2550 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
in Figure 8(c), which were long and parallel in distribu-
tion. Some particles experienced severe structural damage,
resulting in the formation of fine-grained particles. The
increased porosity of the particles leads to an increase in
hydrophilicity, which was unfavorable for flotation (Shen
et al., 2018). Figure 8(d) demonstrates that these cracks did
not only exist on the surface of the particles but penetrated
throughout the particles. EDS analysis indicates that the
main components in these cracked particles were rare earth
oxides, rare earth fluorides, and rare earth oxyfluorides.
BET Analysis
The BET analysis results of raw ore and roasted product
are given in Figure 9. The raw ore exhibited extremely low
N2 adsorption quantity, with type III adsorption isotherms
and H4-type hysteresis loop, indicating that the raw ore
was a solid containing narrow slits (Bardestani et al., 2019).
After roasting, there was a significant increase in N2 adsorp-
tion quantity, attributed to the notable increase in the pores
within the particles. The adsorption isotherms transformed
to type II, and the hysteresis loop became H3-type, indicat-
ing the formation of layered aggregates and slit mesoporous
Figure 8. SEM-EDS analysis results of raw ore (a and b) and roasted sample (c and d) under 650°C for 8 min
0.48
33.65
0.00
0.04
1.48
5.25
0.0 0.2 0.4 0.6 0.8 1.0
0.0
0.2
0.4
0.6
0.8
1.0
Relative pressure (P/Po)
Raw ore
5
10
15
20
25
30
Adsorption
Desorption
Roasted product (a)
1 2 4 8 16 32 64 128
0.000
0.005
0.010
0.015
Pore diameter (nm)
Roasted product
Raw ore
(b)
Raw ore Roasted product
0
10
20
30
40
50
0.00
0.01
0.02
0.03
0.04
0.05
0.06
Surface area Pore volume
Average pore diameter
Samples
(c)
0
2ge
4er
6
Figure 9. BET analysis of the raw ore and roasted product under 650°C for 8 min, (a) N2 adsorption-desorption isotherms,
(b) Adsorption pore volume, (c) Pore structure parameters
Quan
titadsorbed
y
(cm³/g)
Porevolume
(cm³/g·nm)
Porevolume
(cm³/g) Surfacearea(m²/g)
Avera
porediamet
(nm)
in Figure 8(c), which were long and parallel in distribu-
tion. Some particles experienced severe structural damage,
resulting in the formation of fine-grained particles. The
increased porosity of the particles leads to an increase in
hydrophilicity, which was unfavorable for flotation (Shen
et al., 2018). Figure 8(d) demonstrates that these cracks did
not only exist on the surface of the particles but penetrated
throughout the particles. EDS analysis indicates that the
main components in these cracked particles were rare earth
oxides, rare earth fluorides, and rare earth oxyfluorides.
BET Analysis
The BET analysis results of raw ore and roasted product
are given in Figure 9. The raw ore exhibited extremely low
N2 adsorption quantity, with type III adsorption isotherms
and H4-type hysteresis loop, indicating that the raw ore
was a solid containing narrow slits (Bardestani et al., 2019).
After roasting, there was a significant increase in N2 adsorp-
tion quantity, attributed to the notable increase in the pores
within the particles. The adsorption isotherms transformed
to type II, and the hysteresis loop became H3-type, indicat-
ing the formation of layered aggregates and slit mesoporous
Figure 8. SEM-EDS analysis results of raw ore (a and b) and roasted sample (c and d) under 650°C for 8 min
0.48
33.65
0.00
0.04
1.48
5.25
0.0 0.2 0.4 0.6 0.8 1.0
0.0
0.2
0.4
0.6
0.8
1.0
Relative pressure (P/Po)
Raw ore
5
10
15
20
25
30
Adsorption
Desorption
Roasted product (a)
1 2 4 8 16 32 64 128
0.000
0.005
0.010
0.015
Pore diameter (nm)
Roasted product
Raw ore
(b)
Raw ore Roasted product
0
10
20
30
40
50
0.00
0.01
0.02
0.03
0.04
0.05
0.06
Surface area Pore volume
Average pore diameter
Samples
(c)
0
2ge
4er
6
Figure 9. BET analysis of the raw ore and roasted product under 650°C for 8 min, (a) N2 adsorption-desorption isotherms,
(b) Adsorption pore volume, (c) Pore structure parameters
Quan
titadsorbed
y
(cm³/g)
Porevolume
(cm³/g·nm)
Porevolume
(cm³/g) Surfacearea(m²/g)
Avera
porediamet
(nm)