As portable electronics get more popular and the market for electric
vehicles takes off, demand for lithium—a critical element in
rechargeable lithium-ion batteries—could soar. Yet just two countries,
Chile and Australia, dominate global lithium production.
Brine time: A Simbol Materials engineer works on equipment used to separate lithium, manganese, and
zinc from geothermal brine.
California startup Simbol Materials
thinks it can increase domestic production of lithium by extracting the
element, along with manganese and zinc, from the brine used by
geothermal plants.
In the late 1990s, the U.S. produced 75 percent of the world's
lithium carbonate, but now it makes only 5 percent. This is, in part,
because U.S. manufacturers couldn't compete with low-cost lithium
chemicals from Chile. The U.S. produces no manganese at all. "Yet we
have this resource, already being harnessed for geothermal power
production," says Luka Erceg, Simbol's CEO. "This is an enormous
opportunity to harvest clean renewable energy and produce critical
materials in a sustainable manner."
Worldwide demand for lithium chemicals was about 102,000 tons in
2010. This is expected to go up to as much as 320,000 by 2020, mostly
because of increased electric-vehicle use. The world's largest lithium
resources are estimated by the U.S. Geological Survey to be in Bolivia.
Most manufacturers, including the world's largest, in Chile, typically
make the material by pumping brine into pools to evaporate in the sun
for 18 to 24 months. This process leaves behind a concentrated lithium
chloride that's converted into lithium carbonate. The only U.S.
producer, Chemetall Foote, drills for brine at Silver Peak in Nevada.
Simbol plans to piggyback on a 50-megawatt geothermal plant near the
Salton Sea in Imperial Valley, California, that pumps hot brine from
deep underground to generate steam to drive a turbine. The plant
currently injects the brine, which contains 30 percent dissolved solids,
including lithium, manganese, and zinc, back into the ground after the
steam is produced. Simbol will divert the brine from the power plant,
before reinjection, into its processing equipment. There, the still-warm
brine will flow through a proprietary medium that filters out the salts
within hours. Simbol has also acquired the assets and intellectual
property from a now-defunct Canadian company for a purification process
that creates the world's highest-purity lithium carbonate. Erceg expects
to compete with the lowest-cost Chilean producers, which produce
lithium at $1,500 a ton.
Simbol currently runs a pilot plant that filters 20 gallons a minute.
The commercial plant, near Salton Sea, will begin construction in 2012
and will have the capacity to produce 16,000 tons of lithium carbonate
annually. The world's third-largest producer, by comparison, makes
22,000 tons. By 2020, Simbol plans to triple production by expanding to
more geothermal plants, Erceg says. But for now, it is buying low-grade
lithium carbonate from other manufacturers for purification, and it
expects to sell the high-purity product overseas before the end of this
year.
Other lithium-mining projects are planned or underway around the
world, including two more in Nevada. Keith Evans, a geologist and
industrial minerals expert, says that if they all come online, global
production in 2020 could be over 426,000 tons, far outstripping demand.
Nevertheless, more U.S. production could make the country
self-sufficient. Plus, he says, Simbol could have an advantage over
other U.S. companies. "If their process is as good as they say it is, it
could be a very-low-cost producer," Evans says. "It is potentially a
very exciting project, if it works."
By Prachi Patel
From Technology Review
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