Adsorption Kinetics of Various Frothers on Rising Bubbles of Different Sizes under Flotation Conditions

Abstract

This paper studies the effect of the type and concentration of selected frothers, the gas flowrate, and the pore size of the porous frit on the bubble sizes (Sauter mean diameter, SMD) of bubbling flow produced in a micro-flotation cell, and the determination of bubble size distribution (BSD) in the presence of the frothers. The commercial frothers polypropylene glycols (PPG 200, 400, and 600), tri propylene glycol (BTPG), triethylene glycol (BTEG), dipropylene glycol (BDPG), and Methyl Isobutyl Carbinol (MIBC) were used in the present investigation. The frother concentration varied from 1 to 1000 ppm. The flow rate varied in the range of 25 to 100 cm3/min. The pore sizes of the frit were selected as 10–16 μm, 16–40 μm, and 40–100 μm. Each frother exhibited its own unique ability in preventing coalescence of the bubbles in the order of BTEG < BDPG < PPG 200 < MIBC < BTPG < PPG 400 < PPG 600. The factorial experiments established that the type of the frother and its concentration have a major effect on the size of the bubbles. The bubbles decreased twice their size when the frother concentration was increased from 1 ppm to 1000 ppm. The pore size of the frit is a significant factor as well. The size of the bubbles can be reduced from about 10% to about 40% by decreasing the pores from 40–100 μm to 10–16 μm but the level of this decrease depends on the type of the frother. The increase of the flowrate from 25 cm3/min to 100 cm3/min produced bubbles smaller by 25% to 50% for the case of BTEG, BDPG, PPG 200, MIBC, BTPG, while a minimum of the bubble sizes was reached for the case of PPG 400 and PPG 600, beyond which the bubbles enlarged their size. The BSD in the presence of PPG 600 varied around 0.3 mm, whereas BTEG gave a wider BSD which indicated that the type of frother affected the bubble production. Our analysis shows that the first group of frothers adsorbs instantly on the bubbles, once they leave the porous frit, thus reaching equilibrium. PPG 400 and PPG 600 adsorb significantly slower on the bubbles, possibly not reaching equilibrium during their resident time.

From Microbubbles to Nanobubbles: Effect on Flotation

“…The effect of the type and concentration of selected frothers, the gas flow rate, and the pore size of the porous frit on the bubble sizes produced was published [31]. Similarly, measurements of bubble size distributions were examined (by changing surfactant dosage, solid percentage, air velocity, and particle size) as well as establishing the relationships between bubble size distribution properties and flotation performances in a bubble column [32].…”

Investigation of the Frother Effect in Two and Three Phases Systems on Bubble Size, Surface tension, Recovery and Grade in Chalcopyrite Flotation

“…The bubble sizes from these photos were measured using the Image J analysis measurement program Approximately 30 bubbles were measured for each condition. For these experiments, the experimental setup and procedure defined in a recent publication were used in the literature (Guven et al, 2020;Batjargal et al, 2021).…”

“…Aliphatic alcohol frothers are used as mixtures of different carbon lengths and as a mixture of hydrocarbon oils, Bulatovic (2007). It is known from the literature that the efficiency of flotation depends on the use of a frother to control the bubble size (Finch et al, 2006;Bulatovic, 2007;Gupta et al, 2007;Khoshdast and Sam, 2011;Karakashev et al, 2020Karakashev et al, 2021;Batjargal et al, 2021). The effect of frothers on bubble size has been investigated in detail (Cho and Laskowski, 2002a;Laskowski, 2003).…”

“…The effect of frothers on bubble size has been investigated in detail (Cho and Laskowski, 2002a;Laskowski, 2003). In addition, for each type of ore treated by flotation, there is likely to be an optimum bubble size distribution that will produce the optimum recovery at the highest flotation rate (Dobby and Finch, 1991;Batjargal et al, 2021). Thus, controlling the generation of bubbles to achieve an optimum size range in a flotation cell is highly attractive since it may improve the recovery of the flotation process by optimizing the collection of particles, i.e., via better size-by-size flotation (Grau and Laskowski, 2006).…”

Bubbling properties of frothers and collectors mix system

“…In this manner, the flotation kinetics rate and the particle-bubble collision frequency strongly depend on bubble size and bubble size distribution (BSD). Therefore, the properties of frothers such as frother type and concentration have the strongest influence on the gas dispersion properties besides the effects of other parameters on bubble size (Batjargal et al, 2021). The effect of some commercial frothers on bubble size has been investigated recently (Grau et al, 2005;Szyszka, 2008).…”