Influence of slag chemical composition on steel ladle lining lifetime in steelmaking production at Promsort-Tula LLC

This article discusses the influence of slag chemical composition during secondary steel treatment on increasing the lifetime of steel ladle lining. Selection of rational slag compositions with low aggressiveness to the lining is a complex task to achieve higher lifetime. Increased wear of refractories in the slag line zone is associated with the following factors: chemical activity of high basicity slag, high temperature during electric arc heating of steel in the ladle furnace unit, long contact time of the lining with slag, lining erosion from mixing of molten metal during argon blowing. One of the most significant factors affecting the lifetime of ladle lining is the content of calcium oxide (CaO) in ladle slag, which thickens the slag and reduces its aggressiveness, wetting refractory lining products and forms a skull on the refractory surface, which is an additional protection of the refractory working surface from the aggressive effects of liquid steel. One of the goals of this work is to determine the optimal slag composition to achieve the ladle furnace lifetime of more than 100 heats. To achieve the calculated values for steel ladles lifetime, it is necessary to ensure a slag basicity of 2.5. In general, the problem of increasing steel ladle lining lifetime shall be solved not only by taking into account the influence of slag chemical composition, but also by considering the mechanical wear of steel ladle wall lining from the impact of stirred steel volume during intensive inert gas blowing.