Abstract
Cold-bonded composite pellets, consisting of iron ore fines and fines of noncoking coal or char, were prepared by steam curing at high pressure in an autoclave employing inorganic binders. Dry compressive strength ranged from 200 to 1000 N for different pellets. The pellets were heated from room temperature to 1273 K under flowing argon at two heating rates. Rates of evolution of product gases were determined from gas Chromatographie analysis, and the temperature of the sample was monitored by thermocouple as a function of time during heating. Degree of reduction, volume change, and compressive strength of the pellets upon reduction were measured subsequently. Degree of reduction ranged from 46 to 99 pct. Nonisothermal devolatilization of coal by this procedure also was carried out for comparison. It has been shown that a significant quantity (10 to 20 pct of the pellet weight) of extraneous H2O and CO2 was retained by dried pellets. This accounted for the generation of additional quantities of H2 and CO during heating. Carbon was the major reductant, but reduction by H2 also was significant. Ore-coal and ore-char composites exhibited a comparable degree of reduction. However, the former showed superior postreduction strength due to a smaller amount of swelling upon reduction.
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J.F. Gransden, D.A. Reeve, J.H. Walsh, and J.E. Rehder:Can. Min. Metall. Bull., 1978, vol. 71, pp. 153–59.
F.T. Kaiser, L.L. French, and H.G. Rachner:Giesserei, 1980, vol. 67, pp. 200–06.
P.V. Duranet al.:Proc. Conf. 38th Annual Congress ABM, Sao Paulo, Brazil, 1983, vol. 1, p. 203 (Met. A: 8312 42-1587).
M.A. Goksel, T.A. Schott, and F.T. Kaiser:Proc. 4th Int. Symp. on Agglomeration, Toronto, 1985, pp. 401–08.
F.J. Weiss, M.A. Goksel, and F.T. Kaiser:Iron Steel Eng., 1986, vol. 63, pp. 34–40.
H. Xi-Lun:Iron Steel (China), 1979, vol. 14, p. 45 (Met. A: 8002 42-0157).
N. Shivaramakrishna, B.B. Agarwal, A.K. Ray, K.K. Prasad, P.K. Bandopadhyay, and S.K. Gupta:Trans. Indian Inst. Met., 1990, vol. 43, pp. 95–101.
V.E. Lotosh, V.A. Naidenov, and A.A. Chesnokov:Metallurgy, 1987, vol. 12, p. 8 (Met. A: 8804 42-0707).
M.A. Goksel:Agglomeration 77, K.V.S. Sastry, ed., TMS-AIME, New York, NY, 1977, vol. 2, p. 877.
K. Otsuka and D. Kunii:J. Chem. Eng. Jpn., 1969, vol. 2, pp. 46–50.
Y.K. Rao:Metall. Trans., 1971, vol. 2, pp. 1439–47.
R.J. Fruehan:Metall. Trans. B, 1977, vol. 8B, pp. 279–86.
M.C. Abraham and A. Ghosh:Ironmaking and Steelmaking, 1979, vol. 6, pp. 14–23.
D. Bandyopadhyay: Ph.D. Thesis, Indian Institut Technolo. Kanpur, India, 1989.
V.A. Kiselev, L.I. Permyakova, L.J. Leontev, V.A. Kobelov, and S.V. Sharvin:Izv. Akad Nauk SSSR, Met., 1982, vol. 6, p. 33 (Met. A: 8307 42-0866).
C.E. Seaton, J.S. Foster, and J. Velaseo:Trans. Iron Steel Inst., 1983, vol. 23, pp. 490–96.
Ov. Hatarasen and L. Dian:Metallurgia, 1973, vol. 25, p. 7 (Met. A: 7502 42-0077).
A.V. Sidorskii, Yu. L. Dobromirov, and V.V. Leshchenko:Izv. Vyssh. Uchebn. Zaved. Chem. Metall., 1987, vol. 9, p. 126 (Met. A: 8802 42-0326).
C.Y. Wen and S. Dutta: inCoal Conversion Technology, C.Y. Wen and E. Stanley Lee, eds., Addison-Wesley Publishing Co., Inc., Reading, MA, 1979, p. 57.
L.D. Smooth and P.J. Smith:Coal Combustion and Gasification, Planum Press, New York, NY, 1985, p. 37.
S. Sarkar: inFrontiers in Applied Chemistry, A.K. Biswas, ed., Narosa Publishing House, New Delhi, 1989, p. 119.
R. Cypres and C. Soudan-Moinet:Fuel, 1980, vol. 59, pp. 48–54.
R. Cypres and C. Soudan-Moinet:Fuel, 1981, vol. 60, pp. 33–39.
C. Bryk and W.K. Lu:Ironmaking and Steelmaking, 1986, vol. 13, pp. 70–75.
H.S. Ray and P.A. Sewell:Proc. Int. Conf. on Advances in Chemical Metallurgy, BARC, Bombay, 1979, vol. II, p. 43/1/1.
S. Mookherjee, H.S. Ray, and A. Mukherjee:Thermochim. Acta, 1985, vol. 95, pp. 247–56.
S. Prakash and H.S. Ray:Thermochim. Acta, 1987, vol. III, pp. 143–66.
S.K. Dutta: Ph.D. Thesis, Indian Institute of Technol Kanpur, India, 1991.
J.L. Johnson:Kinetics of Coal Gasification, John Wiley & Sons, New York, NY, 1979, p. 19.
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Formerly Graduate Student, Department of Metallurgical Engineering, Indian Institute of Technology, Kanpur, India
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Dutta, S.K., Ghosh, A. Study of nonisothermal reduction of iron ore-coal/char composite pellet. Metall Mater Trans B 25, 15–26 (1994). https://doi.org/10.1007/BF02663174
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DOI: https://doi.org/10.1007/BF02663174