Assessment of viscosity calculation for calcium-silicate based slags using computational thermodynamics

Abstract

This study focuses on the viscosity calculation of molten slags using computational thermodynamics. Different slag systems and their measured viscosities from different references were used and compared with those obtained through FactSage software. To calculate the viscosity of each slag the Viscosity module available in Fact-Sage 6.4 was used. In order to perform the evaluation of computational thermodynamics in viscosity calculation, six different slag systems were presented, all of which were formed of calcium-silicate melts. In total, 162 slags, in temperatures ranges from 1423 K (1150 ºC) to 2089 K (1816 °C) were presented for all slag systems. The software showed a tendency to produce viscosity values lower than those found in the literature measured by an experimental method. The relative deviation between the measured and calculated viscosity values is in the range of 13.31 to 37.53% for evaluated systems. Considering all references and systems, the average deviation between measured and calculated viscosities is 23.61%, which, according to literature, is an acceptable value. The CaO-SiO 2 -Al 2 O 3 and CaO-SiO 2 -FeO systems showed the best agreement between the experimental method and the method calculated through FactSage 6.4 with a very good fitting between viscosity values.

Effect of CaF₂ on Viscosity and Refining Ability of Highly Basic Slags for Duplex Stainless Steel

“…The SF1 slag containing 6% CaF 2 has the largest mean deviation of 38.4%, while the SF2 slag containing 8% CaF 2 has the smallest mean deviation of 20.2%. The mean deviations in this work are in good agreement with the report by Rocha et al 36) that the mean deviation between the calculated viscosities through the FactSage software and the measured viscosities lies in the range of 13.31%-37.53% for 162 slags in total. Note that in the viscosity calculations by Rocha et al 36) solid precipitates in all slags were not considered and thus no viscosity correlations for partially crystalized slags were used.…”

“…The Viscosity module directly relates the viscosity to the structure of the melt, and the structure is calculated from the thermodynamic description of the melt using the Modified Quasichemical Model. 36) Note that the Viscosity module is applicable only for singlephase liquid slags. Presence of solid particles significantly affects the viscosity of the liquid phase containing the solid particles.…”

“…Moreover, the performance of the viscosity modelling through FactSage and Einstein-Roscoe equation was evaluated by the mean deviation between measured and calculated viscosities, as expressed below. 36) '…”

Analysis of Secondary Refining Slag Parameters with Focus on Inclusion Cleanliness

“…The FactSage software gives an adequate result for the viscosity calculations with fluoride slags CaO-SiO 2 -Al 2 O 3 -MgO-CaF 2 . The FactSage model has been validated in previous studies [30][31][32] , showing that the difference between calculated and experimental viscosity are estimated to be about 30 %. In fact, the FactSage method has the least amount of errors, when compared to others models.…”

Laboratorial Analysis of Inclusions Formed by Reoxidation in Tundish Steelmaking

“…The values for oxygen varied from 0 to 80 ppm, since the increase in this element indicates an increase in the reoxidation level. FactSage has been used by LaSid's research group throughout the past years in works related to thermodynamic properties of steel and slag, showing good results …”