EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

The viscosity of molten slags is the most important physical property, which plays key roles in industrial operations. At a given temperature, this macroscopic property depends on the slag structure. Raman spectroscopy is a powerful method to provide valuable information on the structural properties of melts and glasses, providing an applicable technique to relate the variations of macroscopic properties to melt structure. To model viscosity using the Raman spectroscopy data, the ratio of low and high wavenumber vibrational bands is introduced as a structure-related Raman parameter (R). We use the Arrhenius equation for the temperature dependency of the slag viscosity, where its parameters are linked to the R parameter through curve-fitting. We consider a group of 20 synthetic slags in the SiO$_2$-CaO-Al$_2$O$_3$ ternary system. The slag compositions are close to industrial slags in silicon and ferrosilicon production, namely SiO$_2$ contents of 75–35 wt%, CaO contents of 10–40 wt%, and Al$_2$O$_3$ contents of 5–40 wt%. Using a green source laser with 532 nm wavelength, the Raman spectra are measured within the wavenumbers on the order of 200–1300 cm$^{-1}$. In order to model the relationship between structure and viscosity for this group of silicate slags, experimental viscosity values are adopted from literature. Comparing the model predictions and experiments, we find a good agreement between the model and measured values of viscosity. This Raman-based model offers a promising tool for prediction of transport properties of slags in high-temperature metallurgical processes.