(444h) Comparison of the Rise Dynamics of Standard Bubbles and Oil-Coated Bubbles: Experiments and Simulations

Wang, S. - Presenter, Georgia Institute of Technology
Behrens, S. H., Georgia Institute of Technology
Kumar Tripathi, M., Indian Institute of Science Education and Research Bhopal
Chandra Sahu, K., Indian Institute of Technology Hyderabad
Ordinary air bubbles are routinely used in froth flotation, a highly efficient separation method utilized in many industrial processes; and the rise dynamics of standard air bubbles has also been extensively studied for many years. There is also an emerging interest in replacing the standard bubbles with oil-coated bubbles to separate hydrophilic particles with low affinity for the air-water interface, but the rise behavior of oil-coated bubbles has not been well explored yet. In our work, we systematically investigated the shape, velocity and trajectory of bubbles engulfed in a layer of oil, and experimental results were compared to computer simulations to confirm a pronounced effect of the oil coat on the bubble dynamics. We consistently found that oil-coated bubbles display a more spherical shape, lower rise velocity and straighter trajectory than the standard air bubbles, which can benefit the flotation process.