Japan will Test Continuous Deep Sea Rare Earth Mud Lifting

Japan will carry out a government backed, month long test to continuously lift rare earth rich mud from the deep seabed near Minamitorishima beginning on Jan. 11 and running to Feb. 14, project officials announced in Tokyo on Dec. 23. The operation is designed to connect and validate a full deep sea mining system and is presented by project leaders as the first attempt anywhere to continuously bring material from about 6,000 meters to a surface vessel.

The Cabinet Office is leading the program and the Japan Agency for Marine Earth Science and Technology will operate the scientific research vessel Chikyu for the trial. Teams plan to use newly developed pipes and extraction equipment to assess whether the thin, clay like layer of rare earth bearing mud can be feasibly collected and pumped up to shipboard systems. The project has set a throughput target of 350 metric tonnes of material per day on to the vessel during the test period.

Extracted mud will not be refined at sea. Instead the material will be shipped to Minamitorishima Island for initial seawater removal by dewatering equipment described by officials as similar to a washing machine spin dryer. That first stage is expected to shrink the material volume by about 80 percent. Dewatered residue will then be carried to mainland Japan for further separation and refining and a program laboratory will analyze sample concentrations of rare earth elements as part of the trial.

Environmental monitoring will be conducted both on board the Chikyu and directly on the seabed throughout the operation, according to project statements. Briefing materials emphasize that the resource occurs as a thin, diffuse layer across the ocean floor and cannot be mined by creating deep pits as is done on land. If commercial operations are contemplated later, machines may need to change extraction sites frequently to follow the thin deposits, the documents state.

Project leaders have not disclosed estimates of recoverable reserves at the Minamitorishima deposits and they have not set commercial production targets for this phase. Officials say that if system connection and throughput verification succeed in January, a larger recovery demonstration at the same daily volume is planned for February 2027.

The program has received substantial government backing. Since 2018 the initiative has invested about ¥40 billion, approximately US$256 million, according to Shoichi Ishii, a program director at the Strategic Innovation Promotion Program. Authorities frame the effort as part of a broader strategy to strengthen economic and maritime security and to establish a domestic supply chain for rare earths, materials essential to magnets, batteries and other high technology components.

The trial underscores the tension between technological ambition and environmental caution. Proponents argue that validating extraction at extreme depth could reduce import dependence for critical materials, while researchers and conservationists warn that deep sea ecosystems are poorly understood and damage could be long lasting. The January operation will be watched closely at home and abroad as a test of both engineering at great depth and the regulatory and environmental safeguards needed to govern any future development.