Thermodynamic estimation on the reduction behavior of iron-chromium ore with carbon
- Tohoku Univ., Sendai (Japan). Dept. of Metallurgy
Recently, a number of efforts have been made to produce a crude stainless steel melt by direct smelting of iron-chromium ore in a basic oxygen furnace (BOF) without use of ferrochromium alloys, in order to save electric energy and production costs. In this paper, the thermodynamics for reduction of iron-chromium ore by carbon is discussed. The thermodynamic properties of iron-chromium ore were evaluated from previous work on the activities of constituents in the FeO {center_dot} Cr{sub 2}O{sub 3}-MgO {center_dot} Cr{sub 2}O{sub 3}-MgO {center_dot} Al{sub 2}O{sub 3} iron-chromite spinel-structure solid solution saturated with (Cr, Al){sub 2}O{sub 3}, and those of the Fe-Cr-C alloy were estimated by a sublattice model. The stability diagrams were drawn for carbon reduction of pure FeO {center_dot} Cr{sub 2}O{sub 3}, (Fe{sub 0.5}Mg{sub 0.5})O {center_dot} (Cr{sub 0.8}Al{sub 0.2}){sub 2}O{sub 3} iron-chromite solid solution, and South African iron-chromium ore. The evaluated stability diagrams agreed well with the literature data. It was concluded that the lowest temperature for reduction of FeO {center_dot} Cr{sub 2}O{sub 3} in the iron-chromium ore was 1390 K and a temperature higher than 1470 K would be necessary to reduce Cr{sub 2}O{sub 3} in MgO {center_dot} (Cr,Al){sub 2}O{sub 3} in the prereduction process of iron-chromium ore. The composition of liquid Fe-Cr-C alloy in equilibrium with iron-chromium ore was also estimated under 1 atm of CO at steelmaking temperature. The predicted metal composition showed reasonable agreement with the literature values.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 634650
- Journal Information:
- Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science, Vol. 29, Issue 2; Other Information: PBD: Apr 1998
- Country of Publication:
- United States
- Language:
- English
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