Effect of turbulence on the detachment between an air bubble and a glass bead with different hydrophobicity: Experiments and simulations

The effect of turbulence on the detachment between an air bubble and a glass bead (soda-lime) with different hydrophobicity was comprehensively researched. An experimental apparatus was designed to simulate the turbulent environment during the actual flotation process, which was used to research the detachment of different hydrophobic glass beads from bubble surfaces. It is indicated that three different hydrophobic glass beads detached from the bubble surfaces in the same way but at different speeds. The three-phase contact line (TPCL) shrank rapidly when the centrifugal detachment force of glass beads reached a critical value. The deformation of bubbles increased, and the three-phase contact (TPC) area continuously decreased. When the critical value was exceeded, the sliding and contraction speed around the TPCL further increased until a clear necking phenomena appeared near the TPC. Furthermore, the centrifugal detachment force, capillary force and total pressure force increased with increasing hydrophobicity in the detachment process.