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

Waste Manag. 2017 Jan:59:422-431. doi: 10.1016/j.wasman.2016.11.011. Epub 2016 Nov 11.

Abstract

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%.

Keywords: Chemical treatment; Glass recovery; Photovoltaic panels; Physical treatment; Recycling.

MeSH terms

  • Aluminum / chemistry
  • Cadmium Compounds / chemistry*
  • Chemical Fractionation
  • Copper / chemistry
  • Environmental Monitoring / methods*
  • Iron / chemistry
  • Metals, Heavy / analysis*
  • Recycling / methods*
  • Silicon / chemistry
  • Silver / chemistry
  • Tellurium / chemistry*
  • Zinc / chemistry

Substances

  • Cadmium Compounds
  • Metals, Heavy
  • Silver
  • Copper
  • Aluminum
  • Iron
  • Zinc
  • Tellurium
  • cadmium telluride
  • Silicon