Contact person: Sima Hellmers
One of the options for recycling lithium-ion batteries is direct pyrometallurgical processing of whole cells. An advantage of this process is the high robustness and the chance to continuously process the changing cell generations/cell chemistries together or in changing mixtures.
From experience, it is known that under suitable furnace operating conditions Co, Ni, Cu and portions of Fe and Mn are transferred to the molten metal. The C carriers are burned, F is expelled into the dust and waste gas stream. Li and Al can be quantitatively transferred to a Ca- and Si-containing slag. However, it should be possible to concentrate Li with suitable process control, and, if necessary, it is also possible to concentrate and recycle other valuable metals with an affinity for slag. By appropriate processing, the valuable metals concentrated in artificial mineral phases can be separated and a residual slag suitable for building material applications is to be produced. It is planned to separate the valuable material, in this case initially Li, from the pre-concentrates using hydrometallurgical methods and to purify it to such an extent that the product is suitable for battery production as raw material .
Within the scope of this project, iPAT will deal with the targeted processing of the slags. In principle, the first questions are to understand the interrelationships between the synthesized slag structure, the associated fracture properties of the slag particles, the loading mechanism used in the comminution machine and the resulting comminuted product. The aim of these investigations is to enrich certain valuable phases of the slags (e.g. LiAlO2 crystals) in defined fractions of the comminution product. The additional use of separation stages is intended to evaluate whether the valuable substances can be enriched in such a way that they can be fed to a further hydrometallurgical treatment as a pre-concentrated intermediate product. The work is rounded off by the modeling of the combined comminution and separation process and the establishment of material-process-property relationships so that the process can be adjusted according to the slag composition.
