China is the major supplier of those materials as well as elements including cadmium (used in rechargeable batteries), tungsten (in lightbulbs) and arsenic (in semiconductors). Rare earths are in your smartphone and television, hair dryer, and your hybrid or electric car. They are also found in loudspeakers, MRI and x-ray scanners, and other visual displays.
The least common rare earths are heavy rare earths, which experts predict will be exhausted within 20 years. (Anything called “heavy rare earth” sounds as scarce as kryptonite.) The main source is clay from the soil in southern China, which accounts for 81 percent of production. Despite a search for substitutes, the United States produced no rare earths in 2017 and still relies on these imports, making an important segment of its industrial base vulnerable.
Scarcity Drives Innovation
In the search for domestic sources, corporations and government agencies have found almost 11 million tons of rare earth resources in coal deposits across nine US states and have invested in new technologies to extract rare earths from the coal. Researchers have also found ways to pull rare earths from old recycled materials, such as magnets in computer hard-drives. A team from the Ames Laboratory and the Critical Materials Institute in September won this year’s Notable Technology Development Award for a process that recovers rare earth minerals from old magnets by dissolving them in water-based solutions, reports Recycling International.
Even with technical options, the formidable industrial infrastructure for refining rare earths remains an issue. Right now, only two countries refine rare earths: China and Malaysia, where a large compound northeast of Kuala Lumpur on the South China Sea extracts the elements through a complex process that involves baking the material at 1,000°C to yield a pinkish powder.
Variations on a Theme
The rare earth conundrum is the latest in a history of tensions over industrial building blocks that are less visible to the public than conflicts over water or petroleum. Tungsten, as it happens, was a flash point during an episode in World War II, when it was needed to make reinforced armaments, and most U.S.-bound tungsten came from Portugal. That supply was cut off by the Nazi blockade of the Atlantic that started in 1939, which also cut the critical supply of cork.
Cork from cork oak forests around the Mediterranean was vital for industry back then just as rare earths are for today’s electronics. On the eve of World War II, the United States imported nearly half the world’s total cork production, mostly from Portugal and Spain. In the era before plastics, particle-ized cork was the modern industrial material, an effective sealant and insulator. When Nazi Germany blockaded the Atlantic, cork suddenly emerged as an issue of national security, making the cover of Foreign Commerce Weekly. The U.S. cork industry had to slow commercial production and reserve stockpiles for making bombs, planes, and tanks.
The pressure on the U.S. cork industry to meet the nation’s wartime demand grew intense. Smaller producers went out of business, and larger companies sought government contracts to adapt. One of the largest, Baltimore-based Crown Cork and Seal, launched a high-profile nationwide tree-planting campaign named for its CEO, Charles McManus, Sr. The McManus Cork Project engaged governors in more than a dozen states to plant cork seedlings on Arbor Day and promoted plantings by 4-H clubs. Millions of cork seedlings were established across the country to create a domestic supply of cork a decade hence. When the war ended and European imports resumed, cork groves in Arizona, California, Mississippi, Maryland, and the Carolinas languished. It was cheaper to import cork than harvest it domestically.
One of several cork trees planted in the early 1940s by a farmer named Clyde Pittman still grows near the family homestead in Flat Creek, South Carolina. “It was a conversation piece,” his daughter Glenda says. “Most folks had never seen one before.” The tree testifies to a first-generation adaptation to scarcity, borne of the belief that we could ensure future domestic supply of a natural resource on a large scale by developing new technological and environmental responses to solve a shortage.
Before that response crystallized, however, the market shifted and wartime defense research yielded a new technological response. In a word, plastics. The U.S. cork industry still endures, but now accounts for just 22 percent of the world market.
In the search for domestic sources of rare earths, U.S. manufacturers may find new substitutes, just as plastic gaskets replaced cork ones. But China is likely to keep a hold on the global rare earths market for years to come.
David A. Taylor teaches science writing at Johns Hopkins University. He’s the author of the forthcoming Cork Wars: Intrigue and Industry in World War II (Johns Hopkins University Press).
Sources: American Association for the Advancement of Science, “Cork Wars” by David A. Taylor, The New York Times, Recycling International, Reuters, U.S. Congressional Research Service, U.S. Department of Defense