A simulation model of the comminution–liberation of recycling streams: Relationships between product design and the liberation of materials during recycling

Abstract

End-of-Life (EOL) products can be considered to be industrial ores, since the minerals (materials can be considered as minerals) contained are recovered, processed and reintroduced in the material production systems as industrial ores. Therefore, the principles used in classical minerals processing can be applied to describe the comminution and liberation of EOL products during recycling. Similarly as for natural ores, particle size reduction and liberation have an important role in the quality of the recycling streams and on the possibilities for their further processing and reintroduction in the resource cycles. A simulation model is presented that describes the relationships between product design and the liberation level attained by shredding. The model simulates the comminution and liberation phenomena as a function of the product design variables. From the analysis of experimental samples, sensitivity analysis and simulations, relationships are illustrated and discussed. The breakage behaviour of End-of-Life (EOL) products differs largely from these natural minerals. Therefore, although many definitions can be adapted from classical minerals processing, a different approach is required in the modelling of the comminution–liberation of EOL products. This is the first step in the development of these type of models, and much experimental work is required for further development. The simulation results using a passenger vehicle as example show that during product design, the materials and joints among them can be chosen to obtain the best possible liberation and the lowest possible contamination. Therefore, industrial ores can be ‘designed’ for recycling, to reduce recycling losses and optimise resource efficiency. The aim is to implement this knowledge in the product design stage of defining materials and connections.