Electric cars and wind turbines may indeed help wean the U.S. from oil dependence, but these technologies rely on rare-earth metals to operate–metals that are in short supply, and that leave radioactive waste behind after extraction. According to a recent article in MIT’s Technology Review, 95% of the rare-earth metals needed for everything from compact fluorescent bulbs to magnets for electric vehicle motors and wind turbines come from China—and these metals are increasingly difficult to find.
The article reports: “Of particular concern are neodymium and dysprosium, which are used to make magnets that help generate torque in the motors of electric and hybrid cars and convert torque into electricity in large wind turbines. In a report released last December, the U.S. Department of Energy estimated that widespread use of electric-drive vehicles and offshore wind farms could cause shortages of these metals by 2015.” There is no real known alternative to these metals needed to make magnets that are incredibly strong. The article reports that a Toyota Prius motor uses about a kilogram of rare earth metals, while offshore wind turbines need hundreds of kilograms of such metals each.
Very little rare-earth mining is underway in the U.S., although a once-operational mine in Mountain Pass, California, is being reopened. That mine, owned by Molycorp Minerals was once the world leader in rare-earth mining, but shut down in 2002 following environmental problems and difficulties competing with cheaper metals from China. The company has since invented a new method for separating the metals via saltwater reprocessing that will make for cleaner, cheaper production. Beginning in 2012, the California mine operators expect to start producing up to 40,000 tons of rare earths each year.
Molycorp was prompted to reopen the mine as Chinese exports fell, driving up the cost of the metals. And because they are needed not only for computer hard drives, cell phones, electric cars and wind turbines, but also for weapons systems, tank navigation units and Navy radars, failure to develop a domestic source of rare-earth metals is considered a national security issue. Ed Richardson, vice president of Thomas & Skinner Inc., a company that makes magnets with military applications, told National Public Radio that “The gap in terms of the world demand outside of what China has said they’ll export is about 100,000 tons.”
Despite the need for alternatives to these hard-to-find metals, very little research has been done to develop material substitutes. When U.S. mines closed and production of rare-earth metals shifted to Asia two decades ago, most of the studies surrounding high-performing magnets petered out as well.
And there are environmental concerns in the extraction process, as seen when the California mine was first operating. Extracting the rare-earth metals requires crushing rocks and sending the powder through tanks to allow the metals to float to the top. Then the metals are heated in kilns and dissolved in acid. During the process, huge amounts of salty waste water are generated. The Technology Review article reports that the California mine produced some 850 gallons of it every minute every day that it was running. And the waste water contains not just salt, but radioactive thorium and uranium which is sent to evaporation ponds. Several times, pipes carrying this waste water in California burst, “spilling hundreds of thousands of gallons of hazardous waste into the desert.”
And although the new mine may help to secure at least a fraction of the needed rare-earth metals for new technologies, the surrounding industry of turning these into magnets is almost entirely located in China and Japan. From reopening mines to ensuring mine safety to developing alternatives and building a magnet industry, the U.S. is a long way from security.