Japan to test rare-earth mining from deep seabed mud

[Ben Graham]

Japan will conduct a month-long test to extract rare-earth-rich mud from the deep seabed near the remote Minamitorishima Island, marking a first-of-its-kind effort to continuously lift material from about 6,000 metres below the surface.

The operation, led by the Japan Agency for Marine-Earth Science and Technology, will run from Jan. 11 to Feb. 14 about 1,900 kilometres southeast of Tokyo. It aims to connect a full deep-sea mining system and confirm it can raise 350 metric tonnes of mud a day while monitoring environmental impacts onboard and on the seabed.

The test comes as Japan and its Western allies seek more secure access to critical minerals amid tighter export controls by China, the dominant supplier of rare earths. 

“One of our missions is to build a supply chain for domestically produced rare earths to ensure stable supply of minerals essential to industry,” Shoichi Ishii, a program director at the Strategic Innovation Promotion Program, told Nikkei Asia.

Strategic push

No production target has been set, but if the test succeeds, the agency plans a full-scale demonstration by February 2027 to recover the same daily volume. Because the mud cannot be processed at sea, it would be shipped to Minamitorishima, where seawater would be removed using equipment similar to a washing machine’s spin dryer, cutting volume by about 80%, before being transported to mainland Japan for separation and refining.

The government-funded project has spent about 40 billion yen ($256 million) since 2018, Ishii said, though estimated reserves have not been disclosed. He also said a Chinese naval fleet entered waters near Minamitorishima in June this year, while a Japanese research vessel was conducting seabed surveys within Japan’s exclusive economic zone. “We feel a strong sense of crisis that such intimidating actions were taken,” Ishii said.