Rock Zero's weak acid process extracts lithium in under 12 hours

Current lithium extraction methods are costly and environmentally damaging. Brine evaporation requires vast land and is geographically limited, while hard-rock mining involves blasting ore and roasting it at extreme temperatures using dangerous chemicals. Researchers from MIT, led by professor Yet-Ming Chiang, have found a new approach that sidesteps these issues entirely. Their process uses ammonium fluoride—a weak acid found in common glass etching cream—to dissolve silicate minerals like spodumene. Unlike traditional methods that require a kiln to create a phase transformation at super-high temperatures, this new technique operates at just 95°C in simple stirred plastic tanks. The acid selectively frees lithium along with other useful materials such as alumina and silica, which can be sold or reused. The team has already reduced extraction time from days to under 12 hours.

The inspiration came from Chiang's home renovation project 25 years ago, when he used glass etching cream. His startup Rock Zero is now commercializing the technology, aiming to make it the lowest-cost lithium source. The acid can be recycled in the loop, and the byproducts—lithium carbonate for batteries, alumina for aluminum production, and cementitious silica for concrete—add economic value. This “nose-to-tail” mining approach could dramatically cut energy use and carbon emissions, and even allow processing of ores that are too iron-rich for conventional roasting. If scaled, it promises a more sustainable supply chain for EV and energy storage batteries.