Minamitorishima rare earths: read refining reality through standards

For Minamitorishima—Japan’s easternmost outlying island, located over 1,800 km from Tokyo—the issue is not mining but building the midstream. On October 28, Japan and the United States signed a framework to secure supplies of critical minerals and rare earths. Feasibility now depends on conditions for separation, refining, and logistics.

Minamitorishima and heavy rare earths: design on the premise of refining market share

In the supply network, refining is the bottleneck. China holds about 90% refining share (Source: Reuters 2025-10). Heavy rare earths are a subset within rare earths and are used to secure high-temperature performance in magnets.

Securing power, meeting wastewater standards, installing byproduct treatment lines, establishing reagent import procedures, maintaining inventory, and obtaining safety certifications are linked to setting the trial start and the ramp-up rate. On November 6, Prime Minister Takaichi mentioned consideration of Japan–U.S. cooperation on Minamitorishima in a representative interpellation in the House of Councillors. Political agreement is an entry point; operability depends on the alignment of standards and systems.

Domestic refining network: the role and limits of rare earth refining

In the domestic network, public procurement and certifications determine process order. SIP (the Cabinet Office’s Cross-ministerial Strategic Innovation Promotion Program—a government R&D initiative coordinating across ministries) is running demonstrations from seabed mud lifting through refining, targeting 350 metric tons per day in mining and lifting tests (Source: Cabinet Office SIP, “Change to the R&D Plan, Document 2” 2025-06-26).

In Japan, disclosure of live operations data on continuous heavy rare earth separation is limited; without fixed procurement specifications, equipment installation is delayed and metering certifications for wastewater and byproducts during trial runs are stalled. Reporting has repeatedly noted supply constraints tied to China’s refining dominance (Source: Reuters 2025-10).

Standards, ports, power, and wastewater: link alignment conditions to metrics

Across facilities, grid connections and audits govern the effectiveness of traceability. Traceability is the ability to track supply history, and it functions only when physical requirements—such as port intake capacity, power supply contracts, and wastewater throughput—are aligned with data management.

On the demand side, the 2030 guidepost is about 13,000 metric tons per year of NdPr as a light rare earth (Source: METI 2025-06) and about 1,200 metric tons per year of Dy and Tb as examples of heavy rare earths. Standards conformity yield is the share of lots that pass standards tests; it also serves as a production-efficiency indicator. Until this rises, mining news does not convert into supply.