コールド・モデルによる底吹き転炉内スラグ,メタルの混合速度

Abstract

Synopsis:Water model experiments have been conducted to clarify mixing rates of molten steel and mass transfer rates between slag and metal in Q-BOP with a particular emphasis on the comparison with those of LD.Complete mixing time of molten steel determined by a tracer dispersion technique is, respectively, 23 to 26 sec for Q-BOP, and 100 to 200 sec for LD. This indicates that the stirring intensity in Q-BOP is remarkably larger than that of LD when compared with the same flow rate of gas. A simple relationship obtained between the mixing time, τ (sec), the flow rate of gas, Q(Nl/min) and the number of tuyeres, N is τ=41.80 (Q/N)-0.33, from which it is clear that the flow rate of gas per tuyere should be increased to realize the better mixing. Mass transfer capacity coefficient between slag and metal designated by the product of the mass transfer coefficient and the interfacial area, kBa, is given by kBa=3.49 × 10-5 Q3 for Q-BOP and by kBa=-1.53 × 10-5 Q3 for LD, respectively. Through these results, it can safely be concluded that the mass partition between slag and metal in Q-BOP is more closely linked to the thermodynamic equilibrium than that of LD.