This startup wants to make more climate-friendly metal in the US

The star of Magrathea’s process is an electrolyzer, a device that uses electricity to split a material into its constituent elements. Using an electrolyzer in magnesium production isn’t new, but Magrathea’s approach represents an update. “We really modernized it and brought it into the 21st century,” says Alex Grant, Magrathea’s cofounder and CEO. The whole process starts with salty water. There are small amounts of magnesium in seawater, as well as in salt lakes and groundwater. (In seawater, the concentration is about 1,300 parts per million, so magnesium makes up about 0.1% of seawater by weight.) If you take that seawater or brine and clean it up, concentrate it, and dry it out, you get a solid magnesium chloride salt. Magrathea takes that salt (which it currently buys from Cargill) and puts it into the electrolyzer. The device reaches temperatures of about 700 °C (almost 1,300 °F) and runs electricity through the molten salt to split the magnesium from the chlorine, forming magn ... Read full article.