Imaging study on bubble size distribution in presence of frother in froth flotation

The objective of this study is to characterize the bubble size distribution for intermediate bubble swarm in the presence of frother so as to improve the flotation performance. Experiments were thus carried out to investigate the effect of frother on bubble size distribution by changing the frother concentration. Distilled water and Triton X-100 solutions with various concentrations were choosed as continuous liquid phases. Intermediate bubbles with size range of 1~4 mm were released from a porous ceramic sparger by regulating the gas rate. The motion of bubble swarm was then recorded using high-speed camera in a laboratory scale flotation column. The image process technique was employed to determine the parameters relating to flotation performance such as average bubble diameter, sauter mean diameter and the specific surface area of bubbles. The results show that even a small amount of Triton X-100 has a dramatic effect on bubble size distribution. An increase in Triton X-100 concentration is found to narrow the size distribution and reduce the diameter, but increase the specific surface area of bubble swarm. In addition, the bubble size distribution is also widened and Sauter mean diameter increases slightly with increasing gas rate.