MIT Technology Review is reporting that researchers have discovered a new method for extracting lithium, a critical metal for electric vehicle batteries and energy storage. The new technique is described as potentially more environmentally friendly and cheaper than current methods. The research was published in Science, and a startup named Rock Zero is working to commercialize the process.
Yet-Ming Chiang, an MIT professor, study author and serial entrepreneur, said the method could become the lowest-cost way to source lithium globally. Current extraction methods include drawing lithium from brine, which requires vast evaporation pools and is geographically limited, or hard-rock mining, which involves blasting ore, high-temperature processing and dangerous chemicals.
The new method uses a weak acid, ammonium fluoride, to dissolve typically nonreactive silicate minerals. This process frees lithium along with other useful materials like alumina and silica. The inspiration for the method came from Chiang's observation of glass etching cream, which uses ammonium fluoride to dissolve silica without producing dangerous hydrofluoric acid.
This technique avoids the need for high-temperature kilns, which are a key step in processing spodumene ore, saving energy costs and potentially reducing carbon emissions. It also allows for the use of ores that cannot be roasted properly due to high iron content. The process occurs in simple stirred plastic tanks at temperatures up to 95 degrees Celsius (200 degrees Fahrenheit) and can extract nearly all lithium within 12 hours.
The resulting products include lithium carbonate for batteries, alumina for aluminum production and cementitious silica for concrete. The acid can also be reused. Rock Zero estimates the cost of extraction at less than $6,000 per metric ton, which could be competitive with brine extraction. The company plans to build a pilot plant by the end of 2026, with operations starting in 2027.
Simon Jowitt, chair of exploration geology at the University of Nevada, Reno, noted the lithium market's volatility and the crowded field of existing players and new projects. He also mentioned the potential impact of alternative technologies, such as sodium-ion batteries, on lithium demand. Rock Zero's team hopes to apply this technology to other silicate minerals in the future.
Full Article: How a new extraction process could unlock the world’s lithium