Numerical and Physical Modelling of Aluminium Refining Process Conducted in URO-200 Reactor

Abstract:

At present both primary and secondary aluminium needs to be refined before further treatment. This can be done by barbotage process, so blowing small bubbles of inert gas into liquid metal. This way harmful impurities especially hydrogen can be removed. Barbotage is very complex taking into consideration hydrodynamics of this process. Therefore modelling research is carried out to get to know the phenomena that take place during the process better. Two different modelling research can be applied: physical and numerical. Physical modelling gives possibility to determine the level of gas dispersion in the liquid metal. Whereas, numerical modelling shows the velocity field distribution, turbulent intensity and volume fraction of gas. The paper presents results of physical and numerical modelling of the refining process taking place in the bath reactor URO-200. Physical modelling was carried out for three different flow rate of refining gas: 5, 10 and 15 dm3/min and three different rotary impeller speeds: 0, 300, 500 rpm Commercial program in Computational Fluid Dynamics was used for numerical calculation. Model VOF (Volume of Fluid) was applied for modelling the multiphase flow. Obtained results were compared in order to verify the numerical settings and correctness of the choice.

• Periodical: Solid State Phenomena (Volume 191)
• Pages: 3-12
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.191.3
• Online since: August 2012
• Authors: Mariola Saternus, Tomasz Merder
• Keywords: Aluminium Refining, Numerical Modeling, Physical Modeling

References

[1] X.-G. Chen, F.-J. Klinkenberg, S. Engler, Optimization of the impeller degassing process trough continuous hydrogen measurements, Light metals TMS (1995) 1215-1222.

[2] M. Saternus, J. Botor, Aluminium refining process – methods and mathematical models, ALUMINIUM 81 (2005) 209-216.

[3] M. Saternus, J. Botor, Refining of aluminium and its alloys by inert gases, Ores and Nonferrous metals 48 (2003) 154-160.

[4] H.-J. Odenthal, R. Bölling, H. Pfeifer, Numerical and physical simulation of tundish fluid flow phenomena, Steel Research 74 (2003) 44-55.

DOI: 10.1002/srin.200300160

[5] J.W. Evans, A. Field, N. Mittal, Measurements of bubble dispersion and other bubble parameters in a gas fluxing unit at Alcoa using a capacitance probe, Light metals TMS (2003) 909-913.

[6] S.T. Johansen, S. Graadahl, P. Tetlie, B. Rasch, E. Myrbostad, Can rotor-based refining units be developed and optimized based on water model experiment, Light Metals TMS (1998) 805-810.

[7] E. Waz, J. Carre, P. Le Brun, A. Jardy, C. Xuereb, D. Ablitzer, Physical modelling of the aluminium degassing process: experimental and mathematical approach, Light metals TMS (2003) 901-907.

[8] K.A. Carpenter, M.J. Hanagan, Efficiency modeling of rotary degasser head configuration and gas introduction methods, Part 1 – water tank test, Light metals TMS (2001) 1017-1020.

[9] J.L. Song, F. Chiti, W. Bujalski, A.W. Nienow, M.R. Jolly, Study of molten aluminium cleaning process using physical modelling and CFD, Light Metals TMS (2004) 743-748.

[10] L. Müller, Dimensional Analysis Applying in Research of Models, PWN, Warsaw, 1983.

[11] K. Michalek, Physical and Numerical Modelling Using for Optimization of Metallurgical Processes, VSB – Technical University of Ostrava, Ostrava, 2001.

[12] K. Michalek, K. Gryc, M. Tkadlečková, D. Bocek, Model study of tundish steel intermixing and operational verification, Archives of metallurgy and materials 57 (2012) 291-296.

DOI: 10.2478/v10172-012-0025-4

[13] K. Michalek, M. Tkadlečková, K. Gryc, P. Klus, Z. Hudziczek, V. Sikora, P. Střasák, Optimization of argon blowing conditions for the steel homogenization in ladle by numerical modelling, METAL (2011) 143-149.

[14] R. Grybos, The Basic of Fluid Dynamics – part II, PWN, Warsaw, 1998.

[15] T. Merder, J. Pieprzyca, Numerical modeling of the influence subflux controller of turbulence on steel flow in the tundish, Metalurgija 4 (2011) 223-226.

DOI: 10.4028/www.scientific.net/msf.654-656.1557

[16] FLUENT, User's Guide, version 6.0, Fluent Inc., 2003.