The prediction of gas residence times in foaming CaO-SiO2-FeO slags

Abstract

A dynamic, non-equilibrium model of foaming: Sigma=1x10(6)(mu.E-eff/(rho g)(2)d(3)) which relates the residence times of gas bubbles in foams (Sigma) to the viscosity of the liquid phase (mu); the effective elasticity (E-eff) resulting from the dynamic adsorption of surface active species; the liquid phase density (rho); and the mean bubble diameter (d); has been applied to foaming in the CaO-SiO2-FeO system at 1 823 K. In agreement with industrial observations, the model shows a transition from a foaming regime to a non-foaming regime as the slag basicity increase above 1.5. This is due to poor surface elasticity resulting from the negligible adsorption of silica in this region.