Manganese Recovery from Succinic Acid Leach Liquor of Spent Lithium-Ion Batteries Black Powder by Solvent Extraction

The applicability of organophosphorus extractants (D2EHPA, P-507, and Cyanex 272) for the selective separation of Mn, Co, Ni, and Li from the succinic acid leach liquor of cathode material of spent lithium-ion batteries (LIBs) was investigated. Extractant P-507 exhibited superior selectivity in separating Mn from Ni and Li, with separation factors of βMn/Ni = 145.2 and βMn/Li = 130.0, surpassing D2EHPA (71.0 and 70.5). Slope analysis and infrared spectroscopy indicated that Mn extraction by P-507 proceeds via a cation exchange mechanism, while succinic acid acts as a buffer and stabilizes the equilibrium pH. Optimization of process parameters revealed that the concentration of P-507 in the diluent affects Mn recovery and its separation from Ni and Li, whereas temperature and contact time have negligible effects. Scrubbing of the loaded organic phase with 6 g L^–1 MnSO₄ removed 60% of Co and 98% of Ni/Li. Mn stripping exceeding 97% was achieved in a single stage using 50 g L^–1 H₂SO₄ at an O : A ratio of 2 : 1. These results confirm the potential of P-507 for the development of sustainable metal recovery technology from secondary sources.