Trials focus on WEEE separation

Archiv – United Kingdom | Research agency Axion Consulting has trialled the most promising techniques for difficult separations of waste electrical and electronic equipment (WEEE).
The study, commissioned by the UK’s Waste & Resources Action Programme (WRAP), focused on techniques that have emerged over the past three to four years since the UK began to reprocess significant volumes of WEEE. Techniques with the potential to improve the effectiveness and commercial viability of WEEE recycling processes were selected for the project.United Kingdom | Research agency Axion Consulting has trialled the most promising techniques for difficult separations of waste electrical and electronic equipment (WEEE).
The study, commissioned by the UK’s Waste & Resources Action Programme (WRAP), focused on techniques that have emerged over the past three to four years since the UK began to reprocess significant volumes of WEEE. Techniques with the potential to improve the effectiveness and commercial viability of WEEE recycling processes were selected for the project.
The trials demonstrated techniques that could be used to separate and process mixed WEEE plastics and evaluated the techniques in terms of their ability to sort material by polymer type, colour and/or to remove impurities. Four types of technique were trialled: sensor-based separators; shape and density separators; separation by impact milling; and effect of particle size distribution. Tested equipment included: the TiTech Polysort RTT Unisort Flake NIR sorter; the Visys Spyder laser sorter; the Allmineral wet jig; the Delft University Kinetic Gravity Separator; the Holman Wilfley wet shaking table; the University of Nottingham dry jig; the Allmineral Allflux upflow classifier; the Pallmann differential impact mill; and the Alvan Blanch Destoner.
Axion concluded that, with certain conditions, the TiTech NIR sorter would recoup its initial investment within three years whereas the Delft University Kinetic Gravity Separator, the Holman Wilfley wet shaking table and the Allmineral Allflux upflow separator would pay back on the initial investment within two years. The Visys laser sorter, while producing a concentrated circuit board fraction with good separation efficiency, was deemed not economically viable at the present time given the low current market value of circuit boards.
Axion Director Roger Morton comments: ’We expect the results of these trials will be of great use to both primary and secondary WEEE processors facing the technical and economic challenges of reprocessing WEEE materials. The information on the demonstrated techniques will help to improve the efficient and effective reprocessing of this potentially difficult-to-handle waste stream.’