Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Slags from the metallurgical recycling process are an important source of resources classified as critical elements by the EU. One example is Lithium from Li-ion battery recycling. In this context, the thermodynamic properties of the recycled component system play a significant role in the formation of the Li-bearing phases in the slag, in this case, LiAlO2. The LiAlO2 crystal formation could be engineered and result in varying sizes and occurrences by different metallurgical processing conditions. This study uses pure ingredients to provide synthetic model material used to generate the valuable phase in the slag, or so-called engineered artificial minerals (EnAMs). The goal is to study the crystallisation of the LiAlO2 as EnAM by controlling cooling conditions of the 23
model slag to optimise the EnAM formed during crystallisation. Characterisation of the EnAMs is an important step before further mechanically processing the material to recover the valuable element Li, the Li bearing species respectively. Investigations with powder X-ray diffraction (XRD), X-ray fluorescence (μXRF), and X-ray Computer Tomography (XCT) of two different artificial lithium slags from MnO-Al2O3-SiO2-CaO systems with different cooling temperature gradients show the different EnAM morphology along the height of the slag that is formed with different slag production condition in a semi-pilot scale experiment of 5 kg. Three defined qualities of the EnAM are identified based on the different EnAM morphologies, which show granular shape, dendritic shape, or by imaging techniques hardly visible EnAM structures.