The oceans as a source of strategic minerals.

Elements are highly diluted in seawater.

Oceans were once viewed merely as an inexhaustible source of water, food, and biodiversity, but scientists believe they also harbor one of the planet's largest reserves of strategic minerals. Dissolved within billions of tons of water are elements such as lithium and magnesium—materials essential for batteries, electric vehicles, and various modern technologies.

The challenge has always been that these substances exist in extremely low concentrations, making extraction economically unviable; however, researchers at the Pacific Northwest National Laboratory in the United States have now developed a technology that promises to change this landscape. At the heart of this technology is a co-flow reactor where seawater comes into contact with a sodium hydroxide solution. In this carefully controlled environment, a chemical reaction occurs that causes magnesium to precipitate almost instantly as magnesium hydroxide, allowing for much more efficient collection.

Since the chemical composition of the oceans is relatively uniform across the globe, the technology can be adapted to different coastal regions without major process changes. Following that initial stage, the remaining brine passes through an electrically powered electrodialysis system using bipolar membranes; this process separates acidic and basic compounds that can be reused for mineral recovery or in other industrial processes.

In laboratory tests, the acid produced outperformed conventional methods for extracting nickel from certain ores, demonstrating the system's ability to generate multiple high-value products simultaneously. Researchers calculated that if integrated into the large Carlsbad desalination plant in California, this technology could produce over 500 tons of magnesium hydroxide daily—an amount several times greater than the US industry's daily demand. In addition to reducing the need for new land-based mines, the process leverages existing infrastructure and transforms a desalination byproduct into a new source of strategic raw materials.

The PNNL project demonstrates that the next great mining revolution may not take place in mountains or deserts, but rather in the waters covering most of the planet; if the technology continues to evolve, the oceans could become a sustainable source of essential minerals to fuel the energy transition of the coming decades, thereby reducing pressure on land-based natural resources.