Title: Air bubble and oil droplet interactions in centrifugal fields during air-sparged hydrocyclone flotation
Authors: M. Niewiadomski, Anh V. Nguyen, J. Hupka, J. Nalaskowski, J.D. Miller
Addresses: Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112, USA. ' Division of Chemical Engineering, School of Engineering, The University of Queensland, Brisbane, Queensland 4072, Australia. ' Department of Chemical Technology, Gdansk University of Technology, 80-952 Gdansk, Poland. ' Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112, USA. ' Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112, USA
Abstract: The interactions of air bubbles and oil droplets in centrifugal flotation have been considered with respect to process conditions present during Air-sparged Hydrocyclone (ASH) flotation. Encounter efficiency of oil droplets with air bubbles has been found to be significantly smaller when compared to encounter efficiency of mineral particles. Collision and sliding contact times have been determined. Collision has been found to be insufficient for successful contact between oil droplets and air bubbles while sliding allows for film rupture depending on specific system conditions. Although the tenacity of oil droplet attachment to an air bubble is believed to be greater than the tenacity of a mineral particle, emulsification makes oil flotation in centrifugal devices with large dissipation of energy inefficient and hence requires the use of high molecular weight polymeric flocculants.
Keywords: centrifugal flotation; froth flotation; oil flotation; dispersed oil; air-sparged hydrocyclone; ASH flotation; wastewater treatment; water pollution; environmental pollution; air bubbles; oil droplets; polymeric flocculants.
International Journal of Environment and Pollution, 2007 Vol.30 No.2, pp.313 - 331
Published online: 26 Jul 2007 *Full-text access for editors Access for subscribers Purchase this article Comment on this article