Effect of BaO on silica activity in blast furnace slag and silicon distribution between slag and hot metal

Abstract

Daily average analyses of slag and hot metal aggregated from samples taken from a 575 m³ and two 1033 m³ blast furnaces of the Egyptian Iron and Steel Company (HADISOLB) charged with fluxed sinter were used to investigate the effects of slag composition, BaO content, and temperature on the activity of silica in slag, silicate capacity and silicon distribution between slag and metal. Empirical equations have been developed that show that the activity decreases with increasing basicity, BaO content and temperature. The temperature effect is small. Both silicate capacity and silicon distribution ratio, however, increase with increasing basicity and BaO content, and decrease as the temperature rises. The effect of temperature is very large compared with that of the basicity. The best correlation results of activity coefficient, activity, silicate capacity and silicon distribution were obtained when the lime equivalences of all basic oxides were accounted for in the basicity definition. Recent data from HADISOLB confirm the reliability of applying the empirical equations developed in this paper to the silicon distribution between slag and metal under the present investigation conditions. The large temperature effect on the silicate capacity is also substantiated by using published experimental data.

Keywords:

• BLAST FURNACE
• SILICA ACTIVITY IN SLAG
• SILICATE CAPACITY
• SILICON DISTRIBUTION
• BAO EFFECT