A Consideration on the Interfacial Tension between Metal and Slag with Iron Transfer through the Interface

Abstract

An approach based on the thermodynamics of irreversible processes has been applied to the study of the interfacial tension σ′_ms between liquid dilute Fe-Si-O alloys and CaO-SiO₂-FeO slags of nonequilibrium state during iron transfer through the interface. Behaviours of the σ′_ms obtained by experiments could be explained reasonably from the phenomcnological equation, which describes the coupling phenomena between surface flow and mass flow. Surface transfer coefficients M and phenomenological coefficients, L₂₂ and L₂₁ (=L₁₂) were evaluated from the experimental results of σ′_ms. Relations between the iron transfer rate and the values, M, L₂₂, and L₁₂ could be explained reasonably from the movements of the metal-slag interface and the direction of the iron transfer by considering the physicochemical properties of the system. The values, M and L₁₂ in the case of the iron transfer from the metal to the slag in steady state indicate the possibility of the actual increase in the iron transfer rate by the interfacial movements.