Carbothermal reduction kinetics of mechanically activated chromite with graphite

Year 2011, Volume: 15 Issue: 1, 17 - 22, 01.06.2011

Kenan Yıldız

Abstract

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Keywords

chromite, carbothermal reduction, kinetics, mechanical activation

Mekanik aktive edilmiş kromitin grafitle karbotermal redüksiyon kinetiği

Abstract

The carbothermal reduction kinetics of mechanically activated chromite with graphite under an argon atmosphere was investigated at temperatures between 1100 and 1400°C. Zhuravlev-Lesokhin-Tempelman (ZLT) method was used in the reduction kinetics for non-activated chromite and the activation energy was calculated as 401.7 kJ/mol. Solid-state diffusion method was used in the reduction kinetics for 60 min-activated chromite and the activation energy was calculated as 283.3 kJ/mol. This decrease in activation energy was due to structural disordering in chromite structure by mechanical activation.

Keywords

kromit, karbotermal redüksiyon, kinetik, mekanik aktivasyon

References

• H.M. Mikami, Industrial Minerals and Rocks, fifth ed., Vol.1, AIME, New York, 1983.
• K.K. Chatterjee, Uses of Metals and Metallic Minerals, New Age Int. Ltd Pub., New Delhi, 2007.
• G. Yarkadaş, K. Yildiz, Effects of mechanical activation on the soda roasting of chromite, Can. Metal. Quarterly 48(1), 69-72, 2009.
• E. Tahtakıran, Kromit, Ferrokrom ve Paslanmaz Çelik Sektörlerine Genel Bir Bakış, Madencilik Bülteni, 81, 44-47, 2007.
• Y.Z. Kayır, Türkiye’de ve Dünyada Paslanmaz Çelik, Metalurji Dergisi, Sayı 146, 2007.
• P. Weber, R.H. Eric, The reduction of chromite in the presence of silica flux, Minerals Eng. 19, 318-324, 2006.
• Y.L. Ding, N.A. Warner, Catalytic reduction of carbon- chromite composite pellets by lime, Thermochimica Acta 292, 85-94, 1997.
• A. Atasoy, Mineral processing and reduction of Turkish chromite ore, PhD Thesis, UMIST, 2001.
• A.R. Barnes, C.W.P. Finn, S.H. Algie, Prereduction and smelting of chromite concentrate of low chromium to iron ratio, J. South African Inst. of Min. And Metal. 83(3), 49-54, 1983.
• G.W. Healy, Carbon reduction of chromites in Bird River and other ores and concentrates at 1200-1700°C, Can. Metal. Quarterly 27(4), 281-285, 1988.
• R.H. Nafziger, J.E. Tress, J.I. Paige, Carbothermic reduction of domestic chromites, Metallurgical Transactions B 10B(1), 5-12, 1979.
• O. Soykan, R.H. Eric, R.P. King, Reduction mechanism of a natural chromite at 1416°C, Metallurgical Transactions B 22(1), 53-63, 1991.
• O. Soykan, R.H. Eric, R.P. King, Kinetics of the reduction of Bushveld complex chromite ore at 1416°C, Metallurgical Transactions B 22(6), 801-810, 1991.
• A.B. Hazar-Yoruc, Reduction mechanism of chromite spinel with carbon, Minerals and Metal. Proces. 24(2), 115-120, 2007.
• P. Balaz, Extractive Metallurgy of Activated Minerals, Elsevier Science, Amsterdam, 2000.
• P. Balaz, Mechanochemistry in Nanoscience and Minerals Engineering, Springer Verlag, Berlin, 2008
• D. Tromans, J.A. Meech, enhanced dissolution of minerals: stored energy, amorphism and mechanical activation, Minerals Engineering 14(11), 1359-1377, 2001.
• F. Apaydın, A. Atasoy, K.Yıldız, Effects of mechanical activation on the carbothermal reduction of chromite with metallurgical coke, SAU Fen Bilimleri Dergisi, 14(1), 33-38, 2010.
• F. Apaydın, A. Atasoy, K. Yıldız, Kromitin karbotermal redüksiyonuna mekanik aktivasyonun etkisi, 15. Uluslararası Metalurji ve Malzeme Kongresi, 11-13 Kasım 2010, İstanbul.
• F. Apaydın, A. Atasoy, K. Yıldız, Effect of mechanical activation on carbothermal reduction of chromite with graphite, Canadian Metallurgical Quarterly, 50(2), 113- 118, 2011.
• A. Atasoy, F.R. Sale, An investigation on the solid state reduction of chromite concentrate, J. Solid State Phenomena 147-149, 752-757, 2009.
• N.S. Murti Sundar, V. Seshadri, Kinetics of reduction of synthetic chromite with carbon, Transactions ISIJ, Vol.22, 1982.
• F. Habashi, Kinetics of metallurgical processes, Metalurgie Extractive Quebec, Quebec – Canada, 1999.
• S.H. Algie, C.W.P. Finn, Reaction mechanisms in the reduction of Winterveld chrome spinel with graphite and carbon, Mintek, South Africa, 1-40, 1984.
• A. Ataie, S. Heshmati-Manesh, S. Sheibani, R. Khayati, Y. Firozbakht, J. Sargeini, Solid state reduction of chromite in high carbon ferrochromium – chromite composite pellets, Iranian Journal of Material Science and Engineering, 5(1), 22-28, 2008.
• Y.L. Ding, N.A. Warner, Catalytic reduction of carbon- chromite composite pellets by lime, Thermochimica Acta, 292, 85-94, 1997.
• J.N. Meegoda, Z. Hu, W. Kamolpornwijit, Conversion of chrome ore processing residue to chrome steel, Final Report, New Jersey Institute of Technology, December, 2007.