2004 Volume 44 Issue 12 Pages 2046-2051
The effect of the particle size of hematite on the formation rate of calcium ferrite melt and the dissolution rate of solid hematite into molten calcium ferrite were investigated. Without regard to the particle size of hematite, the addition of SiO2 was more effective than the addition of Al2O3 for increasing the melting rate and reducing the melt formation temperature in calcium ferrite system. On the other hand, the addition of Al2O3 was more effective than the addition of SiO2 for increasing the dissolution rate of solid hematite into the generated molten ternary calcium ferrite. The amount of dissolved hematite into molten calcium ferrite increased linearly with increasing the immersion time. The dissolution rate of solid hematite into molten calcium ferrite was mostly determined by Δ(mol%Fe2O3) that was considered to be the driving force of the dissolution and the effect of the revolution speed on the amount of dissolved hematite can be negligible. Therefore, the dissolution reaction of solid hematite at the reaction interface was the rate-controlling step under the condition of this study.