Shape Oscillations of a Particle Coated Bubble during Rise in a Liquid Column

Abstract

Particle coated bubble and its stability plays a major role during particle recovery in flotation process. A rising bubble undergoes shape oscillations which are subjected to change when particles are coated on the surface of a bubble. Experiments were performed to understand the effect of particle coating on a rising bubble in a liquid column. Hydrophobic Low density polyethylene particles were used to coat the bubble surface and water was used as liquid medium. Two images (one direct and mirror image) were taken for all position during rise of the bubble. Effect of different fraction of particle coating on the bubble surface oscillations was studied. It is observed that the shape oscillations of bubbles are arrested as coating fraction increased from 10% to 50% with the latter undergoing almost no deformation in shape. The bubble in this case behaves like a rigid body and exhibits pure rotation as it moves up.