A commercially available glass etchant paste from a craft supply store inspired MIT researchers: this product dissolves silicon dioxide at low temperature, and spodumene, the world's most important lithium-bearing mineral, consists largely of silicon dioxide. Yet-Ming Chiang and his team leveraged this property to develop an extraction method that dissolves lithium from hard rock without high-temperature furnaces and without chemical waste. Published May 28, 2026 in Science, the method gave rise to startup Rock Zero, which estimates production costs below $6,000 per ton, half the cost of today's dominant roasting method.
Spodumene and the Limits of Current Hard Rock Extraction
Lithium occurs in two economically viable main forms: as dissolved salt in brines, especially in Chile, Argentina, and Bolivia, and as minerals in hard rock, particularly spodumene (LiAlSi₂O₆). Australia is the world's largest lithium producer from hard rock, with substantial spodumene deposits; significant reserves also exist in Canada, Portugal, and Zimbabwe. The International Energy Agency expects global lithium demand to rise steeply, driven by electric vehicles and stationary energy storage.
Today's hard rock extraction method is energy-intensive: spodumene concentrate, typically containing 6 to 7 percent lithium oxide, is first roasted above 1,000 degrees Celsius to break up the crystal structure. This is followed by acid leaching, which generates chemical waste. Deposits with high iron content cannot be processed using this method and are considered economically unviable.
Ammonium Fluoride Instead of 1,000 Degrees
The inspiration for the new process was, according to MIT Technology Review, a commercially available glass etchant paste from a craft store. This dissolves silicon dioxide at low temperature, and spodumene consists largely of silicon dioxide. Yet-Ming Chiang, Kyocera Professor of Materials Science at MIT, recognized with his colleagues that ammonium fluoride can exploit the same property: it breaks the crystal structure of spodumene at room temperature up to 95 degrees Celsius, without high-temperature furnaces.
Extraction takes under twelve hours. The ammonium fluoride is recovered and recycled in a closed loop, producing minimal waste. Byproducts include melting-grade aluminum oxide and cement-suitable silicon dioxide, both commercially valuable. Rock Zero thus produces not only lithium carbonate for batteries, but also feedstocks for the aluminum and cement industries. Co-founders are Camden Hunt (CEO) and Benjamin Mowbray (CTO), both former MIT researchers; Mowbray is first author on the paper.
In Comparison: Brines, Roasting, and the Columbia Method
Salt lake extraction from brines, dominant especially in the Atacama Desert, requires evaporation ponds that must be filled over 12 to 24 months and consume large quantities of water. Researchers at Columbia University also unveiled a solvent-based extraction method for lithium from brine in 2026, claiming faster and cleaner extraction. The Rock Zero process is complementary: it applies to hard rock, not brine, and opens access to geographically different deposits in Australia, Canada, Portugal, and other countries with hard rock resources. The two methods do not compete but rather cover different sources.
Another advantage of the MIT method: it can process ores with high iron content, unsuitable for traditional roasting. This opens deposits previously economically unviable. The geographic spread of possible production sites could also reduce dependence on narrow supply chains, increasingly relevant to European industrial nations concerned with supply security.
Below $6,000 per Ton: Pilot Plant by 2027
Rock Zero plans to begin building a pilot plant by the end of 2026, with operations starting in 2027. The team's cost projection below $6,000 per ton is in the range of salt lake extraction and well below current hard rock costs. The estimates are based on laboratory and modeling data so far. Whether they hold in industrial practice will be shown in the pilot phase.
For the energy transition, the cost question is central. Lithium carbonate prices fluctuated between 2020 and 2024 between under $10,000 and over $80,000 per ton, driven by speculative demand and supply bottlenecks during the ramp-up of electric vehicle manufacturing. Cheaper lithium available from previously uneconomical hard rock deposits could stabilize global supply and dampen such price swings. This would benefit not only battery makers, but also countries seeking to secure a broader base of strategic raw materials.