Quantifying the composite microhardness and fracture toughness of iron ore sinter – a phase-based approach

Abstract

Microindentation testing was undertaken on sinter phases in iron ore sinter to determine the range and mean of phase/morphology microhardness. The mean fracture toughness of each sinter phase/texture was calculated from indent-associated radial cracks. A value for the composite microhardness (CH) and composite fracture toughness (CFT) was calculated for each sinter sample, based upon the modal proportion of constituent sinter phases. The CH and CFT of sinter phases and each sinter sample was compared to a range of metallurgical indices and major element chemistry to determine the extent of any correlation. Moderate to strong negative correlations were observed between sinter CH and sinter Tumble Index,

Using a particle-based approach (sinter microtypes) for the geometallurgical characterisation of iron ore sinter

“…Plots of SCHv/k and SCFT against sinter RI and TI are shown in Figures 3 and 4 respectively. As for SCHv/k or SCFT calculated using sinter phase abundance (Peterson 2019), sinter CH/CFT calculated from sinter microtype abundance often grouped into Linear correlations for SCHv/k with RI and TI were weak to modest and variable, generally due to the presence of 1-2 outlying data points (shown within the red ellipses in Figures 3 and 4). For example, R 2 for RI and TI increased to 0.61 and 0.85 respectively, if the outlying values were excluded.…”

“…The sinter samples all included high proportions of the three main sinter phases: hematite (∼34-50%), magnetite (∼20-29%) and SFCA (∼21-36%). Further details of the samples are given in Peterson (2019Peterson ( , 2021.…”

“…Microhardness and fracture toughness data for different sinter phases and phase textures was obtained by microindentation testing using a Durascan-20 microhardness testing machine. Further details of the methodology are provided in Peterson (2019Peterson ( , 2021.…”

“…This study aimed to build on a previous publication which calculated sinter composite microhardness (SCH) and sinter composite fracture toughness (SCFT) using the modal abundance of common sinter phases and textural sub-types (Peterson 2019(Peterson , 2021. That study then examined the relationship between SCH/SCFT and sinter metallurgical indices and major element chemistry.…”

Effects of Basicity and Al₂O₃ Content on the Crystal Structure of Silico-ferrite of Calcium and Aluminum

“…×20 objective) was used to confirm the structural modification of the bonding characteristics of the samples. The micro-Vickers hardness (Shimadzu, Japan, HMV-G, load: 981 mN, holding time: 15 s) was used to verify the overall trends in the bonding characteristic modifications 41,42) . The micro-Vickers hardness test was performed ten times for each sample, and the average value was adopted.…”