Speciation of Manganese in a Synthetic Recycling Slag Relevant for Lithium Recycling from Lithium-Ion Batteries

Lithium aluminum oxide has previously been identified to be a suitable compound recover lithium (Li) from Li-ion battery recycling slags. Its formation is hampered in the presence of high concentrations manganese (9 wt.% MnO2). In this study, mock-up slags system Li2O-CaO-SiO2-Al2O3-MgO-MnOx with up 17 mol% MnO2-content were prepared. The (Mn)-bearing phases characterized inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray diffraction (XRD), electron probe microanalysis (EPMA), and absorption near edge structure analysis (XANES). XRD results confirm decrease LiAlO2 Mn-poor (7 MnO2) Mn-rich (17 grains are predominantly present as idiomorphic relatively large (>50 µm) crystals. XRD, EPMA XANES suggest that form spinel solid solution. absence light elements besides Li O allowed estimate content grain, determine generic stoichiometry solution, i.e., (Li(2x)Mn2+(1?x))1+x(Al(2?z),Mn3+z)O4. coefficients x z determined at several locations grain. It shown concentration decreases, while increases start (x: 0.27; z: 0.54) end 0.34; 1.55) crystallization.