Entrainment of Gangue Minerals in Froth Flotation: Mechanisms, Models, Controlling Factors, and Abatement Techniques—a Review

Wang, Chao; Sun, Chunbao; Liu, Qingxia

doi:10.1007/s42461-020-00295-6

Cited by 11 publications

(5 citation statements)

References 104 publications

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“…The modeling results presented in Table 5 are very similar for entrainment at the −38 µm and +38-75 µm size fractions and not consistent with the fact that coarser fractions are expected to yield lower entrainment [19][20][21][22]. In addition, none of the models make use of the solid concentration, which does not correspond to the discussion provided above, wherein the solid concentration has been proven to play an important role in flotation kinetics and entrainment.…”

Section: Entrainmentmentioning

confidence: 78%

“…Entrainment in a flotation process is the mechanism by which, independently from hydrophobicity, mineral particles are unselectively transported from the pulp zone to the flotation froth zone and then to the concentrate by water hydrodynamics processes [17][18][19][20][21][22][23]. Entrainment decreases the value of quartz recovery in the case of reverse iron flotation due to fine iron minerals transporting to the froth product, while it decreases the grade of iron in the case of direct iron ore flotation due to fine silicate minerals transporting to the concentrate.…”

Section: Designation Equation Kinetic Parametersmentioning

confidence: 99%

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Effect of Solid Concentration and Particle Size on the Flotation Kinetics and Entrainment of Quartz and Hematite

Murhula

Hashan

Otsuki

2022

Metals

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Despite the importance of solid concentration in froth flotation, its effect on flotation kinetics and entrainment has rarely been studied. In this study, the flotation kinetics and entrainment in quartz and hematite single-mineral flotation systems as a function of the solid concentration and particle size were investigated using dodecylamine acetate as a collector. Kinetics modeling showed that the Gamma distribution achieved the best agreement with the experimental data, whereas the Classical and Klimpel models poorly fit the data (e.g., RMSE). The flotation rate constants (k) of both quartz and hematite at a higher solid concentration showed a concave shape, with the inflexion point at the middle-size range, whereas this trend altered at lower solid concentrations. Overall, quartz exhibited higher equilibrium recoveries (R∞) than hematite, which indicates its better overall rate constants. The degree of water recovery in both the quartz and hematite systems was higher at higher solid concentrations, but the hematite system exhibited higher water R∞ than the quartz system, meaning that the entrainment of gangue could be higher in direct hematite flotation than the reverse one. Therefore, a higher solid concentration is associated with better overall quartz recovery and can reduce hematite loss by entrainment during reverse flotation. An inverse relationship was identified between the solid concentration and particle size in terms of the ratio of water recovery to the concentrate. In the reverse flotation of iron ore, refraining from achieving equilibrium recovery could help limit entrainment, but this was not necessarily the case in direct flotation. No entrainment model or method other than the Warren and Ross model approximated the overall trends of flotation at the finest size range (−38 µm). However, extending the Warren method to polynomial distribution led to an improved fit with the experimental results. In addition to the solid concentration, particle density and size were revealed to be key to developing new entrainment models. Finally, after the fast recovery period (true flotation) was over, the slow recoveries were mainly driven by the slow-floating water fraction.

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Section: Entrainmentmentioning

confidence: 78%

Section: Designation Equation Kinetic Parametersmentioning

confidence: 99%

Effect of Solid Concentration and Particle Size on the Flotation Kinetics and Entrainment of Quartz and Hematite

Murhula

Hashan

Otsuki

2022

Metals

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“…This outcome can be explained by two primary factors. First, the primary mechanisms governing flotation of hydrophilic microfine-grained minerals involve foam entrainment and attachment to the surface of valuable minerals [37]. Given that nanobubbles are significantly smaller than mineral particles, they hinder the adhesion of hydrophilic minerals to valuable mineral surfaces when coming into contact with them [29].…”

Section: Analysis Of the Mechanism Of Nanobubbles To Reduce The Recov...mentioning

confidence: 99%

“…Entrainment can be conceptualized as a two-step process involving the movement of particles from the upper pulp to the bubble and then from the bubble to the concentrate. Entrainment is inevitable for both hydrophobic and hydrophilic minerals and is one of the critical factors affecting the concentrate grade [37]. It is important to note that nanobubbles possess relatively weak flotation capabilities; when nanobubbles alone are present, they do not achieve effective mineral recovery [21,30].…”

Section: Analysis Of the Mechanism Of Nanobubbles To Reduce The Recov...mentioning

confidence: 99%

Effect of Nanobubbles on the Flotation Behavior of Microfine-Grained Serpentine

Lu,

Xu,

Luo

et al. 2023

Minerals

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At present, scholars mainly study the relationship between nanobubbles and useful minerals, often ignoring the influence of bubbles on fine gangue minerals. When selecting nickel sulfide ore, scholars often faced with mudded and irrepressible serpentine, which seriously affects the quality of the concentrate. This mudded serpentine mineral often enters foam products with bubbles. In this study, the role of nanobubbles in the flotation behavior of hydrophilic serpentine was examined. Nanobubbles were successfully prepared via ultrasonic cavitation, with sizes ranging from 50 to 250 nm. The size and number of bubbles produced at 1 min and 2 min of sonication were significantly better than those of the prolonged test group, and it was found that longer sonication time did not produce better results. The stability of the nanobubbles produced via ultrasound was studied, and it was found that the nanobubbles were stable, with no change in size and only a slight decrease in number as the resting time increased. Nanobubbles were introduced into serpentine flotation, we found that the presence of nanobubbles significantly reduced the flotation recovery of serpentine. The presence of nanobubbles reduced the froth entrainment rate of microfine-grained serpentine, which in turn reduced its flotation rate. In the depressant group trials, it was found that the nanobubbles also reduced the amount of depressant. In short, the presence of nanobubbles can prevent the floating of fine hydrophilic gangues during flotation.

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“…It is generally accepted that flotation performs optimally when separating particles between 15 µm and 150 µm in size [27]. Ultrafine particles of <10 µm, however, are more vulnerable to being mechanically entrained in the froth, due to fluid drag forces becoming dominant over the hydrophobic/hydrophilic interactions for particles of small mass [28,29]. In the context of black mass flotation, this phenomenon increases the non-selective recovery of hydrophilic cathode particles in the froth and lowers the grade of the graphite concentrate, even if the active particles are fully liberated.…”

Section: Introductionmentioning

confidence: 99%

A Study on the Effect of Particle Size on Li-Ion Battery Recycling via Flotation and Perspectives on Selective Flocculation

Rinne¹,

Araya²,

Serna-Guerrero³

2023

Batteries

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The recycling of active materials from Li-ion batteries (LIBs) via froth flotation has gained interest recently. To date, recycled graphite has not been pure enough for direct reuse in LIB manufacturing. The present work studied the effect of particle sizes on the grade of recycled graphite. Furthermore, selective flocculation is proposed as a novel approach to control particle sizes and thus improve graphite grade by preventing the entrainment of cathode components. Zeta potential and particle size measurements were performed to find an optimal pH for electrically selective flocculation and to study the interaction of flocculants, respectively. Batch flotation experiments were performed to investigate the effect of particle size on the purity of the recovered graphite. Results suggested that, in the absence of ultrafine fine particles, battery-grade graphite of 99.4% purity could be recovered. In the presence of ultrafine particles, a grade of 98.2% was observed. Flocculating the ultrafine feed increased the grade to 98.4%, although a drop in recovery was observed. By applying a dispersant in addition to a flocculant, the recovery could be increased while maintaining a 98.4% grade. Branched flocculants provided improved selectivity over linear flocculants. The results suggest that particle size needs to be controlled for battery-grade graphite to be recovered.

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Entrainment of Gangue Minerals in Froth Flotation: Mechanisms, Models, Controlling Factors, and Abatement Techniques—a Review

Cited by 11 publications

References 104 publications

Effect of Solid Concentration and Particle Size on the Flotation Kinetics and Entrainment of Quartz and Hematite

Effect of Solid Concentration and Particle Size on the Flotation Kinetics and Entrainment of Quartz and Hematite

Effect of Nanobubbles on the Flotation Behavior of Microfine-Grained Serpentine

A Study on the Effect of Particle Size on Li-Ion Battery Recycling via Flotation and Perspectives on Selective Flocculation

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