Determination of the Li Distribution in Synthetic Recycling Slag with SIMS

Abstract

The recovery of technically important elements like lithium from slag of pyrometallurgical recycling of lithium traction batteries will be very important in future due to the expected increasing demand of this element with the upcoming world-wide implementation of electro mobility. Therefore, the investigation of possibilities to recover lithium from pyrometallurgical slag from the recycling of lithium traction batteries is mandatory. In this context, the EnAM (engineered artificial mineral) approach is very promising. Solidified melt of synthetic recycling slag with the compounds Li2O-MgO-Al2O3-SiO2-CaO-MnO contains various Li-bearing phases including spinel solid solution, Li-aluminate and eucryptite-like Li-alumosilicate. Most probably, the Ca-alumosilicate matrix (melilite-like solid solution) incorporates lithium as well. These compounds can be determined and calculated to an acceptable approximation with electron probe microanalysis (EPMA). Nevertheless, an adequate precise measurement of lithium is virtually impossible due to the extremely low fluorescence yield and long wavelength of Li Kα. Secondary mass spectrometry (SIMS) can be used to fill this gap in the analytical assessment of the slag. Therefore, the combination of these two analytical methods can distinctively improve the mineralogical and chemical characterization of lithium-containing solidified (slag) melt.

Characterisation of the Grain Morphology of Artificial Minerals (EnAMs) in Lithium Slags by Correlating Multi-Dimensional 2D and 3D Methods

“…Provided that the phase of interest is lithium aluminate (LiAlO 2 ), the assumption that only Al is present in the element map is used. Despite the thermochemical simulation in Table 3 predicting another Li-Al species (LiAl 5 O 8 ), it is expected that the experimental slag will incorporate LiAlO 2 as the main potential Li-Al species [28].…”

“…Consequently, the thermochemical outcomes may not accurately represent the actual experimental results. Based on prior studies on similar slag systems [8,20,21,27,28], it was observed that only LiAlO 2 , as a Li-Al species, is identified in the experimental slag. It is worth noting that LiAl 5 O 8 , while theoretically plausible, is not found in the system based on these mentioned studies.…”

“…Further downstream liberation also affects the hydrometallurgical extraction of lithium, which uses flotation as a pre-concentration step and is one of the prevalent methods for lithium extraction [15]. Some research has been carried out into artificial lithium slag systems, focusing on the phase composition and speciation [20,21,27,28]. Pure ingredients are used in the artificial slag to provide a synthetic model material with the valuable phase formation in the slag, EnAM, respectively.…”

Control of Interface Migration in Nonequilibrium Crystallization of Li2SiO3 from Li2O–SiO2 Melt by Spatiotemporal Temperature and Concentration Fields

“…The new approach is applied to the oxidic system Li 2 O–SiO 2 since it forms an important subsystem of the multicomponent lithium containing slag that is increasingly generated from Li-ion battery processing industries. Such a slag system has garnered much interest among the scientific community as a potential source for Li recycling. , However, the interplay of complex kinetics influenced by varied process conditions hinders, to some extent, controlled solidification evolution of the melt system of interest or in other words achieving the desired element recovery. Engineering particular crystals out of the slag with a high concentration of the element of interest can only be performed when the internal process kinetics can be understood and tailored according to external process parameters in terms of heat extraction profiles.…”