Portuguese 
Spanish 
Borehole Mining International (BHMI) has developed a technique that drills the seabed and extracts minerals from the rock without needing excavation: a drill descends, injects pressurizing fluid that dissolves and mobilizes the ore, and the material rises through the pipe—all without any large machinery needing to touch the ocean floor, and without creating the craters and sediment disturbance that make seabed mining so controversial.
How borehole mining works and why it is different
Conventional seabed mining—which companies like The Metals Company attempt to do in the polymetallic nodules of the Pacific—uses robotic collectors that sweep the ocean floor, suck up the nodules, and create sediment plumes that spread for hundreds of kilometers. The environmental controversy is enormous, and several European countries have opposed it even before having sufficient data on the impact.
Borehole mining works radically differently. A hole is drilled in the seabed, similar to an oil or water well. Inside the hole, a hydraulic system injects fluid under pressure that fragments and dissolves the ore in situ. The liquefied material is then pumped back to the surface through the pipe. There is no surface collection, no sediment plume, no machinery sweeping the bottom.
The technology is not new on land—borehole mining has been used for decades to extract salt, sulfur, potassium, and uranium on land. What BHMI did was adapt the technique for offshore environments, with pressures and depths that require completely different engineering.
-
Vale Doubles Copper Drilling in Brazil’s Carajás, Plans to Drill 120 Kilometers of Rock by 2026
-
Innovative Vertical Cistern Becomes Water Tank in Container Home Amid Pressure Issues, Offering a Compact 1,000-Liter Solution Without a Tower or Underground Tank
-
Rio de Janeiro Traffic Relief: Long-Awaited Change Promises to Cut 15-30 Minutes from BR-040 Commute, Easing Access to Avenida Brasil.
-
China Installs Massive Domes Over Urban Construction Sites, Blocking Up to 99% of Dust
Which minerals the technique can access
The ocean floor holds significant concentrations of critical minerals for the energy transition—lithium, cobalt, manganese, nickel, and phosphorus appear in submerged rock formations on continental shelves that are well mapped by the oil and gas industry. The same seismic technology used to find oil reveals mineral formations.
Submarine phosphorus is particularly interesting: land reserves of phosphorus—essential for fertilizers—are concentrated in a few countries, mainly Morocco. Submarine phosphate deposits on continental shelves of countries like Namibia, New Zealand, and Brazil represent a strategic alternative that borehole mining can make economically viable.
For lithium and cobalt—the battery metals—ferromanganese crust formations at depths between 800 and 2,500 meters in the exclusive economic zones of several countries have documented concentrations that surpass many land deposits. The challenge has always been to extract them without destroying the ecosystem. Borehole mining suggests a way.
The environmental debate: less impact, but not zero impact
Borehole mining solves the problem of surface disturbance, but it does not eliminate all environmental risks. The fluid injected to dissolve the ore needs to be treated and cannot leak into the submarine environment. The hole itself creates a permanent channel in the bed. And extracting minerals from rock formations can alter the geological structure and chemical composition of the bottom water in a smaller, but still significant radius.
Environmentalists are skeptical, but recognize that the approach is less impactful than surface collectors. For the exclusive economic zones of countries that have these deposits—including Brazil, with its vast continental shelf in the South Atlantic—the technique may represent access to strategic minerals without the reputational cost of destroying submarine ecosystems.
The International Seabed Authority, which regulates mineral exploration in international waters, does not yet have a specific regulatory framework for offshore borehole mining—which represents both an opportunity (less immediate bureaucracy) and a risk (rules may change).
What this means for Brazil and the continental shelf
Brazil has one of the largest exclusive economic zones in the world—3.5 million square kilometers—with a continental shelf that extends for hundreds of kilometers in the South Atlantic. The Blue Amazon, as it is called, was partially mapped by Petrobras in the search for oil—and this mapping reveals formations that may contain strategic minerals.
The CPRM (Geological Survey of Brazil) has continental shelf data that is being reassessed from the perspective of critical minerals. If offshore borehole mining proves economically viable—which BHMI claims is getting close—Brazil has the territory and data to be one of the first countries to evaluate its application.
The energy transition is not just an energy challenge—it’s a minerals challenge. And the ocean may hold part of the answer for extraction with less impact than any land-based alternative available today.
An important technical detail of borehole mining is that it works best in specific geological formations—essentially in rocks that respond to hydraulic treatment with adequate fragmentation and mobilization. Not every submarine mineral deposit is accessible with this technique. Carbonate platforms, evaporite deposits, and certain phosphate formations are more suitable than hard polymetallic nodules or ferromanganese crusts. This means that borehole mining is not a universal solution for all seabed mining—it is a complementary tool that works very well in specific contexts. BHMI has identified phosphate deposits on the continental shelf of Namibia, Australia, and Mexico as priority targets for feasibility tests. For Brazil, Petrobras has already mapped carbonate formations on the Espírito Santo and Bahia shelf that could be evaluated as potential targets for the technique—an additional use of the drilling infrastructure that already exists for the pre-salt.
If the ocean holds the minerals the world needs for the energy transition, will Brazil use its 3.5 million km² of Blue Amazon to become a critical minerals power or will it let other countries get there first?
