The project EarLimet focuses on a primarily hydrometallurgical approach and is being pursued for recycling as completely as possible as a basic prerequisite for closing material cycles in the use of lithium ion batteries. This approach offers numerous of advantages compared to the current predominantly pyrometallurgical processes, since in principle all valuable materials can be recovered. Since lithium in particular is largely lost in conventional recycling processes, it is to be recovered from the black mass right at the beginning of the process chain in order to avoid the dissipation via various material flows of the overall process.
This is achieved by conversion with CO2 forming lithium carbonate which then subsequently can be leached out with water. This allows 95% of the lithium to be recovered in battery quality. Afterwards, remaining non-ferrous metals (cobalt, nickel, manganese, copper) and electrolyte components are chemically leached out and processed to the corresponding pure metals or pure chemical compounds. This is intended to prevent the formation of toxic and climate-damaging emission of fluorine compounds during pyrometallurgical processing, which have received little attention so far. In addition, leaching residues are then treated pyrometallurgically in order to recover still enclosing valuable components, producing a heavy metal-free slag. The suitability of the slag as a concrete constituent is also being investigated. The cost efficiency and resource balance of recycling processes is determined not only by the output of the recyclables and the direct effort required, but also by the use of process chemicals, energy and water. Therefore. this aspect has to be taken into account at an early stage and in EarLiMet a considerable amount of research is carried out on this internal recycling of process chemicals and process water. Finally, a comprehensive material flow balancing is carried out based on partly new analytical concepts, which are also developed in this joint project. Measures for analytical quality assurance will ensure that comparable results are achieved even in the case of assumed high material variability of the black masses to be processed and that the balancing is carried out according to uniform methods.
Since the aim is to achieve complete material recycling, purity of the recovered raw materials for direct reuse (battery grade) as well as minimization of the energy and process chemicals used, the results have enormous practical relevance for recycling companies, battery manufacturers and the environment. This holistic recycling approach will also reducethe dependence on imports of Gewrmany and strengthen the technological competence and competitiveness of local companies.