TMC US seafloor mining hub: project economics and risk notes for engineers
Reviewed by Tom Sullivan

First reported on MINING.com
30 Second Briefing
Deep-sea miner The Metals Company posted a 2025 net loss of $319.8 million and a Q4 loss of $40.4 million, driven by a $131 million increase in NORI royalty liability and a $38 million one-off charge from revised sponsorship agreements, even as cash stood at $117.6 million. The company is pursuing a 12‑million‑tonne‑per‑year polymetallic nodule processing and refining plant on a 1,466‑acre site at the Port of Brownsville, Texas, and integrating AI‑driven process controls with partner Mariana Minerals. NOAA has deemed TMC’s consolidated deep‑seabed mining application in substantial compliance, covering about 65,000 km² in the Clarion Clipperton Zone with an estimated 619 million tonnes of wet nodules, while critics argue its prefeasibility economics rely improperly on resources as well as reserves.
Technical Brief
- Independent reviewers state TMC’s prefeasibility economics rely on 51 Mt reserves plus 113.1 Mt resources, contrary to SEC reserve-only guidance.
- Dr Steven Emerman concludes that even with resources included, the project fails technical, financial and regulatory thresholds for credible development.
- TMC’s NORI royalty liability is explicitly tied to future revenue from its Pacific deep-sea mining project, increasing future cost loading per tonne.
- NOAA’s “substantial compliance” finding moves TMC’s consolidated deep-seabed mining application towards an exploitation permit for Clarion Clipperton Zone nodules.
- The application area expansion to ~65,000 km² with 619 Mt wet nodules materially scales potential production scheduling and infrastructure sizing.
- TMC is still evaluating a “capital-light” tolling route in Japan, implying possible off-balance-sheet processing capacity versus the Texas hub.
- Newly formed The Metals Royalty Co. (ticker TMCR) will hold royalties with TMC retaining ~25% equity and repurchase options.
Our Take
The push to base TMC’s cobalt–nickel–manganese hub in Texas comes just weeks after NOAA deemed its consolidated exploration and commercial recovery permit application complete, signalling that US domestic regulators—not the ISA—may become the decisive gatekeepers for Clarion Clipperton Zone production.
Our database shows that most recent nickel and copper coverage is still dominated by large onshore projects like Canada Nickel’s Timmins district, so TMC’s deep-sea model will be benchmarked by investors against those conventional assets on cost, ESG risk and schedule once its 12 Mt/y Texas processing plan is better defined.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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