A Comparison of Bubble Rise Velocity Profile of two Surfactants to Explain Gas Holdup Data

A previous study comparing n-pentanol and the polyglycol Fl50 showed that the two reagents could give the same gas holdup but with different size bubbles. The finding implies that bubble rise velocity depends on the surfactant (frother) type. A study using bubble swarms supported the frother type effect but bubble interactions were a possible confounding factor. This study resolves the question by measuring the rise velocity of single bubbles of 0.8-2.5mm diameter over a distance :::: 300cm in n-pentanol and F 150. It is shown that at typical frother concentrations used in flotation that the rise velocity in n-pentanol remains comparable to that in water alone while in Fl50 the velocity is significantly reduced. The results confirm the suspected impact of frother type. It is illustrated that in n-pentanol the rise velocity does not reached terminal; while in Fl50 it does and this is the source of the velocity difference. Advances