Andradite titanium: Preparation, characterization and metallurgical performance

Abstract

AbstractAndradite titanium (Ca3Fe2Si1.58Ti1.42O12, abbreviated as AT), which is a significant mineral phase in the sinter of titanium‐containing iron ore, was prepared via a solid‐state reaction with analytical reagents. The crystal structure, cold strength, and high‐temperature heat capacity were individually characterized, and the metallurgical performance, such as melting and reduction behavior, were measured. AT is a variant of andradite (Ca3Fe2Si3O12) formed by the Ti4+ substitution for Fe3+ in the octahedral sites and Fe3+ substitution for Si4+ in the tetrahedral sites. The compressive strength of AT was approximately 14.21 MPa, and its softening, melting, and flowing temperatures were 1453, 1483, and 1509 K, respectively. According to the differential scanning calorimetry measurements, the melting point was approximately 1502 K. The non‐isothermal reduction results revealed that AT was reduced to Fe, perovskite, and wollastonite in a single step, and the isothermal reduction test indicated that the reduction degree of AT was only 0.67 when reduced at 900°C for 150 min, and the order of reduction performance was Fe2O3 > Fe3O4 > CaO·2Fe2O3 > CaO·Fe2O3 > 2CaO·Fe2O3 > AT. The high‐temperature heat capacity of AT as a function of temperature was also measured and modeled.