## Abstract The effect of crystal surface roughness on impurity adsorption was investigated in a fluidized bed crystallizer and in a batch crystallizer. The crystallisation of sucrose in pure and impure systems was the study subject. Calcium chloride was utilized as impurity in this work. The resul
The effect of iron and copper impurities on the wettability of sphalerite (110) surface
β Scribed by Darren J. Simpson; Thomas Bredow; Anand P. Chandra; Giuseppe P. Cavallaro; Andrea R. Gerson
- Publisher
- John Wiley and Sons
- Year
- 2011
- Tongue
- English
- Weight
- 705 KB
- Volume
- 32
- Category
- Article
- ISSN
- 0192-8651
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β¦ Synopsis
Abstract
The effect of impurities in the zinc sulfide mineral sphalerite on surface wettability has been investigated theoretically to shed light on previously reported conflicting results on sphalerite flotation. The effect of iron and copper impurities on the sphalerite (110) surface energy and on the water adsorption energy was calculated with the semiβempirical method modified symmetrically orthogonalized intermediate neglect of differential overlap (MSINDO) using the cyclic cluster model. The effect of impurities or dopants on surface energies is small but significant. The surface energy increases with increasing surface iron concentration while the opposite effect is reported for increasing copper concentration. The effect on adsorption energies is much more pronounced with water clearly preferring to adsorb on an iron site followed by a zinc site, and copper site least favorable. The theoretical results indicate that a sphalerite (110) surface containing iron is more hydrophilic than the undoped zinc sulfide surface. In agreement with the literature, the surface containing copper (either naturally or by activation) is more hydrophobic than the undoped surface. Β© 2011 Wiley Periodicals, Inc. J Comput Chem 2011
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