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The aim of the work is the development of models for predicting the properties of final blast-furnace slags for the rapid assessment of the slag regime and the development of sound management recommendations when using various additives in the operating conditions of blast furnaces in Ukraine. A two-stage approach to calculating the properties of blast-furnace slag is proposed: according to the model of a “homogeneous” melt and taking into account its heterogeneity. A predictive model has been developed for calculating the viscosity of a «homogeneous» slag by including the integral parameter of the slag melt parameter e in the model structure, which takes into account the individual effect on the viscosity of each component of the slag composition. The current production data of the chemical composition of the final slag shows the effect of the magnesia content, alkaline compounds, basicity, Al2O3/MgO ratio on the calculated viscosity of the slags. For various operating conditions of blast furnaces, it has been shown that, due to incomplete combustion of coke and pulverized coal, the viscosity of slags increases by 1.5–2 times and their melting temperatures by 30–500C. Comparative analysis of the calculated properties of slag for different operating conditions of 3 furnaces in Ukraine confirms the appropriateness of using a complex of predictive models for the rapid assessment of the technological properties of slag, which makes it possible to choose a rational slag mode in modern conditions of blast smelting.

The purpose of this work is to implement a new approach to the description of the duration of melting (dissolution) of complex new generation ferroalloys during the deoxidation and doping of a metal melt. This approach is aimed at developing a methodology and criteria for the quantification and accounting of the micro-heterogeneity of multicomponent metal melts and their prediction on such important for steelmaking production characteristics as the melting time of ferroalloys, the description of the inter-mine interaction, which allows a deeper understanding of the process. deoxidation and refining of steel. In the work, the approach developed in the Institute of Ferrous Metallurgy of the National Academy of Sciences of Ukraine to solve problems of modeling of non-conformities that relate the composition, structure and properties of melts is used in the work. It is based on the original concept of physicochemical modeling of the processes of interatomic interaction in melts and solutions, developed by E.V. Prihodko. According to it, metal melts are considered as chemically unified systems. Changing their composition affects the complex of physicochemical properties due to changes in the parameters of their electronic structure. The method of calculation of criteria (∆Zy and d), characterizing the degree of difference between the electronic and structural state of the melt, as a chemically unified system, from the mechanical mixture of their initial components and the parameter was used to evaluate and account for the influence of the micron homogeneity of the structure of the metal melts of ferroalloy production. ρl, which takes into account the cluster spin in metal melts. Using these criteria and the available experimental data, analytical dependences were obtained to calculate the melting time of complex (ma-manganese, vanadium, niobium and boromatic) ferroalloys of the new generation. This will allow them to evaluate their effectiveness of application, which is associated with the highest assimilation of the main elements that affect

Nowadays, one of the pressing issues is the problem of reducing material and energy costs in the production of certain types of products. Of particular importance are issues of slag formation due to the development of a ladle furnace (LF) plant for smelting special and alloyed steel grades with stringent requirements for the content of harmful impurities. Therefore, the question of choosing the rational composition of the slag-forming mixture (SFM) requires special attention. The aim of this work is to carry out research to solve the problems of improving the quality and competitiveness of manufactured metal products. The paper presents analytical and experimental studies of the phase composition and melting temperature of the CaF2-CaO system, which is the basis of the slag-forming mixture for refining steel in a ladle at domestic metallurgical enterprises. Previous studies on the replacement of fluorspar in the SFM with mineral raw materials of the domestic field showed that the alternative is the use of pegmatite from the Eliseevskoye field (Zaporizhzhya region). This contains alkali metal oxides Na2O and K2O, which affect both the decrease in slag viscosity of metallurgical production and the effect of desulfurization of the metal melt. Experimental studies of the melting points of fluorspar, pegmatite, and mixtures thereof with lime have been performed. Also, corundum and periclase-carbon refractory, which is usually used for lining the slag belt of LF buckets, were used as a substrate on which the process of melting of the studied materials and their mixtures took place. It is shown that pegmatite favorably affects the process of lime rarefaction and the formation of slag melt and can be used as a component of the SFM. The use of pegmatite can completely or partially replace fluorspar in the composition of the slag mixture with lime.

The aim of the work is to develop physicochemical bases for predicting the technological properties of finite blast furnace slags, algorithmic and software for the subsystem for diagnosing the slag regime of blast furnace smelting. Based on experimental data on the properties of natural finite blast furnace slags, predictive models for calculating the viscosity of the final slag at a temperature of 1400-1550 °C were improved by including in the model structure an integrated slag melt index of the parameter Δe, which reflects the individual effect. Using the integral parameters of the slag melt characterizing the charge state of the system Δe and the structure of the slag ρ, an equation was developed to determine the viscosity of the slag at any temperature corresponding to the slag temperature at the cast iron outlet. As a result of analytical research, a predictive model for determining the enthalpy of slag depending on the integral parameters Δe and ρ and the temperature of the melt has been developed. It is shown that the viscosity characterizes the fluidity of the slag and provides desulfurizing and drainage properties. The calculation of the viscosity for the specified production of pig iron by the chemical composition of the slag is carried out according to the basic model of slag in a conditionally "homogeneous" state and taking into account its heterogeneity. This takes into account the presence of macroheterogeneous inclusions formed when using coke with low strength characteristics and due to incomplete combustion of pulverized coal fuel in the blast furnace. The improved models for evaluating the viscosity and enthalpy of the final slag are software implemented in the new version of the «Slag» system for operational control of the slag mode of blast furnaces in Ukraine. Rapid assessment of the slag mode using the «Slag» system as part of the DCS allows you to effectively and at a modern level solve the problems of optimizing the slag mode and the quality of pig iron in modern conditions of blast furnace smelting.