Hydrodynamic and kinetic characterization of industrial columns in rougher circuit

Massinaei, M.; Kolahdoozan, M.; Noaparast, Mohammad; Oliazadeh, M.; Yianatos, J.; Shamsadini, R.; Yarahmadi, Mohammadreza

doi:10.1016/j.mineng.2008.10.003

Cited by 33 publications

(6 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While flotation is very much a physiochemical process, the hydrodynamics play a critical role in effecting the final overall separation (Jameson, 2012;Massinaei et al, 2009;Neethling and Cilliers, 2001). Indeed, once the hydrophobic particles have been attached to the air bubbles, flotation can be considered as a separation between relatively large low density entities called air bubbles, and relatively fine high density particles referred to as gangue (George et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…Figure 2 shows the typical operating regime of conventional cells, with the wash water flux plotted versus the gas flux. For the relatively large bubble sizes used in the present study, with the diameter ranging from 0.5 to 3 mm, the gas flux, j g , is typically limited to between 0.6 and 1.5 cm/s, producing bubble surface area fluxes between 30 and 60 m 2 /m 2 .s (Fuerstenau et al, 2007;Massinaei et al, 2009). While larger values can be used, approaching perhaps 2.0 cm/s, there is an increased tendency for the interface between the bubbly zone and the froth to disappear, leading to difficulties in process control of the interface elevation, loss of bubbles to tailings, and very high liquid entrainment rates containing slimes reporting with the froth to the product.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fluidized bed desliming in fine particle flotation – Part II: Flotation of a model feed

Galvin¹,

Dickinson²

2014

Chemical Engineering Science

View full text Add to dashboard Cite

This is the second in a series of papers concerned with the performance of a novel technology, the Reflux Flotation Cell. Part I examined the system hydrodynamics, commencing with a gas-liquid system and examination of the fluidization boundary condition. The desliming, or potential to reject entrained fine gangue particles from the product overflow, was investigated by introducing hydrophilic particles. In Part II, a model feed consisting of hydrophobic coal particles and hydrophilic silica was introduced. The separation of these two components was investigated across an extreme range in the applied gas and wash water fluxes, well beyond the usual limits of conventional flotation. The Reflux Flotation Cell challenges conventional flotation cell design and operation in three ways. Firstly, the upper free-surface of the flotation cell is enclosed by a fluidized bed distributor in order to fluidize the system in a downwards configuration, counter-current to the direction of the rising air bubbles. Secondly, a system of inclined channels is located below the vertical section of the cell, providing a foundation for increasing bubble-liquid segregation rates. Thirdly, the system is operated with a bubbly zone, hence in the absence of a froth zone. This combination of conditions provides for the establishment of a high volume fraction of bubbles in the bubbly zone, of high permeability, ideal for promoting enhanced counter-current washing of the rising bubbles, and hence high quality desliming. The

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fluidized bed desliming in fine particle flotation – Part II: Flotation of a model feed

Galvin¹,

Dickinson²

2014

Chemical Engineering Science

View full text Add to dashboard Cite

show abstract

“…10 are remarkable given the liquid split to the overflow was [18], although fluxes as high as 80 s -1 have been reported [19]. Massinaei et al [20] reported a higher range of 30 to 60 s -1 for industrial flotation columns deployed in rougher circuits. Whereas, in laboratory flotation columns the bubble surface flux typically lies between 12 and 120 s -1 [21].…”

Section: Bubble Surface Area Fluxmentioning

confidence: 95%

Maximizing bubble segregation at high liquid fluxes

Jiang

Dickinson

Galvin

2014

Advanced Powder Technology

View full text Add to dashboard Cite

This study is concerned with a common class of problem involving two phase separation of a dispersed gas flow from a continuous liquid flow under extreme processing conditions. Relatively fine spherical bubbles of order 500 μm were generated in the presence of a surfactant under a high shear rate within a rectangular, multi-channelled, cuboidal downcomer. Liquid fluxes, as high as 176 cm/s through each channel of the downcomer, sheared bubbles from a sintered surface mounted flush to the channel wall before disengaging the downcomer flow into a vertical vessel. Both high feed fluxes, up to 15 cm/s, and high gas fluxes, up to 5.5 cm/s, ensured a high gas holdup beneath the downcomer and the hindered rising of the bubbles. Enhanced bubble-liquid segregation was achieved using an arrangement of parallel inclined channels incorporated below the main vertical chamber. This novel device, referred to as the Reflux Flotation Cell, prevented the entrainment of bubbles to the underflow, and significantly reduced the liquid flux to overflow, even in the absence of a conventional froth zone. Extreme upward bubble surface fluxes of up to 600 s-1 were achieved, while counter-current downward liquid fluxes reached 14.4 cm/s, arguably four times the bubble terminal rise velocity. Hence successful phase separation was achieved while operating well beyond the so-called flooding condition arising from extreme levels of gas and feed fluxes. This hydrodynamic arrangement should find application in increasing surfactant extraction rates in foam fractionation and ion flotation, gas absorption, and even particulate flotation.

show abstract

“…These studies reported a linear relationship between gas holdup and recovery. Linear relationships between gas holdup and the flotation rate constant have also been identified, highlighting its effect on flotation kinetics (Hernandez, Gomez, and Finch, 2003;Massinaei et al, 2009). On the other hand, other researchers have suggested that gas holdup could be used for control purposes in column flotation (Dobby, Amelunxen, and Finch, 1985).…”

mentioning

confidence: 87%

Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD)

Mwandawande

Akdogan

Bradshaw

et al. 2019

J. S. Afr. Inst. Min. Metall.

View full text Add to dashboard Cite

Hydrodynamic and kinetic characterization of industrial columns in rougher circuit

Cited by 33 publications

References 38 publications

Fluidized bed desliming in fine particle flotation – Part II: Flotation of a model feed

Fluidized bed desliming in fine particle flotation – Part II: Flotation of a model feed

Maximizing bubble segregation at high liquid fluxes

Prediction of gas holdup in a column flotation cell using computational fluid dynamics (CFD)

Contact Info

Product

Resources

About