Rare Earth Metals (REMs), also known as Rare Earth Minerals and Rare Earth Elements, are a total of 17 chemical elements consisting of the 15 lanthanides (ln) and scandium (Sc) and yttrium (y). The latter two are considered REMs as they are typically found in the same deposits of ore as lanthanides and also have similar chemical properties.
Rare earth metals are also somewhat of a misnomer because, despite their name, they are not that rare and some are amongst the most abundant elements in the Earth’s crust, with cerium being the 25th most abundant element. The one exception is promethium, of which it is estimated to be around half a kilogram in the entire Earth’s crust. However, unlike other metals that are mined, REMs are not found in high density in exploitable geological seems and tend to be highly elusive and costly to extract.
The rare earth elements were first discovered in the late 18th century in the town of Ytterby in Sweden (hence yttrium and many other of the elements having names derived from the area) as oxidized minerals and like any other ore, needs to be processed and refined in order to obtain the pure metals.
The reason that rare earths’ are so valuable lies in their ability to carry out so many of the tasks required of a modern technology dependent society. All modern devices from televisions, cell phones, computers, batteries etc. rely on the rare earths’ to one degree or another. Europium for instance, is the source of red phosphor for televisions and monitors and has no substitute. Without it the world would be a very different place. Rare earths’ also play a huge role in the modern permanent magnets that have enabled the miniaturization of electronics.
Lanthanum is one of the most important of rare earth elements as it is used extensively in modern battery technology (the “metal” in a “nickel-metal hydride” battery refers to lanthanum) with every Toyota Prius containing more than 4.5 kilograms of the metal (and 30 kilograms of rare earths as a whole). These batteries are lighter, smaller, carry more power and are more efficient than the traditional lead-acid battery.
With Toyota being the largest car manufacturer in the world, and the Prius being a prime focus and accounting for 8 percent of their manufacturing, it is no surprise that Toyota have invested directly into a rare earth mine.
Demand for rare earth metals was approximately 30,000 tons throughout the 1980’s. In 2010 demand had reached 120,000 tons, more than the 112,000 tons produced that year.