Study of effect of frother on bubble characteristic in flotation process

In order to explore the effect on size and kinetic characteristics of bubble produced by frothers dodecylamine (DDA) and 2-octanol in flotation process, the bubble size distribution, surface tensions under different conditions and bubble motion state are analyzed using image analysis method, tensionmeter and high-speed camera, respectively. As indicated by study results, with the increase of concentration of DDA and 2-octanol, the bubble size decreases gradually and stay stabilized when the critical coalescene concentration (CCC value) which is 0.043 2 mmol/L for both DDA and 2-octamol; the surface tension of solution of both agents tends to decrease linearly with increase of concentration of agents, and under identical conditions, the surface tension of DDA solution is lower than that of 2-octanol solution; when DDA is added into 2-octanol, the CCC value, stabilized size of bubble as well as the surface tension of DDA solution and adsorption density are all seen to decrease; the bubble′s aspect ratio during its rising process tends to gradually increase and finally become stabilized with the increase of concentration of reagent, and under otherwise identical conditions, the bubble′s aspect ratio in DDA solution is larger than that in 2-octanol solution; adding DDA in 2-octanol solution can help increase bubble′s aspect ratio; the bubble ascending velocity decreases with increase of concentration of reagents; and under identical conditions, the ascending velocity of bubble in DDA solution is lower than that in 2-octanol solution; addition of DDA in 2-octanol solution can help reduce bubble ascending velocity; bubble ascending velocity is in negatively linear correlation with aspect ratio and such a dependence is unrelated to types and concentrations of reagents and their mixing mechanism.