Abstract
The kinetics of the reduction of chromite ore from the LG-6 layer of the Bushveld Complex of the Transvaal in South Africa were studied at 1416 °C by the thermogravimetric analysis (TGA) technique. Spectroscopic graphite powder was employed as the reductant. The aim of this article is to present a kinetic model that satisfactorily describes the solid-state carbothermic reduction of chromite. A generalized rate model based on an ionic diffusion mechanism was developed. The model included the contribution of the interfacial area between partially reduced and unreduced zones in chromite particles and diffusion. The kinetic model described the process for degrees of reduction from 10 to 75 pet satisfactorily. It was observed that at a given particle size, the rate of reduction was controlled mainly by interfacial area up to about 40 pet reduction, after which the rate was dominated by diffusion. On the other hand, for a given degree of reduction, the contribution of the interfacial area to the rate increased, while that of diffusion decreased, with a decrease in the particle size. The value of the diffusion coefficient for the Fe2+ species at 1416 °C was calculated to be 2.63 x 10-2 cm2/s.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
S.A. de Waal and S.A. Hiemstra: Report No. 1709, Mintek, Randburg, South Africa, 1975.
W.J. Rankin:Trans. Inst. Min. Metall., 1979, vol. 88, pp. 107–113.
Y. Otani and K. Ichikova:Infacon 74, Proc. 1st Int. Ferro-Alloys Congress, The South African Institute of Mining and Metallurgy, Johannesburg, South Africa, 1974, pp. 31–37.
P.J. Read, D.A. Reeve, J.H. Walsh, and J.E. Rehder:Can. Metall. Q., 1974, vol. 13, pp. 587–95.
M.A. Quayyum and D.A. Reeve: Report RP/ERL 75-76 (J), Canada Center for Mineral and Technology Research, Ottawa, Canada, 1975.
A.E.G. Robiette:Electric Smelting Processes, Griffin, London, 1972.
K.P. Shaver and S.B. Lasday:Ind. Heat., 1975, vol. 42 (1), pp. 10–22.
W.A. Scholes:33 magazine, 1974, vol. 12 (12, pp. 38–44.
C.S. Kucukkaragoz, S.H. Algie, and C.W.P. Finn: Report No. M154, Mintek, Randburg, South Africa, Oct. 1984.
M.J. Searle: M.Sc. Thesis, University of Witwatersrand, Johannesburg, South Africa, 1984.
E.D. Kinloch:ICAM 81, Proc. 1st Int. Congress on Applied Mineralogy, The Geological Society of South Africa, Johannesburg, South Africa, 1983, pp. 337–49.
S.H. Algie and C.W.P. Finn: Report No. M157, Mintek, Randburg, South Africa, Dec. 1984.
K.P.D. Perry, C.W.P. Finn, and R.P. King:Metall. Trans. B, 1988, vol. 19B, pp. 677–84.
O. Soykan, R.H. Eric, and R.P. King:Metall. Trans. B, 1991, vol. 22B, pp. 53–63.
R.H. Eric, O. Soykan, and E. Uslu:Infacon 89, Proc. 5th Int. Ferro-Alloys Conf., New Orleans, LA, 1989, vol. 1, pp. 77-87.
L.B. McRae:Agglomeration 77, AIME, New York, NY, vol. 2, 1977.
R.B. Bird, W.E. Stewart, and E.N. Lightfoot:Transport Phenomena, Wiley, New York, NY, 1960.
B.B.L. Seth and H.U. Ross:Trans. TMS-AIME, 1965, vol. 233, pp. 180–85.
R. Sun:J. Chem. Phys., 1958, vol. 28, pp. 290–94.
R. Lindner:Proc. 2nd Int. Conf. on the Peaceful Uses of Atomic Energy, United Nations, Geneva, Switzerland, 1958, vol. 20, pp. 116–19.
H. Wen:Ind. Eng. Chem., 1968, vol. 60 (9), pp. 34–37.
Author information
Authors and Affiliations
Additional information
Formerly Postgraduate Student, Department of Metallurgy and Materials Engineering, University of Witwatersrand,
Formerly with the Department of Metallurgy and Materials Engineering, University of Witwatersrand,
Rights and permissions
About this article
Cite this article
Soykan, O., Eric, R.H. & King, R.P. Kinetics of the reduction of bushveld complex chromite ore at 1416 °C. Metall Trans B 22, 801–810 (1991). https://doi.org/10.1007/BF02651157
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02651157