The Effect of Froth on Flotation Kinetics-A Mass Transfer Approach

Abstract

Abstract The effect of gas rate and froth thickness on the kinetics of transfer in the froth phase of laboratory semi-batch and continuous laboratory cells is described. Increasing froth thickness increases the dropback constant from the froth to the slurry, and decreases transfer rate constant into the concentrate. Increasing gas rate increases both the dropback constant and the froth transfer constant Hydraulic entrainment increases with increasing gas rate and decreasing froth thickness. A reasonable compromise that minimizes hydraulic entrainment and maximizes recovery of hydrophobic particles is the use of higher gas rate and froth thickness Preliminary testwork with wash water added to the froth yielded rejection of fine liberated gangue of up to 70%, at wash water superficial rates of 0.05-0.08 cm/s. Rejection is highly correlated to the rejection of feed water from the concentrate.