Fine mixture characterization by hyperspectral imaging (HSI) in weee demanufacturing plants

Waste from Electric and Electronic Equipment (WEEE) represent the fastest growing waste stream in Europe. The large amount of high values material (i.e. key metals) in these End of Life products, increases the industrial interests in WEEE recycling. Despite the evident economical potentialities of this sector, the high products variability and complexity make the WEEE recycling processes a challenge task, especially considering that mechanical processes currently used by recycling companies are extremely rigid and that the on-line control strategies are not integrated in such a plants. In fact, if the continuous technological evolution increases the complexity of products, requiring the integration of proper control technologies for the characterization of fine particles mixtures, on the other hand, the variability of EoL products calls for the integration of optimization strategies in order to ensure process reconfigurability. In this context, the implementation of a HyperSpectral Imaging (HSI) system can represent a suitable technology able to improve the WEEE recycling efficiency, supporting the process control, operation and reconfiguration. This work presents a detailed step-by-step description of research activities supporting the development of a HSI classification module for fine particles mixtures (lower than 2 mm) characterization of shredded EoL products. An example application of HSI system, implemented at the Demanufacturing Pilot Plant at ITIA-CNR, is presented.The application integrates both hardware and software systems to improve the process recycling rates and the output products quality, gathering in-line data about the processed mixture composition using HSI system and adjusting the parameters of the downstream electrostatic separation process according to the specific mixture under treatment. The preliminary experimental results, obtained by processing shredded Printed Circuit Boards (PCBs), show that a considerable improvement in the output recovery can be achieved by applying an intelligent mechanical separation process. These results pave the way to a next generation of highly adaptable demanufacturing systems.