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Flotation and assimilation of nonmetallic inclusions from metal slag in steel-pouring ladles and tundishes during pouring steels with increased aluminum and sulfur content are considered. The authors study the formation of nonmetallic inclusions in a steel-pouring ladle during steel extra-furnace treatment, the process of submerged nozzle clogging during continuous casting, the change in slag composition in a tundish, and development of an assimilation mixture composition for a steel-pouring ladle. Laboratory studies are made of the physicochemical properties of a developed SFM. It is established that use of the new SFM makes it possible to improve nonmetallic inclusion assimilation in a steel-pouring ladle and does not lead to a marked change in slag chemical composition and physical properties in a tundish. As a result of this, there is less steel contamination with nonmetallic inclusions and a reduction in submerged nozzle clogging.During the manufacture of continuously-cast billets (CCB) of steel with an high aluminum and sulfur content at the Volzhskii Pipe Plant (VTZ) electric steel smelting workshop, an increase was noted in the level of clogging with nonmetallic inclusions, which often leads to critical recycling of molten steel from the continuous billet casting machine (CBCM), and correspondingly to additional expenditure and loss of production. In addition, separation of nonmetallic inclusions (NI) deposits from the walls of a submerged nozzle and descent into the volume of steel in a mold leads to serious CCB defects, and in the worst case may become a reason for an accident in a CBCM (breakthrough of a solidifying billet skin). Nonmetallic inclusions that cause the clogging of submersible nozzles may be separated into two types. The fi rst type includes NIs that formed in steel before the instant of its passage through a submerged nozzle, for example, in the course of steel deoxidation and alloying, and the second includes NIs that form in steel during its movement through a submerged nozzle as a result of cooling. A method is given in this work making it possible before casting in a CBCM to reduce the steel content of the fi rst type of NIs, and thereby improve casting suitability of problem steel grades.Analysis of published data for application in a steel-pouring ladle (SL) of specialized slag-forming mixtures improving the assimilation capacity of a slag melt has shown inadequate study of this problem. The authors in [1] have developed a technology intended for adding to an SL after the end of degassing an acid melt with basicity 0.7-1.1, and after obtaining a uniform and fl uid slag, switching off the heating unit (furnace ladle), after which the metal is sent to the CBCM. 1082A technology is described in [2] for production of steel according to which in an SL before degassing a low basicity slag is added, and then the metal is degassed and transferred to a furnace ladle unit where its composition with respect to carbon and temperature is adjusted, after which it is poured into the CBCM. As a re...

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