2015-Sustainable Industrial Processing Summit
SIPS 2015 Volume 3: Takano Intl. Symp. / Metals & Alloys Processing
| Editors: | Kongoli F, Noldin JH, Mourao MB, Tschiptschin AP, D'Abreu JC |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2015 |
| Pages: | 550 pages |
| ISBN: | 978-1-987820-26-3 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Vacuum Treatment of Ferrosilicon
Jafar Safarian1; Kai Tang2; Kjetil Hildal3;1RESEARCH SCIENTIST, Trondheim, Norway; 2, Trondheim, Norway; 3SENIOR R&D ENGINEER, Kristiansand, Norway;
Type of Paper: Regular
Id Paper: 69
Topic: 3
Abstract:
Ferrosilicon is produced by the carbothermic reduction of iron and silicon oxides in submerged arc furnace. The ferrosilicon smelting process is essentially a slag-free process. Iron and silicon are mainly end up in the liquid metal product and the alloy contains usually over 95% Fe and Si. The other impurity elements existing in the charge materials are distributed between the metal product and the furnace off-gas. There are always certain amounts of Al, Ti, Mn, Ca, Mg, P, B, ... impurities in ferrosilicon. The removal of impurities from ferrosilicon may be necessary for improving the quality of the product to fulfill the required specification for steel makers. Vacuum refining is a process candidate for treatment of molten ferrosilicon in which the volatile impurities are evaporated at the melt surface. In the present study, the behavior of different elements under moderate vacuum conditions at elevated temperatures is studied through the application of the vacuum-induction melting technique. It is indicated that impurities, such as P, Al, Mn and Cu can be removed significantly under vacuum. In contrast, the vacuum removal of Ti and B is impossible. Moreover, the mass transfer coefficients for the evaporation of the volatile elements from the melt are determined and they are compared with theoretical values.
Keywords:
Ferrous; Furnace; Gas; Melting; Metallurgy;References:
[1] R. Harris: Vacuum Refining Copper Melts to Remove Bismuth, Arsenic, and Antimony, Metallurgical Transactions, 15B (1984), 251-257[2] R. Harris and W.G. Davenport: Vacuum Distillation of Liquid Metals, Part 1. Theory and Experimental Study, Metallurgical Transactions, 13B (1982), 581-588
[3] A. Ghosh, Secondary Steelmaking-Principles and Applications, 2000, CRC Press, chapter 6.
[4] J. Safarian, M. Tangstad: Vacuum refining of molten silicon, Met. Mat. Trans., 43B (2012), 1427-1445.
[5] J. Safarian, M. Tangstad: Kinetics and mechanism of phosphorus removal from silicon in vacuum induction refining, High. Temp. Mat. Proc., 31 (2012), 73-81.
[6] J. Safarian, B. Xakalashe, M. Tangstad, Proceedings of 26th European Photovoltaic Solar Energy Conference and Exhibition, Sept. 5-9, 2011, Hamburg, Germany.
[7] J. Safarian, M. Tangstad, Proceedings of Silicon for the Chemical and Solar Industry X, June 28-July 20, 2010, Ålesund-Geiranger, Norway.
[8] O. Kubaschewski and C. B. Alcock, Metallurgical thermochemistry, 5th Edition, 1979, Pergamon press.
[9] K. Tang, E.J. Øvrelid, G. Tranell, and M. Tangstad, Proceedings of 12th International Ferroalloys Congress, June 6–9,2010, Helsinki, Finland, 619–629.
[10] J. Safarian, T.A. Engh: Vacuum evaporation of pure metals, Met. Mat. Trans. 44A (2013), 747-753.
[11] Richardson FD. Physical Chemistry of Melts in Metallurgy, 1974, Academic Press Inc., New York.