Abstract
Phosphorus partition ratios between Na2O-SiO2-PO2.5 slags and carbon saturated iron have been measured as a function of slag composition at 1200 °C. To avoid excessive Na2O loss by reaction with carbon, the initial slag-metal interfacial area was increased by using a powder mixture of slag and metal to reduce the time for the equilibrium. The results indicate that phosphorus partition ratios, Lp, are relatively high, about 20 for an equimolar slag (X Na 2 O/X S 1 O 2 = 1) and are independent of P level in the slag. The phosphate capacity and the activity coefficients of PO2.5 and FeO for these slags are calculated from the experimental results using available thermodynamic data. The oxygen potential at the slag-metal interface was found not to be controlled by Si in metal under an Ar atmosphere or by CO partial pressures in CO-Ar mixtures. Experimental results and thermodynamic calculations show thatP O 2 at the interface between Na2O-SiO2 slags and carbon saturated iron is controlled by the C-CO equilibrium where the CO pressure is determined by C-Na2O equilibrium for which the CO pressure is close to 1 atmosphere in all cases.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
S. Anezaki and Y. Shirota:Trans. ISIJ, 1985, vol. 25(7), pp. 652–58.
M. Muraki, H. Fukushima, and N. Sano:Trans. ISIJ, 1985, vol. 25, pp. 1025–30.
Y. Miyawaki, Y. Matsuda, H. Tanabe, and H. Funanokawa: Oxygen Steelmaking Conf., June 1984, Strasbourg, France, vol. 2, pp. 3.6.1–3.6.15.
F. Tsukihashi, A. Werme, F. Matsumoto, A. Kasahara, M. Yukinobu, T. Hyodo, S. Shiomi, and N. Sano:Proceedings of the Second International Symposium on Metallurgical Slags and Fluxes, TMS-AIME, 1984, pp. 89-106.
M. Frohberg, E. Caune, and M. Kapoor:Arch. Eisenhü’ttenwes., 1973, vol. 44(8), pp. 585–88.
C. Wagner:Metall. Trans. B, 1975, vol. 6B, pp. 405–09.
E. T. Turkdogan:Physical Chemistry of High Temperature Technology, Academic Press, Inc., New York, NY, 1980, pp. 5–24, 81.
H. G. Hudrys, M. G. Frohberg, and J. F. Elliott:Metall. Trans., 1970, vol. 1, pp. 1867–74.
E. T. Turkdogan and J. Pearson:J. Iron Steel Inst., 1953, vol. 175, pp. 393–401.
J.F. Elliott, M. Gleiser, and V. Ramakrishna:Thermochemistry for Steelmaking, Addison-Wesley Publishing Company, Inc., Reading, MA, 1963, vol. II, p. 496.
K. Ito and N. Sano:Trans. ISIJ, 1985, vol. 25, pp. 355–62.
R. Inoue and H. Suito:Trans. ISIJ, 1985, vol. 25(2), pp. 118–26.
M. Muraki, H. Fukushima, and N. Sano:Tetsu-to-Hagané, 1984, vol. 70(4), S203.
K. Iwasaki, N. Sano, and Y. Matsushita:Tetsu-to-Hagané, 1981, vol. 67(3), pp. 536–40.
S. Tabuchi and N. Sano:Metall. Trans. B, 1984, vol. 15B, pp. 351–56.
T. Kawahara, H. Kuwatori, and N. Sano:Tetsu-to-Hagané, 1983, vol. 69(12), S974.
T. Arato, M. Tokuda, and M. Ohtani:Trans. Jpn. Inst. Met., 1984, vol. 25(9), pp. 649–56.
N. Sano:Tetsu-to-Hagané, 1983, vol. 69(3), pp. 378–83.
S. Yamaguchi and K. S. Goto:J. Jpn. Inst. Met., 1984, vol. 48(1), pp. 43–49.
E. Wicks and F. E. Block:Thermodynamic Properties of 65 Elements — Their Oxides, Halides, Carbides and Nitrides, Bulletin 605, Bureau of Mines, United States Government Printing Office, 1963, p. 103.
S. Yamaguchi, A. Imai, and K.S. Goto:Scand. J. Metall., 1982, vol. 11, pp. 263–64.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Pak, J.J., Fruehan, R.J. Soda slag system for hot metal dephosphorization. Metall Trans B 17, 797–804 (1986). https://doi.org/10.1007/BF02657143
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02657143