spring 1949, three prospectors armed with Geiger counters set out to hunt for treasure in the arid mountains of southern Nevada and southeastern California.
In the previous century, those mountains yielded gold, silver, copper and cobalt. But the men were looking for a different kind of treasure: uranium. The world was emerging from World War II and careening into the Cold War. The United States needed uranium to build its nuclear weapons arsenal. Mining homegrown sources became a matter of national security.Here are the steps that get rare earth elements out of the ground and into our hi-tech products. While the United States mines and concentrates rare earths, later steps needed to make magnets currently happen overseas.
Mining U.S. sources of rare earth elements, President Joe Biden’s administration stated in February 2021, is a matter of national security.
Rare earths are not actually rare on Earth, but they tend to be scattered throughout the crust at low concentrations. And the ore alone is worth relatively little without the complex, often environmentally hazardous processing involved in converting the ore into a usable form, says Julie Klinger, a geographer at the University of Delaware in Newark. As a result, the rare earth mining industry is wrestling with a legacy of environmental problems.But there are ways to reduce mining’s footprint, says Thomas Lograsso, a metallurgist at the Ames National Laboratory in Iowa and the director of the Critical Materials Institute, a Department of Energy research center. Researchers are investigating everything from reducing the amount of waste produced during the ore processing to improving the efficiency of rare earth element separation, which can also cut down on the amount of toxic waste. Scientists are also testing alternatives to mining, such as recycling rare earths from old electronics or recovering them from coal waste.
Much of this research is in partnership with the mining industry, whose buy-in is key, Lograsso says. Mining companies have to be willing to invest in making changes. “We want to make sure that the science and innovations that we do are driven by industry needs, so that we’re not here developing solutions that nobody really wants,” he says.
Klinger says she’s cautiously optimistic that the rare earth mining industry can become less polluting and more sustainable, if such solutions are widely adopted. “A lot of gains come from the low-hanging fruit,” she says. Even basic hardware upgrades to improve insulation can reduce the fuel required to reach the high temperatures needed for some processing. “You do what you [can].”
The environmental impact of rare earth mining
Between the jagged peaks of California’s Clark range and the Nevada border sits a broad, flat, shimmering valley known as the Ivanpah Dry Lake. Some 8,000 years ago, the valley held water year-round. Today, like many such playas in the Mojave Desert, the lake is ephemeral, winking into appearance only after an intense rain and flash flooding. It’s a beautiful, stark place, home to endangered desert tortoises and rare desert plants like Mojave milkweed.
From about 1984 to 1998, the Ivanpah Dry Lake was also a holding pen for wastewater piped in from Mountain Pass. The wastewater was a by-product of chemical processing to concentrate the rare earth elements in the mined rock, making it more marketable to companies that could then extract those elements to make specific products. Via a buried pipeline, the mine sent wastewater to evaporation ponds about 23 kilometers away, in and around the dry lake bed.
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