Rare earth elements demand up for high-tech

Transcrição

Rare earth elements demand up for high-tech
MIN I NG
Rare earth elements demand up for high-tech applications
by Peter Caulfield
RARE EARTH ELEMENTS (REEs) are
special metals that are seeing increased use
in high-tech machinery and electronics.
Applications include specialty magnets,
auto catalysts, fluid cracking catalysts,
and phosphors, which are phosphorescent
materials used in a variety of flat screens
and devices.
Chris Grove, President and director of
Commerce Resources Corp. [CCE-TSXV;
CMRZF-OTC; D7H-FSE], a Vancouver-based
exploration and development company,
says the world is only beginning to realize
the potential of REEs. “There should be
many new applications and designs coming down the pike,” said Grove. “More
and more manufacturers and designers are
looking to build new products that use the
attributes of the whole range of REEs.”
Although REEs are plentiful, economic
deposits are rare. In addition, separating
the 17 REEs from each other and the host
minerals can be a challenge. “Processing
is the key to unlocking the commercial
potential of REEs,” said Grove. “That is
what many projects and labs have been
working on for a long time. But nothing
new has been commercialized yet.”
According to the US Environmental
Protection Agency (EPA), the two major
mineral sources of REEs are bastnasite and
monazite. Other minerals, such as xenotime, apatite, yttrofluorite, cerite, and
gadolinite, are also hosts. The last four
minerals on the list have never been processed commercially, however.
Processing REEs into usable products is a
complex, trial-and-error process and varies
from deposit to deposit. The EPA says there
are a number of factors that affect the selection of the most effective treatment process.
They include the type and complexity of
the deposit; the type and nature of other
valuable minerals that are present with
the REEs; the type and composition of the
individual REE minerals; and the social and
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environmental acceptability of the process.
There are a number of primary steps
in processing REEs, says Darren Smith, a
spokesman for Edmonton-based Dahrouge
Geological Consulting Ltd., which discovered Commerce’s Ashram REE deposit in
northern Québec in 2009. They are the
liberation and concentration of the REE
minerals from the host material, dissolution of the mineral concentrate in acidic or
alkaline solutions; separation of the REEs
using solvent extraction or ion exchange;
and reduction of the individual REEs into
pure metals.
Smith says the first step typically
includes crushing the ore and separating
the REE by flotation, magnetic, or gravity
separation; this increases the percentage of
REEs in the working material by creating a
mineral concentrate. Later in the process,
thermal and chemical reactions convert the
mineral concentrate’s REEs into a soluble
form. Hydrometallurgical techniques that
include leaching, extraction, and precipitation are used to bulk precipitate the
REEs and further process them into separated oxides. Additional processing may
refine the oxides into high-purity metals.
Smith says Commerce is one of only two
or three REE companies in development
that has successfully created a mineral
concentrate of more than 40% total rare
earth oxides at more than 70% recovery.
“All major producing REE deposits, apart
from the South China clays, produce a
minimum 30% mineral concentrate for
downstream processing,” he said.
Grove says Orbite Aluminae Inc. [ORTTSX; EORBF-OTCQX] is working on a
new processing technology. According to
Orbite, the process not only extracts alumina from aluminous clay, but also has
the potential to extract high-value elements and rare earths. The Orbite process
of producing metallurgical-grade alumina
involves crushing and then acid-leaching
the aluminous clay stone found at the company’s Grande-Vallée property in eastern
Québec. Then, by varying the temperature
and acidity of the solution, the process
isolates the aluminum component and
removes iron and other impurities.
Grove says there are deposits of REEs
almost everywhere in the world, but China
has until now been the largest single supplier of feed stock, controlling about 95%
of world REE production. “China’s importance as the single largest producer is still
current, but their assets are impacted by
several factors,” said Grove. “For example,
they are generally considered – by the
Chinese themselves and by anyone else in
the world who has visited these sites – to
be significant polluters.”
Grove says China cannot continue REE
production at the same rate of extraction
forever. “As a result, the Chinese are actively
looking for foreign suppliers of feed stock,
especially heavy REE deposits hosted in
xenotime,” he said. Despite China’s size and
importance, it is not a single monolithic
A flotation test on material from the Ashram
deposit on the Commerce Resources Eldor
property.
FEBRUARY/MARCH 2015
producer and processor of the REEs, Grove
says. “Basically, there are two competing
Chinese supply streams,” he said. “One is
sanctioned by the state and the other is produced on the black market.”
Grove says that about 10 years ago China
initiated a two-tiered pricing system, with
an export duty attached to material that
was not processed in China. “It is a multipurpose initiative,” he said. “One goal is
to drive foreign manufacturers to China to
access cheaper feed stock. Another is to
enable China to gain jobs and perhaps the
intellectual property that these companies would bring with them. “You could
say that, no matter what the World Trade
Organization has had to say about the
two-tiered pricing system – basically telling China that it is illegal – the Chinese will
continue to charge more for export REEs.”
Despite China’s price manipulations,
total world supply and demand are roughly
in sync. “Demand is growing slightly in
several applications, such as magnets, auto
catalysts, and fuel cell cracking catalysts,”
FEBRUARY/MARCH 2015
he said. “But it is down for phosphors,
although no successful substitutes for
them have been developed yet.”
Although China has a strangle-hold on
world REE production; there are a number
of Canadian companies that are advancing
rare earth projects. In addition to Commerce
Resources, they include Avalon Rare
Metals Inc. [AVL-TSX, NYSE MKT], Quest
Rare Minerals Ltd. [QRM-TSX], and
Medallion Resources Ltd. [MDL-TSXV].
Avalon’s flagship project is the 100%owned Nechalacho Project at Thor Lake,
Northwest Territories. According to
Avalon, Nechalacho is the most advanced,
large, heavy rare earth project in the world
outside of China. Avalon has completed a
feasibility study of the project and a federally-approved environmental assessment,
and it has reached a refining agreement
with Solvay, a large multinational processing company.
Commerce is developing its Ashram REE
deposit at the Eldor property in northern
Québec. In 2012, Commerce completed a
positive Preliminary Economic Assessment
of the project. The company says the PEA
shows a positive cash flow from a 4,000tpd open-pit operation with a 25-year
mine life, a pre-tax and pre-finance net
present value of $2.32 billion at a 10% discount rate, a pre-tax/pre-finance internal
rate of return of 44%; and a pre-tax/prefinance payback period of 2.25 years.
The company recently announced it has
initiated a program of downstream hydrometallurgical processing for material from
the Ashram deposit. The goal of the testing
is to demonstrate the conceptualized flow
sheet with a target of producing a mixed
rare earth carbonate (REC) product.
Once the hydrometallurgical flow sheet is
fully bench-tested, and mineral processing
has been optimized, a mini-pilot plant will
generate feed for the production of a mixed
REC concentrate for evaluation by a potential joint venture or off-take partner. The
test work also allows for a more thorough
evaluation of other potential end-product
options with ready markets. n
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