title: Recycling of WEEE: characterization of spent printed circuit boards from mobile phones and computers.
abstract: This paper presents a comparison between printed circuit boards from computers and mobile phones. Since printed circuits boards are becoming more complex and smaller, the amount of materials is constantly changing. The main objective of this work was to characterize spent printed circuit boards from computers and mobile phones applying mineral processing technique to separate the metal, ceramic, and polymer fractions. The processing was performed by comminution in a hammer mill, followed by particle size analysis, and by magnetic and electrostatic separation. Aqua regia leaching, loss-on-ignition and chemical analysis (inductively coupled plasma atomic emission spectroscopy - ICP-OES) were carried out to determine the composition of printed circuit boards and the metal rich fraction. The composition of the studied mobile phones printed circuit boards (PCB-MP) was 63 wt.% metals; 24 wt.% ceramics and 13 wt.% polymers; and of the printed circuit boards from studied personal computers (PCB-PC) was 45 wt.% metals; 27 wt.% polymers and ceramics 28 wt.% ceramics. The chemical analysis showed that copper concentration in printed circuit boards from personal computers was 20 wt.% and in printed circuit boards from mobile phones was 34.5 wt.%. According to the characteristics of each type of printed circuit board, the recovery of precious metals may be the main goal of the recycling process of printed circuit boards from personal computers and the recovery of copper should be the main goal of the recycling process of printed circuit boards from mobile phones. Hence, these printed circuit boards would not be mixed prior treatment. The results of this paper show that copper concentration is increasing in mobile phones and remaining constant in personal computers.
authors.affiliation: Department of Metallurgical and Materials Engineering, University of São Paulo, Av. Prof. Mello Moraes, 2463 São Paulo, SP 05508-030, Brazil. lucianayamane@uol.com.br
authors.forename: Luciana Harue
authors.initials: LH
authors.lastname: Yamane
authors.forename: Viviane Tavares
authors.initials: VT
authors.lastname: de Moraes
authors.forename: Denise Crocce Romano
authors.initials: DC
authors.lastname: Espinosa
authors.forename: Jorge Alberto Soares
authors.initials: JA
authors.lastname: Tenório
mesh_terms: D040421:Cell Phone; D002516:Ceramics / Q000032:analysis; D003201:Computers; D003300:Copper / Q000032:analysis*; D006851:Hydrochloric Acid; D008280:Magnetics; D017942:Nitric Acid; D010316:Particle Size; D011108:Polymers / Q000032:analysis; D059027:Recycling / Q000379:methods*; D055672:Static Electricity; D014866:Waste Products
chemical_list: D011108:Polymers; D014866:Waste Products; D017942:Nitric Acid; D003300:Copper; D006851:Hydrochloric Acid; C022102:aqua regia