What are Rare Earths?

Rare earths, also known as "rare earth elements," is a collective term for 17 elements comprising the lanthanides from lanthanum (La, atomic number 57) to lutetium (Lu, atomic number 71), along with scandium (Sc) and yttrium (Y).
Despite the connotation of the name, rare earths are not particularly scarce — their reserve life (confirmed reserves divided by annual production) and concentration in the Earth's crust are actually greater than those of lead and zinc.
By making effective use of rare earths, significant advances are expected in existing technologies, including technological innovation through their novel functional properties, improved durability of structural materials, and enhanced energy efficiency in electrical and electronic equipment.

What are they used for?

The first industrial application of rare earths was as flints in cigarette lighters. At the time, since refining and separation technologies were not yet advanced, they were used in the form of mixed rare earth salts or misch metal (alloys) containing multiple elements.
In the 1960s, when refining and separation became possible, the unique "characteristics" of each rare earth element were identified. Industrial applications began with uses such as phosphors for color TV cathode ray tubes and high-refractive-index lenses for cameras, and then expanded to high-performance permanent magnets and rechargeable batteries, contributing to the miniaturization and weight reduction of devices such as audio equipment, personal computers, and digital cameras. More recently, rare earths have also attracted attention as raw materials for hydrogen storage alloys and magnetostrictive alloys.

Rare Earths Contributing to Energy Saving and a Better Global Environment

One of the reasons rare earths are attracting attention as "resources for the future" is that they are resources that contribute to energy saving and a better global environment.

Hybrid cars were made possible by the use of rare earths in highly efficient permanent magnet motors and safe, clean nickel-metal hydride batteries. Rare earths are also used in automotive exhaust gas purification catalysts and their honeycomb substrates, enabling efficient use of energy in society.
Furthermore, rare earths are an increasingly indispensable resource for the development of safe and recyclable devices going forward.