Redox Equilibria and Kinetics of Gas-Slag Reactions

Measurements of redox equilibria involving a number of transition metals (Fe, Mn, Ti, and V) are summarized and discussed with respect to the effects of oxygen activity and chemistry of the melts on the oxidation state of the transition metal oxide. Recently measured data on kinetics of CO-CO2 on surfaces of calcium silicate-based slags containing 1 to 68 wt pct FeOx or 18 to 38 wt pct MnOx are presented and discussed in terms of the limiting steps and the dependence of the limiting step on concentration of the transition metal oxides in the melts. Similar data on nonferrous-type slags containing PbO, ZnO, or TiOx in the presence or absence of FeOx are also reviewed. The review also includes recent inves tigations of the effects of iron oxide on the diffusivity of iron and oxygen in slags.