New Metal Deposits Found at Rare Earth Mine
Molycorp Minerals announced last week that it had found significant ore deposits of heavy rare earth elements near its mine in Mountain Pass, California, and could start production in two years.
If it proves feasible, the discovery would put Molycorp at the forefront in breaking the United States’ dependence on China’s supply. However, speculation remains as to when, or if, the company can deliver.
“You can probably count on one hand the number of rare earth deposits where there are a predominant amount of heavies,” says Jim Sims, Molycorp’s vice president of corporate communications. “Finding terbium and dysprosium is a big deal. It will increase supply for most applications.”
Rare earth metals are often all found together, typically with far more light than heavy elements. Both light and heavy elements go into making LCD screens, compact fluorescent bulbs, and the strong permanent magnets used in hybrid car batteries and wind turbines. Uses in hybrid car batteries and military equipment require adding heavier elements to keep the materials magnetized at their high operating temperatures.
Molycorp began extracting light rare earth metals from the open-pit Mountain Pass Mine in the 1950s. A costly cleanup, combined with low-cost competition from China, shut the mine down in 2002. China currently supplies at least 95 percent of the world’s rare earth elements and up to 99 percent of the heavy varieties. The nation is cutting back exports amid growing demand to the point where some metals are fetching thousands of dollars a kilogram. Many western markets would welcome news of an alternative supply.
Other companies are surveying potential sites in Canada, Alaska, and Australia. Molycorp is the first such company to declare it has a viable source. Sims says measurements of the grade, mineral matrix, and size of the ore deposit appear favorable to commercial extraction. But it is relatively early in the process to go public with it.
“I’m highly skeptical of the real impact of the announcement this week,” says Gareth Hatch, cofounding principal of Technology Metals Research, a firm that advises rare earth metals stakeholders. “We’re being asked to take it on faith that it will happen, but it doesn’t work like that.”
The motivation may relate to the U.S. Department of Energy’s December 2010 Critical Materials Strategy report, which expresses concern about a short-term supply disruption. The announcement asserting the discovery of four of the report’s critical rare earth metals reassures manufacturers that the elements will be available to the supply chain at reasonable prices until other western suppliers start producing them in the next few years. Such a discovery also minimizes the need for engineers to redesign products so they won’t require problematic components.
Molycorp appears to have faith in its light rare earths: it’s spending $781 million to overhaul its equipment and expand potential production to 40,000 tons a year. But the 8-K statement filed with the U.S. Securities and Exchange Commission last week makes no promises as to what it will find once it starts drilling for the heavier varieties: “Molycorp must do extensive test drilling to determine the quantity and quality of the deposit. Accordingly, there can be no assurance as to the quantity or quality of such rare earth deposit or that such deposit will become proven or probable reserves.”
Geoffrey Hinton tells us why he’s now scared of the tech he helped build
“I have suddenly switched my views on whether these things are going to be more intelligent than us.”
ChatGPT is going to change education, not destroy it
The narrative around cheating students doesn’t tell the whole story. Meet the teachers who think generative AI could actually make learning better.
Meet the people who use Notion to plan their whole lives
The workplace tool’s appeal extends far beyond organizing work projects. Many users find it’s just as useful for managing their free time.
Learning to code isn’t enough
Historically, learn-to-code efforts have provided opportunities for the few, but new efforts are aiming to be inclusive.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.