Perspectives of Mining in Pacific Ocean
LETTERS
PUBLISHED ONLINE: 3 JULY 2011 | DOI: 10.1038/NGEO1185
Deep-sea mud in the Pacific Ocean as a potential resource for rare-earth elements
Yasuhiro Kato1 *, Koichiro Fujinaga1 , Kentaro Nakamura2 , Yutaro Takaya1 , Kenichi Kitamura1 , Junichiro Ohta1 , Ryuichi Toda1 , Takuya Nakashima1 and Hikaru Iwamori3
World demand for rare-earth elements and the metal yttrium—which are crucial for novel electronic equipment and green-energy technologies—is increasing rapidly1–3 . Several types of seafloor sediment harbour high concentrations of these elements4–7 . However, seafloor sediments have not been regarded as a rare-earth element and yttrium resource, because data on the spatial distribution of these deposits are insufficient. Here, we report measurements of the elemental composition of over 2,000 seafloor sediments, sampled at depth intervals of around one metre, at 78 sites that cover a large part of the Pacific Ocean. We show that deep-sea mud contains high concentrations of rare-earth elements and yttrium at numerous sites throughout the eastern South and central North Pacific. We estimate that an area of just one square kilometre, surrounding one of the sampling sites, could provide one-fifth of the current annual world consumption of these elements. Uptake of rare-earth elements and yttrium by mineral phases such as hydrothermal iron-oxyhydroxides and phillipsite seems to be responsible for their high concentration. We show that rare-earth elements and yttrium are readily recovered from the mud by simple acid leaching, and suggest that deep-sea mud constitutes a highly promising huge resource for these elements. At present, 97% of the world’s production of rare-earth elements and yttrium (REY) is accounted for by China, although China has only one-third of global reserves and the Commonwealth of Independent States, the United States, and Australia together have another one-third of reserves1 . China’s dominance pertains to heavy rare-earth elements (HREE;
PUBLISHED ONLINE: 3 JULY 2011 | DOI: 10.1038/NGEO1185
Deep-sea mud in the Pacific Ocean as a potential resource for rare-earth elements
Yasuhiro Kato1 *, Koichiro Fujinaga1 , Kentaro Nakamura2 , Yutaro Takaya1 , Kenichi Kitamura1 , Junichiro Ohta1 , Ryuichi Toda1 , Takuya Nakashima1 and Hikaru Iwamori3
World demand for rare-earth elements and the metal yttrium—which are crucial for novel electronic equipment and green-energy technologies—is increasing rapidly1–3 . Several types of seafloor sediment harbour high concentrations of these elements4–7 . However, seafloor sediments have not been regarded as a rare-earth element and yttrium resource, because data on the spatial distribution of these deposits are insufficient. Here, we report measurements of the elemental composition of over 2,000 seafloor sediments, sampled at depth intervals of around one metre, at 78 sites that cover a large part of the Pacific Ocean. We show that deep-sea mud contains high concentrations of rare-earth elements and yttrium at numerous sites throughout the eastern South and central North Pacific. We estimate that an area of just one square kilometre, surrounding one of the sampling sites, could provide one-fifth of the current annual world consumption of these elements. Uptake of rare-earth elements and yttrium by mineral phases such as hydrothermal iron-oxyhydroxides and phillipsite seems to be responsible for their high concentration. We show that rare-earth elements and yttrium are readily recovered from the mud by simple acid leaching, and suggest that deep-sea mud constitutes a highly promising huge resource for these elements. At present, 97% of the world’s production of rare-earth elements and yttrium (REY) is accounted for by China, although China has only one-third of global reserves and the Commonwealth of Independent States, the United States, and Australia together have another one-third of reserves1 . China’s dominance pertains to heavy rare-earth elements (HREE;