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Lithium may be the oldest metal in the universe. Scientists believe it was created along with hydrogen and helium in the Big Bang. Humans discovered it quite a bit later, in 1817, thanks to the work of yet another industrious Swedish chemist, Johan August Arfwedson. (What is it with those Swedes?) Lithium turned out to be useful for making a handful of niche products, including ceramic glazes, cold-resistant grease, and extra strength rubber tires. In 1949, pharmacists learned that ingesting a small amount of lithium helped stabilize the moods of people with bipolar disorder. It’s still prescribed today for that purpose. But lithium only came to be produced in large quantities in the 1950s, when the US government started stockpiling it to make one of that era’s technological marvels: the hydrogen bomb. The material that makes the H-bomb explode is actually a compound of lithium and hydrogen. The same element that powered my Leaf through the streets of Los Angeles can also be used to blast that city into a smoking crater.
For the next thirty-odd years, nearly all of the world’s lithium came from a couple of mines in North Carolina, where it was dug out of hard rock. Then came the discovery of the lithium-rich brines of South America. Guillermo Chong, a now-retired Chilean geologist, was part of the research expedition that found lithium under the Atacama in the early 1970s. “Conditions were very hard,” he says, sitting in his home in the Chilean coastal city of Antofagasta. There were no roads in the area back then. At night, he and his teammates shivered in their tents as temperatures dropped to well below freezing. The drilling gear they lugged out in four-wheeldrive trucks was barely up to the task. “The crust was hard as the skin of the devil,” says Chong. But after drilling dozens of holes over six weeks in the desert, they knew they were on to something. That something turned out to be the most expansive deposit of lithium ever found to that point. “With geology, you often find nothing,” says Chong. “To find something like that —” He rolls his eyes heavenward and lets out an expressive “huf!”
The Atacama lithium mines got going in the 1980s. Extracting lithium from brine was much cheaper than blasting it out of rock, and, as a result, Chile soon became the world’s top supplier.
Most of the Atacama is utterly sere and barren, all rock or sand or salt flat painted in muted reds and browns. It’s so like the surface of Mars that NASA tests its rovers there, so otherworldly that episodes of The Mandalorian have been filmed there.
And yet, it sustains life. The Atacameño people have called it home for at least twelve thousand years. The desert is strewn with pictographs, etched into stone by their ancestors, and the ruins of ancient stone fortresses called pukkaras. Today, a handful of Atacameño villages dot the foothills to the east of the lithium mines. They are mostly tucked into ravines that channel rain and snowmelt down from the Andes, ribbons of greenery lush with tamarugo trees, tall grasses, and fields of corn, tomatoes, and other crops. The villagers depend on those streams and the underground aquifers they feed.
The mines sit in a huge salt flat—a salar, in Spanish—several miles from the nearest village. Beneath that salt flat lies an enormous reservoir of brine—water thick with salts and minerals, including lithium, that has accumulated over thousands of years. Underground, the fresh and salty bodies of water meet in a mixing zone that forms a kind of border between them. The denser, heavier brines push the lighter freshwater toward the surface, where it forms shallow, brackish lagoons that are home to all kinds of tiny life forms, as well as the rare flamingos that eat them.
The mines slurp up water both sweet and salty. They pipe in fresh water for their employees to drink, wash with, and clean equipment. And they pump up boatloads of brine, at a rate of hundreds of gallons per second, into those colorful surface ponds. The brine is left out in the sun to evaporate over the course of many months. It takes more than one hundred thousand gallons of brine to produce a single ton of lithium.
This process permanently shrinks the total amount of water under the desert. Engineering & Technology, a UK-based professional magazine, estimated that, between 1985 and 2017, some 114 billion gallons of water were lost to the environment of the Salar de Atacama due to brine evaporation from just one company.
Excerpted from Chp 6 of Power Metal: The Race for the Resources that will shape the future by Vince Beiser.