Frother Type Research Articles

Effects of micro- and nano-bubbles on the flotation separation of unburned carbon from coal fly ash

ABSTRACT Nanobubble technology has found extensive use in enhancing the flotation efficiency of various minerals. The utilization of nanobubbles in flotation encompasses bulk nanobubbles, surface nanobubbles, and microbubbles; however, a comprehensive comparison of their respective roles is lacking. Furthermore, there is a dearth of studies on employing nanobubble systems in the flotation of coal fly ash. The coal fly ash characters were initially studied to reveal its ultrafine size (d50: 24.80 μm) and porous structure that includes a multitude of hydrophilic functional groups. These attributes contribute to the inadequate hydrophobicity of unburned carbon within the ash. Subsequently, the effects of different collector types, frother types, and air flow rates on the efficiency of carbon removal using conventional flotation methods were examined. Comparative analysis showed that conventional flotation using diesel oil outperformed that which employed kerosene as the collector. Additionally, higher carbon removal efficiency was achieved using MIBC, with a longer carbon chain length, as the frother, as opposed to sec-Octyl alcohol. Furthermore, a direct relationship between air flow rate and coal fly ash flotation performance was observed – higher air flow rates corresponded to improved flotation outcomes. Finally, a comparison between conventional flotation and nanobubble-assisted flotation (utilizing bulk nanobubbles, surface nanobubbles, and micro-nanobubbles) was conducted. Remarkably, micro-nanobubble flotation yielded the most promising results, with the lowest loss-on-ignition in flotation tailings (3.15%) and the highest removal efficiency of unburned carbon (85.01%). These findings satisfied the loss-on-ignition requirements of Grade I fly ash standards.

Enhancing bubble bize prediction in flotation processes: a drift flux model accounting for frother type

This communication presents a methodology, based on a modified drift flux model, to determine bubble size distribution in column flotation. The modified drift flux model incorporates a surfactant-type parameter. This parameter considers the impact of surfactant on bubble hydrodynamics. The methodology aims to improve the accuracy of bubble size distribution prediction, which presents deviation depending on surfactant type (i.e. polyglycolic based or alcoholic base). Many authors have proposed different mathematical improvements to reduce de experimental data deviations in the presence of different surfactants. However, from 1988 to 2022, the determination coefficient, or the quality of the adjustments, from the proposed mathematical models is, at the most, 92% (relative error). The proposed methodology improves the quality of the adjustments to 98.6, adding a single parameter for groups of surfactants. This methodology incorporates a single parameter in the terminal velocity calculation that can compensate for the impact of surfactant type in bubble hydrodynamic (bubble skin friction or drag coefficient, bubble wake, bubble shape, bubble rigidity). This parameter is a function of the gas holdup calculated from gas velocity measured and the bubble size distribution calculated (deviated) from gas holdup and gas velocity measured. The methodology is validated with reported experimental results and proposed modifications from various authors. The confidence interval (2 σ) is reduced from 0.11mm to 0.05mm in the case of (Yianatos, Banisi, Ostadrahimi). In the case of the recently reported experimental results from Maldonado and Gomez, the confidence interval is reduced from 0.31 mm to 0.09 mm. These results improve bubble size estimation based on drift flux in column flotation, contributing to a better understanding of surfactant impact on bubble swarm hydrodynamics.

Correlation of Flotation Recoveries and Bubble–Particle Attachment Time for Dodecyl Ammonium Hydrochloride/Frother/Quartz Flotation System

Recent studies in the flotation of fine particles have necessitated new techniques and analyses for developing various strategies. Particularly, the improvements in flotation chemistry including the selection of the type of frother, collector, and other reagents have become very significant. In this study, the effect of different commercial polypropylene glycol frothers (PPG200, 400, and 600) in the presence of dodecylammonium hydrochloride (DAH) was investigated for their contribution to flotation recoveries and bubble–particle attachment time values of fine quartz minerals. Zeta potential measurements with DAH were also carried out as a function of pH and reagent concentration to justify the effect of collector usage alone on the charge of particles. A linear increase in flotation recoveries against collector concentration, e.g., 7.4% recovery at 1 × 10−5 mol/L DAH and 65.4% recovery at 1 × 10−3 mol/L DAH, was obtained. In this context, the contribution of frothers was particularly important in that a recovery of 15.91% in the absence of the frother and a modest increase to 19.70% was obtained upon the addition of PPG600 at its critical coalescence concentration (CCC) of 3 ppm. Finally, a strong correlation was found between the bubble–particle attachment time and flotation recovery as a function of collector concentration (lowest attachment time vs. highest flotation recovery). The latter correlation is very promising because bubble attachment time leads to various micro-mechanisms in flotation including bubble film thinning, bubble rupture, and induction time, and consequently, frother efficiency in the presence and absence of a collector. As a result, the experimental findings were gathered to achieve a consistent base for further fundamental studies on the application of the synergistic effect of frothers and collectors in the flotation of fine particles.

Effects of Sec-Octanol and Terpineol on Froth Properties and Flotation Selectivity Index for Microcrystalline Graphite

Microcrystalline graphite is a valuable non-metallic mineral that can be separated by flotation, a physico-chemical processing method that uses air bubbles to capture mineral particles. The size and stability of the bubbles, which depend on the type and amount of frother added, affect the flotation performance and the recovery of water from the froth layer. However, the effects of different types of frother on the froth properties and water recovery of microcrystalline graphite flotation are not well understood. In this study, two common frothers, sec-octanol and terpineol, were compared in terms of their effects on the bubble size, froth layer height, water recovery, and flotation selectivity index (SI) of microcrystalline graphite flotation. It was found that sec-octanol produced smaller bubbles than terpineol, but also a slightly lower froth layer height. The water recovery was higher with sec-octanol than with terpineol. The SI values were similar for both frothers, indicating comparable flotation performance. This study revealed the differences between sec-octanol and terpineol in terms of their effects on the froth properties and water recovery of microcrystalline graphite flotation. These findings can help optimize the choice and dosage of frother for this important mineral processing method.

The Role of Stereological Assumptions in Bubble Size Estimations and Their Implications for Assessing Critical Coalescence Concentrations

Accurate measurement of bubble size is critical for assessing flotation performance. However, the 3D nature of bubbles, in contrast to the 2D nature of photographs obtained using a bubble viewer apparatus, may lead to distortions related to stereological assumptions. This study aimed to quantify the impact of these stereological effects on bubble size measurements in frother characterisations. Our results showed that different assumptions regarding bubble shape and volume resulted in variations in bubble size calculations of up to 10%. Furthermore, these stereological effects were propagated to the calculation of the critical coalescence concentration, leading to uncertainties of up to 14% depending on the type of frother. These findings emphasise the importance of considering stereological effects and selecting an appropriate calculation method when measuring bubble size for flotation and reagent assessments.

Effect of the Molecular Weight of Carboxymethyl Cellulose on the Flotation of Chlorite.

The present study aimed to investigate the influence mechanism of carboxymethyl cellulose (CMC) on the flotation of fine chlorite. To this end, a series of flotation tests, sedimentation tests, and microscope analyses were conducted. Flotation tests revealed an inverse relationship between particle size and the recovery of chlorite, indicating that finer particles exhibited higher recovery rates. Moreover, it was observed that the recovery of fine chlorite was significantly associated with the water recovery (proportion of water entering the floated product to the weight of water in the initial flotation suspension) and a variety of frother types. Based on these findings, it can be inferred that froth entrainment may constitute a crucial component of the recovery mechanism underlying fine chlorite. Thus, reducing froth entrainment (the phenomenon of hydrophilic minerals entering floated products through foam water) is the key to depress chlorite flotation. Flotation tests indicate that fine chlorite recovered into froth products can be depressed effectively by CMC with a high molecular weight. The results of sedimentation tests and microscope analyses in the presence of CMC prove that CMC with a high molecular weight generates flocculation on fine chlorite particles while that with a low molecular weight does not. It is suggested that the depression of chlorite flotation may be attributed to the reduction in the entrainment resulting from the flocculation induced by CMC.

Frothing Performance of Frother-Collector Mixtures as Determined by Dynamic Foam Analyzer and Its Implications in Flotation

In recent years, most of the studies have been adapted to determine the optimum conditions for the flotation of very fine minerals. In this context, besides parameters such as particle size, morphology, and pH, the effects of frother type and its concentration present a very significant role in optimizing the flotation conditions. Therefore, the effects of froth stability during flotation can be considered one of the most important issues. Considering that knowledge in mind, in this study, the foamability and froth decay rate of six frothers (PPG200, PPG400, PPG600, BTEG, BTPG, and BDPG) having different molecular weights but similar polyglycol structures were investigated. In addition, methyl isobutyl carbinol (MIBC) which is a well-known frother type in the industry was also used as a reference. Additionally, a series of tests were also performed in the presence of collectors (Dodecylamine hydrochloride, DAH, and sodium oleate, NaOL) + frother mixtures to mimic the flotation conditions. The results of these tests indicated that the bubble size became finer at even low concentrations of PPG600 and PPG400 frothers. Following that, a significant decrease in bubble size was also found for the collector + frother mixtures system regardless of the concentration of the frothers.

Research on the flotation efficiency of alcohol/ether alcohol frothers for common collectors: Insight of molecular dynamics simulations

To explore the influence of alcohol/ether alcohol frother on the flotation efficiency of common collector dodecane, the molecular dynamics simulation method was used to study the influence of the type and concentration of frother on the microscopic interaction mechanism between the collector and the coal surface, which was verified by the flotation test. The research shows that in a single reagent system, weak hydrogen bond was the main way of interaction between polar groups of two frothers and oxygen-containing functional groups on coal surface The hydrogen bond effect in ether alcohol system was stronger than that in 2-ctanol system, and the dispersion force between the carbon chain of the reagent and the coal surface was stronger when ether alcohol was adsorbed on the coal surface. In the mixed reagent system, both kinds of frothers can promote dodecane spreading on the coal surface for adsorption, and the synergism of ether alcohol was better. The dodecane can promote the adsorption of polar groups of ether alcohol on the coal surface while the ether alcohol formed weak hydrogen bonds with the coal surface, thus increasing the hydrophobic modification of the polar groups on the coal surface. Excessive frother concentration would reduce the hydrophobicity of the coal surface, which was accompanied by poor adsorption of the reagent. The flotation verification test results were consistent with the regularity obtained from molecular dynamics simulation. The research provides theoretical guidance for the development of flotation reagents from the micro level.

The Correlation between Macroscopic Image and Object Properties with Bubble Size in Flotation

This paper studies the correlation between different macroscopic features of image regions and object properties with the Sauter diameter (D32) of bubble size in flotation. Bubbles were sampled from the collection zone of a two-dimensional flotation cell using a McGill Bubble Size Analyzer, and photographed bubbles were processed using image analysis. The Sauter mean diameters were obtained under different experimental conditions using a semiautomated methodology, in which non-identifiable bubbles were manually characterized to estimate the bubble size distribution. For the same processed images, different image properties from their binary representation were studied in terms of their correlation with D32. The median and variability of the shadow percentage, aspect ratio, power spectral density, perimeter, equivalent diameters, solidity, and circularity, among other image or object properties, were studied. These properties were then related to the measured D32 values, from which four predictors were chosen to obtain a multivariable model that adequately described the Sauter diameter. After removing abnormal gas dispersion conditions, the multivariable linear model was able to represent D32 values (99 datasets) for superficial gas rates in the range of 0.4–2.5 cm/s, for four types of frothers and surfactant concentrations ranging from 0 to 32 ppm. The model was tested with 72 independent datasets, showing the generalizability of the results. Thus, the approach proved to be applicable at the laboratory scale for D32 = 1.3–6.7 mm.

Effects of surfactants combination on iron ore flotation

Frothing plays a crucial role in mineral froth flotation. However, the use of only frothing reagents is not common in the reverse cationic flotation of iron ores because etheramines, the commonly applied collectors, also play this role. In alkaline aqueous solution, etheramines dissociate as ionic (collector) and molecular (frother) species, simplifying the chemical system. Despite practical and functional, this practice is limited once etheramines are less efficient to form foam and more expensive than conventional frothers, e.g., alcohols and polyglycols. This study investigated the comparative effects between non-ionic frothers and cationic etheramines on foam properties in two phase systems, and the combination of these etheramines and frothers in three phase systems in comparison to single etheramines and their mixtures. The results show that the frothers DF1012 and MIBC produce smaller bubbles and more stable foams than the single ethermonoamine or etherdiamine. The partial replacement of etheramines by non-ionic frothers reduced the silica content in the concentrate, improving flotation selectivity at specific mixture condition of collector substitution for each frother type, despite decreasing the iron metallurgical recovery. The substitution of etherdiamine by polyglycol at 10 % w/w produced the best result in the cationic/non-ionic surfactants comparison, although the mixture of etherdiamine and ethermonoamine yielded the highest selectivity, because of the synergistic effect on froth stability and mineral surface adsorption.

Reducing the Presence of Clusters in Bubble Size Measurements for Gas Dispersion Characterizations

This short communication evaluates a new strategy to sample bubbles in gas dispersion characterizations. Bubble size is measured in a bidimensional flotation cell using the McGill bubble size analyzer under different types of frothers, frother concentrations and superficial gas rates. The original design of this bubble viewer is modified, changing the deflecting system to photograph only a fraction of the bubbles entering the device. As a result, the new design increases the ability to successfully identify bubbles by a maximum of 20% using an automated algorithm. This increase is caused by a reduction in the formation of clusters in the visual field. The improvement, which is a function of the operating conditions, is most significant in the transition from ellipsoidal/ellipsoidal–turbulent regimes (no frother or low frother concentrations) to conditions with an over-agglomeration of bubbles in the visual field (high superficial gas rates and high frother concentrations). A comparison of the bubble size parameters obtained from the original and proposed deflecting systems shows that the new design does not distort the estimated bubble size distributions. To complement the research findings, alternative sampling designs, using new or existing segmentation algorithms, are then proposed to improve gas dispersion characterizations at different scales.

Influence of operating parameters on nanobubble-assisted flotation of graphite

Although many studies have focused on processing of lithium-ion batteries (LiBs), there is a considerable lack of information concerning the application of nanobubbles (NBs) in their floatabilities. To cover this knowledge gap, the current study aims at exploring the effect of key operating parameters on flotation of two types of graphite i.e., lithium-ion batteries’ graphite (LIBG) and natural ore graphite (NOG) in the presence of NBs. For this purpose, the effects of NB solution ratio, impeller speed, air flow rate, as well as dosage and type of collector and frother on recovery of graphite were investigated in the presence and absence of NBs. Three frothers (i.e., methyl isobutyl carbinol (MIBC), terpenic oil, and 2-octanol), and three collectors (i.e., n-dodecane, kerosene and diesel oil) were employed for comparison purposes using an XFG micro-flotation unit. The hydrodynamic cavitation and dynamic light scattering (DLS) methods were utilized to produce and characterize ultrafine bubbles, respectively. The DLS results confirmed the bubble size distribution ranged between 180 and 400 nm. The maximum recovery of graphite particles (ca. 98%) was obtained for the LIBG particles, at an impeller speed of 1000 rpm, air flow rate of 0.4 L/min, using 2-octanol as a frother, and n-dodecane as a collector. Further, the influential order of the frothers was found as 2-octanol > terpenic oil > MIBC. According to the flotation results, the presence of NBs increased the LIBG flotation recovery and its kinetic rate by 15% and 33%, respectively.

Investigation of the induction time and recovery in a flotation column: A kinetic analysis

ABSTRACT The recovery of coal particles in a flotation column was investigated to determine its dependency on the type of frother, particle size, and gas and feed velocities. The kinetics of the cumulative recovery was established. The induction time and flotation rate constant were analyzed based on the recovery, incorporating the stability, attachment, and collision efficiencies of the particles with the bubbles. An inverse relationship between recovery and induction time was observed. Recovery of the particles was noticed to increase with superficial air velocity and frother dose, while it decreased with increasing particle size and feed circulation velocity. The induction time decreases with increasing superficial air velocity and frother dose but increases with increasing particle size and feed circulation velocity. Low induction time and high recovery were observed in the cationic frother. Small particles with low induction time can be captured with ease and have excellent selectivity. A generalized correlation for the induction time was proposed based on experiments under different operating conditions. The presented research will be beneficial in terms of increasing the transport efficiency of flotation systems.

Bubble Size in a Flotation Column with Oscillatory Air Supply in the Presence of Frothers

ABSTRACT Oscillatory air supply has demonstrated advantages over conventional steady air supply in froth flotation with diffused aeration, but the interaction between oscillatory air supply and frother in determining bubble size remained unclear. In the present work, we measured the size of air bubbles in a laboratory scale flotation column with common frothers such as MIBC, Dowfroth 250, and polypropylene glycol with an average molecular weight of 425 (PPG 425), with conventional steady air supply and with oscillatory air supply. The oscillatory air supply was converted from steady airflow using a fast-switching solenoid valve with the main operating parameters being switching frequency and on/off time ratio. In the absence of frother, the Sauter mean bubble diameter (d 32) remained the same with oscillatory air supply replacing steady air supply, but the d 32 decreased by 13–35% in the presence of frother. It was also found that the critical coalescence concentration (CCC) of each frother were reduced by 11–69% using oscillatory air supply to replace steady air supply. The degree of reduction in d 32 or the CCC appeared to be dependent on the oscillatory airflow condition (i.e., frequency and on/off time ratio) and frother type. The present work also confirms the recent findings by others that the CCC is not solely a material property of frothers.

The interaction of a bubble with a particle-laden interface in frother solutions

Spherical glass particles of varying degrees of hydrophobicity were studied for their monolayer formation and compression behavior on an aqueous subphase containing different frothers at various concentrations. A Langmuir trough was modified to mimic the coalescence between two bubbles by forming a single bubble just below the particle layer. The change in the layer following the film failure between the bubble and the particle-laden particles was captured visually. The movement of particles and the behavior of the ripple formed during the coalescence were also investigated to characterize the interface oscillation under the effect of frothers. The results showed that the surface pressure isotherms of both hydrophobic particles were more sensitive to PPG 425 than 1-pentanol and MIBC and that a small increment in the concentration of PPG 425 in the subphase led to a significant increase in surface pressure. Both 1-pentanol and MIBC behaved like a dispersant in terms of interaction with the particle monolayer. The coalescence of bubbles caused the release of excess energy which was dissipated through the expansion and contraction of the newly formed interface. The speed of the waves (ripples) was found to reduce in the presence of the particle monolayer. While frother types did not have a significant effect on the speed of wave spreading, the increase in the frother concentration reduced the wave speed compared to water.

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

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.

Foam stability of flotation frothers under dynamic and static conditions

The objective of this paper is to provide a detailed understanding of the relationship between frother type and foam stability under dynamic and static conditions. The dynamic foam stability for eighteen non-ionic frothers from different frother families was assessed using foaminess, which quantified the ratio of foam height to the gas superficial velocity. For all tested frothers, the foaminess increased as the concentration was increased. The static foam stability was assessed by measuring the half-life and the decay rate of the foams at different superficial gas velocities and concentrations. The foam stability results showed that for aliphatic alcohols, the greater the number of hydrocarbon groups, the more stable the foam was under dynamic and static conditions. For polypropylene glycols, increasing the number of propylene oxide groups increased foaminess and half-life, however, a further increase in the number of propylene oxide groups (m > 7) led to a decrease in foaminess. There was not a clear relationship between the number of propylene oxide groups and the maximum foam half-life. Interestingly, the foam decay rate coefficient increased by increasing the number of propylene oxide groups. For propylene glycol methyl ethers, foaminess, foam half-life and decay rate coefficient increased with an increase in the number of propylene oxide groups.

The effect of reagent type on generating bulk sub-micron (nano) bubbles and flotation kinetics of coarse-sized quartz particles

Dodecylamine (DDA) is a commonly used collector in the froth flotation of quartz particles. The present work for the first time studies the effect of DDA nanobubbles (NBs) on the flotation of coarse particles (−425 + 300 μm, −300 + 212 μm and − 212 + 106 μm). For this purpose, 50 mg/l DDA was employed as a primary material for producing bulk NBs via hydrodynamic cavitation technique to be used in the flotation kinetics tests. For comparative purposes, pine oil (PO), Methyl Isobutyl Carbinol (MIBC) and polypropylene glycol (A65) with a concentration of 22.4 mg/l were utilized for generating NBs and also as a frother. According to the results, generated NBs categorized based on the stability and mean bubble size as DDA > PO > MIBC>A65. The flotation rate constants (k) and ultimate recoveries (Rmax) obtained in the presence of the DDA-NBs were substantially improved compared to the corresponding values given for the frother types NBs. That was mainly related to the chemical functionality of the agent together with its extended stability. The experimental results showed a Rmax of 97.5% using the DDA-NBs in the condition of without any frother; however, the highest recovery using common air bubbles (CBs) was obtained 90.8% by the PO. Additionally, the influential order of the three frothers and the DDA on flotation rate constant was shown as DDA > PO > MIBC>A65 for each fraction size. Finally, the results indicated that the k and Rmax of coarse particles were improved by 22% and 21% in the presence of the DDA-NBs.

A Method to Predict Water Recovery Rate in the Collection and Froth Zone of Flotation Systems

This paper describes a method to predict water recovery rate into and through the foam in a bubble column operating under different gas rates, froth depths, and frother types and concentrations. Three frothers were considered: Metil Isobutil Carbinol (MIBC), a proprietary blend of alcohols, aldehydes, and esters commercialized under the name PINNACLE® 9891, and a PGE-based Dow Froth 1012 (DF1012). The water rate entering into the froth (foam) layer from the bubbly (collection) zone was estimated as the water rate overflowing the column when operating at a thin stable foam layer, i.e., 0.5 cm. It was observed that the rate at which water entered into the froth phase could be modelled as a unique linear function of the gas holdup below the froth, regardless of the frother chemistry. This is a fundamental result not previously found in the literature that also facilitates the calculation of the froth zone water recovery for deeper froths. The water recovery in the froth was found to be an inverse logarithmic function of the average liquid residence time in the froth. Although the same trend was observed for the three frothers tested, they did not converge into a single function, which suggests that frother chemistry plays a role in determining froth structure and then needs to be incorporated when modeling water transport in the froth. Finally, the water overflow rate calculated as the product of the water rate into the froth and froth water recovery predicted the actual measured values fairly well. The water transport model here proposed provides a simple representation of the interactions between collection and froth zone and its relation to easily measure operating variables.

Correlation of the entrainment factor with frother types and their mixtures in the column flotation

In flotation, entrainment is a mechanical mass transfer process and it is based on the changes depending on the establishment of linear relationship between water and solid recovery. The present paper presents results obtained in investigating the effect of frother mixture concentrations on the entrainment of fine particles’ during the column flotation. The aim of the present study was to investigate more specifically the relationship between the recovery via entrainment of a range of different hydrophilic calcite particles. For this, to determine entrainment factor of fine particle was used a mixture of artificial ore (celestite/calcite; 1:1). The results showed that the frother mixtures had important effect on the grade and recovery, superficial air rate, gas hold-up and entrainment of fine gangue particles. Entrainment factors for frother mixtures were compared in flotation column. Kirjaveinen (1989) model was used for explaining the specific entrainment factor (Pi) of hydrophilic particles and it has been observed that this model supports the results of this study. This, together with the increased recovery, resulted in higher celestite grades of valuable mineral recovered to the concentrate when using the frother mixtures (Pine Oil+MIBC).