US PNNL Study Shows Seawater Could Supply Critical Minerals for 50,000 Years

Researchers at the U.S. Department of Energy’s Pacific Northwest National Laboratory (PNNL) have demonstrated that processing just 0.1 % of the planet’s ocean water could meet humanity’s long‑term demand for critical minerals such as magnesium, lithium, nickel and rare‑earth elements for more than 50,000 years. The team developed an integrated three‑step technology: a low‑cost extraction of magnesium hydroxide, conversion of salty brine waste into acid and base for use in terrestrial mining, and biological filtration using marine algae to capture trace minerals. Laboratory trials recovered magnesium, lithium, nickel, platinum‑group metals and rare‑earths, with magnesium offering the highest concentration (about 2,980 kg per 2.27 million L of seawater). A patented co‑flow reactor could, at full scale, produce around 524,000 kg of magnesium hydroxide per day—over three times current U.S. consumption—potentially reducing reliance on land‑based mining.

The findings suggest a new, virtually inexhaustible source of strategic minerals that could support the expanding green‑energy economy and high‑technology manufacturing while mitigating environmental impacts of traditional mining.