Thermophysical properties of synthetic slags of the FeO – MnO – CaO – Al₂O₃ –– SiO₂ system

Abstract

In the electrometallurgy of manganese alloys, viscosity has an important effect on the production indicators from the physicochemical properties of slag. During the smelting of manganese alloys, the main amount of heat spent on reduction reactions is released due to the current passing through the liquid slag phase, since the resistance of the latter, depending on the composition, affects the completeness of the reduction of manganese from melts. In the case of refined ferromanganese by the silicothermic method, the vast majority of silicon of silicomanganese is refined with higher manganese oxides or it is burned out due to oxygen in the air. The paper presents the results of thermophysical properties of slags representing the FeO - MnO - CaO - Al₂O₃ - SiO₂ system. Laboratory experiments were carried out on synthetic slags by varying the slag basicity CaO / SiО₂ = 1.5 - 1.9 and the concentration of Al₂O₃ = 5 - 15%. As a result, graphs of the dependence of these properties on temperature values are constructed, the activation energies of the viscous flow are calculated and the phase compositions of the experimental slags are determined using a mathematical model of the diagram of the FeO - MnO - CaO - Al₂O₃ - SiO₂ system. Thus, an increase in the concentration of aluminum oxide against its usual level, changing the basicity of the slag, significantly affected the physicochemical properties of the slag and thereby contributes to the adjustment of the parameters of the electric melting process. At the same time, it is advisable to study the interaction of some Physical chemical properties of slags on the melting conditions of manganese ferroalloys in relation to the composition of slags.