| In current steelmaking, the production of high quality steel, including Clean Steel, is one of the most important problems being addressed.;The procedures for Clean Steel making require an increase in the rate of separation of non-metallic inclusions from molten steel, and the prevention of fresh inclusions, caused by slag phase entrainment or by reoxidation reactions.;In this thesis, separation and entrainment phenomena associated with non-metallic inclusions were studied for the purpose of applying these results to the technology needed for producing Clean Steel.;In the first instance, a resistive-pulse method was developed so that the number of inclusions, and their sizes could be measured in situ, in an aqueous model.;The separation of inclusions in aqueous model tundishes of continuous casting machines was next studied, using this resistive-pulse technique. A mathematical model was developed, explaining the separation of inclusions as a function of casting conditions and inclusion size.;Finally, slag phase entrainment phenomena during bottom gas blowing was investigated using a two dimensional oil-mercury model, and an oilwater BOF model. Such phenomena can also be important for the promotion of slag-metal reactions in reactor vessels, such as BOF or secondary refining processes. |
