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

ABSTRACT

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.

KEYWORDS:

• Lime magnetite pellets (LMPs)
• CWF phase (CaFe₃O₅)
• impurity oxides
• reducibility
• tumble index

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Swinburne University of Technology: [Grant Number HDR Publication Award].