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

Abstract

Hydrodynamic behavior of fine particles and bubbles and their influences on the particle-bubble collision efficiency (E c ) 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 (Na 2 SO 4 ) 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 E c . The Reynolds number (Re b ) was calculated to be 4.77 for hydrogen (H 2 ) 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 E c 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.

Dynamics of bubble-particle interaction in different flotation processes and applications - a review of recent studies

“…In electroflotation method, when liquid waste is exposed between cathode and anode and energy supplied, an electric field is produced between the electrodes which causes the generation of hydrogen and oxygen bubbles on cathode and anode electrode respectively. The bubble size produced by this method is in the range of 13-80 µm (Ren et al, 2019). 1.…”

“…Therefore, the calculation of the flotation rate constant flotation rate and collision probability indicates that the cassiterite particle (<10 µm) recovery is best when the size of the bubbles is approximately 20 µm. Also, by decreasing the bubble size, the flotation recovery of fine particles might also enhance (Ren et al, 2019).…”

Microbubble-Enhanced Bitumen Separation from Tailing Slurries with High Solid Contents

“…For the probability of a bitumen droplet captured by a bubble, P Cap , is defined as follows , P Cap = P normalc × P normala × P normals where P c , P a , and P s are the probability of bitumen–bubble collision, bitumen–bubble attachment, and bitumen–bubble stability, which depend on the bubble size. Tiny bubbles tend to have a high surface-to-volume ratio, thereby improving the possibility of collision between bitumen droplets and bubbles . The long residence time of tiny bubbles supplies sufficient time for attachment. − Nanobubbles on a solid surface can enhance the attachment of a larger floating bubble to the substrate .…”

“…Tiny bubbles tend to have a high surface-to-volume ratio, thereby improving the possibility of collision between bitumen droplets and bubbles. 24 The long residence time of tiny bubbles supplies sufficient time for attachment. 25−27 Nanobubbles on a solid surface can enhance the attachment of a larger floating bubble to the substrate.…”

Fine, coarse and fine-coarse particle flotation in mineral processing with a particular focus on the technological assessments

“…Fine FlotationIn this section, technological and conceptual advances in FFS are briefly introduced. Other developments such as electro-flotation (EF)[35][36][37], carrier flotation[38] and reactive oily bubble systems[39][40][41] are not discussed in this paper. In this scope, one can find invaluable information in a manuscript presented by Farokhpay et al[42].…”