IMPROVING THE EFFICIENCY OF THE FERROALLOY SMELTING PROCESS IN ELECTRIC ARC FURNACES BY IMPROVING CONTROL AND MANAGEMENT OF TECHNOLOGICAL MODES

Abstract

The article addresses the issues of improving the efficiency of ferroalloy smelting in electric arc furnaces by enhancing the control and management of technological regimes. Recent global trends, such as the increase in the production of high-quality alloy steels and semiconductor products, have led to a sharp rise in the demand for ferroalloys and crystalline silicon. In this context, the intensification of technological processes and the optimization of energy consumption in ferroalloy electric furnaces have become particularly relevant. The ferroalloy smelting process is based on the carbothermic reduction of metals from their oxides, occurring at high temperatures with significant heat absorption. Although the mechanisms and kinetics of the main reduction reactions have been well studied, in industrial conditions, the techno-economic indicators of the process are significantly inferior to those achieved in laboratory settings. The extraction rate of target elements decreases to 75–80%, and the energy consumption exceeds the theoretically necessary amount by 1.5–2 times. Traditional approaches to improving the ferroalloy smelting process through the enhancement of furnace designs and the selection of charge materials with specific physico-chemical properties have largely exhausted their potential. In the context of continuously rising energy costs and deteriorating raw material quality, the urgent problem now lies in implementing fundamentally new approaches to technological process control, focused on detailed monitoring and analysis of the furnace’s current state. The authors justify the necessity of transitioning from the "input-output" control system to a more advanced "input-state-output" principle, which enables real-time analysis of the furnace workspace parameters and prompt influence on the course of the technological process. In particular, significant attention is devoted to the development of methods for analyzing the electrical, thermal, and physico-chemical characteristics of the active zone of the furnace, which determine the main transformation processes of the charge. The paper discusses the design features of electric arc furnaces and describes the structure of the workspace for different types of processes - slag-free and slag-forming. It is shown that the distribution of energy among the zones of the charge, the arc, and the melt has a substantial impact on the techno-economic indicators of production. The peculiarities of arc burning, heat transfer processes, and ionization in the gas cavities of the furnaces are studied. The article highlights the main methods for investigating processes in furnaces: probing, analyzing oscillograms of current and voltage, determining the resistances of the charge and melt, as well as modern methods for assessing power distribution across furnace zones based on measurements of electrical parameters. Special attention is paid to the problem of increasing the accuracy of assessing the parameters of energy processes without interfering with the technological process. The authors emphasize the importance of optimizing the modes of electric power supply and the structural parameters of furnaces to ensure the stability of the bath operation, reduce the dispersion of fluctuations, and minimize losses. Methods for selecting optimal electrode immersion parameters, managing charge regimes, and selecting charge materials considering their electrophysical properties are presented. The article makes a significant contribution to the creation of a scientific basis for improving the efficiency of ferroalloy smelting, which is of particular importance in the context of the modern energy crisis and the growing demands for the quality of metallurgical industry products.