In seawater, researchers see an untapped bounty of critical metals
Can metals that naturally occur in seawater be mined, and can they be mined sustainably? A company in Oakland, California, says yes. And not only is it extracting magnesium from ocean water — and from waste brine generated by industry — it is doing it in a carbon-neutral way. Magrathea Metals has produced small amounts of magnesium in pilot projects, and with financial support from the U.S. Defense Department, it is building a larger-scale facility to produce about 200 tons of the metal a year. By 2028, it says it plans to be operating a facility that will annually produce more than 11,000 tons. … Brines come from a number of sources: much new research focuses on the potential for extracting metals from briny wastes generated by industry, including coal-fired power plants that discharge waste into tailings ponds; wastewater pumped out of oil and gas wells — called produced water; wastewater from hard-rock mining; and desalination plants.