Effect of impurity oxides on CWF (CaFe3O5) formation in lime magnetite pellets – part II: microstructural analysis and physical and mechanical testing

The physical and mechanical properties of iron ore agglomerates are highly dependent on their chemical, mineralogical and microstructural properties. The effect of Al2O3, MgO and SiO2 on the phases generated during the reaction of lime magnetite pellets (LMPs) were presented in Part-I of the current study. In this Part II study, a detailed chemical and microstructural analysis is presented in order to understand the distributions of phases with respect to CaFe3O5 (CWF) in the LMP microstructure. The reducibility and Tumbler Index of LMPs is also measured. The results suggested no substantial effect of impurities on the reducibility of LMPs. However, the presence of 5 wt-% SiO2 and 2 wt-% MgO reduced the TI by 5% and 3%, respectively. Addition of 2 wt-% Al2O3 improved the TI by 0.2%. This suggests the need for additional evaluation the LMP route as viable feed materials for ironmaking.