XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1861
formed continuously during the reduction process and may
be related to the gradual accumulation and final rupture
of locally trapped gas (e.g., the water) pressure in metal-
lic iron defects (e.g., vacancies, dislocations, or micropores)
(Kim et al., 2021 Ma et al., 2022). The cracks formed by
the rupture of the iron layer exposed the internal unre-
duced iron oxides and shortened the diffusion distance
of O atoms, which was crucial for the mass transfer pro-
cess. Suanite, a decomposition product of szaibelyite, was
encapsulated inside the particle (spot 9) and cracked after
dehydration. The Fe content in spots 7 and 10 (Figure 11)
was significantly higher than that in Spots 5–7 (Figure 10)
and presented a porous structure, suggesting that the lud-
wigite was completely reduced and decomposed to metallic
iron and suanite. The map scanning results of Figure 11 (h)
are illustrated in Figures 12 (j–m). The gray porous par-
ticles in Figure 11 (h) had high Fe and Mg contents, which
exhibited that they were the reduced products of ludwigite.
Figure 10. SEM and EDS results at 500 °C–650 °C: (a–c) 500 °C (d–f) 550°C (g–i) 600 °C (j–l) 650 °C
formed continuously during the reduction process and may
be related to the gradual accumulation and final rupture
of locally trapped gas (e.g., the water) pressure in metal-
lic iron defects (e.g., vacancies, dislocations, or micropores)
(Kim et al., 2021 Ma et al., 2022). The cracks formed by
the rupture of the iron layer exposed the internal unre-
duced iron oxides and shortened the diffusion distance
of O atoms, which was crucial for the mass transfer pro-
cess. Suanite, a decomposition product of szaibelyite, was
encapsulated inside the particle (spot 9) and cracked after
dehydration. The Fe content in spots 7 and 10 (Figure 11)
was significantly higher than that in Spots 5–7 (Figure 10)
and presented a porous structure, suggesting that the lud-
wigite was completely reduced and decomposed to metallic
iron and suanite. The map scanning results of Figure 11 (h)
are illustrated in Figures 12 (j–m). The gray porous par-
ticles in Figure 11 (h) had high Fe and Mg contents, which
exhibited that they were the reduced products of ludwigite.
Figure 10. SEM and EDS results at 500 °C–650 °C: (a–c) 500 °C (d–f) 550°C (g–i) 600 °C (j–l) 650 °C