Rare earth element facts for kids

Rare earth elements are a group of seventeen special chemical elements. They include fifteen elements called lanthanides, plus scandium and yttrium. Scandium and yttrium are grouped with rare earths because they are often found in the same ore deposits and act very similarly.

Even though they are called "rare," these elements are not actually super rare on Earth. They got their name because they are spread out very evenly across the planet. This makes it hard to find a lot of them in one place. One rare earth element, promethium, is truly rare because it is radioactive and breaks down over time.

For example, cerium, which is a lanthanide, is the 25th most common element in the Earth's crust. However, most rare earth elements are not found in pure forms or in large, easy-to-mine amounts.

Meet the Rare Earth Elements

Here is a list of the seventeen rare earth elements. It shows their atomic number, symbol, where their name came from, and some of their cool uses. Some are named after the scientists who found them, and others are named after the places they were discovered.

Where Rare Earths Come From

Rare earth elements are heavier than iron. They are created when giant stars explode in events called supernovae. In nature, tiny amounts of radioactive promethium are made when uranium-238 breaks down. Most promethium is made by people in nuclear reactors.

The amounts of rare earth elements change over time in very small ways. Scientists can use these tiny changes to figure out the age of rocks and fossils.

Finding Rare Earths in the Earth

Rare earth elements are often found together in the ground. Because they are all very similar in size, it has always been hard to separate them. Even over millions of years, nature has only separated them into two main groups: light rare earths (like cerium) and heavy rare earths (like yttrium).

The first two rare earths discovered were yttria in 1794 and ceria in 1803. When they were first found, each was actually a mix of all the rare earths. Today, large deposits of the cerium-group rare earths are found and used around the world. Deposits of the yttrium-group are less common and usually smaller.

Who Produces Rare Earths?

Global production 1950–2000

Before 1948, most rare earths came from sand in India and Brazil. In the 1950s, South Africa became the main producer after a large deposit was found there. From the 1960s to the 1980s, a mine in California was the biggest producer.

Today, India and South Africa still produce some rare earths, but it's much less than what China produces. For a long time, China produced over 95% of the world's rare earth supply, mostly from Inner Mongolia. By 2012, this number had dropped a bit, but China still leads. All the world's heavy rare earths (like dysprosium) come from Chinese sources, such as the Bayan Obo deposit.

There's a growing demand for these elements, and it's higher than the current supply. Experts think that in a few years, the world might need 40,000 more tons of rare earths each year than are available, unless new sources are found.

China's Role

China has announced plans to control its rare earth exports more strictly. They say this is to protect their natural resources and the environment. For example, in 2009, China said it would lower its exports to 35,000 tons per year for 2010–2015. They also reduced export amounts in 2011 and 2012.

Finding New Sources

Because of the high demand and China's export limits, many countries are looking for new rare earth sources. Searches are happening in places like Australia, Brazil, Canada, South Africa, Tanzania, Greenland, and the United States. Many mines in these countries had closed when China offered rare earths at very low prices in the 1990s. It will take a few years to get these mines working again.

Another possible way to get rare earths is from nuclear reprocessing. This process creates many elements, but it's hard to do safely and cheaply because many of these elements are radioactive.

Recycling Rare Earths

We can also get rare earths from electronic waste and other trash that contains a lot of these elements. New recycling technology makes it easier to get rare earths from old electronics. For example, in Japan, there are about 300,000 tons of rare earths in unused electronics waiting to be recycled. In France, factories are being set up to produce rare earths from used fluorescent lamps, magnets, and batteries.

Why Rare Earths are Important

China says its stricter controls on rare earth production are for protecting the environment and saving resources. However, some people think China also wants its own companies to make more valuable finished products using rare earths, instead of just selling the raw materials.

The United States Department of Energy said in 2010 that dysprosium was the most important element for the U.S. because it relies so much on imports.

A 2011 report by the U.S. Geological Survey looked at China's rare earth industry. It noted that China's lead in producing these minerals has grown a lot. In 1990, China produced only 27% of the world's rare earths. By 2009, China produced 129,000 out of 132,000 metric tons worldwide. The report suggested that China would likely continue to limit exports.

The United States Geological Survey is also looking for rare earth deposits in southern Afghanistan. They found an area of rocks in an old volcano that has light rare earth elements like cerium and neodymium. This area might hold about 1.3 million metric tons of useful rock, which could be enough for about 10 years of current demand.

How Rare Earths Are Priced

Rare earth elements are not traded like gold or silver. Instead, they are sold on a private market, which makes their prices harder to track. However, prices are sometimes shared on websites like mineralprices.com. The 17 elements are usually not sold in their pure form. They are often sold in mixtures of different purity levels, like "Neodymium metal ≥ 99.5%". Because of this, prices can change based on how much is needed and how pure it needs to be.

Images for kids

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  A satellite image of the Bayan Obo Mining District in China, where many rare earths are found.

See also

In Spanish: Tierras raras para niños