1992 Volume 78 Issue 3 Pages 383-390
A chemical reaction at the interface between slag and metal can be analyzed as a kind of electrode reaction because of the ionic nature of liquid slag.
In the present work, application of an A.C. impedance method to slag-metal reaction in iron- and steelmaking process was tried to clarify the individual kinetic factors concerning the electrode reactions at the interface between slag and metal. The total impedance between CaO-Al2O3 slag and Cu-S or Fe-C-S melts was measured in this paper.
The results obtained were successfully used to determine the individual factors on kinetics of the electrode reaction between slag and metal, such as solution resistance of slag, interfacial capacitance in electric double-layer, overvoltage of charge transfer, rate constant and so on. In each component of Faradaic impedance, ZF, relating to the electrode reactions at the interface between slag and metal, which were estimated by the parameter fitting, the magnitude of charge-transfer resistance, RC, was about 1/2 to 1/5 of that resistant component in reaction or crystallization impedance with diffusion, RR, for the anodic and cathodic reactions in both systems.