Rate of Reduction of Silica in Slag by Carbon in Liquid Iron

Abstract

The rate of reduction of silica in CaO-Si0₂ and CaO-Al₂0₃-Si0₂ slags by carbon in liquid iron was measured under various experimental conditions to examine effects of slag composition, temperature, atmosphere and slag graphite interfacial area.
Effect of slag composition was ascribed to the change of activity of silica. Apparent activation energies were about 100kcal/mol for binary slags and 70-85kcal/mol for ternary slags.
The rate of reduction increased linearly with the ratio of slag-graphite to slag-metal interfacial area in the low ratio region. It suggests that reaction of silica reduction proceeds electrochemically, and that interfacial reaction is the rate-determining step.
The rate of reduction in argon atmosphere was about twice as fast as that in CO atmosphere.