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1

Effect of air profiling and frother concentration on a flotation bank performance

Maldonado Miguel, Ramos Ignacio, Pinto Alonso, Gomez Cesar O.

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 186274

EN

The impact of air distribution on the metallurgical performance of a flotation bank operating with a mineral slurry having a moderate and high frother concentration is assessed. A flotation bank of two and three 5L Denver cells was implemented, and air flow was distributed down the bank as increasing and decreasing profiles. It was observed that when operating the bank configurations with a moderate frother concentration (10 ppm DF 400) the increasing profile provided the highest Cu enrichment ratio at the expense of a slight reduction in Cu recovery. This increase in selectivity was mainly due to a significant reduction in the water recovery and mass-pull in the first cell. When the bank operated with a high frother concentration, i.e., well beyond the CCC, a significant increase in water recovery was observed, producing a significant loss in selectivity that could not be compensated by air profiling.

2

Beneficiation and upgrading of Jordanian oil shale

Gougazeh Mousa Hasen

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 3

art. no. 147092

EN

Evaluation possibility of a low-quality Jordanian oil shale from Sultani, central Jordan as an alternative clean fuel by flotation technique was investigated. Oil shale sample was characterized with mineralogical and chemical analysis. X-ray fluorescence spectrometer, X-ray diffraction and Fourier transform infrared spectroscopy showed that calcite is the dominant mineral followed by quartz mineral. Other minerals such as apatite and gypsum were detected. Thermogravimetric analysis revealed that mass loss is due to organic matter decomposition at 280–600°C and carbonate decomposition at 650–850°C Fourier transform infrared analysis showed the main organic groups. The effects of collector and frother doses, pulp concentration and pulp pH on the flotation performance were investigated. The kerosene and MIBC were used as collecting and frothing agents, respectively. The optimal flotation performance occurred for a collector dosage of 1000g/t, a frother dosage of 600g/t, a pulp concentration of 20g/L, a pulp pH of 4.

3

Critical coalescence concentration (CCC) of various surfactants used as flotation reagents in mineral

Szyszka Danuta

Mining Science

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2022

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Vol. 29

221--232

EN

The role of flotation frothing agents in the flotation process is generally known, especially due to the size of bubbles and the stability of the foam formed. In recent years, a number of new reagents have been introduced. The purpose of this article is to present a comprehensive database containing the characteristics of surfactant families discussed using the parameter of the so called the Critical Coalescence Concentration (CCC). This article presents an analysis of the experimental data set by the author and the experimental data published in the literature.

4

Which is preferable for coal cleaning by flotation: pine oil or MgCl2?

Gamal Rawya, El-Midany Ayman A., El-Mofty Salah E., Edress Nader A. A.

Inżynieria Mineralna

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2022

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no. 1

129--134

EN

Coal flotation using inorganic salts receives special attention. It utilizes coal hydrophobicity to float coal without adding collectors. Although different salts were tested, chloride salts are the most promising ones. However, the stabilization of froth layer using the salts only is dubious. erefore, in this study, the flotation of coal was tested using either magnesium chloride or pine oil as a frother to see if there is a difference in coal flotation between these reagents in terms of ash removal and coal recovery in the float fraction. Additionally, both magnesium salt and pine oil were added together to clarify their interactive effect using statistical design. e results proved that the presence of either reagent (i.e., pine oil or MgCl.) is significant in reducing the ash content and increasing coal recovery. Using the MgCl. only reduced the ash to less than 4.3% with a coal recovery up to 28% while adding 1.0 kg/t pine oil along with 4 kg/t MgCl. enhanced the reduction of ash to less than 3% with a coal recovery of up to 80% at pH 2.

PL

Szczególną uwagę poświęca się flotacji węgla przy użyciu soli nieorganicznych. Wykorzystuje hydrofobowość węgla do flotacji węgla bez dodawania kolektorów. Chociaż testowano rożne sole, najbardziej obiecujące są sole chlorkowe. Jednak stabilizacja warstwy piany wyłącznie za pomocą soli jest wątpliwa. Dlatego w tym badaniu flotacja węgla była testowana przy użyciu chlorku magnezu lub oleju sosnowego jako spieniacza, aby sprawdzić, czy istnieje różnica we flotacji węgla między tymi odczynnikami pod względem usuwania popiołu i odzysku węgla we frakcji flotacyjnej. Dodatkowo dodano razem zarówno sol magnezową, jak i olejek sosnowy, aby wyjaśnić ich interaktywny efekt przy użyciu projektu statystycznego. Wyniki dowiodły, że obecność każdego z odczynników (tj. oleju sosnowego lub MgCl.) ma znaczący wpływ na zmniejszenie zawartości popiołu i zwiększenie odzysku węgla. Zastosowanie MgCl. tylko zmniejszyło popiół do mniej niż 4,3% z odzyskiem węgla do 28%, podczas gdy dodanie 1,0 kg/t oleju sosnowego wraz z 4 kg/t MgCl. zwiększyło redukcję popiołu do mniej niż 3% przy odzysku węgla do 80% przy pH 2.

5

Surface roughness in bubble attachment and flotation of highly hydrophobic solids in presence of frother – experiment and simulations

Kosior D., Kowalczuk P. B., Zawala J.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 1

63--72

EN

In this paper, the kinetic of the three-phase contact (TPC) formation and the flotation recovery of highly hydrophobic solids with different surface roughness were studied in pure water and aqueous solutions of n-octanol. The surface roughness varied between 1 to 100 μm. It was found that there was a strong influence of surface roughness on both kinetics of TPC formation and flotation. The time of three phase contact formation and flotation rate were much faster for rough surfaces in both water and aqueous solutions of frother. Irrespective of the surface roughness, at above a certain frother dose, the attachment time increased and the flotation rate decreased. It was related to the presence of air at the hydrophobic solid surfaces. The mechanism of this prolongation of the time of TPC formation at the solid surfaces with different roughness due to the frother overdosage was discussed, and the experimental data were confirmed by numerical simulations.

6

Influence of bubble approach velocity on coalescence in α-terpineol and n-octanol solutions

Orvalho S., Stikova L., Stanovsky P., Zednikova M., Vejrazka J., Ruzicka M.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 1

73--80

EN

This work presents results of an experimental study of the influence of the approach velocity on the coalescence of bubbles in aqueous solutions of n-octanol and α-terpineol. Experiments were performed in a coalescence cell allowing synchronized growth of a pair of bubbles in a liquid. High speed camera imaging was used to characterize the growth of bubbles and their interaction in aqueous solution of different concentrations of surfactants. The coalescence efficiency and contact time till coalescence were determined as a function of the approach velocity between bubbles and the concentration of surfactant. It was found that, for both surfactants, when the approach velocity between bubbles was higher than ~1 mm/s, the coalescence efficiency was independent of the approach velocity and that the contact time was independent of the concentration of surfactant. Below ~1 mm/s, both the coalescence efficiency and the contact time were the function of surfactant concentration. For the higher velocities, the suppression of coalescence occurred at concentrations similar to the concentration of immobilization of the surface of free rising bubbles.

7

Evaluation of flotation reagents by normalization procedures

Drzymala J.

Physicochemical Problems of Mineral Processing

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2018

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Vol. 54, iss. 1

182--192

EN

Froth flotation is a dynamic multiphase process in which particulate matter is separated with the help of chemical reagents by gas bubbles immersed in water. The original flotation results are usually presented in the form of kinetic curves relating recovered particulate matter mass (yield ) or mass of a selected component (recovery ), both shortly denoted as y, versus process time t at different concentrations c (g/dm3) of the applied reagents. The kinetic curves can be modified into three: incentive (maximum yield or recovery ymax vs c), limits (ymax vs kinetic constant k or specific rate) and half-life of flotation (t1/2 vs c) curves. The original and modified curves can be normalized by taking into account either an external parameter such as molecular mass (MW), critical coalesce concentration (CCC), critical concentration at the minimum bubble velocity (CMV), dynamic foaming index (DFI), and many other parameters or an internal parameter such as time, concentration needed to achieve certain yield, recovery (y) or kinetic constant. Normalization leads to new flotation curves and provides additional useful information about flotation performance. Normalization can be fully effective, partial or ineffective. Normalization of the original flotation kinetic curves usually is ineffective. Also, normalization of the incentive curve with external parameters such as frother molecular mass, which changes reagent concentration from c (g/dm3) to C (mol/dm3), is also ineffective. Partially effective are normalizations with other external parameters such as CCC and CMV, usually within the same class of regents, for instance alcohols. Only DFI seems to be a universal external normalization parameter for flotation results because it provides fully effective normalization and thus predicts the flotation results. Limited data on DFI restrict a full verification of this hypothesis. Normalization of the modified flotation curves with internal parameters such as k50 (value of 1st order kinetic constant when recovery or yield is 50% after a given flotation time), Ct1/2 (frother concentration in mol/dm3 at which the flotation half-life has an arbitrarily chosen value) and cy75 (frother concentration in g/dm3 at which recovery or yield is 75% after a given flotation time) is a good base for practical classification of flotation reagents.

8

Influence of frother type and dose on collectorless flotation of copper-bearing shale in a flotation column

Kowalczuk P. B., Mroczko D., Drzymala J.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 2

547--558

EN

In this paper the influence of nonionic (methyl isobutyl carbinol, tri(ethylene glycol) monobutyl ether) and cationic (hexylamine) frothers on flotation of copper-bearing shale in a flotation column was investigated. It was shown that naturally hydrophobic shale did not float in pure water but it floated in the presence of the investigated frothers. The real contact angle of shale, measured by the sessile drop method, was equal to about 40°, while its effective contact angle was zero when shale was floated in a flotation column in pure water. The investigated surfactants increased the effective hydrophobicity of shale from zero to 16±1, 22±1 and 33±2° for coarse, medium and fine particles, respectively. The calculations of the effective contact angle were based on a simplified probabilistic model of flotation.

9

In search of an efficient frother for pre-flotation of carbonaceous shale from the kupferschiefer stratiform copper ore

Kowalczuk P. B., Buluc B., Sahbaz O., Drzymala J.

Physicochemical Problems of Mineral Processing

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2014

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Vol. 50, iss. 2

835--840

EN

This papers shows that frothers such as aliphatic alcohols (CnH2n+1OH), poly(propylene glycols) (HO(C3H6O)mH), poly(propylene glycol) alkyl ethers (CnH2n+1O(C3H6O)mH) and poly(ethylene glycol) alkyl ethers (CnH2n+1O(C2H4O)mH), can be used for collectorless flotation of a sample of carbonaceous copper shale manually separated from the Kupferschiefer stratiform copper ore. It was shown that flotation is influenced by the type and dose of frothers. The best flotation results were obtained with tri(propylene glycol) butyl ether C4P3, tri(propylene glycol) propyl ether C3P3 and tri(propylene glycol) P3. For these frothers, the yield vs. frother dose relationship was in the form of convex curves indicating that carbonaceous copper shale can float at relatively low dosages of the frother. It means that these frothers can be used for pre-flotation of carbonaceous matter from the investigated copper ore. Other frothers formed concave yield–frother dose relationships and were less effective.

10

Zeta potential of Polish copper-bearing shale in the absence and presence of flotation frothers

Peng M., Ratajczak T., Drzymała J.

Mining Science

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2014

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Vol. 21

57--63

EN

In this paper, zeta potential as a function of pH of copper-bearing shale, which is mined in Poland by KGHM, was investigated. The measurements were conducted in water and aqueous solutions of selected flotation frothers. It was established that for investigated copper-bearing shale, after dispersion in water, the isoelectric point (IEP) occurs at pH=3.5. Addition of frothers decreased the IEP on the pH scale and the IEP for butanol was 1.93, for MIBC 2.90 and for eicosaethylene glycol hexadecyl ether (C16E20) 2.76. In the case of introducing frothers changed, the zeta potential becomes less negative. An empirical equation, having two adjustable parameters, was used in the paper to approximate the course of the zeta potential-pH curve. The equation showed a very good approximation of the zeta potential of the investigated shale either in water or frother aqueous solutions.

11

When and how α-terpineol and n-octanol can inhibit the bubble attachment to hydrophobic surfaces

Kosior D., Zawala J., Malysa K.

Physicochemical Problems of Mineral Processing

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2011

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Vol. 47

169-182

EN

Kinetics of the three phase contact (TPC) formation and phenomena occurring during collision of the rising bubble with Teflon plates of different surface roughness were studied in distilled water, α-terpineol and n-octanol solutions, using a high-speed camera of frequency 1040 Hz. Influence of solution concentration and surface roughness on time of the TPC formation and the time of drainage of the film formed between the colliding bubble and Teflon surface was determined. The surface roughness of the Teflon plates was varied within range 1- 100 µm. It was found that at small α-terpineol and n-octanol concentrations the time of the TPC formation was shortened in respect to distilled water. However, at their high concentrations the time of TPC formation was again longer and magnitude of this effect depended on the surface roughness. For example for Teflon surface of roughness 40-60 µm the time of TPC formation was even 20-30 ms longer. The data obtained indicate that this effect is related to presence of air at the hydrophobic solid surfaces. The mechanism of this prolongation of the time of TPC formation due to the frother overdosage is proposed.

PL

Badano kinetykę powstawania kontaktu trójfazowego podczas kolizji pęcherzyka w wodzie i w roztworach α-terpineolu i n-oktanolu z płytkami Teflonowymi o różnej szorstkości powierzchniowej, przy użyciu szybkiej kamery o częstotliwości 1040Hz. Określono wpływ stężenia substancji powierzchniowo aktywnych i szorstkości powierzchniowej na czas powstawania kontaktu trójfazowego i czas wyciekania cienkiego filmu ciekłego powstającego pomiędzy pęcherzykiem i powierzchnią Teflonu. Szorstkość powierzchniowa Teflonu była modyfikowana w zakresie 1-100 µm. Wykazano, że w roztworach o małych stężeniach α-terpineolu i n-oktanolu czas powstawania kontaktu trójfazowego uległ skróceniu w porównaniu do wartości zmierzonych w czystej wodzie. Jednakże, przy wysokich stężeniach badanych spieniaczy następowało znowu wydłużenie czasu powstawania kontaktu trójfazowego, a wielkość tego efektu była uzależniona od szorstkości powierzchni płytki teflonowej. Przykładowo dla płytki teflonowej o szorstkości powierzchniowej 40-60 µm czas powstawania kontaktu trójfazowego uległ wydłużeniu nawet o 20-30 ms. Wyniki uzyskane wskazują, że efekt ten jest związany z obecnością powietrza na hydrofobowej powierzchni ciała stałego. W pracy przedstawiono mechanizm wydłużenia czasu powstawania kontaktu trójfazowego przy nadmiernej dawce spieniacza.

12

The influence of flotation reagents on sulfur-oxidizing bacteria Acidithiobacillus thiooxidans

Pacholewska M., Cwalina B., Steindor K.

Physicochemical Problems of Mineral Processing

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2008

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Vol. 42

37-46

EN

It has been demonstrated that various flotation reagents influence, in a different manner, the metabolic activity of the sulfur-oxidizing bacteria Acidithiobacillus thiooxidans (strain C1 being isolated from the Fe-Zn tailings water) growing in the Waksman/Joffe (W/J) liquid culture medium that contains thiosulfate as a sole energy source for bacteria growth. The ethyl- and amyl xanthates as well as the frothing reagent stimulated, to a limited extent, the tested C1-bacteria metabolic activity. The very well documented bacterially-influenced acidification of the W/J solution supplemented with the ethylor the amyl xanthates suggests the possibility of these substances effective acid-degradation in the post-industrial environments rich in various flotation reagents, mainly xanthates. Both the activator containing the carbamate ethyl-derivative and the modifier composed of Cu(II)-ions caused a complete inactivation of the A. thiooxidans C1-metabolism. It is suggested that some unexpected chemical reactions may proceed in the tested systems, as a result of interactions between the culture medium components, flotation reagents, their decomposition products, and also the products of bacterial metabolism.

13

Entrainment-flotation activity of quartz in the presence of selected frothers

Szyszka D., Glapiak E., Drzymała J.

Physicochemical Problems of Mineral Processing

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2008

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Vol. 42

85-90

EN

Flotation is used for separating mineral particles. Flotation is accompanied by entrainment of hydrophilic particles which is an undesirable process. Flotation and entrainment depend on numerous parameters, among them the presence and concentration of frother. This work was devoted to investigate the borderline between entrainment and flotation of quartz particles in the so-called monobubble Hallimond tube in the presence of varying concentrations of selected frothers. The following frothers were used: octyl alcohol, isoamyl alcohol, α-terpineol, tricosene-ethyleneglycol 1-hexadecanoic ether and corflot (a mixture of butyl ethers of di-, tri- and tetraethylene glycols). Entrainment of the quartz particles in pure water has also been conducted as a reference test. The work has confirmed that entrainment depends on particle size. It also confirmed the role of the frother used. Two of the frothers: tricosene-ethylene glycol 1-hexadecanoic ether and octyl alcohol have exhibited both frothing and collecting properties.

PL

Flotacja jest stosowana do rozdziału drobnych ziarn mineralnych. Każdej flotacji towarzyszy zjawisko niepożądane pogarszające jakość końcowego produktu, którym jest wyniesienie mechaniczne ziarn (flotacja mechaniczna). Na flotacje właściwą i mechaniczną wpływa wiele parametrów, które nie zostały całkowicie poznane. W pracy badano flotację mechaniczną ziarn kwarcu w monopęcherzykowym flotowniku Hallimonda w zależności od rodzaju stosowanych spieniaczy. W testach zastosowano takie spieniacze jak: alkohol oktylowy, alkohol izoamylowy, .-terpineol, eter jednoheksadekanowy trikozanoetylenowy oraz corflot (mieszanina eterów butylowych glikoli di, tri i tetraetylenowych). Przeprowadzono także badania dla czystej wody, które obrano jako punkt odniesienia w stosunku do pozostałych wyników testów. W pracy stwierdzono, że eter jednoheksadekanowy trikozanoetylenowy (C16E23) oraz alkohol oktylowy wykazały nie tylko właściwości spieniające, ale również zbierające.

14

Wyniesienie mechaniczne ziaren poddanych flotacji wyłącznie spieniaczem

Szyszka D.

Górnictwo i Geoinżynieria

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2007

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R. 31, z. 4

81-86

PL

W artykule zaproponowano metodę oceny zdolności spierniaczy flotacyjnych do wyniesienia mechanicznego ziaren podczas przepuszczania powietrza przez zawiesinę ziarn hydrofilnych. Polega ona na pomiarze wyniesienia mechanicznego ziarn w komorze flotacyjnej w zależności od czasu flotacji i stężenia spieniacza. W efekcie badań uzyskuje się charakterystyczną liczbę opisującą maksymalne wyniesienie mechaniczne ziaren po długich czasach flotacji i przy podwyższonych stężeniach spieniacza. Dla metyloizobutylocarbinolu (MIBC) ta charakterystyczna liczba wynosi 32%.

EN

The paper describes a method for assessment of ability of flotation frothers for mechanical entrainment during bubbling of air through suspension of hydrophilic particles. The method consists of measurement of particle recovery in laboratory flotation cell at various flotation times and frother concentrations. The result of the measurement is a characteristic number, which describes mechanical flotation of mineral particles after a long flotation time at such frother concentration at which the entrainment does not increases any further. The characteristic number for methylisobutylcarbinol (MIBC) characterizing the recovery of quartz in the investigated flotation machine was equal to 32%.

15

Influence of frother concentration on bubble dimensions and rising velocities

Krzan M., Małysa K.

Physicochemical Problems of Mineral Processing

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2002

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Vol. 36

65-76

EN

Influence of á-terpineol concentration on local and terminal velocities of bubbles, their dimensions and shapes was studied within solution concentration range 1ź 10-5 to 1ź 10-3 mole/dm3. Bubble behaviour was monitored using CCD camera with stroboscopic illumination and high speed camera Speedcam 512. Variations of the bubble local velocity and its deformation were determined as a function of distance from the capillary orifice and analysed in terms of adsorption coverage at interface of the departing bubble. Two kinds of dependencies of the bubbles local velocities on distance were observed. At low á-terpineol concentrations the profiles of the bubble local velocity showed maximum at distances ca. 5-20 mm from the capillary orifice, prior to reaching a value of the terminal velocity. No maximum was observed at distilled water and á-terpineol concentrations c>0.0001 mole/dm3. It was found that á-terpineol adsorption coverage of ca. 6% was the minimum needed to assure the full immobilization of the bubble surface and the lowering of bubble terminal velocity by ca. 60% as result of it.

PL

Badano wpływ stężenia .-terpineolu na prędkości lokalne i graniczne baniek, ich rozmiar oraz deformacje kształtu. Wyznaczono profile prędkości lokalnych baniek i kształtów w funkcji odległości od kapilary (.=0.07mm) na której wytwarzano bańki przy pomocy precyzyjnej pompy strzykawkowej. Pomiary wykonano dla roztworów .-terpineolu w zakresie stężeń od 1*10-5 do 1*10-3 mole/dm3. Ruch baniek był monitorowany za pomocą dwóch kamer, zbierających informacje o położeniu i kształcie z częstotliwościami 100 i 1182 Hz. Stwierdzono występowanie kilku różnych etapów w ruchu baniek wypływających w roztworach .-terpineolu. Bańki bezpośrednio po oderwaniu od kapilary przyspieszają, po czym w zależności od badanego stężenia ich prędkości osiągają stałą wartość graniczną (woda i roztwory .-terpineolu o dużym stężeniu) lub też obserwowane jest przejście przez maksimum i stopniowe spowolnienie prędkości do innej, często znacznie mniejszej niż maksymalna, wartości prędkości granicznej (stężenia mniejsze od 0.0001 mol/dm3). W przypadkach niskich stężeni równocześnie ze zmianami profili prędkości lokalnych są obserwowane dynamiczne zmiany kształtu baniek. Wartości prędkości granicznych unoszących się baniek spadają wraz ze wzrostem stężenia .- terpineolu od 34.8š0.03 cm/s w wodzie destylowanej do 15.4š0.03 cm/s w roztworze .-terpineolu o stężeniu 0.001 mol/dm3 . Stwierdzono, że stopień pokrycia adsorpcyjnego na powierzchni bańki jest czynnikiem decydującym o profilach prędkości lokalnych baniek, jak i ich deformacjach. Największe zmiany występują w obszarze niskich stężeń .-terpineolu, przy których stopień pokrycia adsorpcyjnego zmienia się w zakresie 0-10%. Pokrycie adsorpcyjne .-terpineolem .=6% jest minimalnym pokryciem niezbędnym dla całkowitego unieruchomienia powierzchni bańki w wyniku którego graniczna prędkość baniek ulega znacznemu zmniejszeniu.

16

Factorial design for column flotation of phosphate wastes.

Abdel-Khalek N.A.

Physicochemical Problems of Mineral Processing

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2000

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Vol. 34

35-45

EN

A factorial design was used to study effects, and their interactions, of the main parameters affecting column efficiency to recover phosphates from their wastes. Three-phase experiments were performed using a mixture of fatty acid and fuel oil as a collector for phosphate while pine oil was used as a frother. Meanwhile 2-phase experiments were conducted to correlate the results of 3-phase experiments with that of bubble diameter and air holdup. The result shown that application of statistical design reveals very interesting information about the interaction between the studied parameters. For example it is shown that the interaction (X1X2) between superficial gas velocity (X1) and frother concentration (X2) has a beneficial effect on grade but aversely affect recovery.

PL

Metoda planowania czynnikowego została zastosowana do opisania wpływu i współzależności między podstawowymi parametrami procesu flotacji kolumnowej zastosowanej do odzysku fosforytu z odpadów fosforytowych. Doświadczenia flotacyjne zostały przeprowadzone z wykorzystaniem kwasu olejowego i oleju napędowego jako kolektorów oraz oleju sosnowego jako spieniacza. Planowanie typu 23 zostało przeprowadzone w celu znalezienia korelacji między wynikami eksperymentu a średnicą pęcherzyków powietrza i parametrami procesu. Dla przykładu, zostało pokazane, że X1X2, czyli między prędkością przepływu gazu (X1) a stężeniem spieniacza (X2) na korzystny wpływ na wychód a niekorzystny wpływ na uzysk procesu flotacji.