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)
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)