Geology Reference
In-Depth Information
Table 6.2 The growing demand for REE
Consumption 2010 (%)
Consumption 2015 (%)
Rate of growth (%)
Magnets
21
26
10-15
Alloys
18
19
8-12
Polishing
15
16
8-10
Catalysts
19
15
3-5
Phosphors
7
7
6-10
Glass
9
6
0
Ceramics
6
5
6-8
Other
6
5
6-8
Table 6.3 Compositions of minerals mined for REE
Minerals rich in light REE
Minerals rich in heavy REE
Bastnaesite
Monazite Apatite
Ionic clay
Xenotime
Fergusonite
Bayan Obo
(China)
Orissa
(India)
Arafura
(Australia)
Middle Y
(China)
Pitinga
(Brazil)
Thor Lake
(Canada)
La
26.9
23.7
20
30
tr
0.3
Ce
50.9
44
48.2
3
0.6
4.4
Pr
5.0
5.85
5.9
7
tr
1.7
Nd 15.2
18.7
21.5
26.4
0.4
15.6
Sm 1.15
5.09
2.4
5.1
0.4
10.4
Eu
0.23
0.41
0.65
tr
1.6
Gd
0.32
1.55
1
4.2
1.1
14.3
Tb
0.03
0.08
0.7
0.8
1.8
Dy
0.09
0.31
0.34
2.9
11.2
9.8
Ho
0.01
tr
tr
0.4
3.4
1.2
Er
0.01
tr
tr
1.4
15.4
1.4
Tm
tr
tr
0.3
3.0
0.7
Yb
0.005
tr
tr
1.1
20.4
4.1
Lu
tr
tr
0.2
2.7
0.7
Y
0.20
0.75
17.3
40.6
29.0
The deposit consists of a series of replacement bodies of disseminated, banded
and massive ore, mostly in dolomite marble and more rarely in slate. It is mineral-
ogically very complex and 150 or more minerals have been identified. The principal
REE minerals are bastnaesite (Ce,La,Nd)(CO
3
)
2
F, monazite (Ce,La,Nd)PO
4
and
huanghoite Ba(Ce,La,Nd)(CO
3
)
2
F (Table
6.2
); other ore minerals include those
mined for iron (magnetite, hematite, goethite, martite) and for Nb (e.g. columbite
FeNb
2
O
2
and fergusonite YNbO
4
). Opinion is divided as to the origin of the
deposit. There is evidence of transport of the ore metals in hydrothermal fluids
and of multiple stages of deposition and replacement of the wall rocks, probably
associated with the time of regional metamorphism. Some authors promote a model
of carbonate replacement by fluids derived from carbonatitic or felsic alkaline
magmas; others consider it a variety of iron-oxide copper gold deposit (Table
6.3
).
China contains several other significant REE deposits including Mianning, a
carbonatitie-hosted deposit in Sichuan province, and smaller but economically
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