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GREEN CARS GOOD FOR RARE EARTH MINING
Focus on Industrial Minerals by Harold Hough Oct/Nov 2009
While many sectors of the mining industry are taking a hit, at least
one group may be looking forward to green technology – the rare earths
sector. Many of the technologies that environmentalists are counting on
rely heavily on rare earth elements that, although not rare, are in danger
of becoming scarce. That scarcity made exacerbated by a potential rare
earths export ban by China.
Hybrid cars contain from 20 to 25 pounds of rare earths where a standard
vehicle can contain on the order of 10 pounds. Powerful Neodymium-Iron-Boron
(NdFeB) magnets are vital in the electric motor and regenerative braking
systems found in most electric vehicles and are also crucial to several
other systems in the vehicle. Virtually all “green” cars on
the road today also rely on rare earths (primarily lanthanum) in the battery
pack which stores energy normally wasted during coasting and braking and
saves it until needed by the electric motor. In fact, The Prius automobile
is the biggest user of rare earths of any object in the world.
Rare earths have other applications. They are at the heart of the most
powerful magnets and superconductors. One of the most common green applications
of rare earth elements is their use in energy efficient lighting. Phosphors
of rare earths are applied to the insides of the bulbs and generate light
when energy is applied. These compact fluorescent lamps (CFL's) are replacing
the standard incandescent light bulbs at a rapid rate. Incandescence bulbs
waste 95% of their energy and convert only 5% to actual light. Contrast
this to the CFL which converts 25% of input energy to visible light via
the rare earth phosphor coating. This efficiency results in much lower
lamp temperatures, significantly longer life (estimated at 6 to 10 times
as long), and less total energy consumed.
Rare earths are seventeen elements in the periodic table that are hardly
rare. The term "rare earth" arises from the minerals from which
they were first isolated, which were unusual oxide-type minerals found
in Gadolinite extracted from one mine in the village of Ytterby, Sweden.
However, with the exception of the highly-unstable promethium, rare earth
elements are found in relatively high concentrations in the earth's crust,
with cerium being the 25th most abundant element in the earth's crust.
Until recently, rare earth demand was modest and until after World War
Two, all the demand was met by mining sands in India and Brazil. Later,
South Africa became the rare earths producer. However, recently China
has begun to monopolize the production of these elements. In fact, today
97% of rare earth production comes from China. It supplied 139,000 tons
of refined material in 2008. Output is expected to reach 160,000 tons
a year by the middle of the next decade.
Although Chinese mined rare earths were inexpensive in the 1990s, growing
demand for them has caused prices to rise and supplies to shrink. Now
there is an expected shortfall of 40,000 tons a year by 2015. There is
also increasing talk that China, whose internal demand, especially for
dysprosium and terbium, is overtaking supply may ban export of many rare
earth compounds.
Fortunately, there is a domestic solution. Molycorp intends to reopen
the Mountain Pass Mine in California in 2012. Mountain Pass is considered
the world's richest reserve of its kind, with ore deposits averaging a
concentration of rare earths above 9 percent. Most deposits around the
world outside China report ore grades under 5 percent.
Mountain Pass also has the largest reserves outside of China. Geologists
estimate that the deposit holds 20 million to 47 million tons of ore.
Another benefit is that the mine has negligible traces of uranium and
thorium - radioactive elements often found together with rare earths that
can make processing more expensive.
Mountain Pass first opened in the 1940s, when rare earths were mined
for use in tracer ammunition for the military and the flints of cigarette
lighters. With the growing demand for color televisions in the 1960s,
Mountain Pass became the world's only supplier of europium, used to produce
red picture tones. By the 1980s, lanthanum, neodymium and other rare earths
were being mined for new discoveries in batteries and magnets. Mining
ceased in 2002, when their mining permit expired, although some refining
of previously mined ore took place in 2007.
But Mountain Pass alone will not be able to meet the expected rare earth
shortfall. Molycorp expects to be able to produce about 20,000 tons of
rare earth oxides a year by 2012. Eventually, it expects to double that
rate. But, that will barely meet expected global demand, especially if
China imposes a rare earth export ban. As a result, some mining companies
are looking at a couple of promising sites in Canada that may keep the
rare earths from becoming too rare.
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