Viscosity of slags- an important property in process simulations

摘要

The need for accurate data of slag viscosities and extrapolation of the same as functions of temperature and composition have long been felt by process modellers. A number of viscosity models have been proposed; but the predictive accuracy of the models can only be as accurate as their input data. This presentation outlines the ongoing research work at the Royal Institute of Technology in this field A long-term program on the measurement of slag viscosities and modelling of the same had been initiated in the Division of Metallurgy, Royal Institute of Technology a few years back. Successful measurements of viscosities of silicate slags containing one or more of the following components CaO, MgO, MnO, FeO and Al_2O_3 have been carried out and a model that enables the extrapolation of the experimental data both as a function of temperature as well as composition has been put forward. This model is available as a commercial software. In order to describe the viscosities of mould flux slags, the model was extended to silicate melts containing calcium fluoride. Simultaneous experimental measurements were carried out in the case of lower order systems. Parallel to the studies of the viscosities of single phase melts, water model studies were carried out to describe the viscosities of two phase melts with widely differing viscosities, simulating metal phase dispersed in slags. The effective viscosities were found to be higher than the individual viscosities of the two pure phases.