Аналітичні та експериментальні дослідження властивостей шлаків та шлакоутворюючих сумішей сталеплавильного виробництва

Abstract

The aim of the study is to analyze and generalize the properties of slags within the CaO-SiO2-Al2O3-MgO-CaF2 system in different ratios of components and their concentrations, which is the basis of refining slags in modern steelmaking. To ensure the technological functions, the slag melt should have a set of optimal values of physical and chemical properties, in particular: viscosity, surface tension, electrical conductivity, melting temperature (beginning and end), enthalpy, density and others, which significantly affect the kinetics of heat and mass transfer processes in the "metal-slag" system. The information resource of researches is provided by own experimental data and data of databases "Slag" and "SFM" containing information about technological properties of melts of slag and oxide systems. The analysis of the data on the dependence of the properties of oxide systems on their chemical composition and temperature was performed. Oxide systems within the chemical composition CaO-SiO2-Al2O3-MgO-CaF2 are considered. The connection of the chemical composition of slag systems with the properties of their melts from the point of view of the concept of directed chemical bonding using integral parameters is established: ρ is the stoichiometry index; ∆e is the average number of electrons localized in the direction of the cation-anion (K-A) bond; d is the average inter-nuclear distance K-A; tgα is the change in the electron density in the direction of the K-A bond; ZA(A-A), ZK(K-A), ZK(K-K) are the weighted average values of cation and anion charges in the A-A, K-A, K-K bonds. Based on the results of experimental and analytical studies, predictive models of the properties of the considered oxide systems were obtained, namely for the calculation of viscosity, electrical conductivity, crystallization temperature and density of slag melts in the range of their temperatures from 1200°C to 1800°C. The presented method of predicting the properties of refining slags can be used to evaluate the use of slags of different composition in the ladle, for example, in ladle-furnace installations.