Effect of impurity oxides on CWF (CaFe3O5) formation in lime magnetite pellets – part I: thermodynamic assessments and experimental investigations. (16th March 2021)

• Record Type: Journal Article
• Authors: Purohit, S.; Brooks, G.; Rhamdhani, M. A.; Pownceby, M. I.; Webster, N. A. S.
• Is Part Of: Ironmaking & steelmaking. Volume 48:Number 3(2021)
• Page Start: 299
• Page End: 312
• Publication Date: 2021-03-16
• Subjects: Lime magnetite pellets (LMPs) -- Ca–Fe–O–Al system -- Ca–Fe–O–Si system -- Ca–Fe–O–Mg system -- CWF phase (CaFe3O5) -- Ca2(Al, Fe)2O5) -- Ca2SiO4 -- XRD -- Rietveld QPA; Iron industry and trade -- Periodicals; Steel industry and trade -- Periodicals; 669.1
• DOI: 10.1080/03019233.2020.1774222
• Languages: English
• ISSNs: 0301-9233

Abstract

ABSTRACT: Lime magnetite pellets (LMPs) containing CWF phase (CaFe3 O5 ) provide potential feed materials for ironmaking. In this paper, the effects of typical impurity oxides inherent to magnetite ores such as Al2 O3, MgO and SiO2 on the formation of CWF in LMPs have been investigated. The thermodynamics of the Ca–Fe–O–X systems (X = Al, Mg or Si) were assessed followed by time-series experiments using natural and synthetic materials. The X-Ray Diffraction (XRD) results indicated a significant decrease in CWF percentage by over 45 wt-% and 18 wt-% with the addition of 5 wt-% SiO2 and 2 wt-% Al2 O3, respectively due to the formation of α' Ca2 SiO4 and Ca2 (Al, Fe)2 O5 phases. A 5 wt-% decrease in CWF amount was observed for 2 wt-% MgO added LMPs. In summary, the presence of impurity oxides limits the formation of CWF, which may affect the suitability of LMPs for industrial application.