A study of bubble size/shape evolution in microbubble countercurrent contacting flotation column

Abstract

AbstractCationic collectors are widely used in the flotation of iron ore, silicate, oxides, and so forth. At this stage, so much research has been carried out on flotation column cells, but more attention needs to be paid to the hydrodynamic properties in the presence of cationic collectors in cells. In order to study foaming performance and hydrodynamic characteristics in the presence of GE609, the bubble characteristics are studied in an experimental scale flotation column. A high‐speed camera recorder is used to take bubbles' images, and the bubble size and shape under different conditions is measured by image analysis. This paper aims to explore the effect of dispersed gas and continuous liquid velocities on the bubble size and aspect ratio at different axial heights in a countercurrent flotation column in the presence and absence of GE609. In the systems, the bubble size distributions and shapes at different axial positions were obtained by using high‐speed camera technology in the superficial gas velocity (Ug) ranges of 0.0021–0.0106 m/s and superficial liquid velocity (UL) ranges of 0.00123–0.00209 m/s. Through the comparison with relevant papers and studying the experiment data, the relationship between the Sauter mean diameter and Ug, UL and axial heights have been analyzed by using multiple linear regression and dimensional analysis. The experimental data have been adopted to establish the correlation between the bubble diameter and the dimensionless array, which have been compared with other literature. And the predicted values/results of Weber and Morton number correlation in this work are relatively close to the experimental values.