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1

Kinetic modelling of flotation column and Jameson cell in coal

Karaca Sevgi, Ucar Ali, Sahbaz Oktay

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 5

art. no. 152848

EN

Physical enrichment technologies can be used worldwide in various coal washing plants to enrich up to 500 μm particle size. Conversely, coals smaller than this are discarded as waste, causing storage and environmental issues. In this regard, studies on coal below 500 μm in Turkey have recently acquired attraction. The Jameson flotation cell and flotation column, which have many uses worldwide but are not used throughout the plant in Turkey, were used to investigate the separation possibilities of coals below 500 μm. In the study, the flotation column and Jameson cell performances for three different particle sizes (-500+300, -300+212 and -212+106 μm) were compared. For the first time, both machines operated in a negative bias condition. In addition, the flotation kinetics of the machines were modelled with some critical operating parameters. Models illustrating the main and multiple effects of the parameters were developed using the data derived from the experimental results, and the models were statistically significant at the 95% confidence level. In the experiments performed with both flotation machines, the flotation rate increases with the decrease in particle size in general. According to the results, the velocity increase in the Jameson cell was 0.0050-0.0075 min-1 compared to the flotation column in the experiments performed in the size range of -500+300 μm, and the flotation rate constant increased approximately twice. In the size range of -212+106 μm, the difference became larger, and the flotation rate of the Jameson cell increased up to six times with a difference of 0.0450-0.0500 min-1.

2

Effects of frothers and particle size on the flotation kinetics of the Jameson Cell

Şahbaz Oktay, Demir Muhammet Kubilay

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 5

829--838

EN

Determination of the flotation kinetic is crucial for optimization, simulation, and plant design for flotation processes. Even though there are many studies carried out to clarify the kinetic properties of the conventional flotation cells, there is not enough detailed study about the Jameson cell which is used more than 300 plants but no application in Turkey yet. One of the most important parameters affects the kinetic of flotation is a frother. The effects of common frothers on the kinetic of Jameson cell can be crucial due to the possible further application of the cell in European and Turkish flotation industries. The present study was performed out to reveal the kinetic properties of the Jameson cell by using both pure quartz and coal particles. Besides, the effects of three different types of frothers on the kinetic of the Jameson cell were investigated for various particles sizes. According to the results, aliphatic alcohol type frother (MIBC) provided higher recovery for fine particles, while polypropylene glycol type frother (AF65) gave a better ability to float medium and coarse size particles. Additionally, the results show that the Jameson cell was four times faster than the mechanical cell for medium size while the ratio was three times for coarse particles. Lastly AF65 can be used for flotation of coarse particles in the Jameson cell while MIBC can be preferred for fines.

3

Effects of air-to-pulp ratio and bias factor on flotation of complex cu-zn sulphide ore in the Jameson cell

Gursoy Y. H., Oteyaka B.

Physicochemical Problems of Mineral Processing

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2015

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Vol. 51, iss. 2

511--519

EN

The air-to-pulp ratio and bias factor are important operating parameters in the Jameson flotation cell. These parameters have significant effect on micro-events taking place between particles and bubbles in flotation, and hence on flotation performance. In this study, the possibilities of obtaining a Cu-Zn rich bulk concentrate from complex sulphide ore from the Cayeli region (Turkey) were investigated using the lab-scale Jameson cell. The effect of air-to-pulp ratio and bias factor on flotation recovery were also studied. The ore has problematic flotation behaviour due to very fine liberation size and oxidation. The results showed that the Cu-Zn rich bulk concentrate can be obtained from the ore with satisfactory grade and recovery. It was determined that the air-to-pulp ratio and bias factor have significant effect on the flotation recovery. The optimum values of air-to-pulp ratio and bias factor in flotation of rather fine sized minerals were determined to be within the range of 1-1.5 and 0.70-0.95, respectively.

4

Recycling of colemanite tailings using the Jameson flotation technology

Ucar A., Sahbaz O., Kerenciler S., Oteyaka B.

Physicochemical Problems of Mineral Processing

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2014

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Vol. 50, iss. 2

645--655

EN

In this study, beneficiation of colemanite minerals from tailings of the Emet Boron Processing Plant using a laboratory scale Jameson flotation cell was investigated in detail. Effect of some working parameters of the Jameson cell such as jet length, plunging depth of downcomer, and bias factor was studied for the flotation performance of colemanite. The results showed that all parameters showed a significant effect on colemanite flotation using the Jameson cell which was the first time used in boron flotation with a negative bias factor. The results also indicated that a high recovery could be obtained with a worthy grade values by the negative bias factor. According to the results obtained at the bias factor of -0.3, jet length of 3 cm, and plunging depth of 20 cm, B2O3 content of the sample increased to approximately 46% from 36.8% with a recovery of 98.47%.

5

Determination of turbulence and upper size limit in Jameson flotation cell by the use of computational fluid dynamic modelling

Sahbaz O., Ercetin U., Oteyaka B.

Physicochemical Problems of Mineral Processing

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2012

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Vol. 48, iss. 2

533-544

EN

In the coarse particle flotation, turbulence which can be treated as energy dissipation rate, is one of the most significant parameters effecting the recovery and grade. Therefore, determination of energy dissipation rate is very beneficial for delineation of coarse particle flotation and determining the maximum floatable particle size in any cell. In this study, Computational Fluid Dynamic (CFD) modelling for the Jameson cell has been carried out to determine the high turbulent regions and the effect on the upper floatable size limit. The CFD modelling has been utilized for determining the flow characteristics and hydrodynamic behaviour of the Jameson flotation cell. In parallel with this purpose the turbulence map of the cell has been determined and energy dissipation rate determined by using the CFD modelling. According to the result acquired from the CFD modelling, there are two main turbulent regions which are mixing zone in the upper part of the downcomer and critical region at the separation tank. While the high turbulence at the mixing zone supplies fine bubbles and fast collection of particles, the turbulence at the separation tank causes the main detachment of the bubble-particle aggregate. Then, the increase in turbulence in the tank causes the decrease of the maximum floatable size of particles. In addition, the average energy dissipation rate in the critical region has been determined and used for estimation of the maximum floatable particle size in the Jameson cell. Moreover, the effect of hydrophobicity has been discussed.

6

Gas entrainment rate and flow characterization in downcomer of a Jameson cell

Tasdemir T., Tasdemir A., Oteyaka B.

Physicochemical Problems of Mineral Processing

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2011

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Vol. 47

61-78

EN

The Jameson cell which is a new type of gas-liquid contacting device and can be considered as a type of plunging jet column, has been in use worldwide for the separation of fine minerals, coal particles and wastewater treatment etc. Flow characteristics in the downcomer of a Jameson cell are very important since the hydrodynamics of the cell is largely depends on the flow conditions. The hydrodynamics influences flow regimes in the downcomer and hence the gas holdup and bubble diameter are strongly affected by flow conditions. Depending on the air entrainment rate entered to the system, different flow regimes are observed in the downcomer. Bubbly flow which is observed at less air quantities is desired instead of churn-turbulent flow where the gas entrainment rate increase. In this research, the effect of operating conditions including nozzle diameter, downcomer diameter, jet velocity and jet length on gas entrainment rate, Qg , was evaluated experimentally for an air-water system for the bubbly and churn-turbulent flow. Between these factors, downcomer diameter was found to have very little effect on gas entrainment rate while increasing values of other factors had an increasing effect on it. The results were evaluated by forward stepwise linear regression (MLR) and a piecewise regression with Quasi-Newton estimation of breakpoint (PLR) to estimate the flow conditions and gas entrainment rates. The model by PLR was useful to understand the boundary of the flow characteristics since the two equations were valid in a certain air entrainment ranges, i.e. different flow conditions. The model developed was successful to determine the transition region from bubbly flow to churn-turbulent flow. Experimental data were in good agreement with theoretically predicted value.