Since the Chinese, who supply more than 90% of global supplies, were recently referred to the WTO by the USA, Japan and Europe for restricting supplies, rare earth metals have become headline news.
Some of us may by now be aware that these elements are crucial to many items that we take for granted in our everyday lives and also that some of them are very important to clean energy technology, particularly for wind turbines, solar panels and hybrid cars.
Probably, though, not many people could name one or even say what it is used for.
Lanthanum, for example, is hugely important for the nickel-metal hydride batteries used in hybrid cars. It has been calculated that every Toyota Prius battery requires 10 to 15 kg of the element.
It was discovered in 1839 by Swedish chemist Carl Gustav Mosander and is not only an important constituent in hybrid car batteries. It also plays a part in the process of fluid catalytic cracking, during which crude oil is refined into petrol.
Optical glasses and camera lenses are made from lanthanum and it is also involved as a magnetic material for use at higher temperatures, in electrodes in magneto hydrodynamic generators and during special effects in the film industry.
Another rare earth element that plays a hidden but essential role in many aspects of 21st Century life is tantalum. This REM was named after Tantalus, a character from Greek mythology, who was sentenced to eternal torment after his death because he had stolen ambrosia, nectar and a golden dog from the temple of Zeus.
His torment was to stand knee deep in water, which he could not drink, and with fruit hanging over his head that he could not reach.
The scientist who discovered tantalum, Anders Gustaf Ekeberg, chose the name because tantalum is almost impervious to acids and has a very high melting point, so that it must always "languish in pain and cannot quench its thirst".
However, these properties have made it a very useful resource for many purposes, one of which is that its stability and the fact that it is non toxic and does not react with body fluids makes it the ideal for medical use, such as medical implants, fracture pin nails, screws, surgical instruments and jaw prosthesis. How many people realise that their bodies contain a small quantity of a valuable rare earth metal?
Equally we do not realise that we are using or carrying around tantalum every day. In metal powder form it is used in the production of electronic components, mainly capacitors and some high-power resistors. Mobile phones, video game consoles, computers and radios all require small and high powered capacitors and therefore tantalum.
For equipment where alloys with high melting points are needed, as in nuclear reactors and jet engine components tantalum again provides an essential ingredient.
Our ability to communicate, our entertainment, our health and our physical safety all, therefore, depend on the use of a rare earth element even if we are unaware of it.
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Rare earth elements such as lanthanum and tantalum contribute to our daily communications, mobility, health and safety. By Ali Withers. http://www.denver-trading.com
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