工程科学学报 (Sep 2020)
Structurally-based viscosity model for multicomponent slag systems
Abstract
Viscosity is a physical property of fluids and shows resistance to flow. In metallurgical slag, it directly affects various parameters of a metallurgical process such as reaction rate, separation effect, etc. The estimation of viscosity by models during a production process is considered to be much more effective owing to the production fluctuations and complexities of the slag composition. Many viscosity models have been developed in the past, such as the structural model with a wide range of adaptability and complex calculation process and the empirical and semiempirical models with simple structure and a narrow range of adaptability. The present paper proposed a new method to calculate the structural parameter (NBO/T) ratio (the amount of nonbridging oxygen per tetrahedral-coordinated atom), based on which the relationship between the viscosity of molten slag and (NBO/T) ratio was investigated. First, the viscosity model was applied to SiO2–ΣMxO slags, with the model parameters obtained by fitting the viscosity data of pure oxide and SiO2–MxO binary slag, and the average deviations were in the range of 9%–18.5%. Then, the model was extended to calculate the viscosity of SiO2–Al2O3–ΣMxO, a multicomponent complex aluminosilicate system, and Al2O3 was split into acid and basic oxides. Then the oxides were used for calculating the (NBO/T) ratio and viscosity activation energy based on the amphoteric behavior of Al2O3 in SiO2–Al2O3–MxO ternary slag system. Using the parameters of a SiO2–MxO binary system, the model parameters of the Al2O3-containing slag system were obtained by fitting the viscosity data of the SiO2–Al2O3–MxO ternary slag system with average deviations between 10% and 25%. In addition, the viscosity of a multi-complex system (SiO2–Al2O3–CaO–MgO–FeO–Na2O–K2O–Li2O–BaO–SrO–MnO) and its subsystems were also calculated using the model proposed in this paper, and the average deviations is less than 25%, which shows relatively accurate prediction results. The present model is based on the analysis of a slag structure and processing of data by an empirical method. This method has a better prediction effect and wider application range compared with the traditional empirical model, and it uses a simpler calculation process compared with the structure model.
Keywords
