# Japanese trading houses expand cobalt refining ties to counter supply risk *Sumitomo Metal Mining, Marubeni, and Mitsui build alternative hydrometallurgical refining channels to feed Japanese battery precursor production.* **Published:** August 28, 2026 **By:** Ryo Matsuda **Section:** Energy & Critical Minerals — Japan **Format:** Company Watch **Confidence:** high **Source:** https://eastasiabrief.com/energy-minerals/japanese-trading-houses-expand-cobalt-refining-ties-counter-supply-101 **Publisher:** East Asia Brief (https://eastasiabrief.com/) --- ## What to know - The company moved to take 100 percent ownership of Coral Bay Nickel Corporation by purchasing the remaining 15. ![An engineer stands at a control console overlooking a coastal refining facility supporting battery material supply chains. (AI-generated image)](https://eastasiabrief.com/media/2026-08-28-63bca51f336a.webp) *An engineer stands at a control console overlooking a coastal refining facility supporting battery material supply chains. (AI-generated image)* Japanese trading conglomerates and specialized metals producers are committing fresh capital to offshore cobalt recovery infrastructure and dedicated refining partnerships to shield domestic battery makers from concentrated supply bottlenecks. The investments direct financial resources into hydrometallurgical extraction, third-party toll refining, and long-term chemical off-take contracts across Southeast Asia, North America, and Australia. The objective is to secure alternative supply conduits for battery-grade cobalt sulfate and electrolytic cobalt without passing intermediate materials through mainland Chinese processing facilities. Global cobalt refining remains heavily centralized, with Chinese chemical processors controlling more than 75 percent of global refined cobalt chemicals, even though the majority of mined cobalt originates in the Democratic Republic of the Congo. Japanese battery manufacturers, including Panasonic Energy and Prime Planet Energy & Solutions, require stable access to high-purity cobalt sulfate to manufacture nickel-cobalt-manganese and nickel-cobalt-aluminum cathode precursors for automotive clients such as Toyota Motor Corporation and Honda Motor. To insulate these production lines from single-source export controls or regulatory shifts, Japanese resource houses are structuring localized closed-loop recovery circuits. Sumitomo Metal Mining Co., Ltd. serves as the primary operational anchor of this model in Southeast Asia through its high-pressure acid leach operations in the Philippines. The company operates Coral Bay Nickel Corporation on Palawan Island and Taganito HPAL Nickel Corporation in Surigao del Norte, Mindanao. The two facilities process low-grade nickel laterite ores into an intermediate mixed sulfide containing roughly 55 to 60 percent nickel and 4 percent cobalt. Sumitomo Metal Mining ships this intermediate sulfide directly to its domestic facilities in Japan the Niihama Nickel Refinery in Ehime Prefecture and the Harima Refinery in Hyogo Prefecture where Matte Chlorine Leach Electrowinning and solvent extraction processes yield battery-grade electrolytic cobalt and nickel sulfate. The company moved to take 100 percent ownership of Coral Bay Nickel Corporation by purchasing the remaining 15.625 percent equity held by Philippine partner Nickel Asia Corporation, following earlier investments that added a 105,000-metric-ton commercial byproduct recovery line at Taganito. Sumitomo Metal Mining previously evaluated the Pomalaa HPAL project in Indonesia alongside PT Vale Indonesia but withdrew prior to construction, choosing instead to concentrate capital on wholly owned Philippine assets and domestic refining lines. This focus preserves full operational control over recovery chemistry and prevents technology transfer into regional joint ventures dominated by Chinese industrial groups. Trading giant Marubeni Corporation is executing a parallel strategy by partnering with specialized chemical refiners. Marubeni entered into a tripartite Memorandum of Understanding with Taiwan-headquartered battery raw material manufacturer Mechema Chemicals International Corp. and Luxembourg-based Eurasian Resources Group. Under the agreement, Eurasian Resources Group supplies cobalt hydroxide feedstock from its Metalkol tailings recovery facility in the Democratic Republic of the Congo, while Mechema undertakes engineering feasibility studies for a dedicated cobalt refining facility to convert the hydroxide into cobalt sulfate. Marubeni manages the downstream distribution, off-take placement, and commercial integration into Japanese cathode active material lines. Mitsui & Co. and specialized gas and resources distributor Iwatani Corporation are expanding similar dedicated off-take and refining mechanisms across Pacific supply corridors. Mitsui finalized a multi-year off-take agreement valued at $850 million with EVelution Energy to secure up to 3,000 metric tons per year of refined cobalt metal and chemical intermediates from a proposed solar-powered processing facility in the United States. In Australia, Iwatani entered into a project evaluation agreement with Cobalt Blue Holdings to explore equity co-funding and off-take terms for the planned Kwinana Cobalt Refinery in Western Australia, which tests third-party feedstock to produce cobalt sulfate tailored to Japanese battery specifications. For battery material procurement directors and cathode manufacturers like Nichia Corporation and Tanaka Chemical Corporation, these structured refining routes establish transparent chain-of-custody documentation. Traceability from mine or tailings extraction to chemical crystallization complies with the European Union Battery Regulation and United States Inflation Reduction Act sourcing provisions. That compliance enables Japanese automotive exporters to qualify for Western electric vehicle tax credits while reducing balance-sheet exposure to spot-market price volatility in Shanghai. Physical flows under these agreements follow fixed industrial milestones. Coral Bay Nickel Corporation and Taganito HPAL continue scheduled bulk shipments of mixed sulfide into the Port of Niihama, while Marubeni and Mechema advance commercial terms following initial pilot sample testing for Japanese precursor producers. ## Impact map | Event | Korea | China | Japan | Global impact | | --- | --- | --- | --- | --- | | Cobalt supply diversification | cathode material competition | merchant refining bypassed | proprietary sulfate supply | IRA compliance secured | ## In this story - **Companies:** Sumitomo Metal Mining, Marubeni Corporation, Mitsui & Co., Iwatani Corporation - **Tickers:** 5713.T, 8002.T, 8031.T, 8088.T - **Exposed:** Panasonic Energy, Toyota Motor, Eurasian Resources Group, Nickel Asia Corporation - **Policy:** Economic Security, Subsidies - **Impact:** Supply Chain, Order Book, Capex, Compliance ## Primary sources 1. mmc.co.jp 2. europa.eu 3. smm.co.jp 4. eurasianresources.lu 5. mining.com --- Cite as: East Asia Brief, "Japanese trading houses expand cobalt refining ties to counter supply risk," August 28, 2026. https://eastasiabrief.com/energy-minerals/japanese-trading-houses-expand-cobalt-refining-ties-counter-supply-101