The influence of particle size reduction and liberation on the recycling rate of end-of-life vehicles

Abstract

Particle size reduction and liberation of materials during the shredding of modern end-of-life products plays an important role in the composition (and quality) of the intermediate recycling streams and the ultimate material recovery and therefore recycling rate. This affects among others the realisation of the EU legislation, which imposes a recycling rate of 95% on the recycling of passenger vehicles to be achieved in 2015. In this paper a model is discussed describing the relationship between product ‘mineralogy’; and particle size reduction and liberation during shredding and recycling of end-of-life vehicles. This is partly based on the modelling techniques applied in traditional minerals processing demonstrating how classical theory can be applied to solve modern problems. The model describes the influence of breakage on mechanical separation efficiency and material recovery in metallurgical processing for the various materials present in the car. The model has been developed in order to optimise material recovery and to minimise waste generation in recycling of end-of-life vehicles. It is illustrated that the modelling of the breakage behaviour for modern consumer products differs fundamentally from traditional minerals processing based on various simulations presented in this paper. Moreover various theoretical simulations will illustrate the effect of changes in product design and hence particle size reduction and liberation on the recycling of end-of-life vehicles.