If you follow the economic news, you have probably heard that rare earth elements are a hot commodity on international markets. China, which has a disproportionate share of the world's supply of these valuable minerals recently began restricting their export. These minerals are important parts of many advanced electronic equipment, including batteries for electric cars. But many people are puzzled by the term "rare earth."
Cell phones, tablet computers, video games, 3D TV sets: Practically all advanced electronic devices - including lots of critical military hardware - contain parts made with a group of exotic minerals called "rare earths." If you remember the Periodic Table of Elements from your high school chemistry class, rare earth refers to a group of 17 elements, also called lanthanide elements, with similar metallic characteristics, but differing from other metals. That is exactly the reason why they are such a hot commodity.
But how rare are the rare earth elements and why are they called earths?
"Rare is a bit of a misnomer here. In some cases a better word for rare might be 'hidden,' because these rare earth elements are found, in most cases, fairly commonly in the earth's crust," noted Jeffrey Post, a research geologist at the Smithsonian's National Museum of Natural History, in Washington, DC.
Post says many rare earth elements are actually as common as tin, nickel, copper or zinc, but they tend to be widely dispersed in very small quantities. There are only a few places where natural processes concentrated these elements enough to be mined. So "rare," in fact, means that there's not enough of them in one place.
Nevertheless, rare earths have become a very hot commodity on the world's markets and prices for some of them are rising rapidly. According to mineralprices.com, last December, a kilogram of yttrium cost $82 while now it costs around $200. Dysprosium was $700 per kilogram and now it is $1,000. Jeff Post notes that in our electronic age, many everyday devices depend on rare earth metals.
"The color images you see on LCD screens, on the computer screens… in many cases the phosphorus that produces these are based on rare earth elements," Post added. "Many of the electronic components, the very miniature, smaller components that we need to drive these small cell phones, the small computers in a very efficient way depend on some amount of rare earth elements. The batteries, the magnets that are used in these devices, again make use of rare earth elements."
There are places on earth where natural geological processes created mineral deposits that contain large quantities of rare earth elements in crystallized form. As the prices of rare earth metals increase it becomes profitable to mine mineral deposits that contain even small percentages of these metals. A former iron ore deposit in China's inner Mongolia has become the world's largest mine for rare earth elements providing up to 90 percent of world's production.
Jeff Post notes that separating rare earth metals from other minerals is a complicated process. "You need to have a specialized chemical process that will separate the rare earth elements, not only from the ores but from each other. Almost every rare earth element ore, like this one, contains not just one rare earth element but typically some amount of all the rare earth elements."
The rare earth elements are chemically very similar, so separating them from each other is a complex operation. Geologists around the world are constantly looking for new deposits of these valuable minerals. At the same time, the interest in recycling the elements from electronic waste is also on the rise.