Rare Earth Elements: Not really rare
If you’ve paid attention to the popular press over the last few years, you’ve probably heard various stories about “Rare Earth Elements”. These elements, which I’ll abbreviate REEs from now on, have gained importance as applications have developed for them in high powered magnets, lasers, renewable energy generation, and other high-tech gadgets. The laptop I’m typing this on probably contains a fair amount of them, as does the smartphone sitting to my side.
Go find a periodic table; I’ll wait (http://webelements.com/). The REEs are found in one of those rows at the bottom of the periodic table; the row labeled the “lanthanides”. They are mostly heavy elements, with atomic weights between 57 and 70, and therefore also have large electron clouds around them. 2 other elements, Scandium and Yttrium, are generally included with REEs due to similar chemical properties. There are a number of unique properties of certain elements, such as low melting points, strong magnetic fields, and even radioactive decay that can make REE very interesting to scientists. They generally shrink from left to right across the row, so the properties of each element are a little different from the nearby elements.
REEs have been mined for industrial applications for decades. For a long time, the Mountain Pass mine in California’s Mojave Desert (just across the border from Nevada) was the worlds’ largest producer of REEs, and it appears in this photo. That changed, however, in the 1990’s, when production from mines in China began increasing.
That’s the general story of these elements. They’re called Rare, but they’re only sort of rare. There are lots of deposits of REEs around the globe, but many have only recently been recognized. For decades, there was really no need to evaluate these type of deposits; REEs were only used in rare applications and the price was generally low.
The real story of REEs is not that they’re rare, but instead that it’s really hard to get them. Almost all of them are more abundant than silver in the Earth, and Cerium (the most abundant REE) is actually more abundant than copper. The problem is they are only concentrated in certain stable phases and stay in those phases unless they are dissolved. Extracting them involves large amounts of caustic acids, which can both kill people and render areas uninhabitable if they’re spilled. The waste products can contain other heavy metals like barium, lead, and uranium, which can render water undrinkable.
The low REE price through the 1990’s and 2000’s was, to some extent, maintained by Chinese government policy. The Chinese production of REEs in the 1990’s ramped up so fast that the prices of the elements dropped, and in 2002 the Mountain Pass mine closed, unable to maintain profitability against Chinese competition. The country made a decision to support this industry decades ago and was willing to tolerate substantial pollution as a consequence.
Over the last decade, however, demand for REEs in products such as electronics, windmills, solar panels, and hybrid cars has grown substantially, and at the same time, in the late 2000’s there was a major price spike as China curtailed its own production to begin to deal with the environmental consequences. The main mine is close to the Gobi desert, so the nearby population is low, but dust and pollution from the mine can reach all the way to Beijing, across the entire country. Thus, supply suddenly became constricted just as demand was skyrocketing, leading to a price spike.
The environmental issues with REE mining are not confined to China. The Mountain Pass mine, for example, has had multiple wastewater spills during its lifetime that have contaminated surrounding areas, and releases dust that can impact communities including Las Vegas.
China was able to corner the market on REEs by tolerating these issues, but as pollution of their cities becomes an increasing problem, their willingness to tolerate the environmental impacts has declined. But, since the price has risen substantially, deposits that would not have been worth developing a few years ago have suddenly become economical.
For that reason, recent press reports have included reports of large, billions-to-trillions of dollar REE deposit finds, in environments such as the mountains of Afghanistan and the seafloor off the coast of Japan. Production has also recently restarted at the Mountain Pass mine in the U.S. And occasionally, people will even cite REE abundances as reason to begin mining asteroids.
Really though, these reports of huge amounts of money depend on the market price. If the market was flooded with REEs again from new production, as happened in the 1990’s, the price would plummet and the value of deposits in difficult to reach places like the ocean floor would drop as well. There are strategic reasons for countries to develop these resources as defense industries are heavy users of REEs as well, but readers should have some skepticism when a new trillion dollar valued find is discovered; that deposit is only worth trillions of dollars if prices don’t change upon the start of production, which they always do.
Demand for these elements is going to continue growing with time as countries transition to high-tech industries and move to renewable energy sources. These mines are the downside of that transition. They can be kept clean by strong regulation, but that costs money. For several decades, the Chinese population effectively subsidized the world by tolerating the pollution themselves, but that’s a situation which can’t continue forever.
New developments of REEs are going to come on line in the next few years, and as the price has skyrocketed, people have started looking for deposits they would otherwise have ignored. A few years ago, China had >50% of the world’s proven reserves of REEs, today that number has dropped to less than 25%, entirely because other countries have started actually looking for new deposits. But the downside is that, like much mining, this is a messy industry. It produces a lot of waste and the byproducts can be very toxic. Eventually, some balance will have to be struck between REE price, REE demand, and the technology of the industry to operate these mines safely and cleanly. REEs will become more important in the lives of people with time, but if nothing else, the problems with their extraction should be understood as well.
Image credit: ELEMENTS Magazine: http://elements.geoscienceworld.org/content/8/5/369/F1.expansion.html
REE Mining and Exploration in North America: http://elements.geoscienceworld.org/content/8/5/369.full
Diversity of Rare Earth deposits: http://elements.geoscienceworld.org/content/8/5/361.full
Rare Earth Element mining at Mountain Pass: http://www.docstoc.com/docs/140923732/Rare-Earth-Mining-At-Mountain-PassWriting-A-New----Desert-Report
Congressional Research Service Report: http://www.fas.org/sgp/crs/natsec/R41347.pdf
REE In Afghanistan : http://www.scientificamerican.com/article.cfm?id=afghanistan-holds-enormous-bounty-of-rare-earths
TES article on REE’s on seafloor near Japan: http://tinyurl.com/d754vpq
Rare Earth Elements: Not So Rare http://technorati.com/politics/article/rare-earth-elements-not-so-rare/
Rare Earth Elements Not Rare, Just Playing Hard to Get http://blogs.smithsonianmag.com/science/2010/11/rare-earth-elements-not-rare-just-playing-hard-to-get
China's Ace in the Hole: Rare Earth Elements http://www.ndu.edu/press/chinas-ace-in-the-hole.html
