Japan’s supply of rare earths is once again in the spotlight – this time with a technologically sophisticated practical test on the high seas. On Monday, the Japanese research vessel “Chikyu” set sail for a mission to the remote coral atoll of Minamitori Island (approximately 1,900 kilometers southeast of Tokyo). The aim is to recover mud from the seabed containing rare earths over a period of about one month – from a depth of around six kilometers. According to sources close to the project, the plan is to carry out the world’s first continuous extraction of such sediments from the deep seabed directly onto a ship. The “Chikyu” is expected to return to port on February 14.
The test is part of a broader strategy by Tokyo to reduce its dependence on China for critical raw materials. Rare earths are key materials for magnets, electronics, vehicles, wind turbines, and numerous applications in the defense and high-tech sectors. Japan is considered particularly exposed, especially for so-called heavy rare earths – for example, for high-performance magnets in electric and hybrid vehicles – according to market observers.
Rare earths from 6,000 meters deep: What Japan wants to test now
The “Chikyu” mission is designed as a confirmation test. After years of preparation, the aim is to verify whether rare-earth-containing deep-sea mud can be extracted from extreme depths under real conditions and handled on board. Project managers spoke of a milestone because it not only tests a new source of raw materials, but also a complex technical process under high-pressure conditions.
Minamitori Island plays a special role in Japan’s raw materials policy: The area has been considered a potentially promising location for marine raw material deposits for years. At the same time, it is remote and logistically challenging, which makes economic evaluation difficult. The Japanese government therefore explicitly regards the test as part of a long-term program. Reports put government spending since 2018 at around 40 billion yen (approximately US$250 million). A specific target size for reserves or a binding production plan has not yet been published. If the test phase is successful, a larger mining trial is expected for February 2027.
Economically, the extraction of such sediments had long been classified as difficult to achieve – costs and technical risks were considered too high. In the background, however, is the question of whether the calculation shifts when geopolitical risks increase and customers are prepared to accept higher prices for security of supply.
China risk and new export restrictions increase the pressure
The timing of the mission is also politically charged. China has recently imposed export restrictions on so-called dual-use goods to Japan’s military – including, according to reports, critical minerals. In addition, there are indications from media reports that Beijing is considering further restrictions on rare earths to Japan; however, official confirmation is pending. Japan has criticized the dual-use measures, but referred to a lack of reliable information in reports about a broader ban.
The fact that raw materials policy is becoming a foreign trade lever is not a new scenario for Japan. As early as 2010, China temporarily throttled the export of rare earths after tensions arose in the area surrounding disputed islands in the East China Sea. Since then, Tokyo has systematically strived for diversification: According to information from Reuters, China’s share of Japan’s imports has fallen from around 90% to around 60% – partly through investments, recycling programs, and the promotion of alternative supply chains. A frequently cited example is the cooperation between the Japanese trading company Sojitz and Australia’s Lynas Rare Earths (WKN 871899).
The issue is also gaining momentum at the international level: According to Reuters, the G7 finance ministers wanted to put the supply of rare earths on the agenda at a meeting in Washington – a signal that the industrialized nations are increasingly treating the issue as a strategic supply chain issue.
Long-term project with open economic viability question
For Japan, the Minamitori project is primarily a step towards an “inland solution”: a source of rare earths within its own sphere of influence. However, economists point out that a substantial reduction in dependence on China remains difficult – especially since certain elements and processing steps are still heavily concentrated globally.
In addition: Even if extraction is technically successful, the next bottleneck is often right behind it – in processing, separation, and refining. These value-added stages in rare earths in particular are still heavily influenced by China worldwide. Accordingly, the success of the project will not only depend on whether sediment can be extracted, but also on whether marketable products of consistent quality can be produced from it – and whether this can be scaled at competitive costs.
With the “Chikyu” mission, Japan is nevertheless signaling that it wants to broaden its raw materials strategy: away from pure import solutions, towards technologically supported alternatives that should also work under geopolitical pressure. Whether this will create a new source of rare earths in the medium term remains open – however, the test provides data that should be decisive for further planning and possible large-scale testing.
