Rare earth mineral deposits discovered in 2013 could contain more than 16 million tonnes of these precious minerals, used in the manufacture of high-tech products (wind turbines, smartphones, electric motors, etc.), according to a study published on April 10, 2018 in the journal Scientific Reports. They are located in a vast area of 2,500 km2 near the island of Minamitorishima, some 2,000 km southeast of Tokyo.
In previous research in the same region, scientists, some of whom are also involved in the new study, had made an estimate of about 6.8 million tonnes, a finding that was already considered important. These findings are good news for Japan, which imports rare earth minerals from China, where most of the world’s rare earths, 90% of these crucial metals, come from.
The researchers analyzed samples of sludge taken from more than 5,000 meters deep and extrapolated the amount of mineable minerals. They estimated that the amount of dysprosium, an element used for example in permanent magnets, represented 730 years of global consumption, while the reserves of yttrium, used in the manufacture of lasers, were likely to meet the needs of the world for 780 years.
They also found large amounts of europium and terbium. The research area “has the potential to provide the world with these metals on an almost infinite basis,” the authors of the study insist.
To achieve this result, the researchers applied a centrifugation technique that allows extracting even more minerals. They have managed to increase the concentration of exploitable rare earths, and thus the profitability of development projects, they ensure. And if, in the future, a way is found to use this method of extraction directly underwater, then “it will help improve the economic efficiency” of the exploitation of these deposits located at great depths, they added.