Effects of bubble size, velocity, and particle agglomeration on the electro‐flotation kinetics of fine cassiterite

Abstract

AbstractHydrodynamic behavior of fine particles and bubbles and their influences on the particle–bubble collision efficiency (Ec) in an electro‐flotation system were analyzed in this study. The influence of sodium oleate on the agglomeration of cassiterite particles and the effect of electrolyte (Na2SO4) concentration on the zeta potential of cassiterite were investigated in detail, respectively. Bubble trajectory was recorded by using a high‐speed camera to investigate the dynamic process in terms of bubble velocity. Moreover, bubble size was taken into account in the determination of the relationship between bubble velocity and Ec. The Reynolds number (Reb) was calculated to be 4.77 for hydrogen (H2) bubbles with a mean diameter of 52 μm. The highest recovery of cassiterite particles (<10 μm) was obtained by using 20 μm bubbles during flotation. The results indicate that the Yoon–Luttrell intermediate fluid (between the Stokes and potential flows) condition is applicable for the cassiterite electro‐flotation system, and Ec is improved by controlling the size and velocity of the hydrogen bubble, and the agglomeration of fine cassiterite particles in electro‐flotation. Additionally, it was greatly inspired to explore bubble–particle attachment in dissolved air flotation from these results.