Leaching of NMC industrial black mass in the presence of LFP

This study focuses on the effect of an emerging source of waste, lithium iron phosphate (LFP) cathode materials, on the hydrometallurgical recycling of the currently dominant industrial battery waste that is rich in transition metals (Ni, Co, Mn, and Li). The effects of the dosage of LFP, initial acidity, and timing of LFP reductant addition were investigated in sulfuric acid (H2SO4) leaching using conditions of time at 3 hours, temperature at 60 °C, and rotation at 300 rpm. The results demonstrated that the addition of LFP increased both transition metal extraction and acid consumption. Furthermore, the redox potential was lowered due to the increased presence of Fe2+. An initial acidity of 2.0 mol/L H2SO4 with an acid consumption level of 1.3 kg H2SO4/kg black mass provided optimal conditions for achieving a high leaching yield of 100% for Co, 87.6% for Ni, 91.1% for Mn, and 100% for Li, while also creating process solutions with concentrations of Co at 8.8 g/L, Ni at 13.8 g/L, Li at 6.7 g/L, Mn at 7.6 g/L, and P at 12.1 g/L.