A rare wisdom

We have written quite a bit about rare earths, perhaps making our readers wonder if they really rare! Well, the rare part is actually that which allows for economical extraction. And why this attention on rare earths (RE) is simply because the world of tomorrow we plan to build on clean energy will lean a lot on these rare elements. Whether it be wind farms or CFLs and LEDs, or electric vehicles, they depend on REs.

A massive wind turbine has 40-meter-long blades made from fiberglass, towers 90 meters above the ground, weighs hundreds of metric tons, and relies on roughly 300 kilograms of a soft, silvery metal known as neodymium—a rare earth. This element forms the basis for the magnets used in the turbines. The stronger the magnets are, the more powerful the generator.

An interesting article in Scientific American looks at the whole laborious process of extraction of rare earths. Found with other ores, Chinese companies supplying them employ acid to dissolve them out of ore rock that often also contains radioactive elements like thorium, radium or even uranium.

Intensive boiling with strong acids—repeated thousands of times because the elements are so chemically similar—finally separates out the neodymium, dysprosium or cerium. The whole slew of rare earth elements are a challenge to separate because of their chemical similarity—and they are never found alone. Processing costs are high and water and energy intensive.

Geologists have found deposits in Australia, Canada, Mongolia, Vietnam and even Greenland. Perhaps it is wiser before opening up pristine places to look at recycling options given the mountain loads of electronics we discard today. So also, research is working at how best to use as little of these REs or maybe even some alternatives. Whatever it be, recycling will have to be part of the solution.