Fundamentals of silico-ferrite of calcium and aluminium (SFCA) and SFCA-I iron ore sinter bonding phase formation. Effects of MgO source on phase formation during heating

The relative effects of dolomite and serpentine/olivine as MgO flux sources on the formation of SFCA and SFCA-I iron ore sinter bonding phases during heating was investigated using in situ synchrotron X-ray diffraction. Results showed that a sinter mix containing serpentine/olivine as the primary source of MgO is more likely to form high quality sinter due to the higher proportion of SFCA-I being formed compared to SFCA. SFCA-I is the phase thought to impart high strength and good reducibility characteristics to iron ore sinter. For example, in mixtures containing 2 mass% MgO, when dolomite was used the maximum concentrations of SFCA-I and SFCA attained were 19 and 9 mass%, respectively, and when serpentine/olivine was used the maximum concentrations were 20 and 3 mass%, respectively. In mixtures containing 3 mass% MgO, the maximum concentrations were 18 and 4 mass% (dolomite) and 28 and 2 mass% (serpentine/olivine). (author)