6
Oxaline Leaching of REE from Its Ore
Figure 8 illustrates the conversion of cerium, lanthanum,
neodymium, and praseodymium during the leaching pro-
cess with Oxaline DES at 80°C. Unlike Reline, recovery
improved as time increased. Recovery gradually increased
from 1 hour and sharply rose at 3 hours. This slow and
sharp increase in recovery may suggest a mixed control
system of diffusion and chemical mechanisms. However,
kinetic analysis will be conducted to confirm if the system
is a mixed control system. For neodymium and praseo-
dymium, recovery reaches a plateau after six hours, while
cerium and lanthanum continue to show potential for
improved recovery with extended leaching times. Studies
indicate that lower pH levels result in improved recovery
of REEs [28]. The superior recovery of REEs in Oxaline, as
opposed to Reline, can be linked to the more acidic charac-
teristics of Oxaline DES [29].
Table 6. Sample IDs and parameters used for the leaching experiment
Sample ID
Temperature
°C REE (g)
DES
volume,
mL
S/L
ratio
(g/L)
Stirring
rate
rpm Particle size
Duration/
hours Type of DES
Eth (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Ethaline
Eth (70°C) 70 0.1 10 1 300 –100 +45 μm 8 Ethaline
Eth (80°C) 80 0.1 10 1 300 –100 +45 μm 8 Ethaline
Eth(90°C) 90 0.1 10 1 300 –100 +45 μm 8 Ethaline
Gly(60°C) 60 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Gly(70°C) 70 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Gly(80°C) 80 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Gly(90°C) 90 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Rel (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Reline
Rel(60°C) 70 0.1 10 1 300 –100 +45 μm 8 Reline
Rel(70°C) 80 0.1 10 1 300 –100 +45 μm 8 Reline
Rel(70°C) 90 0.1 10 1 300 –100 +45 μm 8 Reline
Lac (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Lactic Acid- Choline Chloride
Lac(70°C) 70 0.1 10 1 300 –100 +45 μm 8 Reli Lactic Acid- Choline
Chloride ne
Lac (80°C) 80 0.1 10 1 300 –100 +45 μm 8 Reli Lactic Acid- Choline
Chloride ne
Lac (90°C) 0 0.1 10 1 300 –100 +45 μm 8 Reli Lactic Acid- Choline
Chloride ne
Ox (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Oxaline
Ox (70°C) 70 0.1 10 1 300 –100 +45 μm 8 Oxaline
Ox (80°C) 80 0.1 10 1 300 –100 +45 μm 8 Oxaline
Ox (90°C) 90 0.1 10 1 300 –100 +45 μm 8 Oxaline
0 1 2 3 4 5 6 7 8 9
0
5
10
15
20
25
30
Time/ Hours
Ce- Reline(80°C)
La- Reline(80°C)
Nd- Reline(80°C)
Pr- Reline(80°C)
Figure 7. %Recovery of Cerium, Lanthanum, Neodymium,
and Praseodymium during leaching in Reline DES
%
Recovery
Oxaline Leaching of REE from Its Ore
Figure 8 illustrates the conversion of cerium, lanthanum,
neodymium, and praseodymium during the leaching pro-
cess with Oxaline DES at 80°C. Unlike Reline, recovery
improved as time increased. Recovery gradually increased
from 1 hour and sharply rose at 3 hours. This slow and
sharp increase in recovery may suggest a mixed control
system of diffusion and chemical mechanisms. However,
kinetic analysis will be conducted to confirm if the system
is a mixed control system. For neodymium and praseo-
dymium, recovery reaches a plateau after six hours, while
cerium and lanthanum continue to show potential for
improved recovery with extended leaching times. Studies
indicate that lower pH levels result in improved recovery
of REEs [28]. The superior recovery of REEs in Oxaline, as
opposed to Reline, can be linked to the more acidic charac-
teristics of Oxaline DES [29].
Table 6. Sample IDs and parameters used for the leaching experiment
Sample ID
Temperature
°C REE (g)
DES
volume,
mL
S/L
ratio
(g/L)
Stirring
rate
rpm Particle size
Duration/
hours Type of DES
Eth (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Ethaline
Eth (70°C) 70 0.1 10 1 300 –100 +45 μm 8 Ethaline
Eth (80°C) 80 0.1 10 1 300 –100 +45 μm 8 Ethaline
Eth(90°C) 90 0.1 10 1 300 –100 +45 μm 8 Ethaline
Gly(60°C) 60 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Gly(70°C) 70 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Gly(80°C) 80 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Gly(90°C) 90 0.1 10 1 300 –100 +45 μm 8 Glycerol-Choline Chloride
Rel (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Reline
Rel(60°C) 70 0.1 10 1 300 –100 +45 μm 8 Reline
Rel(70°C) 80 0.1 10 1 300 –100 +45 μm 8 Reline
Rel(70°C) 90 0.1 10 1 300 –100 +45 μm 8 Reline
Lac (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Lactic Acid- Choline Chloride
Lac(70°C) 70 0.1 10 1 300 –100 +45 μm 8 Reli Lactic Acid- Choline
Chloride ne
Lac (80°C) 80 0.1 10 1 300 –100 +45 μm 8 Reli Lactic Acid- Choline
Chloride ne
Lac (90°C) 0 0.1 10 1 300 –100 +45 μm 8 Reli Lactic Acid- Choline
Chloride ne
Ox (60°C) 60 0.1 10 1 300 –100 +45 μm 8 Oxaline
Ox (70°C) 70 0.1 10 1 300 –100 +45 μm 8 Oxaline
Ox (80°C) 80 0.1 10 1 300 –100 +45 μm 8 Oxaline
Ox (90°C) 90 0.1 10 1 300 –100 +45 μm 8 Oxaline
0 1 2 3 4 5 6 7 8 9
0
5
10
15
20
25
30
Time/ Hours
Ce- Reline(80°C)
La- Reline(80°C)
Nd- Reline(80°C)
Pr- Reline(80°C)
Figure 7. %Recovery of Cerium, Lanthanum, Neodymium,
and Praseodymium during leaching in Reline DES
%
Recovery