Gas dispersion properties: bubble surface area flux and gas holdup

Finch, J.A.; Xiao, Jiening; Hardie, C. A.; Gómez, C.O.

doi:10.1016/s0892-6875(00)00019-4

Cited by 82 publications

(25 citation statements)

References 10 publications

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“…For this particular application measurements were taken at 15-second intervals and no smoothing was applied. Finch et al (2000) investigated the relationship between gas holdup and S b using cell operating data collected from published research, finding that the S b can be approximated from gas holdup using the following empirical relationship: These relationships are deemed accurate for typical values of gas holdup and area flux. Note that both methods require knowledge of the air rate (J g ) to the flotation cell.…”

Section: Drift Flux Analysis Methodsmentioning

confidence: 99%

The Online Determination of Bubble Surface Area Flux Using the CiDRA GH-100 Sonar Gas Holdup Meter

Amelunxen¹,

Rothman²

2009

IFAC Proceedings Volumes

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Abstract:In recent years it has been well documented that the bubble surface area flux plays a fundamental role in the performance of industrial flotation machines. Modern instrumentation is not yet capable of providing a robust direct measurement of this parameter, and the widespread industrial use of the available indirect methods have been hampered by the limitations of the available instruments and the complexity of the required calculations. This paper describes a reliable and maintenance-free method for online inference of bubble diameter and bubble surface area flux using CiDRA's GH-100 gas holdup meter. A method is presented for coding the iterative drift-flux analysis calculations for column cell bubble diameter and surface area flux using standard expert system or DCS programming language. An alternative empirical method applicable to mechanical cells is also demonstrated. Operating data from an industrial plant historian is presented.

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Section: Drift Flux Analysis Methodsmentioning

confidence: 99%

The Online Determination of Bubble Surface Area Flux Using the CiDRA GH-100 Sonar Gas Holdup Meter

Amelunxen¹,

Rothman²

2009

IFAC Proceedings Volumes

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“…The importance of the gas dispersion properties (i.e., bubble size, number of bubble, gas hold up, bubble surface area flux) on flotation have been advocated by many researchers (Ahmed and Jameson, 1985;Gorain et al, 1997;Finch et al, 2000;Yoon, 2000;López-Saucedo et al, 2012). More specifically, several studies found a close relation between bubble surface area flux and gas hold up with the flotation performance (Gorain et al, 1997;Finch et al, 2000;López-Saucedo et al, 2012).…”

Section: Dispersion Of Airmentioning

confidence: 99%

A comparative study of methyl cyclohexanemethanol and methyl isobutyl carbinol as frother for coal flotation

Park

Wang

2016

International Journal of Mineral Processing

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Methyl isobutyl carbinol (MIBC), an aliphatic alcohol, is widely used as a frothing reagent in coal flotation but it has safety concerns owing to its low flash point (approximately 40 °C). In the present work, we studied a cyclic alcohol, methyl cyclohexanemethanol (MCHM) with a high flash point (approximately 110 °C) and compared its coal flotation performance with that of MIBC. A bottom-driven mechanical flotation cell and two coking coals of distinct floatability, namely A and B, were used. Collectorless flotation tests were carried out with process water for coal A. Flotation tests with diesel as collector at 50 ppm were carried out with simulated process water (0.03 M NaCl solution) and highly saline water (0.5 M NaCl solution), respectively, for coal B. The flotation results showed that MCHM was an effective alternative to MIBC. The highly saline water produced sufficient frothing, obviating the necessity of adding MIBC or MCHM. To understand the effect of frother type and concentration and NaCl concentration on the coal flotation performance, we conducted surface tension measurement for the frother solutions, characterised the dispersion of air near bubble sparger, and measured the stabilities of froth, foam, and foam film. It was found that MCHM was more surface active and more capable of stabilizing froth and foam than MIBC.Foam film stability measured at a broad range of interface approach velocity followed a bellshaped trend and at a given NaCl concentration, the observed peak foam film stability of 15 ppm MCHM was higher than that of 15 ppm MIBC. Increasing NaCl concentration from 0.03 M to 0.5 M had the effect of stabilizing the froth and foam but destabilising the thin foam film.

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“…Os parâmetros relacionados à dispersão ar-polpa no processo de flotação incluem, principalmente, medidas de velocidade superficial de gás (Jg), do tamanho de bolhas (normalmente o diâmetro médio de Sauter, D 32 ), do holdup de gás (Ԑg) e da estimativa do fluxo superficial de bolhas (Sb) (Finch et al, 2000), definido como:…”

Section: Introductionunclassified

Avaliação Do Tamanho De Bolha Produzido Por Aeradores Tipo Tubo Poroso E Micro-Venturi Em Coluna De Flotação Minipiloto

Troian

Wiehe

Oliveira

et al. 2015

HOLOS

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RESUMOO tipo de aerador (sparger), assim como a dosagem de espumante, possuem um papel fundamental no controle do tamanho de bolha em colunas de flotação, com influências na cinética de flotação e no desempenho metalúrgico (recuperação e teor). Este trabalho apresenta estudos de avaliação online da distribuição de tamanho de bolhas geradas por um sparger tipo tubo poroso e um micro-venturi acoplados em uma coluna de flotação minipiloto automatizada. EVALUATION OF THE BUBBLE SIZE PRODUCED BY A POROUS TUBE AND A MICRO-VENTURI IN A MINI PILOT COLUMN FLOTATION ABSTRACTThe sparger type as well as the frother dosage have a fundamental role on the bubble size control with influences on the kinetic flotation and metallurgical performance (recovery and grade). This work shows online evaluation studies of the the bubble size distribution generated by a porous tube sparger and a micro-venturi coupled in an automatized mini pilot flotation column. The effects of the frother (DF250 -propylene glycol methyl ether) dosage and the air flow rate on the bubble size and holdup were evaluated. The mean bubble diameter was strongly influenced by the frother dosage for both spargers; nevertheless, the micro-venturi was more efficient than the porous tube, because it was able to disperse the air more finely and with smaller dosages of frother. The smaller mean diameters obtained, according to the applied experimental conditions, were of 1.25 mm (154.8 mg/L of DF250) for the porous tube and 0.45 mm (44.2 mg/L of DF250) for the micro-venturi.

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Gas dispersion properties: bubble surface area flux and gas holdup

Cited by 82 publications

References 10 publications

The Online Determination of Bubble Surface Area Flux Using the CiDRA GH-100 Sonar Gas Holdup Meter

The Online Determination of Bubble Surface Area Flux Using the CiDRA GH-100 Sonar Gas Holdup Meter

A comparative study of methyl cyclohexanemethanol and methyl isobutyl carbinol as frother for coal flotation

Avaliação Do Tamanho De Bolha Produzido Por Aeradores Tipo Tubo Poroso E Micro-Venturi Em Coluna De Flotação Minipiloto

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