Mechanisms of nanobubble-enhanced flotation of galena from pyrite

• Nanobubbles significantly enhance flotation recovery and selectivity of galena from pyrite compared to conventional flotation. • Nanobubbles preferentially form on more hydrophobic galena surfaces, increasing surface hydrophobicity and particle agglomeration. • Nanobubble introduction increases the maximum three-phase contact line length and detachment length, improving bubble-particle attachment. • Hydrodynamic cavitation does not significantly accelerate pyrite oxidation due to rapid surface nanobubble formation, preserving selectivity.