Polymetallic nodules offer the cleanest source of critical base metals.

Polymetallic nodules, also called manganese nodules, contain four essential base metals, cobalt, nickel, copper and manganese, as well as meaningful concentrations of rare earths, in a single ore. Formed over millions of years by precipitating metals from seawater and sediment pore water, these nodules lie unattached to the abyssal seafloor. Unlike land ores, nodules do not contain toxic levels of heavy elements, meaning we are able to convert nearly 100% of nodule mass into products and have designed a metallurgical flowsheet that generates no tailings and leaves nearly no solid waste streams behind.

Polymetallic nodules were discovered in the 19th century. In the 1970s, four U.S.- based consortia started to collect the rocks in the Clarion Clipperton Zone (CCZ) of the Pacific Ocean to determine the commercial viability of their exploitation. The initial tests suggested that nodules could be collected and processed to produce usable metals with the technology available at the time, but the activity then slowed, as first the United States, then later a separate international organization, set about developing regulations to govern activities in international waters.

Following these early trials, Congress enacted the Deep Seabed Hard Mineral Resources Act (DSHMRA) in 1980 to regulate the mining activities of U.S. citizens, swiftly followed by the establishment of exploration regulations by the U.S. National Oceanic and Atmospheric Administration in 1981 and commercial recovery regulations in 1989. Five years later, the International Seabed Authority (ISA) was set up by the U.N., tasked with adopting an international regulatory framework.

To date, TMC’s subsidiaries have submitted applications to and hold certain rights under both regulatory frameworks: TMC USA has submitted a consolidated application under DSHMRA for a commercial recovery permit and an exploration license over the USA A area, and for an additional exploration license over the USA B area. The ISA has also granted exploration contracts to Nauru Ocean Resources Inc. (NORI), sponsored by the Republic of Nauru, and to Tonga Offshore Mining Limited (TOML), sponsored by the Kingdom of Tonga.

Through surveying with underwater drones and taking box core samples, we’re able to estimate the grade and abundances of minerals in our exploration areas in the CCZ. Two SEC-compliant technical resource reports, a world-first prefeasibility study for our first project and an initial assessment for the remainder of our resource, highlight an estimated 1.6 billion tonnes of polymetallic nodules on our exploration areas, with potential exploration upside of 300 million tonnes. The pre-feasibility study, a world-first for a polymetallic nodule project, also marked the first ever declaration of nodule reserves, demonstrating the economic viability of our first project.

Several independently-authored and reviewed lifecycle assessments demonstrate that our nodule projects can deliver four critical metals with fewer lifecycle impacts, including up to 90% lower global warming potential and fewer waste emissions compared to conventional ores. Nodule exploitation also means no disruption to Indigenous communities, no deforestation and no child labor.

Our production process begins with the collector, designed to collect polymetallic nodules from the abyssal seafloor. Data shows that 95–98% of the entrained sediment is separated from the nodules inside the collector and discharged behind it, with most sediment settling back to the seafloor within a few hundred meters. From the collector, nodules travel up a riser system to our production vessel. Once aboard, nodules get dewatered and seawater, along with the 2–5% of sediment not separated at the seafloor, is returned below the most productive ocean layers at a depth of 2,000 meters, scientifically chosen to avoid the majority of marine life far above.

Throughout this process, our adaptive management system, a mix of marine hardware and cloud-based artificial intelligence designed to create a virtual replica of the deep-sea environment, will give eyes and ears to the regulator and various stakeholders during operation and ensure that our activities remain within safe ecological thresholds, from the surface to seafloor. The nodules will then head to shore where they’re offloaded for processing.