Ore-blending optimization for Canadian iron concentrate during iron ore sintering based on high-temperature characteristics of fines and nuclei

Canadian iron concentrate (CIC) can elevate the ferrous grade and lower the contents of gangue components and harmful elements in the sinter. To understand high-temperature characteristics of CIC and typical iron ore, the formation of the melt was calculated mainly through FactSage 7.2, and melt fluidity (MF) test for iron ore fines and penetration characteristic test of CIC melt into iron ore nuclei were carried out via micro-sintering method. The results show that hematite, calcium ferrites, dicalcium silicate, and magnetite take part in the formation of the melt in N-2. The formation temperature of the liquid for CIC is higher than that for hematite/limonite ore. The MF of CIC is lower than that of hematite/limonite ore fines. The MF of hematite/limonite ore fines is dominated by the liquid amount and melt viscosity. The penetration depth (PD) of CIC melt into limonite ore nuclei is smaller than that into hematite ore nuclei. The PD is related to the reaction ability of the nuclei with the melt. Based on above results, sinter pot tests were conducted. The result shows that in the base ore blends including two hematite ores and two limonite ores, adding CIC deteriorates the sintering indexes. Increasing the proportion of high-MF and small-PD hematite ore can significantly improve the sintering indexes. 10 mass% is a suitable proportion for adding CIC in ore blends.