The mechanism responsible for the effect of frothers on the degree of entrainment in laboratory batch flotation. (January 2017)

• Record Type: Journal Article
• Authors: Wang, L.; Peng, Y.; Runge, K.
• Is Part Of: Minerals engineering. Volume 100(2017)
• Page Start: 124
• Page End: 131
• Publication Date: 2017-01
• Subjects: Froth flotation -- Degree of entrainment -- Frother -- Interface liquid velocity -- Drag force; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2016.10.023
• Languages: English
• ISSNs: 0892-6875

Abstract

Highlights: Frother type and concentration adjust gangue particle motion relative to water. Frother effect on ENT is a result of water motion at the pulp/froth interface. Frother affects water velocity and thus the drag at interface in determining ENT. The classification of entrained particles mainly occurs at the pulp/froth interface. Abstract: The effect of frothers on the degree of entrainment is important for selective flotation, but the mechanism underpinning the effect is still poorly understood. In this study, gangue only batch flotation tests were performed using fully liberated quartz in a 3.5 L conventional Agitair flotation cell, and the degree of entrainment was assessed at different frother concentrations using Dowfroth 250 and MIBC. Results show that the effect of frothers on the degree of entrainment was the consequence of changes in the upward liquid motion across the pulp/froth interface. The frothers changed the bubble size, resulting in a change in liquid content and liquid velocity at the interface. The change in interface liquid velocity then changed the drag force which determined the motion of a particle against the downward gravitational force on the particle due to its weight, resulting in a change in the amount of hydrophilic solid particles following the water phase and being recovered in the water phase, and hence the degree of entrainment. The results also suggest that the classification of hydrophilic solid particles occurred at the interface region.