Japan Agency for Marine-Earth Science and Technology (Jamstec) collected the first batch of deep-sea mud containing rare earth elements from a depth of around 6,000m around Minamitorishima on 1 February.
Jamstec's deep-sea drilling vessel Chikyu arrived the test site of the rare-earth mud mining system in the waters around Minamitorishima on 17 January. The first rare earth recovery operation began on 30 January and the first batch of mud was brought onboard on 1 February, Jamstec said.
The Cross-Ministeral Strategic Innovation Promotion Program (SIP) will conduct an initial treatment test by April once Chikyu returns to Japan on 15 February.
This trial is part of SIP's plan to evaluate the feasibility of deep-sea mining in Japan's exclusive economic zone near Minamitorishima. SIP plans to run a full-scale test excavation in February 2027 to recover up to 350 t/d of rare earth mud. SIP will then compile a report by March 2028 to assess the project's profitability and feasibility.
The possibility of deep-sea rare earth mining first emerged in 2013 when the University of Tokyo discovered mud with a high concentration of rare earth elements near Minamitorishima. The area is estimated to hold about 16mn t of rare earth resources. If materialised, this would make Japan's national reserves the third-largest in the world. The industry at the time expressed concerns about economic viability, because the cost to recover rare-earth from deep-sea mud is likely to be significantly higher than processing costs in China.
The increased price gap for certain rare earth products between the Chinese domestic market and the European and US markets, driven by China's export restrictions, may have increased the commercial feasibility of deep-sea rare earth mining and recovery. But this will remain a concern until SIP releases more details about mining and recovery costs, and what elements are available in its future reports.
Deep-sea mining is one of Japan's strategies to reduce its dependency on Chinese imports of critical minerals. Japan relies heavily on imports of rare earths for its high-performance and electronics industries. About 60-70pc of Japan's rare earth imports come from China.
