Flue gas induced lithium carbonate crystallization from industrial black mass

Spent lithium-ion batteries (LIBs) are a valuable secondary source of lithium, but conventional recovery methods using sodium carbonate (Na₂CO₃) often result in sodium contamination, limiting the purity of recovered lithium carbonate (Li₂CO₃). The present study introduces a novel process for lithium recovery from industrial black mass (BM) using a CO₂ blend, which addresses the issue of sodium contamination. Lithium was selectively extracted from an industrial black mass through water leaching. The feasibility of Li₂CO₃ crystallization with CO₂ blend injection was first demonstrated using synthetic lithium hydroxide (LiOH), revealing that high reaction temperatures and precise pH control are essential for maximizing lithium recovery, with optimal recovery occurring near the pH maximum. In-situ focused beam reflectance measurement (FBRM) confirmed Li₂CO₃ dissolution during excess CO₂ injection. Finally, Li₂CO₃ was recovered from the concentrated water leachate via gas-liquid reactive crystallization using the CO₂ blend, achieving a purity exceeding 99.8 %.