How a new extraction process could unlock the world’s lithium

A new lithium extraction method could revolutionize the production of a critical metal for electric vehicles and energy storage. Researchers from MIT and startup Rock Zero published a study in *Science* detailing a process that uses a weak acid—ammonium fluoride—to dissolve silicate minerals, including spodumene, without requiring high-temperature kilns or hazardous chemicals like hydrofluoric acid. The current lithium extraction methods, such as brine evaporation or hard-rock mining, are either geographically limited or energy-intensive. Hard-rock mining involves blasting ore, heating it to extreme temperatures, and processing it with dangerous chemicals. The new technique could reduce costs and carbon emissions by eliminating the need for high-temperature roasting, which is a key step in processing spodumene. The discovery stemmed from research by MIT professor Yet-Ming Chiang, a serial entrepreneur behind climate tech startups like Form Energy and Addis Energy. Chiang recalled glass etching cream—a weak acid—used during a home renovation project 25 years ago. Testing revealed that ammonium fluoride could dissolve silicate minerals effectively without producing hydrofluoric acid, a toxic byproduct of traditional methods. Rock Zero, co-founded by Chiang and Camden Hunt, aims to commercialize the process. Hunt, CEO and study co-author, noted that avoiding kilns could also unlock access to lower-grade ores that cannot be properly roasted. The method could also recover additional valuable materials like alumina and silica alongside lithium. The team initially explored reactive silica for cement production through Sublime Systems, another Chiang-founded startup. The lithium extraction breakthrough came after focusing on spodumene, a lithium-rich mineral, with input from advisor Doug Wicks, a former ARPA-E official. If scaled, the process could become the lowest-cost lithium source globally, according to Chiang.