Selective lithium recovery from LFP-Type black Mass: Comparative evaluation of inorganic and organic acid systems under Constant-pH leaching conditions

significantly improved efficiency. Oxalic acid dissolved Li completely but lacked selectivity due to ferrioxalate complexation. Acetic acid delivered the best overall performance, achieving 96% Li recovery with negligible Fe (<0.1%) and minimal P (3%) dissolution at pH 4.3 and 25 °C. Cost analysis showed that while sulfuric acid is least expensive, acetic and hydrochloric acids offer the best balance of selectivity, efficiency, and safety. This study provides a unified framework for evaluating leaching systems and demonstrates that selective lithium recovery from LFP can be achieved under mild, low-acid conditions with minimal environmental impact.