In 2016, Georgia State University graduate student Danny Gardner wrote a thesis that called for digging a little deeper into materials mined near the town of Sandersville, the self-proclaimed “Kaolin Capital of the World,” two hours southeast of Atlanta. His professor, Dr. W. Crawford Elliott was curious. Together, they visited the vast white mines, collected samples from their corporate sponsor Thiele Kaolin Company, and returned to their lab in downtown Atlanta. There, they discovered something mixed in the dusty powder and rocks that Elliott describes as remarkable: a concentration of valuable rare-earth elements—used in everything from smartphones to x-ray machines—more than 100 times greater than what’s normally found in the planet’s upper-continental crust.
“Wow,” the professor recalls saying at the time. “This is a lot.”
Let’s talk kaolin ore. Used in paints, plastics, caulks, and the coating of six-pack cartons and glossy magazines, among many other everyday items, this “white gold” is a clay material formed by weathering rocks and deposited in a huge subterranean belt from roughly Columbus to Augusta. Annually, it’s an $800 million industry in Georgia, the leading domestic producer.
Scientists have found “rare earths,” for short, in kaolin before, but Elliott and his pupil may have uncovered a new method of tapping it. Their process involves separating minerals in the kaolin “grit”—that is, sandlike material that’s purged in the creation of kaolin products. In addition, grit samples from Middle Georgia showed an enrichment of heavy rare-earth elements, which are less common and typically more important for technologies that power most people’s lives today, such as cellphones, computers, television screens, fiber optics, x-ray and MRI machines, and magnets used for loudspeakers and electric cars. “I don’t think anybody had found this amount of heavy rare earths here [in Georgia’s kaolin],” Elliott notes. “That, to me, was a real eye-opener.”
“I don’t think anybody had found this amount of heavy rare earths here.”
And no place in the U.S. currently produces rare earths, following the closure of a California mine, Mountain Pass, in 2015. Today, more than 95 percent of the world’s rare earths are sourced from China. The laborious and often toxic processing required to refine rare earths from materials mined in China has triggered environmental hazards, including poisoned drinking water. It’s possible, however, that extracting rare earths from kaolin leftovers could be easier—and cleaner—than more traditional sources, such as solid rock, says Kevin Clemens, an engineer who covers battery and energy technologies at Design News, a trade magazine.
Following the lab results, Elliott and Gardner presented their findings to a roomful of Thiele Kaolin bigwigs, who the professor says were delighted, naturally. But what could their discovery mean for consumers? For the kaolin industry? And for Georgians? According to Elliott and officials with the mining company, it’s too soon to know whether Georgia has a gold rush on its hands.
Rare earths (a misnomer, in that they aren’t exactly rare) have been found in at least a dozen U.S. states and more recently in silt and clay deposits off Japan’s coast. “The key question,” says Clemens, “is how many of these sites have deposits that are of sufficient concentrations to be financially viable for extraction?”
Thiele Kaolin officials—while “excited” by the proven existence of heavy rare earths—have no plans to mine the elements from kaolin right now, says Dr. Prakash Malla, the company’s director of research and development. With limited data, he says, it’s impossible to know how much valuable material might exist or what potential methods might be required to obtain it.
“While it’s interesting scientifically and academically, we’re a long way from commercially exploring rare-earth elements in Middle Georgia,” Malla says. “So, it’s too early in declaring much of an economic boon for us or the state, [and] the environmental concerns are a moot point.” Still, Malla believes that finding commercially viable sources of rare earths beyond China is an “urgent” issue of “national security.”
The Georgia State research was published last year in the journal Clays and Clay Minerals, and media buzz wasn’t far behind. The attention is cause for Neill Herring, a longtime environmental activist and southeast Georgia resident who’s studied the state’s kaolin belt for years, to be skeptical of the timing and the potential long-term value. Rare-earths prices have plummeted, he notes, following a surge in China’s pricing a few years ago.
“Mining is an incredibly speculative industry,” says Herring. “Values sink and rise very quickly. Rumors are really important. If you try to study mining economics, you’re going to find yourself in an amazing tangle of theories and facts.”
As for what’s next, Elliott says he plans to keep digging in Middle Georgia—ideally with the assistance of federal funding that has yet to pan out. “It should lead to further research in this area; that’s the first thing,” says Elliott. “And I think China should take notice. I’ve talked to colleagues there, and they think [the Georgia State] work’s good. I don’t think it competes with their deposits—I don’t think—but still, they’re on notice.”
This article appears in our April 2019 issue.