Influence of lime particle and slag properties on lime dissolution in BOF converter

Abstract

The aim of this study was to evaluate the influence of lime particle size and lime calcination level as well as slag properties (basicity, viscosity, CaO activity and density) on lime particle dissolution at temperature in the early stage of process blowing time of the basic oxygen furnace (1400 °C in the present paper). Experiments were carried out in an electric furnace using lime samples of 6 mm and 9 mm particle size and 80% and 100% calcined at different FeO and SiO2 contents at 1600 °C. The results showed that the dissolution is faster using 6 mm particles, the lowest level of calcination and lower ratios between FeO and SiO2 content in the slag. The smaller particle size favors a larger area of specific contact of the particle with the slag. The increase in the ratio between the FeO and SiO2 content in the slag resulted in a decrease in the rate of dissolution that can be attributed to the increase in lime activity and consequent decrease in the percentage of CaO saturation. This result suggests that lime-slag contact area and percentage of CaO saturation seem to be more significant than basicity in the lime dissolution process obtained in the experiments.

Keywords

• Lime dissolution
• Particle size
• Lime calcination
• Basicity
• Basic oxygen furnace