Physics + Math

02
Apr

Where to Find Rare Earth Elements

Every time I see a commercial for a new cell phone, I feel a bit nauseous. I love a new cell phone just like the next person, but because of my training as a materials scientist, I feel like a worker in a sausage factory. Cell phones, like sausages, may be great, but you don’t really want to know what it takes to make them.

Our lust for new devices isn’t sustainable, at least not yet. Some of the key materials used to make them, mainly rare earth elements, are in tight supply, in part because the primary source of rare earths are mines in one country, China. About 97% of rare earths come from China, which has become increasingly protective of its bounty.

iPhone headphones
Headphones rely on magnets, often made of neodymium, to produce lots of sound from a small enclosure.

Rare earth elements are peppered throughout your phone, from the glass display, making it harder, to magnets in speakers, headphones, and vibrating motors, making them more powerful despite their small size. China’s monopoly has driven up prices on rare earths, raising costs for manufacturers.

But cell phones aren’t the only products affected by the monopoly. They are found in electric cars, wind turbines, solar cells, and batteries—key components of a future powered by alternative energy. Demand for rare earths is high and certain to grow in the coming decades. A hybrid Toyota Prius, for example, uses nearly 20 pounds of rare earths in its battery alone. There are more than 2 million Priuses on the road, and it’s just one of many hybrid and electric vehicles being sold today. A restricted supply of rare earths could thwart efforts to wean ourselves off oil.

Digging Deeper

Now, rare earths are not common, but they’re actually not that rare, either. The name is leftover from the 15th century when “rare” referred to “strange” or “unusual” materials and “earths” were any mineral or a metal combined with oxygen. If you look at a periodic table, rare earths sit in a row at the bottom called the lanthanides. Those elements, from lanthanum on the left to lutetium on the right plus yttrium and scandium are called the rare earths.

Rare earths in the periodic table
Rare earth elements include the lanthanide series, ytterium, and scandium, highlighted here in light blue.

Rare earths are not easy to mine. Like many minerals, they aren’t often found in pure veins, so they need to be separated from the surrounding rock and from one another. But the difficulty in obtaining them hasn’t dampened demand. Rare earths are ubiquitous in the consumer electronics industry, not just cell phones. Nearly every item with an on-off switch contains rare earths.

From 1940 to 1990, the United States produced and mined its own rare earths. One huge mine in southern California, called Mountain Pass, was the biggest resource in the U.S. The invention of the color TV in the mid-1960s, which required the rare earth europium to produce the color red, put Mountain Pass on the map. Up until the late 1980s, the mine was the world’s biggest supplier of rare earths.

It wouldn’t last. Mountain Pass was shut down in 2002, having been knocked out by a one-two punch of environmental violations and globalized markets. One of the dirty little secrets about rare-earth mining is that a major by-product is radioactive waste in the form of thorium. As early as 1985, ground-water samples showed the tailing ponds were leaking. By the late 1990s, Mountain Pass had leaked 300,000 gallons on seven separate occasions, spoiling the surrounding desert, which is habitat for the endangered desert tortoise. But the real knockout blow came from China, which has its own substantial deposits. It also had cheap labor, so it could mine the minerals at lower prices. Deng Xiaoping, an influential politician in China, recognized the importance of rare earths in 1992, when he said, “The Middle East has oil, but China has rare earths.” Production in China grew rapidly between 1990-2000, from 16,000 to 73,000 metric tons, an increase of 450%. Meanwhile, production in other countries dropped by 60%.

Sea Change

The tables may be turning, though. In 2004, the owner of Mountain Pass, Molycorp, pledged that it had cleaned up its act and was granted a permit to restart the mining of rare earths. It takes many years to reboot such an involved operation, but in 2012, Molycorp said they were on track to produce nearly 20,000 metric tons of rare earths. This year, that amount should double.

David Pogue visits the Mountain Pass mine in California, currently the only operational rare earth mine in the U.S. For more on rare earths and other elements, watch the complete program.

Many countries, including the U.S., Australia, India, Brazil, Vietnam, and Russia, are looking for new deposits of their own. Japanese scientists found large amounts of rare earth elements in mud at the bottom of the Pacific Ocean, and similar studies have shown they’re also in mud in Jamaica. In the far future, we could even turn to the Moon, which is unusually rich in rare earths.

Over the next few years, says Thomas Graedel, an industrial ecologist at Yale University and an expert in rare earths, the U.S. government should encourage domestic production at Mountain Pass. That’s because it takes up to 12 years to make a new mine operational, and we’ll certainly need more rare earths in the intervening years. “We [should] push Congress to do what is possible to help Mountain Pass remain a reasonable business,” he says.

Mining Your Desk Drawers

But that’s not all we can do. One way we can all contribute is by digging our old cell phones out of our desks. Each phone contains up to a few grams of rare earths. That might not seem like much, but when you add up the over 500 million retired cell phones that live in desk drawers, closets, and shoeboxes, you start to get somewhere. Recycling old electronics will not only free up valuable rare earths, but also copper, gold, palladium, and platinum. Think of your used cell phone as a miniature gold mine.

White iPhone 5 bottom view
In a few years, when you replace your iPhone 5, consider recycling it to free up its valuable materials.

Companies would be wise to initiate incentives to promote this recycling habit, too. Currently, only about 1% of cell phones get recycled. Credits toward new purchases or gift cards could get things rolling. In the meantime, you can drop off your retired cell phones at certain businesses (the EPA maintains a list), or they can be mailed to a recycling facility or donated to a charity. Every little bit helps. Just think, if you recycle your old phone today, your future self may thank you for the brilliant new features on the iPhone 10.