Lithium Recovery From Lithium Phosphate Using Acid-based Leaching With Additives

초록

This study evaluated three inorganic acids (HCl, HNO3, and H2SO4) and three oxidizing additives (H2O2, KMnO4, and K2S2O8) to determine the optimal leaching conditions for an additive-assisted hydrometallurgical process for efficient and sustainable lithium recovery from insoluble lithium phosphate (Li3PO4). Among the tested conditions, the combination of 0.5 M HNO3 and 0.01 M H2O2 showed the most stable and effective performance, achieving nearly complete lithium (Li) leaching. More than 98.5% of Li was leached within 10 min, and extending the reaction time beyond 30 min did not significantly improve the leaching efficiency. In addition, under the conditions investigated in this study, temperature had little influence on Li leaching, indicating that a high recovery efficiency can be achieved at relatively mild temperatures and with a short reaction time. In contrast, excessively strong oxidizing additives such as KMnO4 and K2S2O8 caused side reactions or reduced process controllability. A life cycle assessment based on the ReCiPe 2016 Midpoint method showed that electricity consumption and HNO3 production were the major environmental hotspots in terms of global warming potential and resource scarcity. These results provide fundamental insights into Li recovery from insoluble lithium compounds and suggest practical directions for simultaneously improving process efficiency and environmental performance.

키워드