Mining Supervolcanoes For Lithium

From Smithsonian Magazine, August 25:

Will Supervolcanoes Help Power Our Future?

Vast new deposits of lithium could change the global politics of battery production—if we can get at them

A geologist looks out into a caldera in Nevada's McDermitt Volcanic Field. (Tom Benson)

There’s no doubt that in coming years, we’re going to need a lot of lithium. The growing market of electric automobiles, plus new household energy storage and large-scale battery farms, and the current lack of any technology better for storage than lithium ion batteries, puts the future of energy storage in the hands of just a few places around the world where the alkali metal is extracted.

Earlier this decade, researchers from the University of Michigan projected the growth in demand for lithium up until the year 2100. It’s a lot—likely somewhere between 12 million and 20 million metric tons—but those same scientists, as well as others, at the USGS and elsewhere, have estimated that global deposits well exceed those numbers. The issue is not the presence of lithium on Earth, then, but being able to get at it. Most of what we use currently comes from just a few sources, mostly in Chile and Australia, which produce 75 percent of the lithium the world uses, and also by Argentina and China, according to USGS research from 2016.

Looking to solve this problem, Stanford geologists went in search of new sources of the metal. They knew it originates in volcanic rock, and so they went to the biggest volcanoes they could find: Supervolcanoes, which appear not as a mountain with a hole in it, but a big, wide, cauldron-shaped caldera where a large-scale eruption happened millions of years ago. There, they saw high concentrations of lithium contained in a type of volcanic clay called hectorite. Geologists already knew generally that lithium came from volcanic rocks, but the team from Stanford was able to measure it in unexpected locations and quantities opening up a wider range of potential sites.

“It turns out you don’t really need super high concentrations of lithium in the magma,” says Gail Mahood, a Stanford geology professor and author of the study, in Nature Communications, about the discovery. “Many of the volcanoes that erupted in the western U.S. would have enough lithium to produce an economic deposit, as long as the eruption is big enough … and as long as [it] created a situation where you could concentrate the lithium that was leached out of the rocks.”...

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