Experimental studies of the melting points of CaF2, pegmatite, and mixtures thereof with lime

Abstract

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.