Research on the behavior differences between nanobubbles (NBs) flotation and traditional flotation in fine particle gold ores

In this paper, the effect of flotation parameters on recover of fine particle gold is investigated by comparing the NBs flotation with conventional flotation. Meanwhile, contact Angle instrument and Zeta potential analyzer were used to study recovery mechanism of fine particle gold strengthened by NBs. The results showed that existence of NBs can significantly improve flotation effect of fine gold particles, effectively reduce consumption of flotation reagents, and flotation selectivity is better than that of conventional flotation even at 40% high pulp density. In particle size range of 0.02- 0.01 mm (micro-fine particles) and 0–0.01 mm (ultra-fine particles), particle size recovery (PSR) is increased by 7 and 5 percentage points compared with conventional flotation, respectively. The research also found that when nanobubbles were present, the contact Angle increased by 9° and the nanobubbles significantly reduced the surface potential of hydrophobic particles by 6.88 mV (pH8), enhanced hydrophobic attraction between pyrite particles and reduced electrostatic repulsion between particles. Finally, the stability of hydrophobic aggregates of fine particle pyrite was enhanced, which play a role in strengthening the recovery of fine gold particles.