An Oct. 31, 2013 news item on Azonano features information about rare earth elements and their use in technology along with a new technique for recycling them from wastewater,
Many of today’s technologies, from hybrid car batteries to flat-screen televisions, rely on materials known as rare earth elements (REEs) that are in short supply, but scientists are reporting development of a new method to recycle them from wastewater.
The process, which is described in a study in the journal ACS [American Chemical Society] Applied Materials & Interfaces, could help alleviate economic and environmental pressures facing the REE industry.
… Attempts so far to recycle them from industrial wastewater are expensive or otherwise impractical. A major challenge is that the elements are typically very diluted in these waters. The team knew that a nanomaterial known as nano-magnesium hydroxide, or nano-Mg(OH)2, was effective at removing some metals and dyes from wastewater. So they set out to understand how the compound worked and whether it would efficiently remove diluted REEs, as well.
The Oct. 30, 2013 ACS PressPac news release, which originated the news item, provides a few details about how the scientists tested their approach,
To test their idea, they produced inexpensive nano-Mg(OH)2 particles, whose shapes resemble flowers when viewed with a high-power microscope. They showed that the material captured more than 85 percent of the REEs that were diluted in wastewater in an initial experiment mimicking real-world conditions. “Recycling REEs from wastewater not only saves rare earth resources and protects the environment, but also brings considerable economic benefits,” the researchers state. “The pilot-scale experiment indicated that the self-supported flower-like nano-Mg(OH)2 had great potential to recycle REEs from industrial wastewater.”
Here’s a link to and a citation for the published paper,
Recycling Rare Earth Elements from Industrial Wastewater with Flowerlike Nano-Mg(OH)2 by Chaoran Li †‡, Zanyong Zhuang, Feng Huang, Zhicheng Wu, Yangping Hong, and Zhang Lin. ACS Appl. Mater. Interfaces, 2013, 5 (19), pp 9719–9725 DOI: 10.1021/am4027967 Publication Date (Web): September 13, 2013
Copyright © 2013 American Chemical Society
As for the short supply mentioned in the first line of the news item, the world’s largest exporter of rare earth elements at 90% of the market, China, recently announced a cap according to a Sept. 6, 2013 article by David Stanway for Reuters. The Chinese government appears to be curtailing exports as part of an ongoing, multi-year strategy. Here’s how Cientifica‘s (an emerging technologies consultancy, etc.) white paper (Simply No Substitute?) about critical materials published in 2012 (?), described the situation,
Despite their name, REE are not that rare in the Earth’s crust. What has happened in the past decade is that REE exports from China undercut prices elsewhere, leading to the closure of mines such as the Mountain Pass REE mine in California. Once China had acquired a dominant market position, prices began to rise. But this situation will likely ease. The US will probably begin REE production from the Mountain Pass mine later in 2012, and mines in other countries are expected to start operation soon as well.
Nevertheless, owing to their broad range of uses REE will continue to exert pressures on their supply – especially for countries without notable REE deposits. This highlights two aspects of importance for strategic materials: actual rarity and strategic supply issues such as these seen for REE. Although strategic and diplomatic supply issues may have easier solutions, their consideration for manufacturing industries will almost be the same – a shortage of crucial supply lines.
Furthermore, as the example of REE shows, the identification of long-term supply problems can often be difficult, and not every government has the same strategic foresight that the Chinese demonstrated. And as new technologies emerge, new elements may see an unexpected, sudden demand in supply. (pp. 16-17)
Meanwhile, in response to China’s decision to cap its 2013 REE exports, the Russian government announced a $1B investment to 2018 in rare earth production,, according to a Sept. 10, 2013 article by Polina Devitt for Reuters.
For those who like to get their information in a more graphic form, here’s an infographic from Thomson Reuters from a May 13, 2012 posting on their eponymous blog,There is a larger version on their blog.
All of this serves to explain the interest in recycling REE from industrial wastewater. Surprisingly,, the researchers who developed this new recycling technique are based in China which makes me wonder if the Chinese government sees a future where it too will need to import rare earths as its home sources diminish.