Effect of Al₂O₃ on the Formation Mechanism of Calcium Ferrite

In the production of fluxed sinter,calcium ferrite as a low melting point compound which appears to be the starting point of liquid phase formation.During the sintering of iron ore the calcium ferrite acts as a reactant to form complex calcium ferrite in sinter,its amount and distribution affect the ore phase structure of sinter.In this paper,the influence of Al₂O₃ on the formation mechanism of calcium ferrite was studied by means of modern analysis and testing techniques,such as XRD and SEM.At temperature of 850 ~900 ℃,Al₂O₃ reacting with dicalcium ferrite（C₂F） forms calcium CA₂ and Calcium ferrite（CF）.When the temperature exceeds the 900 ℃,dicalcium ferrite starts reaction into ferrite calcium. When Al₂O₃ is lower in mixed ore,Al₂O₃ particles react almost completely with C₂F to form CA₂,at the same time some C₂F remained in the ore phase takes part into the reaction and eventually form the complex calcium ferrite.