A Kinetic Study of Hot Metal Desulphurization by Calcium Carbide Powder Injection

Abstract

<p>Currently, sulphur is the most problematic impurity which affects the physical and mechanical properties of steel. Therefore all the integrated steel producers desulphurize iron before steelmaking. Calcium carbide is one of the reagents used to desulphurize hot metal from the blast furnace, yet the kinetic reaction phenomena are not clear. The present work was initiated to study the kinetics of hot metal desuIphurization by calcium carbide powder Injection at the 3 Tonne scale.</p> <p>The most Important variables which affect the rate and efficiency of calcium carbide desulphurization are the type of top slag, the Injection conditions and the oxygen activity In the hot metal.</p> <p>The present results quantitatively demonstrate these effects. The experimental results indicate that control of the Initial slag condition can effectively improve the, rate and efficiency of calcium carbide desulphurization. It was found that lower solid loading Is kinetically favorable for both slag/metaI and plume desuIphurization. Oxygen activity measurements show that oxygen plays a crucial role in desuIphurization, particularly to achieve extra-low suIphur levels.</p> <p>A steady-state, one-dimensional, three-phase model was developed to model the plume desulphurization kinetics. The model permits a quantitative analysis of the present experimental results. The computed results from the model are found to be consistent with the experimental data.</p>