Chemical Engineering October 2010 - 17

Newsfront
RaRe-eaRth Metals
FoR the FutuRe
A
Economics, workforce and R&D will determine the
future of these critical technology metals
s demand for rare-earth metals
in a wide range of technology applications
continues to increase,
efforts to reestablish mining
and production of rare-earth elements
(REEs) is underway outside China,
currently the dominant force in REE
production. Future supplies of REEs
and the myriad products in which they
appear will depend less on absolute
geological reserves and global trade
politics and more on issues of economic
viability, workforce development and
technological innovation.
With Chinese REE exports shrinking
to keep material in the country for
its own rising demands, developing
an REE supply chain outside China
appears to be essential in meeting
a global demand that is projected to
grow from the current 140,000 ton/yr to
over 200,000 ton/yr by 2015. Whether
a diversified REE marketplace takes
shape and whether global demand for
REEs is met will be determined to a
large extent by how chemical engineers
address challenges associated
with mining economically, extracting
metals efficiently and developing ways
to extend the current metal supplies.
Energy dependence
Issues surrounding the supply of REEs
are closely interrelated with those of
energy consumption. The same is true
of other critical metals (box, p. 23). In
many ways, meeting the demand for
metal minerals depends on our access
to cheap and plentiful energy, explains
Andre Diederen, analyst at the
not-for-profit organization TNO Defense,
Security and Safety (Rijswijk,
the Netherlands; www.tno.nl). " The
light rare
earths
Cerium
Lanthanum Hybrid electric-vehicle
engines, metal alloys
Auto catalysts, petroleum
refining, metal alloys
Neodymium Auto catalysts, petroleum
refining, magnets for
hard drives, lasers
Samarium
Europium
Magnets
Red color for television
and computer screens
Gadolinium Magnets
Source: U.S. Geological Survey (USGS)
problem is not that we will run out of
metal in the earth's crust, " Diederen
says, " it's that mining and extracting
it at current rates will become prohibitively
energy intensive. "
Removing ore from the ground and
concentrating the metals require huge
amounts of energy, and the energy required
grows exponentially with lower
ore grades. " Because of energy constraints,
the largest parts of mineral
deposits are out of reach for economically
viable exploitation, " Diederen
says. A decades-old paradigm - that
lower ore grades will be exploited when
a supply gap exists - will no longer be
valid without cheap and plentiful energy.
And Diederen and others think
the world will likely reach an oil production
maximum within the next ten
years and a coal production maximum
in 25 years, after which, energy supply
will no longer keep up with demand.
For REEs, the amount of metals in
existing and undiscovered deposits is
not an issue, says industry consultant
Jack Lifton. " It's not about how much
is there, " he says, " it's about how much
we can do. " Extracting and refining rare
earth metals is really an economic problem
and a personnel workforce problem.
" The capital costs are staggering " for
setting up mining, refining operations
and infrastructure, Lifton explains.
Since every ore deposit is different, each
site represents a unique chemical engineering
problem, and " there are not
enough chemical engineers with the
[rare earth] expertise to do the job. "
REEs not rare, but critical
Occupying the " lanthanide " row of
the periodic table, REEs are actually
moderately abundant in the earth's
crust, with some more plentiful than
other important metals, such as copper,
gold, platinum and lead. Although
relatively abundant, REE deposits are
ChemiCal engineering www.Che.Com oCtober 2010 17
Figure 1. Rare-earth magnets similar
to this one, produced at Ames Laboratory
using a new process, are critical
in many technology applications
Table 1. SelecTed end-uSeS for rare earTh elemenTS
major end-use
heavy rare
earths
major end-use
Terbium Phosphors, permanent
magnets
Dysprosium Permanent magnets,
hybrid engines
Praseodymium Permanent magnets Erbium
Yttrium
Phosphors
Red color, fluorescent
lamps, ceramics,
metal alloy agents
Holmium Glass coloring, lasers
Thulium Medical x-ray units
Lutetium Catalysts in
petroleum refining
Ytterbium Lasers, steel alloys
http://www.tno.nl http://www.Che.Com
Chemical Engineering October 2010

Table of Contents for the Digital Edition of Chemical Engineering October 2010
