Direct Lithium Extraction from α-Spodumene through Solid-State Reactions for Sustainable Li 2 CO 3 Production.

With increasing battery demand comes a need for diversified Li sources beyond brines. Among all Li-bearing minerals, spodumene is most often used for its high Li content and natural abundance. However, the traditional approach to process spodumene is costly and energy-intensive, requiring the mineral be transformed from its natural α to β phase at >1000 °C. Acid leaching is then applied, followed by neutralization to precipitate Li 2 CO 3 . In this work, we report an alternative method to extract Li directly from α-spodumene, which is performed at lower temperatures and avoids the use of acids. It is shown that Li 2 CO 3 is formed with >90% yield at 750 °C by reacting α-spodumene with Na 2 CO 3 and Al 2 O 3 . The addition of Al 2 O 3 is critical to reduce the amount of Li 2 SiO 3 that forms when only Na 2 CO 3 is used, instead providing increased thermodynamic driving force to form NaAlSiO 4 and Li 2 CO 3 as the sole products. We find that this reaction is most effective at 4 h, after which volatility limits the yield. Following its extraction, Li 2 CO 3 can be isolated by washing the sample using deionized water. This energy-saving and acid-free route to obtain Li 2 CO 3 directly from spodumene can help meet the growing demand for Li.