A review of factors that affect contact angle and implications for flotation practice

Chau, T. T., Bruckard, W. J., Koh, P. T. L. and Nguyen, A. V. (2009) A review of factors that affect contact angle and implications for flotation practice. ADVANCES IN COLLOID AND INTERFACE SCIENCE, 150 2: 106-115. doi:10.1016/j.cis.2009.07.003

Author Chau, T. T.
Bruckard, W. J.
Koh, P. T. L.
Nguyen, A. V.
Title A review of factors that affect contact angle and implications for flotation practice
Journal name ADVANCES IN COLLOID AND INTERFACE SCIENCE   Check publisher's open access policy
ISSN 0001-8686
Publication date 2009-09-30
Year available 2009
Sub-type Article (original research)
DOI 10.1016/j.cis.2009.07.003
Volume 150
Issue 2
Start page 106
End page 115
Total pages 10
Editor Amirfazli, A.
Miller, R.
Place of publication Amsterdam, The Netherlands
Publisher Elseiver
Collection year 2010
Language eng
Subject 0904 Chemical Engineering
970103 Expanding Knowledge in the Chemical Sciences
Abstract Contact angle and the wetting behaviour of solid particles are influenced by many physical and chemical factors such as surface roughness and heterogeneity as well as particle shape and size. A significant amount of effort has been invested in order to probe the correlation between these factors and surface wettability. Some of the key investigations reported in the literature are reviewed here. It is clear from the papers reviewed that, depending on many experimental conditions such as the size of the surface heterogeneities and asperities, surface cleanliness. and the resolution of measuring equipment and data interpretation, obtaining meaningful contact angle values is extremely difficult and such values are reliant on careful experimental control. Surface wetting behaviour depends on not only surface texture (roughness and particle shape), and surface chemistry (heterogeneity) but also on hydrodynamic conditions in the preparation route. The inability to distinguish the effects of each factor may be due to the interplay and/or overlap of two or more factors in each system. From this review, it was concluded that: Surface geometry (and surface roughness of different scales) can be used to tune the contact angle: with increasing surface roughness the apparent contact angle decreases for hydrophilic materials and increases for hydrophobic materials. For non-ideal surfaces. such as mineral Surfaces in the flotation process, kinetics plays a more important role than thermodynamics in dictating wettability. Particle size encountered in flotation (10-200 mu m) showed no significant effect on contact angle but has a strong effect on flotation rate constant. There is a lack of a rigid quantitative correlation between factors affecting wetting, wetting behaviour and contact angle on minerals; and hence their implication for flotation process. Specifically, universal correlation of contact angle to flotation recovery is still difficult to predict from first principles. Other advanced techniques and measures complementary to contact angle will be essential to establish the link between research and practice in flotation. (C) 2009 Elsevier B.V. All rights reserved.
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Document type: Journal Article
Sub-type: Article (original research)
Collections: 2010 Higher Education Research Data Collection
School of Chemical Engineering Publications
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Citation counts: TR Web of Science Citation Count  Cited 84 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 03 Mar 2010, 15:31:16 EST by Amanda Lee on behalf of School of Chemical Engineering