Thermochemically driven crystal phase transfer via mechanical activation-assisted chlorination roasting toward the selective extraction of lithium from spodumene

Abstract

With the rapid advancement and widespread application of lithium-ion batteries, the demand for lithium experiencing a precipitous surge. Hence, there is an increased emphasis on lithium extraction from spodumene deposits. However, the sustainable expansion of the lithium industry encounters challenges. Conventional processes suffer from drawbacks such as elevated transformation temperatures, high acid consumption, and challenges in leachate purification. In response to these challenges, this work proposes a selective and efficient lithium extraction process from α-spodumene through the combined approach of mechanical activation-assisted chlorination roasting and water leaching. Utilizing density functional theory (DFT) calculations to tailor chloride salts for the thermal treatment of spodumene, the combination of thermal behavior characterization and thermochemical calculations indicates the favorable propensity of CaCl₂ and its hydrates for preferential reactions. Through the amalgamation of mechanical activation and chlorination roasting, the outcomes reveal that mechanical activation could reduce the phase transition temperature. Following a 3-hour activation period, a complete chlorination reaction is achievable at 900℃, yielding a lithium extraction efficiency of 91.34%. This endeavor holds the potential to furnish novel insights into the mechanism of selectively extracting chlorination roasting, thereby offering promising avenues for developing environmentally sound and selectively efficient technologies for lithium extraction from spodumene.