KINETIC-STUDIES IN FLOTATION COLUMNS - BUBBLE-SIZE EFFECT

The collection first order rate constant of a flotation column was investigated as a function of bubble size within ranges commonly seen in industrial column flotation practice. The experimental work was done in a 2.5 an diameter glass column. High purity minerals (silica, pyrite and galena) were used for the test work. Bubble size was varied by varying the frother dosage, and several flotation tests were performed with different bubble sizes at constant gas rate. Collection efficiencies were calculated using the relationship presented by Jameson. For silica flotation under typical column flotation conditions (of bubble size and gas rate) the collection rate constant was measured to be proportional to d(b)-1.54. This is a much smaller effect of bubble size than other researchers had speculated. It was also observed that the magnitude of the bubble size effect on the rate constant was affected by the particle size. A size by size analysis of the results explains observations found with some industrial columns.