Japan targets rare earth mining from deep Pacific seabed mud
After a successful 6,000-metre mud collection, Japan is weighing economic security against the high cost of Pacific seabed mineral extraction.
- Japan has successfully conducted a test to extract rare earth-rich mud from a depth of 6,000 meters near its remote Minamitorishima island in the Pacific.
- The initiative is driven by a strategic goal to reduce Japan's reliance on China for critical minerals, which are essential for technologies like electric vehicle motors and wind turbines.
- While the government targets commercial production as early as 2028, the project faces significant hurdles regarding its economic viability and the high costs of scaling up the operation.
Japan is stepping up efforts to extract critical minerals, including rare earth elements, from the seabed around Minamitorishima, a remote Japanese island in the Pacific, as it looks toward future domestic rare earth production.
For resource-poor Japan, securing these minerals is seen as essential. In February this year, the country successfully collected rare earth-bearing mud from about 6,000 metres beneath the sea surface near the island, which is part of Ogasawara village in Tokyo.
The government hopes commercialisation could begin in 2028 at the earliest. However, it still has to balance the project’s value for economic security against questions over whether the mining can be made economically viable.
The seafloor around Minamitorishima is believed to contain rich mineral deposits. Cobalt-rich crusts and manganese nodules have already been found there, and both cobalt and manganese are used in batteries for electric vehicles.
Mud containing scarce and expensive heavy rare earth elements, including neodymium and dysprosium, has also been confirmed. Development is being led by the government because these elements are needed for high-performance motors used in EVs and wind power generators.
Shoichi Ishii, a Cabinet Office official who heads the rare earth-rich mud development project, said: “We have promoted technical development over the years to make the world’s first attempt” at deep-sea rare earth mining.
In the current initiative, the Cabinet Office and the Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, used the Chikyu deep-sea drilling vessel. About 600 pipes, each around 10 metres long, were connected from the ship to the seabed. A mining device attached to the end enclosed the mud, mixed it with seawater and pumped it back up.
“We were nervous until the mining device reached the seabed,” Ishii said. “We are relieved that the test succeeded.”
The government and JAMSTEC previously carried out a pipe-connection test off Ibaraki Prefecture, northeast of Tokyo, in 2022, and have since improved the system. In 2027, the government plans to assess whether rare earth recovery is economically feasible by mining 350 tonnes of mud per day. A budget of 16.4 billion yen has been secured for fiscal 2025.
The industry ministry estimates that profitability would require mining 3,500 tonnes of mud per day. Achieving that scale would require upgrades to vessels and dewatering facilities. “It will cost a tremendous amount,” a senior official at an economy-related government agency said.
China holds an overwhelming share of the global rare earth market and has repeatedly weaponised that dominance, including through tighter export controls whenever Japan-China relations have worsened. This has increased the importance of securing stable rare earth supplies and reducing reliance on China from an economic security perspective.
Japan’s economic security minister, Kimi Onoda, indicated that the government is prepared to accept high costs for seabed mining. “We should act with a perspective focused on protecting our country,” she said.
[Copyright The Jiji Press, Ltd.]
