On the Importance of Critical Impeller Speed and Complete Gas Dispersion for Enhancing Flotation Kinetics | ||
| Journal of Mining and Environment | ||
| مقاله 9، دوره 16، شماره 6، آذر و دی 2025، صفحه 1983-1990 اصل مقاله (1.2 M) | ||
| نوع مقاله: Original Research Paper | ||
| شناسه دیجیتال (DOI): 10.22044/jme.2025.16200.3130 | ||
| نویسندگان | ||
| Hossna Darabi1؛ Faraz Soltani* 2 | ||
| 1Department of Mineral Processing, Tarbiat Modares University, Tehran, Iran | ||
| 2Department of Mining Engineering, Arak University of Technology, Arak, Iran | ||
| چکیده | ||
| The main characteristic of mechanical flotation cells is to have an impeller, which is responsible for creating particle suspension, gas dispersion, and producing turbulence necessary to create effective bubble-particle interactions. For this purpose, in this paper, the conditions for complete gas dispersion in a Denver laboratory flotation cell have been investigated. Then, the critical impeller speed has been investigated for quartz particles with different size fractions. The effect of complete dispersion of introduced gas and critical impeller speed on the flotation rate constant (k) of particles was investigated. The results showed that k was the minimum value at an impeller speed of 700 rpm in the superficial gas velocity of 0.041- 0.125 cm/s for all size fractions. The impeller speed of 700 rpm was sufficient to keep -106µm quartz particles suspended, but at all superficial gas velocities, the minimum impeller speed required for complete gas dispersion was 850 rpm. Therefore, it can be stated that the reason for the low k value at a stirring speed of 700 rpm is the incomplete distribution of bubbles and particles (+106µm), resulting in a reduced probability of air bubbles colliding with solid particles. By increasing the impeller speed to values greater than 700 rpm, the k value increased, which is due to the complete distribution of particles and air bubbles in the flotation cell (increased probability of bubble-particle collision). Therefore, it is necessary to provide suitable operating conditions for the complete dispersion of air bubbles and also to keep solid particles suspended. | ||
| کلیدواژهها | ||
| Mechanical flotation cell؛ Critical impeller speed؛ Flotation kinetics؛ Complete gas dispersion | ||
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| مراجع | ||
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[1]. Schubert, H. (1999). On the turbulence-controlled microprocesses in flotation machines. International journal of mineral processing, 56(1-4), 257-276.
[2]. Darabi, H., S.J. Koleini, D. Deglon, B. Rezai, and M. Abdollahy. (2019). Investigation of bubble-particle interactions in a mechanical flotation cell, part 1: Collision frequencies and efficiencies. Minerals Engineering, 134, 54-64.
[3]. Darabi, H., S.J. Koleini, D. Deglon, B. Rezai, and M. Abdollahy. (2020). Investigation of bubble-particle attachment, detachment and collection efficiencies in a mechanical flotation cell. Powder Technology, 375, 109-123.
[4]. Darabi, H., S.M.J. Koleini, B. Rezai, and M. Abdollahy. (2017). The Investigation of Critical Impeller Speed in a Laboratory Mechanical Flotation Cell. Nashrieh Shimi va Mohandesi Shimi Iran, 36(3), 211-223.
[5]. Darabi, H., S.M.J. Koleini, F. Soltani, M. Abdollahy, and M. Ghadiri. (2020). Investigation of cell geometry effect on the turbulence characteristics and flotation performance using particle image velocimetry technique. Powder Technology, 376, 458-467.
[6]. Shen, Z. and Z. Shen. (2021). Dynamic Characteristics and Evaluation of Flotation Machines. Principles and Technologies of Flotation Machines, 59-83.
[7]. Darabi, H., F. Soltani, and D. Deglon. (2024). Enhancing flotation kinetics: Investigating hydrodynamic impact for improved predictive modeling. Minerals Engineering, 215, 108832.
[8]. Harris, C. (1974). Impeller speed, air, and power requirements in flotation machine scale-up. International Journal of Mineral Processing, 1(1), 51-64.
[9]. Harris, C. and R. Mensah-Biney. (1977). Aeration characteristics of laboratory flotation machine impellers. International Journal of Mineral Processing, 4(1), 51-67.
[10]. Paglianti, A. (2002). Simple model to evaluate loading/flooding transition in aerated vessels stirred by Rushton disc turbines. The Canadian Journal of Chemical Engineering, 80(4), 1-5.
[11]. Lins Barros, P., F. Ein-Mozaffari, and A. Lohi. (2022). Gas dispersion in non-Newtonian fluids with mechanically agitated systems: A review. Processes, 10(2), 275.
[12]. Nienow, A. Effect of scale and geometry on flooding, recirculation and power in gassed stirred vessels. in 2nd Euro, Conf. Mixing, Cambridge, England. 1977.
[13]. Yawalkar, A.A., A.B. Heesink, G.F. Versteeg, and V.G. Pangarkar. (2002). Gas—liquid mass transfer coefficient in stirred tank reactors. The Canadian Journal of Chemical Engineering, 80(5), 840-848.
[14]. Schubert, H. and C. Bischofberger. (1998). On the microprocesses air dispersion and particle-bubble attachment in flotation machines as well as consequences for the scale-up of macroprocesses. International journal of mineral processing, 52(4), 245-259.
[15]. Arbiter, N., C. Harris, and R. Yap. (1969). Hydrodynamics of flotation cells. SME Transactions, 244, 134-148.
[16]. Van der Westhuizen, A. and D. Deglon. (2007). Evaluation of solids suspension in a pilot-scale mechanical flotation cell: The critical impeller speed. Minerals Engineering, 20(3), 233-240.
[17]. Van der Westhuizen, A. and D. Deglon. (2008). Solids suspension in a pilot-scale mechanical flotation cell: A critical impeller speed correlation. Minerals Engineering, 21(8), 621-629.
[18]. Zwietering, T.N. (1958). Suspending of solid particles in liquid by agitators. Chemical engineering science, 8(3-4), 244-253.
[19]. Ndlovu, B., M. Becker, E. Forbes, D. Deglon, and J.-P. Franzidis. (2011). The influence of phyllosilicate mineralogy on the rheology of mineral slurries. Minerals engineering, 24(12), 1314-1322.
[20]. Ndlovu, B., E. Forbes, M. Becker, D. Deglon, J. Franzidis, and J. Laskowski. (2011). The effects of chrysotile mineralogical properties on the rheology of chrysotile suspensions. Minerals Engineering, 24(9), 1004-1009.
[21]. Ralston, J., The influence of particle size and contact angle in flotation, in Developments in mineral processing. 1992, Elsevier. p. 203-224.
[22]. Jameson, G., S. Nam, and M.M. Young. (1977). Physical factors affecting recovery rates in flotation. Miner. Sci. Eng.;(South Africa), 9(3).
[23]. Gui, X., G. Cheng, J. Liu, Y. Cao, S. Li, and Q. He. (2013). Effects of energy consumption on the separation performance of fine coal flotation. Fuel Processing Technology, 115, 192-200.
[24]. Lima, O.A.d., D.A. Deglon, and L.d.S. Leal Filho. (2009). A comparison of the critical impeller speed for solids suspension in a bench-scale and a pilot-scale mechanical flotation cell. Minerals Engineering, 22(13), 1147-1153. | ||
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