Large deposits of mud containing a large amount of (rare earth) rare earth（レアアース（希土類）を大量に含む泥 の大鉱床）

The bottom of the sea in the exclusive economic zone (EEZ) around (Ogasawara-mura, Tokyo) Minamitorishima of the most easterly of Tokyo, Japan that there is a large deposit of mud containing a large amount of (rare earth) rare earth high-tech products essential to large team of researchers have found. Similar mud had been found in the southeast, such as on the high sea of ​​the Pacific Ocean, is the first in the EEZ of Japan. Seen as the amount of reserves in excess of 200 years' worth of domestic annual consumption, may be able to escape the dependence on imports from China If realized, it would be to mine.
It was discovered from the University of Tokyo Graduate School of Prof. Kato (Earth Resource Sciences). 28, was presented at the Society of Resource Geology being held in Tokyo.
Analysis of the drilling seabed in the EEZ around Marcus Island were collected in such international joint research, at high concentrations 1700ppm about, up to a maximum of 1100ppm about average in the mud of the seabed 5600 meters 310 km approximately southwest of the island, water depth ascertained that it contains the rare earths.
Such as density and thickness of the layer from the amount of rare earth reserves of around 6.8 million tons is estimated to be about, say, is worth about 230 years worth of rare earth consumption in Japan. Also, talk with mud in concentrations above ppm 1 thousand 180 kilometers north of the island have been found, Professor Kato is "seen the distribution is wide, surrounded asleep rare earths can not use even if it takes thousands of years" . Rare earths are, the performance is dramatically improved by simply adding a small amount of high-tech materials. China accounts for the majority of world output, after a Chinese fishing boat collision incident occurred off the coast of the Senkaku Islands in Okinawa Prefecture in September 2010, and to suspend exports to Japan, has been used as a diplomatic card, depends on China departure from Japan has become the urgent need of.
But speaking of the future challenges the establishment of mining technology and cost competitiveness, meaning was found in the EEZ on the high seas rather than large, Professor Kato "We need further investigation."
Sea, it is indispensable to the future of humanity from various viewpoints. It will be developed to accumulate the world's first art as a maritime nation, to make effective use of the sea. All of this also, to a detailed investigation as soon as possible, I want to establish early mining technology and recovery techniques. Then, in the hope that it will be able to use in practice. At the same time, it will also require the establishment of technology does not rely on rare earths.




日本の最東端の南鳥島（東京都小笠原村）周辺の排他的経済水域（ＥＥＺ）内の海底に、ハイテク製品に欠かせないレアアース（希土類）を大量に含む泥 の大鉱床があることを東京大の研究チームが発見した。同様の泥は南東太平洋の公海上などで見つかっていたが、日本のＥＥＺ内では初。国内の年間消費量の ２００年分を超える埋蔵量とみられ、採掘が実現すれば中国からの輸入依存を脱却できる可能性がある。
　発見したのは東大大学院の加藤教授（地球資源学）ら。東京都内で開催中の資源地質学会で２８日、発表した。
　国際共同研究などで採取された南鳥島周辺のＥＥＺ内の海底ボーリング試料を分析した結果、島の南西約３１０キロ、水深約５６００メートルの海底の泥に最大約１７００ｐｐｍ、平均約１１００ｐｐｍの高濃度でレアアースが含まれることを突き止めた。
　 濃度や層の厚みなどから、周辺のレアアース埋蔵量は約６８０万トンと推定され、日本のレアアース消費量の約２３０年分に相当するという。また、島の北約 １８０キロでも１千ｐｐｍを超える濃度の泥が見つかっており、加藤教授は「分布は広く、周辺には何千年かかっても使い切れないレアアースが眠っているとみ られる」と話す。レアアースは、ハイテク素材に少量添加するだけで性能が飛躍的に向上する。世界産出量の大半を占める中国は、平成２２年９月に沖縄県の尖閣諸島沖で 発生した中国漁船衝突事件後、日本向け輸出を一時停止するなど、外交カードとして利用しており、中国依存からの脱却は日本の急務となっている。
　採掘技術の確立やコスト競争力が今後の課題だが、公海上ではなくＥＥＺ内で見つかった意味は大きく、加藤教授は「さらに詳細な調査が必要だ」と話す。
　海は、様々な観点から人類の未来に欠かせない存在ですね。海洋国家として、海を有効活用する術を世界に先駆けて開発し蓄積していくべきでしょうね。今回の件も、早急に詳細な調査をし、採掘技術や回収技術を早く確立して欲しいですね。そして、実際に使えるようになることを期待します。同時に、レアアースに頼らない技術の確立も必要でしょうね。