Physical and chemical treatment of end of life panels: An integrated automatic approach viable for different photovoltaic technologies

• Published in: Waste management (Elmsford) Vol. 59; pp. 422 - 431
• Main Authors: Pagnanelli, Francesca, Moscardini, Emanuela, Granata, Giuseppe, Abo Atia, Thomas, Altimari, Pietro, Havlik, Tomas, Toro, Luigi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.01.2017
• Subjects: Acid leaching; Aluminum - chemistry; Automation; Cadmium; Cadmium Compounds - chemistry; Chemical Fractionation; Chemical treatment; Copper - chemistry; Crushing; Environmental Monitoring - methods; Fragments; Glass; Glass recovery; Heat treatment; Iron - chemistry; Metals, Heavy - analysis; Panels; Photovoltaic panels; Physical treatment; Recycling; Recycling - methods; Silicon - chemistry; Silver - chemistry; Tellurium - chemistry; Zinc - chemistry; Photovoltaic panels; Recycling; Chemical treatment; Glass recovery; Physical treatment
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2016.11.011

•Si and CdTe panels were treated by the same process route.•Physical treatment by crushing and thermal treatment of >1mm fraction (62% w/w).•Fe, Al and Zn are concentrated in 0.08–0.4 and <0.08mm fractions (22% w/w).•Leaching of the 0.08–0.4mm fraction allows reaching 91% w/w glass recovery.•Ag, Ti, Te, Cu and Cd are concentrated in <0.08mm fraction (3% w/w). Different kinds of panels (Si-based panels and CdTe panels) were treated according to a common process route made up of two main steps: a physical treatment (triple crushing and thermal treatment) and a chemical treatment. After triple crushing three fractions were obtained: an intermediate fraction (0.4–1mm) of directly recoverable glass (17%w/w); a coarse fraction (>1mm) requiring further thermal treatment in order to separate EVA-glued layers in glass fragments; a fine fraction (<0.4mm) requiring chemical treatment to dissolve metals and obtain another recoverable glass fraction. Coarse fractions (62%w/w) were treated thermally giving another recoverable glass fraction (52%w/w). Fine fractions can be further sieved into two sub-fractions: <0.08mm (3%w/w) and 0.08–0.4mm (22%w/w). Chemical characterization showed that 0.08–0.4mm fractions mainly contained Fe, Al and Zn, while precious and dangerous metals (Ag, Ti, Te, Cu and Cd) are mainly present in fractions <0.08mm. Acid leaching of 0.08–0.4mm fractions allowed to obtain a third recoverable glass fraction (22%w/w). The process route allowed to treat by the same scheme of operation both Si based panels and Cd-Te panels with an overall recycling rate of 91%.