New method for viscosity estimation of slags in the CaO–FeO–MgO–MnO–SiO₂ system using optical basicity

Abstract

Several models have been proposed to estimate the viscosity of molten slag using optical basicity. In this work, a new method for viscosity estimation of silicate slag using optical basicity has been proposed. The temperature dependence of viscosity was described by the general Arrhenius equation, and the contributions of bridging oxygen (O 0 ), non-bridging oxygen (O 2 ) and free oxygen (O 22 ) to viscous activation energy in this equation were taken into account. Compositions of three types of oxygen were calculated from optical basicity using the Toop-Samis model combined with the method proposed by Ottonello and Moretti. The present method has been applied to estimate the viscosity of silicate slag in CaO-FeO-MgO-MnO-SiO 2 system. The comparison between estimated and experimental values shows good agreements, with a mean deviation of ,20%.

Influence of alumina on physical properties of an industrial zinc-copper smelting slagPart 1 – viscosity

“…In order to avoid the difficulties associated with experimental measurements and meet the industrial demands for viscosity data as a function of temperature and composition, several viscosity models have been developed (Urbain, 1987;Iida et al, 2000;Nakamoto et al, 2005;Shu and Zhang, 2006). Recently, attempts have been made to estimate the viscosity of molten slags by using the optical basicity (Shu et al, 2010;Ghosh et al, 2010). Among these, the most commonly applied models were proposed by Seetharaman et al (Sichen et al, 1994;Seetharaman and Sichen, 1994;Seetharaman and Sichen, 1997), Zhang and Jahanshahi (1998a,b) and Kondrative and Jak (2001).…”

Model for diffusion coefficient estimation of calcium ions in CaO–Al2O3–SiO2slags

“…NBO/T, optical basicity, free oxygen, bridging oxygen and non-bridging oxygen are commonly used to describe the structure of the slag. [10][11][12][13][14][15] In the current model, the structure of the slag was described by the optical basicity, which is also successfully used to estimate other physical properties of slag.…”

Structural viscosity model for aluminosilicate slags

“…14 For aluminosilicate slags, the charge compensation behaviour of Al-O tetrahedral was also considered in some models, 14,16 however, most of these models assumed full charge compensation of Al-O tetrahedral, which is not strictly correct from the structural view point. A viscosity estimation model for silicate slag was presented by the present author in a previous study 17 and takes the contributions of bridging oxygen (O 0 ), non-bridging oxygen (O 2 ) and free oxygen (O 22 ) to viscous activation energy into account. The compositions of three types of oxygen were calculated from optical basicity by the Toop-Samis model 18 combined with a method presented by Ottonello et al 19 20 proposed that the three types of oxygen are in a chemical equilibrium: (O 22 ) are the number of moles of bridging oxygen, non-bridging oxygen and free oxygen per mole of silicate melts.…”