[article]
| Titre : |
Kinetic Modelling and Equilibrium of Amphoteric Collector Adsorption on Silica and Hematite |
| Type de document : |
texte imprimé |
| Auteurs : |
K. A. Selim, Auteur ; F. H. Abd El-Rahiem, Auteur ; Ayman A. El-Midany, Auteur |
| Année de publication : |
2009 |
| Article en page(s) : |
p. 85-91 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Adsorption
Hématite
SiliceLa silice est la forme naturelle du dioxyde de silicium (SiO2) qui entre dans la composition de nombreux minéraux.
La silice existe à l'état libre sous différentes formes cristallines ou amorphes et à l'état combiné dans les silicates, les groupes SiO2 étant alors liés à d'autres atomes (Al : Aluminium, Fe : Fer, Mg : Magnésium, Ca : Calcium, Na : Sodium, K : Potassium...).
Les silicates sont les constituants principaux du manteau et de l'écorce terrestre. La silice libre est également très abondante dans la nature, sous forme de quartz, de calcédoine et de terre de diatomée. La silice représente 60,6 % de la masse de la croûte terrestre continentale.
Surfactants
|
| Index. décimale : |
668.1 Agents tensioactifs : savons, détergents |
| Résumé : |
Most of the world iron ores are associated with siliceous impurities. Upgrading schemes depend mostly on the removal of these impurities by flotation and/or selective flocculation techniques, which mainly influenced by the adsorption of collectors on both valuable and gangue minerals. In this study, the adsorption of amphoteric collector (dodecyl-N-carboxyethyl-N-hydroxyethyl-imidazoline) on silica and hematite was studied. The collector adsorption exhibits the preferential adsorption on silica at acidic pH range. While in case of hematite, the adsorption was the same over entire the studied pH range. The temperature was kept constant at 298 K and contact time of 60 min was found, from kinetic study, to be adequate to achieve equilibrium. In addition, two simplified kinetic models including a pseudo first-order equation and pseudo second-order equation were used to determine kinetic parameters, rate constants, and equilibrium sorption capacities. It was shown that the pseudo first-order equation perfectly describes the adsorption of collector. Moreover, the analysis of experimental isotherm data using the Langmuir, Freundlich, Temkin and Dubinin-Radushkevich equations showed that the Freundlich model reasonably fits the experimental data in the studied concentration range. |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4576 |
in TENSIDE, SURFACTANTS, DETERGENTS > Vol. 46, N° 2/2009 (02-03/2009) . - p. 85-91
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Kinetic Modelling and Equilibrium of Amphoteric Collector Adsorption on Silica and Hematite in TENSIDE, SURFACTANTS, DETERGENTS, Vol. 46, N° 2/2009 (02-03/2009)
