Enhanced metals separation for electronics recycling
All objects reflect, absorb or emit electromagnetic (EM) radiation based on their specific compositions. Multi- and hyper-spectral imagers evaluate the spectral ‘fingerprint’ of materials enabling identification of components. European researchers set out to employ spectral technology for the separation of metals in waste from electric and electronic equipment (WEEE). The EU-funded Sormen project focused on overcoming shortcomings of current separation technology that is primarily manual and thus labour and time intensive as well as incapable of producing pure recycled materials. Non-ferrous metals such as aluminium, copper and lead account for approximately 13 % of total WEEE weight. Current recyclation technology produces waste fractions of small size that still contain significant quantities of non-ferrous metals and stainless steel, decreasing the value of the scrap and thus the price at which it can be sold by the recycling small and medium-sized enterprises (SMEs). Researchers developed a classification algorithm for use with multi- and hyper-spectral analysis capable of perfectly separating metals in a sample. Such classification was previously unattainable manually for metal pieces of similar shape, size and colour in the visible spectrum such as is the case with aluminium and stainless steel. The algorithm was integrated with a camera, an illumination module, a feeder-transportation-separation module and a controller producing a fully automated system for separation of non-ferrous metals from WEEE as well as the capability of separating aluminium from stainless steel previously impossible with conventional methods. Sormen project researchers thus delivered an automated system for separation of metals in WEEE. The system has the potential to significantly increase the competitiveness of European recycling SMEs via reduction in processing and labour time as well as enhancement in purity of final product, enabling resale at a higher price. In addition, commercialisation of the method could help reduce costs associated with destruction, disposal and land filling, and contribute to sustainability of the huge worldwide electric and electronic components sector.
