Understanding the Properties of Slags

摘要

Understanding of the properties of slags is a pre-requisite in optimizing their functions towards the making and refining of steel. Important contributions towards this objective have been made over the past half a century, in different parts of the world, especially in USA, UK, Germany and most of all in Japan. Knowledge of the slag properties enables in understanding the slag structure as well. The present review paper summarizes the contributions made in this field by the Division of Materials Process Science, Royal Institute of Technology, Stockholm, Sweden.The paper deals with the measurement and modeling of (a) thermochemical properties of slags, (b) ther-mophysical properties and (c) inter-property correlations. Some important contributions during recent years, such as the determination of the valence states of Cr and V in slags, wetting characteristics related to hot-metal desulphurization, diffusion of sulphide ions in slags, partition of phosphorus between slag and metal phases and studies on process phenomena such as foaming are highlighted. The research work has led to the evolution of a new basicity concept. Dynamic physical property measurements are pointed out to be an experimental tool towards understanding of reaction mechanisms. Developments with respect to slag/metal interfacial phenomena, viz. the concept of surface velocity and surface viscosity and quantification of these properties are presented.