In the last 20 years, rare earth metals have become key materials for all sorts of high-tech products: Blackberries, iPods, notebook computers, digital cameras and several others. They are a driving force behind emerging alternative energy technologies – electric vehicles and wind turbines – and different defence applications such as missile guidance systems, smart bombs and Patriot missiles.
These metals (which include terbium, dysprosium, neo-dymium and lanthanum) are deemed so essential to our society that some policy analysts have suggested insufficient or non-guaranteed supply can put a nation’s future at risk. But a shortage of supply may well be emerging at the moment, prompting calls for urgent action to promote recycling.
China created a stir in 2009 when it was learned that it was considering an immediate cessation of its heavy rare earth exports. In the end this did not happen, but Chinese restrictions on overall exports of rare earth metals are increasing every year.
“It could well be that China is not going to export any rare earths in about five years from now,” says Professor Karl Gschneidner Jr., a metallurgist at the Ames Laboratory of the United States Department of Energy who as part of his work tracks the use of rare earth metals.
In March of 2010, Gschneidner testified before the U.S. House Science and Technology Subcommittee on Investigations and Oversight at a hearing on the threat of a rare earth supply shortage. On that occasion, he cautioned that “rare earth research in the U.S. on mineral extraction, rare earth separation, processing of the oxides into metallic alloys and other useful forms, substitution, and recycling is virtually zero.”
“Every day, demand for rare earth metals is increasing, but supply isn’t,” observes Jack Lifton, co-founder and director of Technology Metals Research LLC, based in Illinois in the United States. Between 2003 and 2008, global demand for these metals increased from 85,000 tonnes to 124,000 tonnes per year.
China has a production monopoly and is the only country in the world capable of refining rare earth oxides into different rare earth metals.
In 2016, this figure will have jumped to 200,000 tonnes, according to Dudley Kingsnorth of the Industrial Metals Company of Australia. In his opinion, by around 2016, from the global perspective, demand could surpass supply.
At present, companies around the world are opening new mines or are bringing old mines back into use.
“This would stabilise supply of rare earths a bit, but the domination of China will not be gone,” says Stanley Trout, an independent consult on rare earth metals based in Indiana in the United States. “In five or 10 years, I think the Chinese number will be down to 70 or 75 percent,” says Trout.
Currently, though, China is also the only country in the world capable of refining rare earth oxides into the different rare earth metals. “We are only beginning to wake up to the fact that we may have access to ores, but not to the refining technology,” says Stuart Burns, who works from an office in Eastleigh, United Kingdom, for consulting firm Aptium Global Inc.
Chemical properties of rare earth elements are very much alike, which makes it difficult to separate them from each other, according to Lifton. “Once they are separated, you best keep them in that form and recycle them after use,” he comments.
“Also, if you mine an ore you get a lot of cerium, which is the least interesting of all the rare earths. In general, an ore contains much lower quantities of neodymium and even lower amounts of dysprosium. If you recycle these, you are sure of what you get.”
‘I have a feeling that the price of rare earth metals does not need to be much higher than it is now to make recycling economically viable.’
Terbium – which is used in energy efficient light bulbs – dysprosium, neodymium and lanthanum are among the most wanted rare earth metals. Dysprosium and neodymium are both essential ingredients for neodymium-iron-boron (NdFeB) magnets. Lanthanum is considered indispensable for nickel-metal-hydride (NiMH) batteries.
Since 2004, prices of neodymium and dysprosium have increased by a factor of five. Neodymium has risen from $8 to $40 per kilogram and dysprosium from $50 to $250 per kilogram. Over the same period, the price of terbium has per kilogram.
“I have a feeling that the price does not need to be much higher than it is now to make recycling of rare earths economically viable,” says Dr. Alan Russell, one of three Ames Laboratory researchers who have developed a process to recover neodymium from permanent magnet scrap by using molten magnesium. “It may be [that] we are already there.”
Although the recovery process was patented in 1995, it has never been used because prices of rare earth metals had been low until recently. “After a term of 20 years, a patent generally goes into the public domain. Anyone who wants to use it without paying licensing fees is then free to do so,” notes Russell.
At present, the Ames Laboratory is doing research on two other methods to recycle rare earth metals, but this research is kept confidential, as it is in an early stage and not patented. Russell only discloses that both projects are focused on the extraction of rare earths out of alloys and that it has something to do with the recycling of sludge.
The newly founded Centre for Resource, Recovery and Recycling (CR³) in the United States may give another boost to the research on the recovery of rare earth metals. A 5-year, $400,000 award from the National Science Foundation made the establishment of this centre by the Worcester Polytechnic Institute (WPI) and Colorado School of Mines (CSM) possible.
The Centre for Resource, Recovery and Recycling will start three projects that are focused on rare earth metals recovery.
Additional funding is being solicited by the recruitment of 30 to 40 corporate members who will pay an annual fee of $30,000. “There are already 25 companies participating and that may even be 30, since Purdue University, one of our partners, is bringing in lots of electronic companies,” says Professor Diran Apelian, director at CR³.
In 2010, three projects will start that are focused on rare earth metals recovery: the recycling of fluorescent light rare earth phosphors; the separation of rare earth metals from a contaminated rare earth metal source by using molten salt; and the recovery of neodymium from wastes generated during magnet manufacturing and separation of rare earth metals in alloys, such as NdFeB.
Also, the Colorado School of Mines (CSM) might conduct another research project on the recovery of rare earths, apart from CR³. Professor Patrick Taylor, director at Kroll Institute of Extractive Metallurgy at CSM, remarks, “We made a proposal to a battery company on the rare earth metal recovery out of NiMH batteries.”
A global effort
Meanwhile, Japanese scientists have already experienced how difficult it is to develop recycling technology for rare earth metals.
“It took four years to commercialise the technology on the recovery of rare earth metals out of discarded NiMH batteries, because generation of these batteries has been lower than expected,” says Hideya Metsugi, Director of Planning and Research at the Japan Oil, Gas and Metals Corporation (JOGMEC).
In 2009, Mitsui Metal Mining announced that it would build a nickel, cobalt and rare earth recovery plant that uses the technology developed by JOGMEC.
Also, Hitachi is aiming to begin recycling rare earths from the motors of hard disk drives, air conditioners and other items by 2013. “We are expecting to recycle [a few dozen] tons of permanent magnets by mechanical separation,” says communications officer Sayori Nishino, who will not disclose any other information “because we are applying for a patent.”
At present, they are developing an apparatus for the recycling which will cost a 100 million yen (around $1.1 million) in the first two years.
‘Every day, boat loads with scrap that contains rare earth metals going to China. This is insane.’
In the United States, the first company established to actually recycle rare metals – including rare earth metals – out of products could be established in the near future.
“I’m tired of waiting for somebody to do this,” says Lifton, who has been urging investors and corporate executives to start such recycling companies for many years.
According to Lifton there are many possibilities for obtaining this sort of scrap: “There are very large companies that use rare earth magnets in their operations, and this industrial scrap can be recycled,” he notes.
“Other companies are processing huge quantities of hard disk drives, and the tiny magnets in them will provide significant material. Every day, boat loads of electric motors are going to China for scrap.”
Concludes Lifton, “We cannot be shipping away material that we use but don’t produce. This is insane. Recycling is one of the very few ways that non-producers can get these metals, so we should preserve them and start recycling.”
Published: July 2010 in Recycling Today.