Half the Cost and Zero Waste: The Extraction Method That Could Change Lithium
A research group led by MIT has developed a method to extract battery-grade lithium from spodumene, the mineral that is the most widely available source, by processing it at low temperatures instead of 'cooking' it in an oven. The process halves costs compared to traditional rock refining and reduces waste to almost zero, according to a study published Thursday in Science.
The United States, Europe, and Australia have large lithium deposits within their borders, but refining remains almost entirely in China: the bottleneck is the capacity to convert it into usable salts. This dependence has been felt recently when Beijing limited the export of technologies for producing lithium carbonate and hydroxide from spodumene. A low-cost Western method to close that gap could change the balance before it even reaches industrial scale.
From 1,000 °C Ovens to Glass Etching Cream
Currently, extracting lithium from rock involves applying heat to spodumene at temperatures over 1,000 °C to make it amenable, then chemically treating it with lye and discarding the remaining mineral. It is an expensive and energy-intensive process, often less economical than extraction from brine, which, however, has heavy environmental impacts and limited geography.
The team's idea originated from a home renovation. About twenty-five years ago, Yet-Ming Chiang, a materials science professor at MIT, bought a glass etching cream and noticed it corroded the surface; the active ingredient was ammonium fluoride. Drawing on that intuition, the researchers used a mixture of water and ammonium fluoride to first dissolve silica, reversing classical hydrometallurgy, where silicate is usually the last component to yield. The reagent is a weak acid, and under the right conditions, it dissolves silicates without resorting to hydrofluoric acid, the highly dangerous compound that remains the most known route for this purpose. Other fluoride-based reagents avoid it as an ingredient but release it during the reaction, while here it does not form at any stage.
The central point is the closed loop: by dissolving the rock, lithium, aluminum, and silica are released, and by recovering the ammonia generated during the reaction, silica is precipitated and the starting ammonium fluoride is regenerated. This results in three marketable products: battery-grade lithium carbonate, metallurgical-grade alumina, and silica usable in cement. Chiang compares it to eating an animal "from nose to tail," using every part of the mineral. The method has been tested on 17 sources of spodumene, with a recovery rate exceeding 95%. It aligns with other low-energy lithium research we've discussed, where the limits of traditional methods are precisely strong acids and high consumption.
From the Laboratory to the Pilot Plant
The technology is already being industrialized through Rock Zero, a company spun out of MIT. The process operates in plastic tanks agitated at temperatures up to about 95 °C and has reduced extraction time from several days to less than 12 hours; in the lab, each batch treats about three kilograms of concentrate. Camden Hunt, CEO and co-founder of Rock Zero, recalls that by 2040, global lithium production will need to quadruple, and avoiding high-temperature furnaces also allows for processing ores that are too rich in iron for traditional baking.
Regarding costs, MIT Technology Review estimates a value below $6,000 per ton once fully operational, assuming a high recycling rate of the reagent: half the cost of traditional rock extraction and potentially competitive with brine. The pilot plant is expected to be under construction by the end of 2026 and operational in 2027, with negotiations ongoing with potential mining partners.
Several factors complicate the real picture: lithium prices fluctuate greatly, the quality of deposits is not uniform, and transitioning to the new method would require investments in facilities. Simon Jowitt, a geologist at the University of Nevada, Reno, remarks that the market is crowded and still small, hence volatile, and that some of the company’s economic estimates may be optimistic; the competition from sodium-ion batteries, which can do without lithium, also weighs in.
Chiang maintains that, when fully operational, it will be the cheapest way to obtain lithium overall, not just from rock. The already verified part is the self-regenerating chemistry that works on seventeen different minerals, but proof at industrial scale relies on the pilot plant in 2027, in a market where the price of lithium collapsed at the end of 2024 and only began to rise again in early 2026.