Japanese drill ship retrieves rare earth mud from depths never reached before

Far out in the Pacific Ocean, a Japanese drilling vessel has achieved a world first. Using a long chain of pipes, the research ship Chikyu successfully pumped rare-earth-rich mud from nearly 6,000 metres below the ocean surface in a continuous flow for several days.

The government-backed project deployed around 600 pipe sections—each roughly ten metres long—to reach the seabed. These were connected to a mining device that pumped a slurry of mud and seawater back to the vessel, as described in an article by EcoNews.

Recovery operations conducted between January 30 and February 1 near the tiny coral atoll of Minamitorishima, about 1,900 kilometres southeast of Tokyo, confirmed that sediment containing rare earth elements could be lifted from depths of around 6,000 metres at three different sites—something no country had previously accomplished at such depths.

The mud is believed to contain valuable elements, including Neodymium and Dysprosium, which are used in powerful magnets for electric vehicle motors, as well as Gadolinium and Terbium, materials used in medical imaging systems and advanced electronics.

For Japan—which imports most of its critical minerals—the development represents more than a technological milestone. Officials see the deep seabed near the atoll as a potential strategic reserve for the materials used in electric cars, wind turbines, smartphones and modern weapons systems. The effort also reflects concerns over export controls and political pressure from China, which dominates the global rare earth supply chain.

Research conducted by university teams in the 2010s suggested the wider seabed area may contain roughly 16 million tonnes of rare earth resources. If these deposits can be economically extracted, Japan could rank among the world’s largest holders of such reserves.

Since 2018, Tokyo has invested about 40 billion yen (approx. $250 million) in the project, which is still considered a test phase. If the engineering proves reliable and the recovered sediment contains sufficient concentrations of minerals, planners hope to trial a system capable of lifting around 350 tonnes per day by 2027. A decision on full-scale industrial mining could follow after 2028.

Japan currently relies on China for roughly 60 percent of its rare earth imports, leaving its automotive and electronics sectors vulnerable during periods of diplomatic tension.

Government advisers have estimated that a three-month disruption in Chinese supply could reduce Japan’s economic output by more than 600 billion yen (approx. $3.8 billion). For that reason, officials describe the Minamitorishima deposits less as a commercial venture and more as a strategic safeguard for industries producing batteries, motors and electronic components used in devices such as laptops.

However, academic research on Japan’s rare earth strategy suggests deep-sea mud extraction will likely remain an expensive fallback resource rather than a low-cost alternative to traditional mining.

Environmental groups and several Pacific nations have also warned that seabed mining could damage fragile ecosystems by disturbing habitats, stirring up sediment clouds and releasing heavy metals into marine food chains—impacts that could last decades.

Project leaders in Japan have sought to address these concerns, saying their system keeps the sediment inside a closed pipe to minimise plumes and that water quality and marine life around the test site will be closely monitored.

Compared with many land-based rare earth mines, the seabed mud also appears to contain very low levels of radioactive elements such as uranium or thorium, potentially reducing radioactive waste during processing.

By Nazrin Sadigova