Modeling and Flow Sheet Simulation of Selected Mechanical Recycling Processes for Li‐Ion Batteries

Abstract

Dedicated to Prof. Dr.-Ing. Joachim Werther on the occasion of his 80th birthdayTo investigate the mechanical processes of Li-ion battery recycling in more detail, models for the different unit processes are to be developed. Here, model approaches for the cutting mill and the zig-zag-sifter are presented. These models are to be used in dynamic flow sheet simulations, with which the individual unit processes as well as the combination to a small process chain were simulated. Thereby, the dynamic interactions between the process steps were investigated, which can be used later for optimization and regulation of the processes. The particle sizes after the cutting mill process as well as the mass flow between the processes influence the separation behavior of the sifter. These changes in the separation function due to an increasing mass flow out of the mill are shown.

Modelling the Sorting of Lithium-Ion Battery Components in a Zig-Zag Air Classifier

“…As shown by Punt et al [27], electrode foils can be described by the model of Tomas and Gröger [24]. However, in these investigations, untreated electrode foils instead of real recycling products have been investigated, and the separation parameter of the plate-like foils has been particle size instead of settling velocity.…”

“…V H are the volume rates for the light and heavy fraction, the separation velocity v T , the settling velocity v s , and the number of effective separation stages z. This modelling was already used for recycled materials like building scrap [26] and battery materials [27]. Punt et al [27] showed flow-sheet simulations involving a ZZAC to separate the separator foil from electrode foils and anode and cathode foils from each other, implementing the model of Tomas and Gröger.…”

“…This modelling was already used for recycled materials like building scrap [26] and battery materials [27]. Punt et al [27] showed flow-sheet simulations involving a ZZAC to separate the separator foil from electrode foils and anode and cathode foils from each other, implementing the model of Tomas and Gröger. In that study, however, the shape of the particles was plate like, and it was not clearly stated whether foils from end-of-life LIBs or production scrap were used.…”

“…In addition, the study admits that the electrode foils were processed separately in a zig-zag air classifier, indicating an idealised experimental design. Consequently, the mixing state in the classifier could not be validated and the effect of the possible interaction of the cathode and anode foils in the separating chamber during their split into heavy and light fractions is therefore neglected in the approach of Punt et al [27]. As a result, the separation can be considered as being too idealised, since important influencing factors were disregarded.…”