecyltrihydrosilane, was studied above and below the isoelectric point (or pHiep). The advancing water contact angle is at a maximum at the pH iep, decreasing ...
The Journal of Physical Chemistry C, 2011
Colloid probe atomic force microscopy experiments were carried out between a titania particle and... more Colloid probe atomic force microscopy experiments were carried out between a titania particle and an air bubble in KCl solutions. The surface charges of both the bubble and the particle were controlled by varying the electrolyte concentration and pH of the solution. In ...
The Journal of Physical Chemistry C, 2012
... 6. Ata, S.; Davis, ES; Dupin, D.; Armes, SP; Wanless, EJ Langmuir 2010, 26, 7865 [.
The Journal of Physical Chemistry B, 2003
The Journal of Physical Chemistry B, 2003
... Conclusion. The formation of very small gas bubbles (so-called nanobubbles) at structured s... more ... Conclusion. The formation of very small gas bubbles (so-called nanobubbles) at structured solid−water interfaces has been studied using the tapping mode atomic force microscopy (TMAFM) imaging technique. ... (1) Dai, Z.; Fornasiero, D.; Ralston, J. J. Chem. ...