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Rare Earth Elements
What do we know about them?
James R. Kuipers, P.E., Kuipers & Associates
Presented at
Western Mining Action Network 2011 Conference
“Working Together As One: Sustaining Water, Culture and Healthy
Communities”.
Saskatchewan, Canada
Rare Earth Elements
What Are They?
– The 30 rare earth elements are composed of the
lanthanide and actinide series.
• One element of the lanthanide series and most of the
elements in the actinide series are called trans-uranium,
which means synthetic or man-made.
– 17 common rare earth elements found in nature:
cerium, dysprosium, erbium, europium, gadolinium,
holmium, lanthanum, lutetium, neodymium,
praseodymium, samarium, terbium, thulium,
ytterbium, yttrium, ferrocerium, monazite, bastnasite,
mischmetal
Rare Earth Elements
Present and Future Uses
• Estimated 2009 distribution of rare earths by end use, in decreasing
order, was as follows (USGS 2011):
–
–
–
–
–
–
chemical catalysts, 22%;
metallurgical applications and alloys, 21%;
petroleum refining catalysts, 14%;
automotive catalytic converters, 13%;
glass polishing and ceramics, 9%;
rare-earth phosphors for computer monitors, lighting, radar, televisions, and x-rayintensifying film, 8%;
– permanent magnets, 7%;
– electronics, 3%;
– and other, 3%.
• The trend appears to be for a continued increase in the use of rare
earths in many applications, especially automotive catalytic converters,
permanent magnets, and rechargeable batteries for electric and hybrid
vehicles.
Rare Earth Elements
Occurrence
– First discovered in the 19th Century in Sweden, they were believed to be
some of the most uncommon elements.
– Rare-earths have been found to be relatively abundant in the Earth's crust,
but rarely concentrated.
– High cost of extraction means that only deposits with high concentrations
are likely to be developed.
Rare earth minerals are usually found in association with alkaline to
peralkaline igneous complexes, in pegmatites associated with alkaline
magmas and in or associated with carbonatite intrusives. Perovskite mineral
phases are common hosts to rare earth elements within the alkaline
complexes. Mantle derived carbonate melts also are carriers of the rare
earths. Hydrothermal deposits associated with alkaline magmatism contain a
variety of rare earth minerals.
Rare Earth Elements
Mine Production and Reserves
Country/Region
Mine Production
2009
Reserves
2010
Total
United States
—
—
13,000,000
Australia
—
—
1,600,000
Brazil
550
550
48,000
China
129,000
130,000
55,000,000
—
—
19,000,000
2,700
2,700
3,100,000
350
350
30,000
—
—
22,000,000
133,000
130,000
110,000,000
Commonwealth of Independent States
India
Malaysia
Other countries
World total (rounded)
USGS 2011
Rare Earth Elements
World Resources
• Rare earths are relatively abundant in the Earth’s crust, but discovered
minable concentrations are less common than for most other ores.
• U.S. and world resources are contained primarily in bastnäsite and
monazite.
• Bastnäsite deposits in China and the United States constitute the largest
percentage of the world’s rare-earth economic resources, while monazite
deposits in Australia, Brazil, China, India, Malaysia, South Africa, Sri Lanka,
Thailand, and the United States constitute the second largest segment.
• Apatite, cheralite, eudialyte, loparite, phosphorites, rare-earth-bearing
(ion adsorption) clays, secondary monazite, spent uranium solutions, and
xenotime make up most of the remaining resources.
• Undiscovered resources are thought to be very large relative to expected
demand.
• A very large resource enriched in heavy rare-earth elements is inferred for
phosphorites of the Florida Phosphate District.
USGS 2011
Rare Earth Elements
Future Mines
• Exploration efforts to develop rare earths projects surged in
2010, and investment and interest increased dramatically.
• Economic assessments continued in North America at Bear
Lodge in Wyoming; Diamond Creek in Idaho; Elk Creek in
Nebraska; Hoidas Lake in Saskatchewan, Canada; Lemhi
Pass in Idaho-Montana; and Nechalacho (Thor Lake) in
Northwest Territories, Canada.
• Other economic assessments took place in other locations
around the world, including Dubbo Zirconia in New South
Wales, Australia; Kangankunde in Malawi; Mount Weld in
Western Australia, Australia; and Nolans Project in
Northern Territory, Australia.
Rare Earth Elements
Mining, Processing and Refining
• Typically mined by bulk tonnage open pit methods
– Higher grade deposits could be mined underground
• Mineral processing typically done on-site using
flotation and gravity processing
– Other processes may also be applicable
• Refining is most difficult/toxic step
– acid or alkaline leach methods
– Pyrometallurgy
• Environmental Impacts
– Typical to hardrock mining (water, air, soil contamination)
– Strong association with deposit type (acid or alkaline)
Rare Earth Elements
Environmental Toxicity
• Few toxicological data are available compared to
other elements (e.g. lead, cadmium, chromium,
mercury, nickel, zinc, arsenic, selenium) for either
human or other ecological receptors
• Some suggestion of chronic exposure impacts
and strong suggestion of impacts when exposed
to compounds (metallurgical and chemical,
possible ecological)
• Possible effects include:
– lung disease, liver disease, eye and skin irritation,
other effects
Rare Earth Elements
Conclusions
• Rare Earth mining will increase but is likely to
occur in only limited circumstances
– High grade and high tech with large funding required
– Sector is highly vulnerable to promotions and scams
• In more suitable locations with good practices
should be possible with minimal impacts
– Potential opportunity to work with industry?
– 100% from reprocessed tailings and waste rock?
• Need more environmental data
– Human health impacts (workforce and local residents)
– Ecological impacts (aquatic life, wildlife, riparian)