DYNAMIC-MODEL OF SLAG FOAMING IN OXYGEN STEELMAKING CONVERTERS

The foaming and emulsification of steelmaking slags can be analyzed in terms of an emulsion number which is defined as the ratio of the velo city of gas bubbles and that of metal droplets present in slag at any given stage of the blow. An improved procedure is suggested to evaluat e the viscosity of gas-slag foam at high gas void fractions. The calcu lated velocity of gas bubbles in foaming slags is verified using the e xperimental results reported in literature. A critical comparison is a lso made with the other approaches available in the literature. II is shown that the emulsion number is directly related to foaming conditio ns. A dynamic model of slag foaming is developed on the basis of the b ubble and droplet velocities, changing slag composition and temperatur e and the continuous reduction of iron oxide content of slag during th e main blow period. Combined effects of lance nozzle design and blowin g regime on slag foaming are discussed.