Interactional effects of bubble size, particle size, and collector dosage on bubble loading in column flotation

The success of flotation operation depends upon the thriving interactions of chemical and physical variables. In this work, the effects of particle size, bubble size, and collector dosage on the bubble loading in a continuous flotation column were investigated. In other words, this work was mainly concerned with the evaluation of the true flotation response to the changes in the operating variables in column flotation. Two bubble sizes of 0.8 and 1.8 mm, three size fractions of 63-106, 106-150, and 150-300 μm, and three different dosages of dodecylamine, as the collector, were tested. According to the results obtained, the particle size fraction of 106-150 μm had the maximum bubble loading for bubble diameter of 1.8 mm, while the particle size of 63-106 μm had the maximum bubble loading for bubble diameter of 0.8 mm. It was also shown that increasing the bubble diameter from 0.8 to 1.8 mm increased the bubble loading in all the particle size fractions and collector dosages. However, the mass loading of air bubbles was strongly related to the collector dosage (contact angle), especially for coarse particles. The amount of collector dosage had an upper limit due to the clustering event, which significantly affected the bubble loading. The clustering was found to be more important in the presence of small particles due to a higher number of particles attached to the bubble surface. It was shown that such interactions of variables of true flotation could reasonably be monitored by the bubble loading measurement.