What are Rare Earth Elements?

Despite their name, these elements aren’t that rare in the earth’s crust. Cerium, for instance, is the 25th most abundant element overall.

Rare Earth Elements

The rare-earth elements (REE) are a set of 15 metals of the lanthanide series on the periodic table. These are: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu). In addition to these, yttrium (Y) and scandium (Sc) are also known as REE.

Where are rare earth elements found?

Despite their name, these elements aren’t that rare in the earth’s crust. Cerium, for instance, is the 25th most abundant element overall. They are called “rare” earth elements because it is uncommon to find them in their pure form.

They are mostly found within alkaline igneous rocks, carbonatites, placer deposits with monazite-xenotime mineralisation and ion-adsorption clay deposits.

What are rare earth elements used for?

While the rare earth elements may not exactly be household names, their uses are numerous, and they have become an integral part of many industries. In fact, they are especially crucial in many high-tech and “greener” technologies. Experts suggest that the use of rare earth elements in computers has grown almost as fast as cell phones.

Magnets

Neodymium is often used to make incredibly powerful magnets that are used in greener technologies and renewable energy, including the manufacture of both hybrid cars and wind turbines.

Visual displays

REEs such as terbium and europium are relied upon in the manufacture of computer and television screens as they are used to produce materials that give off the vivid colours we have come to expect.

Currency security

Europium is used as an anti-counterfeiting system in Euro banknotes, due to its luminescence from a phosphor compound. Under UV light, parts of the note glow red – the lack of the element will alert counting machines to forgeries.

Catalytic converters

Cerium oxide is used in the manufacture of catalytic converters, which convert smog molecules into carbon dioxide. It is also essential for its ability to polish glass and semiconductors.

High-strength alloys

Praseodymium is used in a variety of alloys to create strong metals for use in aircraft engines.

Glass industry and camera lenses

One of the largest consumers of REE materials, the glass industry uses the elements as additives that offer special optical properties, for glass polishing and as additives that provide colour. Lanthanum also makes up a large proportion of digital camera and cell phone camera lenses.

Batteries

Rare earth compounds are used in the manufacture of many rechargeable batteries in portable electronic devices, such as smartphones, e-readers, laptops and cameras.

Defence

REEs are used in many defence applications by the military, such as in night-vision goggles, precision-guided weapons, and GPS and communications equipment.

The demand for rare earth elements

With the ever-increasing demand for high-tech gadgets and devices, the need for REEs continues to rise, especially amid growing concerns for energy independence and climate change. With the metals becoming highly valuable, with the global market seeking new sources outside of China, where the majority of REEs are mined.

Ellipsis’s current project in the greater Aghracha area in southern Morocco is exploring the region for both vanadium and rare earth elements, and shows great promise.