title: Mechanical pre-treatment of mobile phones and its effect on the Printed Circuit Assemblies (PCAs).
abstract: The recycling of Waste Electrical and Electronic Equipment (WEEE) has attracted a notable amount of interest during the last few decades due to the high metal concentrations and substantial increase in the growth rate of WEEE. In addition, higher recovery and recycling rates required by the European Union demand more comprehensive treatment of WEEE. However, complex product design and the presence of harmful substances together with low concentrations of special metals present challenges for processing. This study examines the effect of mechanical treatment of mobile phones on metal concentrations in the printed circuit assembly (PCA) fraction compared to manual dismantling. The designed mechanical treatment process including crushing, sieving, magnetic-, eddy current- and sensor-based separation was able to separate plastics, ferrous metals, PCA and stainless steel for further treatment. The process separated PCA with an efficiency of 85%. However, the quality of the separated PCAs was poor compared with "pure" manually dismantled PCAs. The primary crushing of mobile phones destroys PCAs thus resulting in the loss of especially precious metals used in the connector coatings and in the surface-mounted components. As a result, the theoretical value of the produced PCA fraction is only half compared to using manual dismantling. However, high labour costs in western countries and low capacity may hinder the feasibility of hand dismantling.
authors.affiliation: VTT Technical Research Centre of Finland Ltd, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT, Finland. Electronic address: john.bacher@vtt.fi.
authors.forename: J
authors.initials: J
authors.lastname: Bachér
authors.affiliation: Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, Osterfelder Strasse 3, 46047 Oberhausen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Mrotzek
authors.affiliation: VTT Technical Research Centre of Finland Ltd, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Wahlström
mesh_terms: D040421:Cell Phone; D059029:Electronic Waste / Q000032:analysis*; D008670:Metals / Q000032:analysis; D010969:Plastics / Q000032:analysis; D059027:Recycling / Q000379:methods*; D018505:Waste Management / Q000379:methods*
chemical_list: D008670:Metals; D010969:Plastics
keywords: Manual dismantling; Mechanical pre-treatment; Mobile phone; Waste Electrical and Electronic Equipment (WEEE)