XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1189
Bear Lodge, an upstart rare earth carbonite mine in
Wyoming, has made attempts to produce a rare earth con-
centrate using physical separation methods. Their plan is
to use gravity and magnetic separation as upgrading meth-
ods, then use an acid leach to extract the rare earths. It was
reported that while using the physical separation methods
the mine would be able to obtain an 88% recovery of rare
earth oxides with a 55% mass pull (Norgren, 2018)
Government controls and policy aside, China is pres-
ently blessed with having some of the more forgiving REE
occurrences within its borders, alongside possessing a sig-
nificant volume of REE’s, thus leading to something of a
natural domination of global production. In the case of
Bayan Obo, the largest and highest grade REE mine in
China, the economics of REE production are compara-
tively more favorable than for most REE mines as REE’s are
recovered as a necessary byproduct of iron (Fe) production.
Additionally, the head grade of Bayan Obo, as expressed in
Rare Earth Oxide (REO), is amongst some of the highest
in the world at ~6% REO, a simplified process flowsheet is
shown below in Figure 3 (Gupta &Krishnamurthy, 2005).
Flotation Chemistry
Hydroxamates are collectors that have been proven to be
more selective to bastnaesite than the gangue minerals. This
could be due to chelation, which is a type of bonding that
Table 1. Bastnaesite minerals
Mineral Example of Locations
Chemical
Formula
Theoretical Chemical Composition in
Oxides
Bastnäsite-(Ce) Bayan Obo, Inner Mongolia, China.
Mountain Pass, California, USA.
Fen, Norway
Ce(CO3)F Ce =63%. C=5%. O=21.9%. F=8.67%
Bastnäsite-(La) Pike Peaks, Colorado, USA La(CO3)F La= 63%. C=5%. O=22%. F=8.72%
Bastnäsite-(Nd) Clara Mine, Baden-Württemberg,
Germany
Stetind pegmatite, Tysfjord, Nordland,
Norway
Nd(CO3)F Nd =26%, La =18%, Ce=18%, F=9%, (CO2
was not measured due to paucity of mineral).
Bastnäsite-(Y) Bayan Obo, Inner Mongolia, China.
Nissi Bauxite Laterite Deposit, Lokris,
Greece
Y(CO
3 )F Y=52%. C=7.15%. O=28%.F=11%
Thorbastnäsite Yaja granite, Northern Tibet, China
Eastern Siberia, Russia
ThCa(CO
3 )
2 F
2 3H
2 O
Ce=6.88%, C=4.72%, Ca=5.9%,
Th=45.57%, H=1.19%, F=7.46%
Hydroxylbastnäsite-
(Ce)
Kami-houri, Miyazaki Prefecture, Japan,
Trimouns, Luzenac, France
Ce (CO3)( OH) Ce=64%, O=29%, C=5.53%, H=0.46%
Hydroxylbastnäsite-
(Nd)
Montenegro, Yugoslavia. Nd (CO3) (OH) Nd=65%, O=28%, C=5.43%, H=0.46%
Parisite-(Ce) Muzo, Bayaca, Columbia CaCe
2 (CO
3 )
3 F
2 Ce=28%. La=23%. C=6%. O=26% F=7%.
Ca=7%
Parisite-(La) Mula Mine, Bahia, Brazil CaLa
2 (CO
3 )
3 F
2
*Parisite-(Nd) Bayan Obo, Inner Mongolia,China
found in 1986
CaNd2(CO3)3F2 Nd=23%. La=20%. Ce=10%. C=6%.
O=25%. F=6%. C=6%
Röntgenite-(Ce) Narssârssuk, Greenland (Denmark) Ca
2 Ce
3 (CO
3 )
5 F
3 Ce=37%. La=12%. C=7%.O=28%. F=6%.
Ca=9%.
Synchysite-(Ce) Songwe Hill, Malawi.
Springer Lavergne, Ontario, Canada
CaCe(CO
3 )
2 F Ce=43%. C=8%. O=30%. F=6%. Ca=13%
Synchysite-(Y) Kutessay, Kyrgyzstan CaY(CO
3 )
2 F Y=33%. C=9%. O=36%. F=7%. Ca=14%.
Synchysite-(Nd) Triolet Glacier, Italy
Grebnik bauxite deposit, Yugoslavia.
CaNd(CO
3 )
2 F Nd=44%. C=7%. O=30%. F=6%. Ca=12%.

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Extracted Text (may have errors)

XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1189
Bear Lodge, an upstart rare earth carbonite mine in
Wyoming, has made attempts to produce a rare earth con-
centrate using physical separation methods. Their plan is
to use gravity and magnetic separation as upgrading meth-
ods, then use an acid leach to extract the rare earths. It was
reported that while using the physical separation methods
the mine would be able to obtain an 88% recovery of rare
earth oxides with a 55% mass pull (Norgren, 2018)
Government controls and policy aside, China is pres-
ently blessed with having some of the more forgiving REE
occurrences within its borders, alongside possessing a sig-
nificant volume of REE’s, thus leading to something of a
natural domination of global production. In the case of
Bayan Obo, the largest and highest grade REE mine in
China, the economics of REE production are compara-
tively more favorable than for most REE mines as REE’s are
recovered as a necessary byproduct of iron (Fe) production.
Additionally, the head grade of Bayan Obo, as expressed in
Rare Earth Oxide (REO), is amongst some of the highest
in the world at ~6% REO, a simplified process flowsheet is
shown below in Figure 3 (Gupta &Krishnamurthy, 2005).
Flotation Chemistry
Hydroxamates are collectors that have been proven to be
more selective to bastnaesite than the gangue minerals. This
could be due to chelation, which is a type of bonding that
Table 1. Bastnaesite minerals
Mineral Example of Locations
Chemical
Formula
Theoretical Chemical Composition in
Oxides
Bastnäsite-(Ce) Bayan Obo, Inner Mongolia, China.
Mountain Pass, California, USA.
Fen, Norway
Ce(CO3)F Ce =63%. C=5%. O=21.9%. F=8.67%
Bastnäsite-(La) Pike Peaks, Colorado, USA La(CO3)F La= 63%. C=5%. O=22%. F=8.72%
Bastnäsite-(Nd) Clara Mine, Baden-Württemberg,
Germany
Stetind pegmatite, Tysfjord, Nordland,
Norway
Nd(CO3)F Nd =26%, La =18%, Ce=18%, F=9%, (CO2
was not measured due to paucity of mineral).
Bastnäsite-(Y) Bayan Obo, Inner Mongolia, China.
Nissi Bauxite Laterite Deposit, Lokris,
Greece
Y(CO
3 )F Y=52%. C=7.15%. O=28%.F=11%
Thorbastnäsite Yaja granite, Northern Tibet, China
Eastern Siberia, Russia
ThCa(CO
3 )
2 F
2 3H
2 O
Ce=6.88%, C=4.72%, Ca=5.9%,
Th=45.57%, H=1.19%, F=7.46%
Hydroxylbastnäsite-
(Ce)
Kami-houri, Miyazaki Prefecture, Japan,
Trimouns, Luzenac, France
Ce (CO3)( OH) Ce=64%, O=29%, C=5.53%, H=0.46%
Hydroxylbastnäsite-
(Nd)
Montenegro, Yugoslavia. Nd (CO3) (OH) Nd=65%, O=28%, C=5.43%, H=0.46%
Parisite-(Ce) Muzo, Bayaca, Columbia CaCe
2 (CO
3 )
3 F
2 Ce=28%. La=23%. C=6%. O=26% F=7%.
Ca=7%
Parisite-(La) Mula Mine, Bahia, Brazil CaLa
2 (CO
3 )
3 F
2
*Parisite-(Nd) Bayan Obo, Inner Mongolia,China
found in 1986
CaNd2(CO3)3F2 Nd=23%. La=20%. Ce=10%. C=6%.
O=25%. F=6%. C=6%
Röntgenite-(Ce) Narssârssuk, Greenland (Denmark) Ca
2 Ce
3 (CO
3 )
5 F
3 Ce=37%. La=12%. C=7%.O=28%. F=6%.
Ca=9%.
Synchysite-(Ce) Songwe Hill, Malawi.
Springer Lavergne, Ontario, Canada
CaCe(CO
3 )
2 F Ce=43%. C=8%. O=30%. F=6%. Ca=13%
Synchysite-(Y) Kutessay, Kyrgyzstan CaY(CO
3 )
2 F Y=33%. C=9%. O=36%. F=7%. Ca=14%.
Synchysite-(Nd) Triolet Glacier, Italy
Grebnik bauxite deposit, Yugoslavia.
CaNd(CO
3 )
2 F Nd=44%. C=7%. O=30%. F=6%. Ca=12%.

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1190 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
allows two or more bonds to form between a ligand and a
separate metal ion (Assis, et al., 1996). Four new collectors
have proven to be selective to bastnaesite in recent stud-
ies using micro flotation and bench scale flotation (Everly,
2018, Everly, et al., 2012).
Although collectors are the primary reagents used in
flotation, there are others which are used to enhance selec-
tivity. Some other reagent types include depressants, pH
modifiers and frothers. Depressants are used as an aid in a
flotation separation by selectively coating a gangue or tar-
get mineral surface, inhibiting the adsorption of the collec-
tor onto that mineral surface. Lignin sulphonate is used in
the flotation of bastnaesite to depress barite. Common pH
modifiers are potassium hydroxide and soda ash. Soda ash
has a dual purpose, as a pH modifier and a depressant or
dispersant, because it is a potential determining ion, which
makes the flotation of bastnaesite more effective at a spe-
cific pH.
Gravity Separation
Gravity separation is a technique involving the manipula-
tion of particle densities to separate the less dense particles
from the denser ones. A recent study used the ultrafine
Falcon centrifugal concentrator as gravity concentrator.
This allows effective separation to occur even with reduced
particle size s( Norgren, 2018) In related research efforts,
it was determined that, using gravity separation, the REE
bearing minerals can be effectively separated from calcite
and dolomite (Schriner, 2015, Schriner &Anderson, 2015,
Norgren, 2018, Norgren &Anderson, 2021, Norgren &
Anderson, 2021).
The Gakara deposit in Burundi is noteworthy for
a number of reasons, the most relevant of which are its
Figure 1. The Mountain Pass flotation flow sheet

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Extracted Text (may have errors)

1190 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
allows two or more bonds to form between a ligand and a
separate metal ion (Assis, et al., 1996). Four new collectors
have proven to be selective to bastnaesite in recent stud-
ies using micro flotation and bench scale flotation (Everly,
2018, Everly, et al., 2012).
Although collectors are the primary reagents used in
flotation, there are others which are used to enhance selec-
tivity. Some other reagent types include depressants, pH
modifiers and frothers. Depressants are used as an aid in a
flotation separation by selectively coating a gangue or tar-
get mineral surface, inhibiting the adsorption of the collec-
tor onto that mineral surface. Lignin sulphonate is used in
the flotation of bastnaesite to depress barite. Common pH
modifiers are potassium hydroxide and soda ash. Soda ash
has a dual purpose, as a pH modifier and a depressant or
dispersant, because it is a potential determining ion, which
makes the flotation of bastnaesite more effective at a spe-
cific pH.
Gravity Separation
Gravity separation is a technique involving the manipula-
tion of particle densities to separate the less dense particles
from the denser ones. A recent study used the ultrafine
Falcon centrifugal concentrator as gravity concentrator.
This allows effective separation to occur even with reduced
particle size s( Norgren, 2018) In related research efforts,
it was determined that, using gravity separation, the REE
bearing minerals can be effectively separated from calcite
and dolomite (Schriner, 2015, Schriner &Anderson, 2015,
Norgren, 2018, Norgren &Anderson, 2021, Norgren &
Anderson, 2021).
The Gakara deposit in Burundi is noteworthy for
a number of reasons, the most relevant of which are its
Figure 1. The Mountain Pass flotation flow sheet

1188
4177
A Review of the Beneficiation of Bastnaesite and
Monazite Rare Earth Bearing Minerals
Dr. Corby G. Anderson
Kroll Institute for Extractive Metallurgy, Mining Engineering Department, Colorado School of Mines, Golden, Colorado
ABSTRACT: Rare earth minerals are processed based on their site specific deposit characteristics and the
minerals which they contain. Mines typically upgrade the minerals from the deposit before hydrometallurgical
processing is performed to obtain the rare earths. Two current industrial beneficiation methods are flotation and
physical separation via gravity. Moreover, bastnaesite and monazite are currently the focus for primary industrial
production. This paper will review the beneficiation of these specific minerals for rare earth production.
BASTNAESITE BENEFICIATION
REE (rare earth element) fluoro carbonates are minerals
which consist of, but are not limited to, REE, F (fluorine)
and CO3 (carbonate)ions, most commonly in the general
form REE (CO3) F .Substitutions of elements such as tho-
rium, sodium, barium and calcium into the lattice are rare,
but in geological settings like Mont Saint Hilaire, excep-
tional minerals are formed such as Horváthite (NaY(CO3)
F2) and Lukechangite (Na3 Ce2 (CO3) F) (Owens, et. al,
2018). REE are primarily sourced through the fluorcarbon-
ate mineral bastnäsite-(Ce), sometimes spelled bastnaesite,
which is the main ore mineral at the REE mine, Bayan
Obo, China. Historically it was also mined in the Mountain
Pass deposit, California, USA. Bastnäsite-(Ce) is also the
most common mineral within the REE fluorcarbonate set
of minerals and a member of the bastnäsite group which
contains seven minerals (bastnäsite–(Ce), bastnäsite–(La),
bastnäsite–(Nd), bastnäsite-(Y), hydroxylbastnäsite-(Nd),
hydroxylbastnäsite-(Ce) and thorbastnäsite). Others min-
erals that are often linked to bastnäsite are parisite, synch-
ysite and röntgenite. First discovered in the bastnäs mine in
Sweden, after which it was named, bastnäsite has since been
found in localities ranging from Pikes Peak Colorado to the
moon (Owens, et. al, 2018). In comparison, röntgenite was
discovered in 1953 by Donnay and has only been found
in four localities (Owens, et al. 2018). The nomenclature
of rare earth fluorocarbonates requires that the dominant
REE when specific to denoting a species is within parenthe-
sis [14]. Table 1 illustrates the bastnäsite group of minerals
plus the analog parisite, röntgenite and synchysite minerals
(Owens, et. al, 2018).
Industrial Practice
The primary rare earth mineral at the Mountain Pass mine
is bastnaesite. The mine has used a rougher and cleaner
flotation process to produce a 60% rare earth oxide con-
centrate, which was further processed to produce pure rare
earth oxides (Anderson 2015). The process begins with a
crushing and grinding circuit. The ore is crushed with an
impact, jaw and cone crusher, followed by grinding in a ball
and rod mill. Cyclones are used to separate out material of
the desired size for flotation. The oversized material gets
reground in a ball mill. A simplified flow sheet is shown in
Figure 1, while the full traditional flow sheet is shown in
Figure 2. (Anderson, 2015)

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Extracted Text (may have errors)

1188
4177
A Review of the Beneficiation of Bastnaesite and
Monazite Rare Earth Bearing Minerals
Dr. Corby G. Anderson
Kroll Institute for Extractive Metallurgy, Mining Engineering Department, Colorado School of Mines, Golden, Colorado
ABSTRACT: Rare earth minerals are processed based on their site specific deposit characteristics and the
minerals which they contain. Mines typically upgrade the minerals from the deposit before hydrometallurgical
processing is performed to obtain the rare earths. Two current industrial beneficiation methods are flotation and
physical separation via gravity. Moreover, bastnaesite and monazite are currently the focus for primary industrial
production. This paper will review the beneficiation of these specific minerals for rare earth production.
BASTNAESITE BENEFICIATION
REE (rare earth element) fluoro carbonates are minerals
which consist of, but are not limited to, REE, F (fluorine)
and CO3 (carbonate)ions, most commonly in the general
form REE (CO3) F .Substitutions of elements such as tho-
rium, sodium, barium and calcium into the lattice are rare,
but in geological settings like Mont Saint Hilaire, excep-
tional minerals are formed such as Horváthite (NaY(CO3)
F2) and Lukechangite (Na3 Ce2 (CO3) F) (Owens, et. al,
2018). REE are primarily sourced through the fluorcarbon-
ate mineral bastnäsite-(Ce), sometimes spelled bastnaesite,
which is the main ore mineral at the REE mine, Bayan
Obo, China. Historically it was also mined in the Mountain
Pass deposit, California, USA. Bastnäsite-(Ce) is also the
most common mineral within the REE fluorcarbonate set
of minerals and a member of the bastnäsite group which
contains seven minerals (bastnäsite–(Ce), bastnäsite–(La),
bastnäsite–(Nd), bastnäsite-(Y), hydroxylbastnäsite-(Nd),
hydroxylbastnäsite-(Ce) and thorbastnäsite). Others min-
erals that are often linked to bastnäsite are parisite, synch-
ysite and röntgenite. First discovered in the bastnäs mine in
Sweden, after which it was named, bastnäsite has since been
found in localities ranging from Pikes Peak Colorado to the
moon (Owens, et. al, 2018). In comparison, röntgenite was
discovered in 1953 by Donnay and has only been found
in four localities (Owens, et al. 2018). The nomenclature
of rare earth fluorocarbonates requires that the dominant
REE when specific to denoting a species is within parenthe-
sis [14]. Table 1 illustrates the bastnäsite group of minerals
plus the analog parisite, röntgenite and synchysite minerals
(Owens, et. al, 2018).
Industrial Practice
The primary rare earth mineral at the Mountain Pass mine
is bastnaesite. The mine has used a rougher and cleaner
flotation process to produce a 60% rare earth oxide con-
centrate, which was further processed to produce pure rare
earth oxides (Anderson 2015). The process begins with a
crushing and grinding circuit. The ore is crushed with an
impact, jaw and cone crusher, followed by grinding in a ball
and rod mill. Cyclones are used to separate out material of
the desired size for flotation. The oversized material gets
reground in a ball mill. A simplified flow sheet is shown in
Figure 1, while the full traditional flow sheet is shown in
Figure 2. (Anderson, 2015)