REE deposits and prospective areas in Southeast Asia

1: Geological Survey of Japan, AIST 2: CODES, University of Tasmania

20th March 2015 PACRIM @ Hong Kong

Kenzo SANEMATSU1,2

k-sanematsu@aist.go.jp

Contents

Demand of REE REE deposits in northern Vietnam

Ion-adsorption type REE deposits Placer REE

Conclusions

Demand of REE

Demand of REE

Nd-Fe-B magnet (incl. Dy)

TV

Fluorescent material

LED

And in other products (Ni-H battery, exhaust gas catalyst, optical lens, abrasive compound, etc)

Minowa (2008)

Air conditioner Vehicles (HEV and EV)

Mobile phone

Wind power generator

REE abundances in the crust

HREE are much less than LREE in the crust.

(Rudnick & Gao, 2003)

LREE HREE

REE abundances in mantle and continental crust normalized by the primitive mantle compositions. (Chakhmouradian & Wall (2012) and references therein).

Bulk rock-melt partition coefficients

LREE are more incompatible than HREE in melt. LREE are more incompatible than HREE in magma.

Production and prices of REE

Price of Ce, Nd and Dy oxides (Metal-Pages Ltd.)

1134 $/kg Ag (35.26 $/oz

Ag)

Ce

or N

d ox

ide

(99%

) ($/

kg)

REE prices WERE very high. >98% of HREE in the world!

(USGS, 2014)

Dy

oxid

e (9

9%) (

$/kg

)

Distribution of REE deposits in the world

British Geological Survey (2011) and Wall (2014)

Many REE deposits are found in intercontinental alkaline rocks.

Modified from McLean (2001) and Ishihara et al. (2008).

REE resource potential in SE Asia REE deposit types are confined to placer and ion-adsorption type with the exception of the Red River Fault Zone in northern Vietnam.

Name Deposit type Grade REE minerals References

Dong Pao Carbonatite (weathered) type

1.5 - 3.2 % REE+Y REE fluorocarbonates (bastnasite and synchysite)

Fujii et al. (2010)

Nam Xe Carbonatite (weathered) type

Weathered carbonatite: 3.4 - 4.3 % REE+Y Carbonatite: 1.2 % REE+Y

REE fluorocarbonates (bastnasite, parisite and synchysite)

Trinh (1991) and Kušnír (2000)

Sin Quyen Cu-Fe-Au-REE type

928 - 34680 ppm LREE 11 - 355 ppm HREE

Allanite [Ca(LREE)Al2FeSiO11O(OH)]

McLean (2001), Ishihara et al. (2011) and Gas’kov et al. (2012)

Na Son Carbonate-hosted Pb-Zn

802 ppm LREE 70 ppm HREE (ave. of 13 samples)

Allanite [Ca(LREE)Al2FeSiO11O(OH)] Anh et al. (2012)

However, carbonatite-type and allanite-type are depleted in HREE.

LREE-rich LREE minerals

REE resource potential in SE Asia

REE deposit types

Metallurgy Deposit type REY grade Resources Commodity

Carbonatite type LREE Developed Medium to High

Medium to Large

Alkaline-rock related type

LREE & HREE+Y +/- Zr, Nb, Ta

Developed (?) but high cost or low recovery

Medium Medium to Large

Bayan Obo type LREE, Nb & Fe Developed

Medium to High Large

Example

Mt. Pass (USA) Maoniuping (China)

Bayan Obo (China)

Lovozero (Russia) Nechalacho (Canada)

Fe-oxide-apatite type (By-product)

Kiruna type (Sweden) Mushgai (Mongolia) P, LREE +/- Low to

Medium High cost or low recovery

Medium to Large

U deposit type (By-product)

W. Mynkuduk (Kazakhstan)

U, LREE +/- HREE+Y Low Developed ?

Weathering carbonatite type

Mt. Weld (AU) Araxa (Brazil) Dong Pao (Vietnam)

LREE +/- (Nb, P)

Medium to High

Medium to Large

Developed but low recovery (?)

Ion-adsorption type

China Madagascar Myanmar

LREE & HREE+Y Low Small to

Medium Developed

Placer type India Malaysia

LREE +/- (HREE+Y)

Low to Medium

Small to Medium

Developed

Parent rock

REE3+

REE

Residual type (including placer)

Ion-adsorption type Leaching of REE

Weathering product (clays, etc)

Chemical weathering ±hydrothermal alteration ±erosion

REE

REE-bearing minerals are resistant to weathering

Chemical weathering ±hydrothermal alteration

REE-bearing minerals are weatherable

Ion-adsorption type deposits

Monazite, zircon, xenotime, etc

REE fluorocarbonates, allanite, titanite, etc

Climate and distribution of ion-adsorption type REE

World map of Köppen-Geiger climate classification (Peel et al., 2007)

A: Tropical B: Arid C: Temperate D: Cold E: Polar

Ion-adsorption type deposits and prospects have been found in the temperate and tropical areas.

Ion-adsorption type deposits in southern China

Parent rocks: Calcalkaline or alkali granites (typically ilmenite-series) Age: Jurassic to Cretaceous (Yanshanian age) Ore: weathered granite (ion-adsorption ore) REY = 140 - 6500ppm (ave. ~800ppm) / Cut-off grade depends on HREE cont. REY are adsorbed on clays (e.g. kaolinite, halloysite) (Adsorbed REY / whole-rock REY) x 100 > 50 % No need for crushing, grinding or mineral processing REY are extracted by ion-exchangeable electrolyte solution Low Th and U concentration in extracted solution (Th<3ppm; U<1ppm)

Ishihara (2005)

Characteristics (Wu et al., 1990; Bao & Zhao, 2008; Sanematsu and Watanabe, in press)

Ore reserves > 0.5 Mt : Large 0.05-0.5 Mt : Medium < 0.01 Mt : Small

Simplified flowsheet of REE extraction using ammonium sulfate solution (1 – 4 %) (Chi & Tian, 2009)．

Ion-adsorption type deposits in southern China

[Al2Si2O5(OH)4]mnREY(s)3+ + 3nHN4

+(aq)

[Al2Si2O5(OH)4]m(NH4+)3n(s)3+ + nREY(aq)

3+

Dingnan County in Jiangxi Province

Geologic map of the HREE-rich Longnan deposit

Huang et al. (1989)

Most HREE-rich

Most HREE-rich

Geochemical characteristics of parent granites

Boundaries from (Rickwood,1989)

Data from Yang et al. (1981), Deng (1988), Huang (1989), Huang et al. (1989), Zhang (1990), Wu et al. (1990, 1993), Yuan et al. (1993), Chen and Yu, (1994), Hua et al. (2007), Bao and Zhao (2008), Ishihara et al. (2008).

LaN/YbN ratios are controlled by the degree of fractional crystallization of magma. HREE(+Y) are enriched in strongly fractionated Ms granites or Ms-Bt granites (SiO2 > ~75%).

HREE-rich deposits (Longnan, Datian and Zhaibeiding)

HREE-rich deposits (Longnan, Datian and Zhaibeiding)

N: Chondrite-normalized (Sun & McDonough, 1989)

Geochemical characteristics of parent granites

REY contents are influenced by the degree of partial melting of magma. High REY contents are found in alkali granites, however they are rich in LREE (LREE are more incompatible than HREE).

Data from Yang et al. (1981), Deng (1988), Huang (1989), Huang et al. (1989), Zhang (1990), Wu et al. (1990, 1993), Yuan et al. (1993), Chen and Yu, (1994), Hua et al. (2007), Bao and Zhao (2008), Ishihara et al. (2008).

LREE-rich deposits (Heling)

LREE-rich deposits (Heling)

Boundaries from (Rickwood,1989)

REE extraction experiment

Weathered rock Split Pulverized

Mechanically shaken for 24 hrs

Centrifugal force for 15 min

Split

Whole-rock analyses (XRF&ICP-MS)

1g 0.5M (NH4)SO4 pH = ~5.7, 40ml

REE extraction experiment

Rinsed by H2O

Add HNO3

5% HNO3 equiv.

Diluted for ICP-MS analysis

Filtered (ϕ=0.22μm)

Extract solution

A case study of Phuket, Thailand

Parent granite (Kata Beach Granite) contains REE fluorocarbonate

A case study of Phuket, Thailand

Accumulation zone (REY=606-1158ppm)

Leached zone (REY=181-567ppm)

Parent granite (REY=634ppm)

Parent granite (REY=634ppm)

Accumulation zone

Leached zone

Phuket, Thailand

Sanematsu et al. (2013)

Ce-enriched

Ce-depleted

Whole-rock REY

Ion-exchangeable REY

REE are sourced from REE fluorocarbonates, allanite and titanite. REE are mobile during weathering

Phuket Is., Thailand

Genesis of ion-adsorption ores

CeO2

Mn oxy-hydroxide

Sanematsu and Watanabe (in press)

Implications for exploration

Ion-adsorption ores

Ion-adsorption ores

Depletion of Ce (negative Ce anomaly) in weathered granite is a good indicator of ion-adsorption ores.

Ion-exchange experiment and solution analysis are required.

Weathered granites collected from SE Asia and southern China.

Placer REE deposit

Parent rock

REE3+

REE

Residual type (including placer)

Ion-adsorption type Leaching of REE

Weathering product (clays, etc)

Chemical weathering ±hydrothermal alteration ±erosion

REE

REE-bearing minerals are resistant to weathering

Chemical weathering ±hydrothermal alteration

REE-bearing minerals are weatherable

Monazite, zircon, xenotime, etc

REE fluorocarbonates, allanite, titanite, etc

Placer REE Southern Myanmar

TiO2 = 9.5 % La = 0.32 % P2O5 = 0.69 % Ce = 0.56 % Zr = 3.8 % Y = 0.21 % Th = 0.13 % (semi-quant. data by XRF)

Beach sand (zircon- and monazite-rich)

Mining method is simple and low cost.

Occurrences of placer REE

Flowsheet of beach sand at Cable Sands Pty Ltd plants, Australia (Houot et al., 1991).

Placer REE

Radioactive!

Mineral processing is simple.

Flowsheet of caustic soda treatment of monazite in a plant of Indian Rare Earths Ltd. (Gupta and Krishnamurhy, 2005).

Radioactive!

Radioactive!

Placer REE

Conventional hydrometallurgical technique is applicable, but production is dependent on the costs and radioactive elements.

Placer REE

India will use Th as a nuclear fuel. Placer ore/conc.

Monazite $ Xenotime $$$ Development of placer REE

deposits is strongly influenced by HREE grades and treatment of Th and U.

Conclusions

Highly differentiated (SiO2 > ~75%) and phosphate-poor (< ~0.08 % P2O5) muscovite(-biotite) granite is a good source rock for HREE-rich ion-adsorption ores.

(Weathered) carbonatite type and allanite-type (IOCG-like) deposits in northern Vietnam but they are poor in HREE.

LREE Not expensive. Mostly mined from carbonatite. HREE Expensive and high demand compared to LREE.

Occurrence of xenotime is required for HREE-rich placer deposits. Treatment of radioactive elements (Th and U) is inevitable.

CODES Centre for Ore Deposit research University of Tasmania

Acknowledgements

I would like thank the following individuals for helpful comments and supports.

Dr. Yoshiaki Kon, Dr. Mihoko Hoshino, Dr. Atsuyuki Ohta, Dand Dr. Shunso Ishihara (Geological Survey of Japan, AIST)

Dr. Akira Imai and Dr. Yasushi Watanabe (Akita Univ.)

Dr. Khin Zaw (CODES, UTAS)

Japan Society for the Promotion of Science (JSPS)

This research was supported by the Granit-in-Aid for scientific research from the Japan Society for the Promotion of Science (JSPS).