1826 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Figure 4(a-c). Based on the magnetic hysteresis loops, the
saturation magnetization, remanence, and coercivity are
shown in Table 2. The roasted ores in different cooling
processes all exhibited strong magnetism, and their satura-
tion magnetizations were all above 30 Am2/kg. Although
magnetite was oxidized into maghemite in the air-cooling
process, the magnetism of roasted ore was not affected due
to its ferrimagnetism. The roasted ore in water quenching
and nitrogen cooling has similar saturation magnetization
(33.16, 33.07 Am2/kg) and remanence (8.23, 8.71 Am2/
kg). The saturation magnetization (30.10 Am2/kg) and
remanence (5.90 Am2/kg) of roasted ore in air cooling
is relatively smaller. This is because some magnetite was
over-oxidized into hematite in the air-cooling process.
Additionally, the coercivity (8.7 kA/m) of roasted ore in air
cooling is much smaller than that in water quenching and
nitrogen cooling. This is because magnetite was oxidized
Figure 4 Magnetic hysteresis loops of cooling ores in magnetizing roasting of limonite ore (a) air cooling (b) water quenching
(c) nitrogen cooling
Table 2. Magnetic parameters of cooling ores in different cooling processes
Samples
Saturation Magnetization
(Am2/kg)
Remanence
(Am2/kg)
Coercivity
(kA/m)
Air cooling 30.10 5.90 8.7
Water quenching 33.16 8.23 15.5
Nitrogen cooling 33.07 8.71 19.6
Figure 4(a-c). Based on the magnetic hysteresis loops, the
saturation magnetization, remanence, and coercivity are
shown in Table 2. The roasted ores in different cooling
processes all exhibited strong magnetism, and their satura-
tion magnetizations were all above 30 Am2/kg. Although
magnetite was oxidized into maghemite in the air-cooling
process, the magnetism of roasted ore was not affected due
to its ferrimagnetism. The roasted ore in water quenching
and nitrogen cooling has similar saturation magnetization
(33.16, 33.07 Am2/kg) and remanence (8.23, 8.71 Am2/
kg). The saturation magnetization (30.10 Am2/kg) and
remanence (5.90 Am2/kg) of roasted ore in air cooling
is relatively smaller. This is because some magnetite was
over-oxidized into hematite in the air-cooling process.
Additionally, the coercivity (8.7 kA/m) of roasted ore in air
cooling is much smaller than that in water quenching and
nitrogen cooling. This is because magnetite was oxidized
Figure 4 Magnetic hysteresis loops of cooling ores in magnetizing roasting of limonite ore (a) air cooling (b) water quenching
(c) nitrogen cooling
Table 2. Magnetic parameters of cooling ores in different cooling processes
Samples
Saturation Magnetization
(Am2/kg)
Remanence
(Am2/kg)
Coercivity
(kA/m)
Air cooling 30.10 5.90 8.7
Water quenching 33.16 8.23 15.5
Nitrogen cooling 33.07 8.71 19.6