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MgO solubility in BOF slag equilibrated with ambient air
Author(s) -
Park Jong Min
Publication year - 2001
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.200100098
Subject(s) - solubility , slag (welding) , oxide , iron oxide , metallurgy , inorganic chemistry , chemistry , steelmaking , materials science , chemical engineering , engineering
The MgO solubility in the CaO‐MgO‐Fe 2 O 3 ‐FeO‐SiO 2 ‐(MnO)‐(Al 2 O 3 ) slag was measured under the condition of equilibrium with the ambient air at 1873 K as a fundamental study for precise slag coating control in BOF operation. The CaO/SiO 2 mass ratios of the main slag were 1, 1.5, 2, 3 and 4, and total iron content was in the range of 10 to 35 %. Moreover, 1 to 13 % of MnO and 2 to 12 % of Al 2 O 3 were added to the melt to evaluate their effects on the MgO solubility. The effect of slag composition on the MgO solubility was discussed and quantified by means of a newly developed formula. As the basicity in slag increases, the MgO solubility decreases. The effect of iron oxide content is observed to be dependent on the basicity of slag. An increase in iron oxide content makes the MgO solubility higher for basic slag but lower for acidic slag. It is revealed that the MgO solubility in steelmaking slag is controlled by the complex anion formation reaction of iron oxide. Both Al 2 O 3 and P 2 O 5 increase the MgO solubility by diluting the basic oxides as SiO 2 does, while manganese oxide affects the MgO solubility in a similar manner as iron oxide. The MgO solubility can be described as a function of slag composition, X = (%CaO) + 0.45(%Fe 2 O 3 + %FeO) + 0.55(%MnO), in the equation of (%MgO) = 0.00816 X 2‐ 1.404 X + 62.31. Based on the results, the guidance for addition of MgO‐containing material could be suggested for best slag coating practice.