Easier recycling of electronic waste

Paul Boughton

Tecnalia Technological Corporation is studying an innovative method based on multispectral artificial vision systems to enhance the value of electronic scrap, which currently represent 4 per cent of urban waste in Europe. Europe generates more than 6.5 million tons of electrical and electronic waste per year, of which more than 90 per cent goes to waste dumps.

The aim of this project, known as Sormen, is to develop a technology for the separation of scrap metal from electronic waste based on a multispectral vision system and incorporate it into a recycling plant. This new machine overcomes the limitations of current, essentially manual, methods that are labour-intensive and time-consuming, and which are unable to separate metals whose characteristics of colour, shape and weight are similar.

The solution proposed by Tecnalia enables elements of the same colour - such as aluminium, nickel or stainless steel to be separated so they can be recycled. It represents a highly significant advance over other techniques of separation based on colour vision and is useful for other processes such as separating lead impurities from copper, for example. In the case of aluminium, the Tecnalia system will enable 30 and 40 per cent more of this metal to be recovered.

To make the recycling of electronic products more economic, it is important to have machines that can automatically identify each one of the elements in a non-destructive manner. Moreover, in this way it will be less contaminating for the environment and workers will not be exposed to the emission of substances that could be damaging to health.

Metals such as aluminium or stainless steel are impossible to separate by colour, so this is where multispectral identification comes in. This technique is based on the fact that each pure metal has a unique spectral reflectivity response. Unlike colour cameras, multi- and hyper-spectral systems can appreciate multiple bands, from ultraviolet to infrared, with very good resolution of up to 2.5nm between bands. This versatility makes it possible to detect, classify and identify different materials, thereby overcoming some of the limitations of colour cameras that operate in the visible range.

The application of this type of technology to the classification of metals is the novel approach. It is expected that in 2015, although it is estimated that electrical and electronic waste generated annually will double to 12 million tons, the amount of material recycled will rise significantly.

Apart from Tecnalia, taking part in this project are the CSL technological centre at the University of Liège (Belgium), the recycling companies Indumental Recycling (the Basque Country) and Ige Hennemann (Germany), the recycling machine manufacturer Hevac Ambient (Barcelona), the Specim multispectral system designers (Finland) and the Aclima Environment Cluster (the Basque Country).

For more information, visit www.basqueresearch.com/berria_irakurri.asp?hizk=I&Berri_Kod=1778