Pyrometallurgical Recycling Process Routes – Distribution analysis of valuable metals and the economic consequences

Summary:

Recycling is highly dependent on the material stream to be treated. If the waste stream contains valuable materials, recycling is rewarding, this can change if the amount of valuable materials is reduced. Lithium-ion battery technology is subject to a constant optimization process in which no cell chemistry has yet finally prevailed. However, the potential recycling value depends on the chosen cell chemistry. The following poster demonstrates, with the help of modelling, effects of changes in valuable metal content in cathode material on pyrometallurgical recycling. For the modelling cell systems with varying and not existing cobalt and nickel content have been chosen. It is assumed that batches consisting exclusively of one of the battery systems are treated to clearly highlight the effect of minimizing the valuable material content.

In both process routes considered here, the disassembly of the lithium-ion battery packs takes place down to module/cell level of these packs. The fractions obtained do not differ for different battery cell chemistries. In one of the shown recycling routes (marked as „multi-step“), the batteries are divided into the following material streams by thermal pre-treatment and subsequent mechanical processing: A ferrous fraction, recovering steel scrap, non-ferrous fraction, leading to recovery of copper foil and the active mass. The active mass is then prepared and pyrometallurgically treated. Based on this process step, an alloy containing valuable metals, slag as well as flue dust and waste gas are generated. In the other pyrometallurgical route (marked as „direct“), batteries are melted without prior preparation and separation of fractions. This process also generates an alloy, slag, flue dust and waste gas.

In order to provide a brief insight on economic implications of different battery cell chemistries, potential revenues from selling marketable outputs from the pyrometallurgical recycling process for different battery cell chemistries are shown. These marketable products include alloys produced as well as outputs from mechanical processing in the multi-step route. The calculation is based on the input of one ton of LIB Packs with different cathode material (idealized) and market prices are based on data from 2021. Costs (such as personnel-, investment-, process costs) incurred during the different recycling routes are not considered on the poster.

The results show clear differences in the potential revenues, which can be generated by selling marketable outputs from the pyrometallurgical recycling process, with NMC111 batteries generating the highest revenues in this context. If revenues obtained with recycled products cannot cover the costs of the recycling process, disposer fees will become more relevant in the future. Furthermore, from the recycler’s point of view, it is important to follow the optimization process of lithium-ion battery technology to be able to adapt recycling processes to future material flows.