1928 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
models in the process of minerals phase transformation is
indicated in Figure 13.
As illustrated in Figure 13, the particle of oolitic hema-
tite were initially heated, leading to a uniform tempera-
ture distribution. As the reduction temperature increased,
hematite was transformed into magnetite by the reductant
when the reductant was introduced, causing the formation
of fissures and cracks in the oolitic structures. The reduc-
tant is consumed and generates H2O and CO2, leaving the
particle along the cracks. Therefore, the formation of fis-
sures and cracks, destruction of the oolitic structure, and
magnetic properties of the reduction product are the pri-
mary factors contributing to the enrichment of iron from
oolitic hematite. Due to the emission of reductant, the den-
sity of the product is not particularly high, facilitating the
monomer dissociation of iron minerals and gangue.
CONCLUSIONS
In conclusion, the iron enrichment from oolitic hematite
was successfully demonstrated via the process of minerals
phase transformation and magnetic separation, which iron
concentrate was obtained with an iron grade in concen-
trate of 56.84% and iron recovery of 96.31%. Based on
the above experiments and characterization studies, hema-
tite was transformed to magnetite during the process of
minerals phase transformation. The evolution of mineral
phases, magnetic properties, and microstructures evolu-
tion was investigated during minerals phase transforma-
tion by XRD, VSM, XPS, and SEM. The magnetization
and specific magnetization susceptibility of the reduction
product reached a maximum value at 28.7436 A·m2·kg–1,
0.1975×10–3 m3·kg–1, respectively. Moreover, SEM analy-
sis revealed that fissures and cracks grew and extended to
the inner core, facilitating the monomer dissociation of
iron minerals and gangue. The process of minerals phase
transformation provides significant support for the efficient
utilization of oolitic hematite and reveals high practicability
and application prospects.
Table 3. EDS component analysis results of points (wt.%)
Position
Element Mass n(Fe)/
n(O) Fe O Total
Point 1 58.58 41.42 100.00 1.41
Point 2 60.45 39.55 100.00 1.53
Point 3 64.83 35.17 100.00 1.84
Point 4 70.21 29.79 100.00 2.35
Point 5 70.24 29.76 100.00 2.36
Point 6 71.94 28.06 100.00 2.56
Point 7 72.01 27.99 100.00 2.57
Point 8 74.45 25.55 100.00 2.91
Point 9 75.11 24.89 100.00 3.02
Point 10 76.43 23.57 100.00 3.24
Point 11 77.31 22.69 100.00 3.41
Point 12 75.35 24.65 100.00 3.06
Figure 13. Schematic of the influence mechanism of the transformation of oolitic hematite
models in the process of minerals phase transformation is
indicated in Figure 13.
As illustrated in Figure 13, the particle of oolitic hema-
tite were initially heated, leading to a uniform tempera-
ture distribution. As the reduction temperature increased,
hematite was transformed into magnetite by the reductant
when the reductant was introduced, causing the formation
of fissures and cracks in the oolitic structures. The reduc-
tant is consumed and generates H2O and CO2, leaving the
particle along the cracks. Therefore, the formation of fis-
sures and cracks, destruction of the oolitic structure, and
magnetic properties of the reduction product are the pri-
mary factors contributing to the enrichment of iron from
oolitic hematite. Due to the emission of reductant, the den-
sity of the product is not particularly high, facilitating the
monomer dissociation of iron minerals and gangue.
CONCLUSIONS
In conclusion, the iron enrichment from oolitic hematite
was successfully demonstrated via the process of minerals
phase transformation and magnetic separation, which iron
concentrate was obtained with an iron grade in concen-
trate of 56.84% and iron recovery of 96.31%. Based on
the above experiments and characterization studies, hema-
tite was transformed to magnetite during the process of
minerals phase transformation. The evolution of mineral
phases, magnetic properties, and microstructures evolu-
tion was investigated during minerals phase transforma-
tion by XRD, VSM, XPS, and SEM. The magnetization
and specific magnetization susceptibility of the reduction
product reached a maximum value at 28.7436 A·m2·kg–1,
0.1975×10–3 m3·kg–1, respectively. Moreover, SEM analy-
sis revealed that fissures and cracks grew and extended to
the inner core, facilitating the monomer dissociation of
iron minerals and gangue. The process of minerals phase
transformation provides significant support for the efficient
utilization of oolitic hematite and reveals high practicability
and application prospects.
Table 3. EDS component analysis results of points (wt.%)
Position
Element Mass n(Fe)/
n(O) Fe O Total
Point 1 58.58 41.42 100.00 1.41
Point 2 60.45 39.55 100.00 1.53
Point 3 64.83 35.17 100.00 1.84
Point 4 70.21 29.79 100.00 2.35
Point 5 70.24 29.76 100.00 2.36
Point 6 71.94 28.06 100.00 2.56
Point 7 72.01 27.99 100.00 2.57
Point 8 74.45 25.55 100.00 2.91
Point 9 75.11 24.89 100.00 3.02
Point 10 76.43 23.57 100.00 3.24
Point 11 77.31 22.69 100.00 3.41
Point 12 75.35 24.65 100.00 3.06
Figure 13. Schematic of the influence mechanism of the transformation of oolitic hematite