110,000,000 Tons of Rare Earth Elements Found in Ocean Mud

Rare-earth elements are crucial for novel electronic equipment and green-energy technologies and world demand is rapidly increasing.  

Associate Professor Yasuhiro Kato and his team at the Department of Systems Innovation of the University of Tokyo's Graduate School of Engineering have discovered a new type of mineral resource, named REY (rare-earth elements and yttrium)-rich mud, distributed in vast quantities throughout a large part of the Pacific Ocean. 

REY-rich mud containing up to approximately 0.2 percent by weight total REY occurs across the central north and southeastern Pacific Ocean in average thicknesses of approximately 24 m and 8 m, respectively. 

Their data show that REY stored in these Pacific mud deposits amounts to a possible resource 100 to 1,000 times greater than the world's current land reserves of 110,000,000 tonnes of REY oxides, depending on local stratigraphic continuity and thickness of the REY-rich mud. 

Uptake by materials such as hydrothermal Fe-oxyhydroxides and phillipsite seems to be responsible for the high REY content, and consequently REY are readily recovered by simple acid leaching and are a suitable resource for development. The newly discovered REY-rich mud may constitute a highly promising source of rare earth elements.

Source: University of Tokyo

Citation:
Yasuhiro Kato, Koichiro Fujinaga, Kentaro Nakamura, Yutaro Takaya, Kenichi Kitamura, Junichiro Ohta, Ryuichi Toda, Takuya Nakashima and Hikaru Iwamori, "Deep-sea mud in the Pacific Ocean as a potential resource for rare-earth elements" Nature Geoscience Online Edition: 2011 / 7 / 4 at 2:00 (Japan time) (doi:10.1038/ngeo1185)

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