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1
Content available Application of uniform test design in optimizing the flotation reagents of iron anionic reverse flotation circuit
Hou Ying, Sobhy Ahmed
Physicochemical Problems of Mineral Processing
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2022
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Vol. 58, iss. 1
37--49
EN
Most iron reserves are low in grade with quartz as the main gangue mineral, and anionic reverse flotation has become the most crucial separation method in the processing plants of iron ore. Thus, a flotation feed sample that is a mixture of low-intensity and high-gradient magnetic separators concentrates was acquired from a processing plant. The sample characterizations with X-ray diffraction (XRD), X-ray fluorescence (XRF), laser particle size analyzer, and mineral liberation analysis (MLA) confirmed that the sample consists of iron oxide as a valuable mineral and quartz as a gangue mineral with adequate liberation degree. In the anionic reverse flotation, the interaction of the flotation reagents with the constituents of the feed makes the flotation a complex system. Thus, the selection and optimization of regent dosages were performed using a uniform experimental design to estimate the optimum separation efficiency. The optimum reagent system was 1.6 kg/Mg starch depressant, 1.0 kg/Mg calcium oxide (lime) activator, and 0.8 kg/Mg TD-II anionic collector. At the optimum, 68.90% iron grade with 92.62% recovery was produced.
2
Content available Investigating the effect of lip froth washing on coal yield during flotation of a high ash South African coal
du Plessis Cherryl, Sibanda Vusumuzi, Dworzanowski Marek, Danha Gwiranai, Mamvura Tirivaviri A.
Physicochemical Problems of Mineral Processing
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2021
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Vol. 57, iss. 6
169--181
EN
An investigation was conducted to evaluate the effect of lip washing on coal flotation at Anglo American’s Goedehoop South (GHS) fine coal plant in South Africa. In the test-work, performance of cells with lip washing system were compared with baseline cells without lip washing in terms of coal yield and coal quality. Yields observed with lip washing were significantly higher than those of baseline cells. Improvements of up to 15% were recorded. The product obtained at low flotation reagent dosages (1.30–1.45 kg/t) on lip wash cells had ~16.85% ash content against ~17.65% with baseline cells, suggesting that higher yields could be achieved at superior qualities to those achieved with baseline cells. At higher reagent dosages (1.60–1.75 kg/t), coal yields further improved but quality reduced on lip wash cells. Calorific Values (CV) of coal products obtained by lip washing and baseline flotation were similar. When different coal particle size fractions were floated separately, the yield increased as particle size increased from 75 to 300 μm and then decreased from 300 to 500 μm for both baseline and lip washing flotation. Lip washing caused a marked increase in the yield for finer particles (< 300 μm) with optimum size class of between 212 – 300 μm. In addition, a much bigger increase in the yield was achievable with lip washing of lower quality coal. The ash content after lip washing of poor-quality coal were also comparable to the ash content after lip washing of good quality coal.
3
Content available Perspectives from literature on the influence of inorganic electrolytes present in plant water on flotation performance
Manono M. S., Corin K., Wiese J.
Physicochemical Problems of Mineral Processing
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2018
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Vol. 54, iss. 4
1191--1214
EN
The interaction of inorganic electrolytes with reagents in the flotation of sulphidic PGM bearing ores is not well explored. It has been shown that specific inorganic electrolytes such as Ca2+ and SO42- can affect the wettability of gangue minerals. These could also hinder the adsorption of collectors onto valuable minerals and concurrently enhance or retard froth stability. This presents a challenge as regards understanding what the overarching or controlling mechanisms of interaction between electrolytes, reagents and minerals are as well as predicting how flotation performance will be affected. This review shows that studies in literature have simplified the question of electrolyte-reagent-mineral interactions and that current approaches have not provided fundamental solutions to the challenge of water quality. It is proposed that the complexity of the flotation system requires an in-depth knowledge of the individual electrolyte-reagent-mineral interactions so as to establish whether there are any dominant or synergistic interactions. Such in-depth knowledge should enable the development of pulp chemistry control measures against water quality variations in flotation.
4
Content available Influence of controlled dispersion on rheology of swelling clay suspensions in the presence of coal flotation reagents
Zhang M., Cao Y., Chen Y., Yu W.
Physicochemical Problems of Mineral Processing
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2017
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Vol. 53, iss. 2
1148--1160
EN
Swelling clay minerals, which are innately capable of dispersing into thin flakes in water, can significantly depress coal flotation. Some researchers partially attribute depression to pulp viscosity increments. This study sought to understand the role of swelling clay minerals in fine coal flotation, by investigating the rheological behavior of bentonite suspensions under controlled and uncontrolled dispersion conditions. The effect of collector, frother, and solution pH on rheological properties of the pulp was studied. Findings showed that at a natural pH, Newtonian flow properties were displayed when bentonite was directly added into a swelling suppressed solution containing calcium ions. The same process was repeated under uncontrolled conditions, and the suspensions transferred from Newtonian to non-Newtonian flows with pseudo-plastic characteristics, depending on the solid density. Further, pH value, methyl isobutyl carbinol (MIBC) and kerosene had the potential to alter the rheological behavior of controlled and uncontrolled systems, especially pH value in the uncontrolled system.
5
Content available Froth flotation of Aljustrel sulphide complex ore
Sousa R., Futuro A., Pires C. S., Leite M. M.
Physicochemical Problems of Mineral Processing
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2017
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Vol. 53, iss. 2
758--769
EN
Froth flotation of copper-zinc-lead ores is a complex process based on similar metallurgy processing and strong interactions between chalcopyrite and sphalerite. These types of ores represent 15% of the world production and 7.5% of copper deposits all over the world. In the present study, an attempt is made to assess the feasibility of froth flotation of a complex sulphide ore, where the effect of liberation grade as well as depressant, collector and frother dosage was studied. Copper flotation is dependent on the mineral liberation grade, which is significantly related with the size distribution. It was shown that longer grinding time increased the Cu grade but decreased the copper recovery due to the presence of very fine particles. Lime and sodium metabisulphite, used as depressants, allowed to achieve a good flotation performance. It was shown that for this type of ore lower dosage of the collector should be applied. Finally, a higher frother dosage led to a greater selectivity and reduced entrainment of very fine particles, but also caused low kinetic ratio and low recovery of valuable minerals. A well-defined flotation objective was imperative for a good liberation grade and reagents dosage selection, mainly for complex sulphide ores. A useful contribute was given to a better technical understanding of flotation of a complex sulphide ore from the Moinho deposit.
6
Content available remote Ewolucja odczynników flotacyjnych do flotacji węgla kamiennego
Tora B., Kurzac M.
Przegląd Górniczy
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2011
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T. 67, nr 7-8
99--103
PL
W artykule przedstawiono podział odczynników flotacyjnych stosowanych do flotacji węgla kamiennego w zależności od ich składu chemicznego i sposobu produkcji. Przedstawiono najbardziej nowoczesne odczynniki stosowane do flotacji węgla w polskich zakładach wzbogacania – odczynniki RF oraz odczynniki Bio.
EN
The article presents the division of flotation reagents used for hard coal flotation according to their chemical composition and production method. The most modern reagents used for coal flotation in Polish preparation plants were presented – the RF reagents and Bio reagents.
7
Content available remote 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.
8
Content available remote Effect of flotation procedure and composition of reagents on yield of a difficult-to-float coal
Ahmed H. A. M., Drzymała J.
Physicochemical Problems of Mineral Processing
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2004
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Vol. 38
52-63
EN
The paper discusses two procedures of flotation of difficult-to-float oxidized coal. The first one is the normal flotation procedure which relies on wetting coal with water followed by addition of flotation reagents (dodecane, dodecyl tetraoxyethelene ether (C12E4), and 1-pentanol). The second, direct contact procedure consists of mixing pure reagents with dry coal followed by addition of water. Investigation showed that for both procedures and applied chemicals, the yield - reagent dosage curves reached a plateau. The yield plateau level was 10 g/kg for normal flotation and 20 g/kg for direct contact flotation. At the plateau dosage, normal flotation provided a maximum clean coal yield of only 70% with mixed two-reagent (C12E4 + 1-pentanol). The second procedure resulted in a maximum clean coal yield of ~94 % using the same two reagent but at a higher dosage. It was also concluded that always two-reagent systems provided better flotation yields compared to one-reagent and three-reagent systems. Thus, flotation of difficult-to-float oxidized coal can be successfully accomplished by applying the direct contact flotation procedure with appropriate reagents.
PL
W artykule przedstawiono dwie różne procedury flotacyjne stosowane we flotacji trudno flotowalnego, utlenionego węgla. Pierwsza procedura jest to tradycyjna procedura flotacyjna, która polega na zmieszaniu węgla z wodą, a następnie dodaniu odczynników (dodekan, eter dodecylotetraoksylenu C12E4 i 1-pentanolu. Druga procedura polega na bezpośrednim kontakcie mieszaniny czystych odczynników z suchem węglem, a następnie dodawaniu wody. Badania pokazały, że dla obu zastosowanych procedur, krzywe obrazujące zależność wychodu od ilości dodanego reagentu osiągnęły plateau. Wartość plateau dla normalnej flotacji wynosiła 10 g/kg i 20 g/kg dla flotacji z bezpośrednim kontaktem reagentu. Przy dodatku odczynników odpowiadającym plateau, flotacja prowadzona zgodnie z normalną procedurą dostarcza węgiel z wydajnością 70% w przypadku mieszaniny odczynników (C12E4 + 1-pentanol). Zastosowanie drugiej procedury pozwala uzyskać wydajność czystego węgla ~94% przy zastosowaniu tej samej mieszaniny odczynników, ale w większej ilości. Ustalono, że układy składające się z dwóch odczynników zapewniają lepszy wychód węgla w porównaniu do układów z jednym lub trzema odczynnikami. Flotacja trudno flotowalnego węgla może być z powodzeniem zrealizowana przy użyciu procedury bezpośredniego kontaktu odczynników z węglem.
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