Rare earth mining may be key to our renewable energy future. But at what cost?

In spring 1949, three prospectors armed with Geiger counters got down to hunt for treasure within the arid mountains of southern Nevada and southeastern California.

Within the earlier century, these mountains yielded gold, silver, copper and cobalt. However the males have been searching for a unique type of treasure: uranium. The world was rising from World Struggle II and careening into the Chilly Struggle. The US wanted uranium to construct its nuclear weapons arsenal. Mining homegrown sources grew to become a matter of nationwide safety.

After weeks of looking, the trio hit what they thought was pay grime. Their devices detected intense radioactivity in brownish-red veins of ore uncovered in a rocky outcrop inside California’s Clark Mountain Vary. However as a substitute of uranium, the brownish-red stuff turned out to be bastnaesite, a mineral bearing fluorine, carbon and 17 curious components identified collectively as uncommon earths. Traces of radioactive thorium, additionally within the ore, had set the Geiger counters pinging.

As disappointing as that should have been, the bastnaesite nonetheless held worth, and the prospectors bought their declare to the Molybdenum Company of America, later referred to as Molycorp. The corporate was eager about mining the uncommon earths. Through the mid-Twentieth century, uncommon earth components have been turning into helpful in quite a lot of methods: Cerium, for instance, was the idea for a glass-polishing powder and europium lent luminescence to lately invented coloration tv screens and fluorescent lamps.

For the following few many years, the positioning, later dubbed Mountain Move mine, was the world’s high supply for uncommon earth components, till two pressures grew to become an excessive amount of. By the late Eighties, China was intensively mining its personal uncommon earths — and promoting them at decrease costs. And a sequence of poisonous waste spills at Mountain Move introduced manufacturing on the struggling mine to a halt in 2002.

However that wasn’t the top of the story. The green-tech revolution of the twenty first century introduced new consideration to Mountain Move, which later reopened and stays the one U.S. mine for uncommon earths.

Uncommon earths at the moment are integral to the manufacture of many carbon-neutral applied sciences — plus an entire host of instruments that transfer the trendy world. These components are the constructing blocks of small, tremendous­environment friendly everlasting magnets that preserve smartphones buzzing, wind generators spinning, electrical autos zooming and extra.

Mining U.S. sources of uncommon earth components, President Joe Biden’s administration stated in February 2021, is a matter of nationwide safety.

Uncommon earths will not be truly uncommon on Earth, however they are usually scattered all through the crust at low concentrations. And the ore alone is price comparatively little with out the complicated, usually environmentally hazardous processing concerned in changing the ore right into a usable kind, says Julie Klinger, a geographer on the College of Delaware in Newark. In consequence, the uncommon earth mining trade is wrestling with a legacy of environmental issues.

Uncommon earths are mined by digging huge open pits within the floor, which may contaminate the atmosphere and disrupt ecosystems. When poorly regulated, mining can produce wastewater ponds full of acids, heavy metals and radioactive materials which may leak into groundwater. Processing the uncooked ore right into a kind helpful to make magnets and different tech is a prolonged effort that takes massive quantities of water and probably poisonous chemical substances, and produces voluminous waste.

“We want uncommon earth components … to assist us with the transition to a climate-safe future,” says Michele Bustamante, a sustainability researcher on the Pure Sources Protection Council in Washington, D.C. But “every part that we do once we’re mining is impactful environmentally,” Bustamante says.

However there are methods to scale back mining’s footprint, says Thomas Lograsso, a metallurgist on the Ames Nationwide Laboratory in Iowa and the director of the Critical Materials Institute, a Division of Power analysis heart. Researchers are investigating every part from lowering the quantity of waste produced throughout the ore processing to enhancing the effectivity of uncommon earth factor separation, which may additionally lower down on the quantity of poisonous waste. Scientists are additionally testing alternate options to mining, akin to recycling uncommon earths from previous electronics or recovering them from coal waste.

A lot of this analysis is in partnership with the mining trade, whose buy-in is essential, Lograsso says. Mining firms should be prepared to put money into making modifications. “We need to be sure that the science and improvements that we do are pushed by trade wants, in order that we’re not right here growing options that no one actually needs,” he says.

Klinger says she’s cautiously optimistic that the uncommon earth mining trade can develop into much less polluting and extra sustainable, if such options are extensively adopted. “Quite a lot of good points come from the low-hanging fruit,” she says. Even fundamental {hardware} upgrades to enhance insulation can scale back the gasoline required to achieve the excessive temperatures wanted for some processing. “You do what you [can].”

The environmental influence of uncommon earth mining

Between the jagged peaks of California’s Clark vary and the Nevada border sits a broad, flat, shimmering valley often known as the Ivanpah Dry Lake. Some 8,000 years in the past, the valley held water year-round. Immediately, like many such playas within the Mojave Desert, the lake is ephemeral, winking into look solely after an intense rain and flash flooding. It’s a phenomenal, stark place, dwelling to endangered desert tortoises and uncommon desert vegetation like Mojave milkweed.

From about 1984 to 1998, the Ivanpah Dry Lake was additionally a holding pen for wastewater piped in from Mountain Move. The wastewater was a by-product of chemical processing to pay attention the uncommon earth components within the mined rock, making it extra marketable to firms that might then extract these components to make particular merchandise. By way of a buried pipeline, the mine despatched wastewater to evaporation ponds about 23 kilometers away, in and across the dry lake mattress.

The pipeline repeatedly ruptured over time. Not less than 60 separate spills dumped an estimated 2,000 metric tons of wastewater containing radioactive thorium into the valley. Federal officers feared that native residents and guests to the close by Mojave Nationwide Protect is perhaps liable to publicity to that thorium, which may result in elevated threat of lung, pancreatic and different cancers.

Unocal Company, which had acquired Molycorp in 1977, was ordered to scrub up the spill in 1997, and the corporate paid over $1.4 million in fines and settlements. Chemical processing of the uncooked ore floor to a halt. Mining operations stopped shortly afterward.

Half a world away, one other environmental catastrophe was unfolding. The overwhelming majority — between 80 and 90 % — of uncommon earth components available on the market for the reason that Nineties have come from China. One web site alone, the huge Bayan Obo mine in Interior Mongolia, accounted for 45 % of uncommon earth manufacturing in 2019.

Bayan Obo spans some 4,800 hectares, about half the dimensions of Florida’s Walt Disney World resort. It is usually probably the most closely polluted locations on Earth. Clearing the land to dig for ore meant eradicating vegetation in an space already vulnerable to desertification, permitting the Gobi Desert to creep southward.

In 2010, officers within the close by metropolis of Baotou famous that radioactive, arsenic- and fluorine-containing mine waste, or tailings, was being dumped on farmland and into native water provides, in addition to into the close by Yellow River. The air was polluted by fumes and poisonous mud that lowered visibility. Residents complained of nausea, dizziness, migraines and arthritis. Some had pores and skin lesions and discolored enamel, indicators of extended publicity to arsenic; others exhibited indicators of brittle bones, indications of skeletal fluorosis, Klinger says.

An aerial view of part of the Bayan Obo mine in China’s Inner Mongolia region
The Bayan Obo mine (proven) in China’s Interior Mongolia area was accountable for almost half of the world’s uncommon earth manufacturing in 2019. Mining there has taken a heavy toll on the native residents and the atmosphere.WU CHANGQING/VCG VIA GETTY IMAGES

The nation’s uncommon earth trade was inflicting “extreme injury to the ecological atmosphere,” China’s State Council wrote in 2010. The discharge of heavy metals and different pollution throughout mining led to “the destruction of vegetation and air pollution of floor water, groundwater and farmland.” The “extreme uncommon earth mining,” the council wrote, led to landslides and clogged rivers.

Confronted with these mounting environmental disasters, in addition to fears that it was depleting its uncommon earth assets too quickly, China slashed its export of the weather in 2010 by 40 %. The brand new limits despatched costs hovering and kicked off concern across the globe that China had too tight of a stranglehold on these must-have components. That, in flip, sparked funding in uncommon earth mining elsewhere.

In 2010, there have been few different locations mining uncommon earths, with solely minimal manufacturing from India, Brazil and Malaysia. A new mine in remote Western Australia came online in 2011, owned by mining firm Lynas. The corporate dug into fossilized lava preserved inside an historic volcano referred to as Mount Weld.

Mount Weld didn’t have wherever close to the identical type of environmental influence seen in China: Its location was too distant and the mine was only a fraction of the dimensions of Bayan Obo, in accordance with Saleem Ali, an environmental planner on the College of Delaware. The US, in the meantime, was desirous to as soon as once more have its personal supply of uncommon earths — and Mountain Move was nonetheless the very best prospect.

Mountain Move mine will get revived

After the Ivanpah Dry Lake mess, the Mountain Move mine modified fingers once more. Chevron bought it in 2005, however didn’t resume operations. Then, in 2008, a newly shaped firm referred to as Molycorp Minerals bought the mine with formidable plans to create a whole uncommon earth provide chain in the USA.

The purpose was not simply mining and processing ore, but in addition separating out the fascinating components and even manufacturing them into magnets. Presently, the separations and magnet manufacturing are completed abroad, principally in China. The corporate additionally proposed a plan to keep away from spilling wastewater into close by fragile habitats. Molycorp resumed mining, and launched a “dry tailings” course of — a way to squeeze 85 % of the water out of its mine waste, forming a thick paste. The corporate would then retailer the immobilized, pasty residue in lined pits by itself land and recycle the water again into the power.

Sadly, Molycorp “was an epic debacle” from a enterprise perspective, says Matt Sloustcher, senior vice chairman of communications and coverage at MP Materials, present proprietor of Mountain Move mine. Mismanagement in the end led Molycorp to file for Chapter 11 chapter in 2015. MP Supplies purchased the mine in 2017 and resumed mining later that yr. By 2022, Mountain Move mine was producing 15 % of the world’s uncommon earths.

MP Supplies, too, has an formidable agenda with plans to create a whole provide chain. And the corporate is set to not repeat the errors of its predecessors. “We have now a world-class … unbelievable deposit, an untapped potential,” says Michael Rosenthal, MP Supplies’ chief working officer. “We need to assist a sturdy and numerous U.S. provide chain, be the magnetics champion within the U.S.”

The challenges of separating uncommon earths

On a sizzling morning in August, Sloustcher stands on the fringe of the Mountain Move mine, a large gap within the floor, 800 meters throughout and as much as 183 meters deep, large enough to be seen from house. It’s a powerful sight, and a great vantage level from which to explain a imaginative and prescient for the longer term. He factors out the varied buildings: the place the ore is crushed and floor, the place the bottom rocks are chemically handled to slough off as a lot non–uncommon earth materials as attainable, and the place the water is squeezed from that waste and the waste is positioned into lined ponds.

The tip result’s a extremely concentrated uncommon earth oxide ore — nonetheless nowhere close to the magnet-making stage. However the firm has a three-stage plan “to revive the total uncommon earth provide to the USA,” from “mine to magnet,” Rosenthal says. Stage 1, begun in 2017, was to restart mining, crushing and concentrating the ore. Stage 2 will culminate within the chemical separation of the uncommon earth components. And stage 3 can be magnet manufacturing, he says.

Since coming on-line in 2017, MP Supplies has shipped its concentrated ore to China for the following steps, together with the arduous, hazardous technique of separating the weather from each other. However in November, the corporate introduced to traders that it had begun the preliminary steps for stage 2, a “major milestone” on the way in which to realizing its mine-to-magnet ambitions.

With investments from the U.S. Department of Defense, the corporate is constructing two separations services. One plant will pull out lighter uncommon earth components — these with smaller atomic numbers, together with neodymium and praseodymium, each of that are key substances within the everlasting magnets that energy electrical autos and plenty of client electronics. MP Supplies has extra grant cash from the DOD to design and construct a second processing plant to separate aside the heavier uncommon earth components akin to dysprosium, additionally an ingredient in magnets, and yttrium, used to make superconductors and lasers.

Like stage 2, stage 3 is already beneath manner. In 2022, the corporate broke floor in Fort Value, Texas, for a facility to provide neodymium magnets. And it inked a take care of Common Motors to produce these magnets for electrical automobile motors.

However separating the weather comes with its personal set of environmental issues.

The method is tough and results in numerous waste. Uncommon earth components are extraordinarily comparable chemically, which suggests they have a tendency to stay collectively. Forcing them aside requires a number of sequential steps and quite a lot of highly effective solvents to separate them one after the other. Caustic sodium hydroxide causes cerium to drop out of the combo, for instance. Different steps contain options containing natural molecules referred to as ligands, which have a robust thirst for steel atoms. The ligands can selectively bind to specific uncommon earth components and pull them out of the combo.

However one of many greatest points plaguing this extraction course of is its inefficiency, says Santa Jansone-Popova, an natural chemist at Oak Ridge Nationwide Laboratory in Tennessee. The scavenging of those metals is sluggish and imperfect, and firms should undergo loads of extraction steps to get a sufficiently marketable quantity of the weather. With the present chemical strategies, “you want many, many, many levels so as to obtain the specified separation,” Jansone-Popova says. That makes the entire course of “extra complicated, dearer, and [it] produces extra waste.”

Beneath the aegis of the DOE’s Crucial Supplies Institute, Jansone-Popova and her colleagues have been trying to find a strategy to make the method extra environment friendly, eliminating lots of these steps. In 2022, the researchers recognized a ligand that they are saying is rather more environment friendly at snagging sure uncommon earths than the ligands now used within the trade. Business companions are on board to check out the brand new course of this yr, she says.

Along with issues about heavy metals and different poisonous supplies within the waste, there are lingering worries concerning the potential impacts of radioactivity on human well being. The difficulty is that there’s nonetheless solely restricted epidemiological proof of the influence of uncommon earth mining on human and environmental well being, in accordance with Ali, and far of that proof is expounded to the toxicity of heavy metals akin to arsenic. It’s additionally not clear, he says, how a lot of the issues over radioactive waste are scientifically supported, because of the low focus of radioactive components in mined uncommon earths.

Such issues get worldwide consideration, nonetheless. In 2019, protests erupted in Malaysia over what activists referred to as “a mountain of poisonous waste,” about 1.5 million metric tons, produced by a uncommon earth separation facility close to the Malaysian metropolis of Kuantan. The ability is owned by Lynas, which ships its uncommon earth ore from Australia’s Mount Weld to the positioning. To dissolve the uncommon earths, the ore is cooked with sulfuric acid after which diluted with water. The residue that’s left behind can comprise traces of radioactive thorium.

A photo of machinery at a plant near Kuantan, Malaysia built by Australian company Lynas
Australian firm Lynas constructed a plant close to Kuantan, Malaysia, (proven in 2012) to separate and course of the uncommon earth oxide ore mined at Mount Weld in Western Australia. Native protests erupted in 2019 over how the corporate disposes of its thorium-laced waste.GOH SENG CHONG/BLOOMBERG VIA GETTY IMAGES

Lynas had no everlasting storage for the waste, piling it up in hills close to Kuantan as a substitute. However the alarm over the potential radioactivity in these hills could also be exaggerated, consultants say. Lynas studies that employees on the web site are uncovered to lower than 1.05 millisieverts per yr, far under the radiation publicity threshold for employees of 20 millisieverts set by the Worldwide Atomic Power Company.

“There’s loads of misinformation about by­merchandise akin to thorium.… The thorium from uncommon earth processing is definitely very low-level radiation,” Ali says. “As somebody who has been a dedicated environmentalist, I really feel proper now that there’s not a lot science-based resolution making on these items.”

Given the issues over new mining, environmental suppose tanks just like the World Sources Institute have been calling for extra recycling of present uncommon earth supplies to scale back the necessity for brand spanking new mining and processing.

“The trail to the longer term has to do with getting probably the most out of what we take out of the bottom,” says Bustamante, of the NRDC. “In the end the largest lever for change just isn’t within the mining itself, however within the manufacturing, and what we do with these supplies on the finish of life.”

Which means utilizing mined assets as effectively as attainable, but in addition recycling uncommon earths out of already present supplies. Getting extra out of those supplies can scale back the general environmental impacts of the mining itself, she provides.

That could be a worthwhile purpose, however recycling isn’t a silver bullet, Ali says. For one factor, there aren’t sufficient spent uncommon earth–laden batteries and different supplies out there for the time being for recycling. “Some mining can be crucial, [because] proper now we don’t have the inventory.” And that offer drawback, he provides, will solely develop as demand will increase.

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