Rare earth elements are also called "industrial vitamins" and are essential metal materials for cutting-edge industries in which Japan has technological advantages, such as renewable energy technology, electronics, and medical technology.On the other hand, the production of rare earths is oligopolistic in China, and securing new supply destinations for rare earths can be said to be a national proposition for Japan.

 Under these circumstances, Professor Yasuhiro Kato of the University of Tokyo and others confirmed the existence of seabed deposits (rare earth mud) containing high concentrations of rare earths in Japan's Exclusive Economic Zone (EEZ) around Minamitorishima. It has been desired to attract attention as a new rare earth resource, and to grasp its accurate distribution and resource amount.

 This time, the research groups of Waseda University, The University of Tokyo, Chiba Institute of Technology, Japan Agency for Marine-Earth Science and Technology, Toa Construction Industry Co., Ltd., Pacific Cement Co., Ltd., Tokyo Institute of Technology, Kobe University, etc. are located in the South Torishima EEZ area. We conducted a detailed survey of promising areas and succeeded in visualizing the distribution of rare earth resources for the first time.As a result, it became clear that there are more than 1,600 million tons of rare earth resources in this area, which is equivalent to hundreds of years of global demand.

 In this study, we also examined a method for beneficiation of rare earth mud and succeeded in increasing the total rare earth concentration in rare earth mud up to 2.6 times by particle size separation.This is said to reach 20 times that of China's onshore rare earth deposits, and since the weight of mud can be significantly reduced, it can be expected to reduce the cost of lifting mud to the sea and smelting costs.

 This achievement, which has an extremely large impact on Japan's resource strategy, is expected to lead to the development and creation of various cutting-edge industries that utilize rare earths.

Paper information:[Scientific Reports] The tremendous potential of deep-sea mud as a source of rare-earth elements

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