Recovery of Fine and Ultrafine Mineral Particles by Electroflotation – A Review

Tadesse, Bogale; Albijanic, Boris; Makuei, Fidele; Browner, Richard

doi:10.1080/08827508.2018.1497627

Cited by 32 publications

(30 citation statements)

References 69 publications

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“…Bubble formation can also be accomplished by decreasing the slurry pressure by aspiration as in vacuum flotation, resulting from expansion of the pre‐existing gas nuclei . Bubble formation by electrolysis of water (ie, electro‐flotation), proposed in 1904, is also regarded as an alternative flotation technique for wastewater treatment . An emerging trend is to integrate the useful features of these aeration methods to develop the next generation of flotation technologies.…”

Section: Aeration Of Ore Slurriesmentioning

confidence: 99%

Role of mineral flotation technology in improving bitumen extraction from mined Athabasca oil sands—II. Flotation hydrodynamics of water‐based oil sand extraction

Zhou¹,

HaiHong²,

Chow³

et al. 2019

Can J Chem Eng

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Bitumen flotation hydrodynamics in water‐based oil sand extraction is critically reviewed by comparing aeration of oil sand slurries with mineral flotation. The role of the two‐stage particle‐bubble attachment model in flotation is emphasized as a means to accelerate bitumen flotation recovery. It involves the generation of micro/nanobubbles and their frosting on hydrophobic bitumen droplets, followed by their attachment to a flotation‐size bubble via its coalescence with the nanobubbles frosted on the bitumen. Nanobubble generation by hydrodynamic cavitation demonstrates that the size of nanobubbles can be reduced, and the number of nanobubbles increased by fast liquid flow, intensified agitation, high dissolved gas content and surfactant concentration. The mechanism of pre‐existing gas nuclei in enhancing nanobubble generation by cavitation is utilized to produce a large volume of stabilized nanobubbles for practical flotation, by continuously recirculating the stream through a gas saturation tank or a cavitation tube. The aeration of oil sand slurries in hydrotransport pipelines is analyzed based on its similarity to dissolved air flotation. Bitumen extraction recovery increased significantly with the presence of nanobubbles in the system. The role of improved flotation hydrodynamics in bitumen recovery is briefly discussed in terms of the Suncor operation using flotation columns to process oil sand middling streams. Future research should be directed at understanding bitumen flotation kinetics, optimizing size ranges of nanobubbles for maximized flotation recovery, minimizing wearing of cavitation tubes in industrial operations, and intensifying the role of in‐situ nanobubble nucleation on hydrophobic particles/bitumen droplets in flotation, especially for bitumen extraction from underperforming oil sands.

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Section: Aeration Of Ore Slurriesmentioning

confidence: 99%

Role of mineral flotation technology in improving bitumen extraction from mined Athabasca oil sands—II. Flotation hydrodynamics of water‐based oil sand extraction

Zhou¹,

HaiHong²,

Chow³

et al. 2019

Can J Chem Eng

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“…Traditional froth flotation cannot separate mineral particles finer than approximately 10 μm efficiently and selectively because fine particles tend to reduce the probability of collision between particles and bubbles. Therefore, it is of great value to study the collision efficiency between fine particles and bubbles . The contact efficiency of solid particles with air bubbles is related to different physicochemical properties of minerals.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, alternative flotation methodologies, such as dissolved air flotation and electro‐flotation, have been developed and investigated . Electro‐flotation, which produces small hydrogen and oxygen bubbles with a mean diameter from 17 to 105 μm on the basis of the conditions of electrolysis to collect fine particles, is deemed to be a promising method in fine particle flotation …”

Section: Introductionmentioning

confidence: 99%

“…The reason may be that hydrogen and oxygen bubbles, occurring during electrolysis, are more active than air bubbles generated during dispersed air flotation because oxygen and hydrogen can adsorb on mineral surfaces, causing various electrochemical reactions particularly on surfaces of sulfide minerals . And the adsorption of hydrogen bubbles on some oxidized mineral can make its surfaces more hydrophobic.…”

Section: Introductionmentioning

confidence: 99%

“…It has been reported that the diameter of detached bubbles increases when the wire (electrode) diameter increases . What is more, the velocity of bubble in electro‐flotation system was influenced by many elements including current density, Faradaic charge, and electrode rotation speed . Wang et al observed that the bubble–particle detachment process was stochastic in a turbulent field, and they identified different detachment mechanisms.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Ren

Zeng

Nguyen

et al. 2019

Asia-Pacific J Chem Eng

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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.

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Real‐Time Monitoring of Hydrogen Production by Water Electrolysis Using a Tapered Polarization‐Maintaining Optical Fiber Mach–Zehnder Interferometer

et al. 2022

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Gas microbubbles easily cover surface active sites of the solid electrodes in most gas evolution reactions, hindering the transfer of mass and energy and declining the reaction efficiency. However, online monitoring of gas bubbles’ behaviors on the surface of solid electrodes accurately in real time remains challenging. Herein, a tapered polarization‐maintaining fiber Mach–Zehnder interferometer for in situ monitoring of H2 bubbles detachment in water electrolysis is reported. In the experiment, the H2 bubble released from the platinum microelectrode can be detected by recording the variation of transmitted optical power in the optical fiber. By comparing it with the electrochemical measurement and the charge‐coupled device imaging, the measurement accuracy can be regarded as near 100%, and the time resolution is determined to be ≈ms. It is found that the size of the detached bubbles on the microelectrode surface is positively correlated with the electrolysis voltage. The increasing electrolysis time causes a long detachment time. Three different charged surfactants are all proved to accelerate the H2 detachment. This method is adapted to study gas bubble behaviors in various complex gas‐involving reaction systems, even for the invisible gas bubbles in a dark environment.

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Recovery of Fine and Ultrafine Mineral Particles by Electroflotation – A Review

Cited by 32 publications

References 69 publications

Role of mineral flotation technology in improving bitumen extraction from mined Athabasca oil sands—II. Flotation hydrodynamics of water‐based oil sand extraction

Role of mineral flotation technology in improving bitumen extraction from mined Athabasca oil sands—II. Flotation hydrodynamics of water‐based oil sand extraction

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

Real‐Time Monitoring of Hydrogen Production by Water Electrolysis Using a Tapered Polarization‐Maintaining Optical Fiber Mach–Zehnder Interferometer

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