221 / 2024-03-13 18:32:26

Effect of Surface Hydrophobicity and Roughness on Particle-bubble Detachment Behavior: Comparative Study of Air-water and Oily Bubbles

detachment, ultrasound, oily bubble, hydrophobicity, roughness

Our preliminary study shows that oily bubbles were capable of enhancing particle-bubble adhesion and inhibiting the detachment probability of coarse particles in column flotation. However, the effect of surface hydrophobicity and roughness on the detachment behavior of particles from oily bubbles was not comprehensively studied. To fill the gap, an ultrasound oscillation system was designed to simulate turbulent disturbance in the pulp zone, and the slippage distance of particles on the air-water and oily bubbles’ surface was recorded. The results indicated that an increase in ultrasonic power caused the gradual rise of fluctuations of the projected area of air-water and oily bubbles without loaded particles. The oily bubbles always fluctuated less than air-water bubbles, which proved the oily bubbles exhibited better stability due to the oil film. When particles were introduced, high hydrophobic particles showed lower detachment probability and displacement than that of low hydrophobic particles under both air-water and oily bubble conditions. The increase in roughness increased detachment probability and displacement for low hydrophobic particles, while particles with higher hydrophobicity and rougher surface presented an inhibition on the detachment probability. In conclusion, the oily bubble significantly reduced the detachment probability and displacement of particles with different surface properties, and the feasibility of the oily bubble flotation was verified.