Abstract: The gas holdup of flotation column is a very decisive factor for the flotation result. Study is made on the effect of the fluid static pressure, flowrate and aeration rate of the swirl injection flotation column when using clear water without any frothing agent on the gas holdup and the change of gas holdup when baffles are added. The results indicate that the gas holdup increases with the increase in the fluid static pressure, flowrate and aeration rate, with the flowrate having the greatest influence and the static pressure the least. When baffles are added, the gas holdup increases with the increase in the baffle height and the distance between the baffles and the pulp injection port. For a proper gas holdup, the baffle height should be 2/10 of the total column height and the distance should be controlled at 5/10 to 7/10 of the column length.

Key words: Swirl injection flotation column, Gas holdup, Fluid static pressure, Fluid flowrate, Aeration rate, Baffle