Kinetics of the bubble attachment and quartz flotation in mixed solutions of cationic and non-ionic surface-active substances

Abstract

The effect of cationic (n-cetyltrimethylammonium bromide − CTAB) and non-ionic (n-octanol) surface-active substances (SAS) on the kinetics of rising bubble attachment to a quartz surface and flotation recovery of quartz particles was investigated. The measured time of the three-phase contact (TPC) formation (tTPC) and the advancing contact angle (sessile drop) values, in pure and mixed CTAB and n-octanol solutions, allowed to evaluate the importance of electrostatic interactions and solid surface hydrophobicity in stability and rupture of the wetting films formed between a quartz surface and a colliding bubble. It was shown that electrostatic interactions inside the wetting film as well as the quartz hydrophobicity was changing with the composition of the mixed solutions. The experiments revealed that, within the concentration range of the SAS used in this study, CTAB modified properties of liquid/gas and liquid/solid interfaces, while non-ionic n-octanol adsorbed primarily at liquid/gas interface hindering its fluidity and, as a result, decreased bubble bouncing time. The correlation between the times of bubble attachment and the flotation recovery of quartz particles was established.