REE
Source
REEs wt%
Chelating
agents
Pressure (MPa)
Temperature
(°C)
Residence
Time
(h)
Efficiency (%)
Pre-treatment/
Other Additions
Reference
Bastnasite cconcentrate
La
(25.1)
Ce
(33.1)
Pr
(3.0)
Nd
(7.7)
Sm
(0.5)
Eu
(0.2)
Gd
(0.2)
Tb
(0.1)
Ba
(3.6)
Ca
(1.0)
Sr
(1.7)
TBP/HNO
3
34
65
1.5
La
(93)
Ce
(100)
Pr
(99)
Nd
(101)
NaOH
digest
(Sinclair,
Baek
et
al.
2017)
NiMH
battery
La
(18)
Ce
(7.3)
Pr
(2.4)
Nd
(2.1)
TBP(HNO
3
)x(H
2
O)y
31.0
35.0
2
La
(86)
Ce
(86)
Pr
(88)
Nd
(90)
Methanol
added
(Yao,
Farac
et
al.
2018)
Fluoride
lamp
Y
(41.2)
Eu
(2.7)
Ce
(8.5)
Tb
(3.0)
La
(11.0)
TBP/HNO
3
and
H
2
O
31
40
3
Y
(70)
Eu
(70)
La,
Ce,
Tb
(50)
(Zhang, Anawati
et
al.
2022)
Fluoride
lamp
(Y
and
Eu oxides,
La
and
Ce
phosphates,
and
Tb
in unidentified
form)
Y
(29.6)
Eu
(2.3)
La
(10.6)
Ce
(5.0)
Tb
(2.6)
TBP/HNO
3
and
H
2
O
15
60
2
Y
(99.7)
Eu
(99.8)
La,
Ce,
Tb
all
7
(Shimizu, Sawada
et
al.
2005)
Fluoride
lamp
Y
(3.27)
La
(0.55)
Tb
(0.22)
Ce
(0.43)
TBP/HNO
3
31
40
3
Ce
(56.1)
Y
(71.2)
Tb
(51.3)
La
(55.4)
(Zhang
and
Azimi
2020)
NdO
2
3
powder99%
TTA-TBP
15
50
2
Nd
(67.5)
Methanol
added
(Vincent, Mukhopadhyay
et
al.
2009)
Table
1.
Summary
of
recent
literature
studying
the
use
of
scCO
2
extraction
for
the
recovery
of
REEs
(continued)
XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1369
Source
REEs wt%
Chelating
agents
Pressure (MPa)
Temperature
(°C)
Residence
Time
(h)
Efficiency (%)
Pre-treatment/
Other Additions
Reference
Bastnasite cconcentrate
La
(25.1)
Ce
(33.1)
Pr
(3.0)
Nd
(7.7)
Sm
(0.5)
Eu
(0.2)
Gd
(0.2)
Tb
(0.1)
Ba
(3.6)
Ca
(1.0)
Sr
(1.7)
TBP/HNO
3
34
65
1.5
La
(93)
Ce
(100)
Pr
(99)
Nd
(101)
NaOH
digest
(Sinclair,
Baek
et
al.
2017)
NiMH
battery
La
(18)
Ce
(7.3)
Pr
(2.4)
Nd
(2.1)
TBP(HNO
3
)x(H
2
O)y
31.0
35.0
2
La
(86)
Ce
(86)
Pr
(88)
Nd
(90)
Methanol
added
(Yao,
Farac
et
al.
2018)
Fluoride
lamp
Y
(41.2)
Eu
(2.7)
Ce
(8.5)
Tb
(3.0)
La
(11.0)
TBP/HNO
3
and
H
2
O
31
40
3
Y
(70)
Eu
(70)
La,
Ce,
Tb
(50)
(Zhang, Anawati
et
al.
2022)
Fluoride
lamp
(Y
and
Eu oxides,
La
and
Ce
phosphates,
and
Tb
in unidentified
form)
Y
(29.6)
Eu
(2.3)
La
(10.6)
Ce
(5.0)
Tb
(2.6)
TBP/HNO
3
and
H
2
O
15
60
2
Y
(99.7)
Eu
(99.8)
La,
Ce,
Tb
all
7
(Shimizu, Sawada
et
al.
2005)
Fluoride
lamp
Y
(3.27)
La
(0.55)
Tb
(0.22)
Ce
(0.43)
TBP/HNO
3
31
40
3
Ce
(56.1)
Y
(71.2)
Tb
(51.3)
La
(55.4)
(Zhang
and
Azimi
2020)
NdO
2
3
powder99%
TTA-TBP
15
50
2
Nd
(67.5)
Methanol
added
(Vincent, Mukhopadhyay
et
al.
2009)
Table
1.
Summary
of
recent
literature
studying
the
use
of
scCO
2
extraction
for
the
recovery
of
REEs
(continued)
XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1369