PROCESS OF REFINING STEEL IN A LADLE BY MAKING USE OF SYNTHETIC SLAG AND A SLAG-FORMING MIXTURE FOR MAKING THE SAME

摘要

This invention relates to the refining of steel external to a primary steelmaking vessel, for example in the ladle. More particularly, it is: A.) a method of synthesizing a slag on the steel that (i) mitigates the detrimental effects of existing natural slag carried over from the primary steelmaking vessel, (ii) is low in specific bulk density, due to gas evolution and foaming, (iii) is suitable for refining of steel, and (iv) is not aggressive to the ladle refractory lining; B.) a method, and composition for treating any primary slag that has entered the ladle; C.) a method and composition for coating refractory linings. The present invention involves the manufacture in situ of a secondary ladle slag, the treating of ladle slag, and the protection of refractory linings by the addition of materials including calcium carbide, foaming agents such as one or more carbonates of calcium, magnesium, and sodium, and other components used to adjust slag composition. The properties of the secondary ladle slag are engineered using an optical basicity scale.