Rare Earths: Key Elements for Modern Technology

The so-called “rare earths” are neither earths nor particularly rare, but their importance in the technological and energy industry has made them a strategic resource. They are a group of 17 chemical elements with similar properties that are found in nature, although their extraction and refining are expensive and harmful to the environment.

What are rare earths?

Rare earths include the following elements: 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), lutetium (Lu), scandium (Sc) and yttrium (Y). Although their abundance varies, the difficulty of their separation and purification makes them valuable and strategic.

Production and geopolitics

Global reserves of rare earths amount to approximately 300 million tons. China leads production with 240,000 metric tons by 2023, followed by the United States (43,000 tons), Vietnam, Brazil and Ukraine (25,000 tons each). This Chinese dominance has led to growing global concern about dependence on a single supplier and has encouraged the exploration of new sources and recycling methods.

Environmental impact and need for sustainability

The processing of rare earths generates toxic waste and represents a high environmental impact. The search for sustainable alternatives, such as improved recycling and less polluting extraction methods, is crucial to minimize ecological damage and ensure a more responsible supply of these elements.

Key applications

Rare earths are essential in numerous technological and industrial sectors:

Magnets: They represent approximately half of the total use of rare earths. They are used in electric motors, wind turbines and hard drives.

Batteries: Lanthanum and neodymium are key in rechargeable batteries for electric vehicles.

Displays and lasers: Europium and terbium are used in LED lighting and LCD displays.

Catalysts: They are used in oil refining and car manufacturing.

Evolution of rare earth magnets

Rare earth magnets have evolved significantly since their discovery:

First generation (1960s): Samarium-cobalt magnets (SmCo5), with good thermal resistance but lower magnetic strength.

Second generation (1970s): Sm2Co17, with greater magnetic strength and thermal stability.

Third generation (1980s to today): Neodymium-iron-boron magnets (NdFeB), the most powerful, although less resistant to high temperatures.

Future prospects

The future of rare earths will depend on innovation in recycling and sustainable extraction. In addition, diversification of supply sources and the development of alternative materials will be key to reducing dependence on these strategic elements.

In conclusion, although their name may be misleading, rare earths are essential for the technological and energy progress of the modern world, and their sustainable management will be a crucial challenge in the coming decades.