PROSPECTS FOR THE USE OF OUT-OF-FURNACE CAST IRON REFINING TECHNOLOGIES IN THE CONTEXT OF DOMESTIC METALLURGICAL PRODUCTION

Abstract

In today's environment, domestic steelmaking enterprises, and especially steelmaking within them, are experiencing a significant negative impact from the shortage of high-quality raw materials and the lack of stability of incoming charge materials. At the same time, in order to overcome these problems, technical solutions are used in the world practice for out-of-furnace treatment of charge materials, including liquid iron. Thus, an urgent issue of domestic metallurgical science is to determine the effectiveness of the most common methods of out-of-furnace pig iron treatment in relation to the current realities of domestic steelmaking.
 A general classification of technical solutions for out-of-furnace pig iron refining has been made and a comparative analysis of the efficiency of the technologies under consideration has been performed. Engineering calculations were performed using mathematical models of material and heat balances of converter smelting, adapted for 250-ton oxygen converters, using a top tuyere of classical design. The influence of the considered technical solutions for out-of-furnace iron treatment on such basic technological indicators of BOF melting as specific consumption of liquid iron, specific consumption of lime, and yield of usable iron was analyzed. The comparison was carried out in relation to the indicators of basic melting without the use of out-of-furnace melt treatment technologies. The expediency of using out-of-furnace refining methods based on the injection of globular magnesium and mixtures of the CaO-Mg system was confirmed. As for the complex refining technologies, it was determined that it is advisable to develop a technology for domestic conditions that provides for the removal of sulfur and phosphorus from the melt without significantly reducing the concentration of silicon in the melt.