A Raman-Structure Model for the Viscosity of SiO2-CaO-Al2O3 System
Shokouh Haghdani, Merete Tangstad, Kristian Etienne Einarsrud
Abstract
Abstract The relationship between structure and viscosity of molten slags is investigated using the Raman spectroscopy technique. To this end, a group of 20 synthetic slags in the SiO 2 -CaO-Al 2 O 3 ternary system is considered. The slag compositions are close to industrial slags in silicon and ferrosilicon production, namely SiO 2 contents of 35 to 75 wt pct, CaO contents of 10 to 40 wt pct, and Al 2 O 3 contents of 5 to 40 wt pct. Using a green source laser with 532 nm wavelength, the Raman spectra are measured within the wavenumbers on the order of 200 to 1300 cm −1 . 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 ). The Arrhenius equation is employed for the temperature dependency of the slag viscosity, where its parameters are linked to the R parameter through curve fitting. To model the relationship between structure and viscosity, experimental viscosity data are adopted from the literature. Comparing the model predictions and experiments, a good agreement is found between the model and measured values of viscosity.