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.