Sustainable technology for mass production of Ag nanoparticles and Al microparticles from damaged solar cell wafers. (October 2019)

• Record Type: Journal Article
• Authors: Yousef, Samy; Tatariants, Maksym; Tichonovas, Martynas; Makarevicius, Vidas
• Is Part Of: Waste management. Volume 98(2019)
• Page Start: 126
• Page End: 134
• Publication Date: 2019-10
• Subjects: Waste solar cell wafers -- Recycling -- Eco-friendly solvents -- Leaching -- Etching -- Circular economy; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2019.08.019
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: Al layer was disintegrated from damage solar cells using DMSO solvent. Leaching process was used to recover Ag nanoparticles from damage solar cells. Etching process was used to purify Si substrate. Al, Ag, and Si were recovered with yield 98.2%, 92.4%, and 99.8% respectively. GHG was reduced by −8099 kg CO2-eq /ton by the suggested technology. Abstract: Solar cell industry produces high quantities of waste in form of broken, damaged, and rejected cells, whereas milling and filtering practices are typically used to recover the valuable materials (Al, Ag and Si) from such Waste Solar Cell Wafers (WSCWs). This recycling approach has its disadvantages, e.g. excessive energy consumption and dust emission causing loss of valuable metals. To fulfil the concept of Zero Waste for WSCWs, the authors present a sustainable technology for liberation of valuable metals from WSCWs and synthesis of added value products, in particular Ag nanoparticles and Al microparticles. The suggested technology consisted of three different approaches combined to liberate each material individually. The technology started with an Al layer disintegration process using Dimethyl Sulfoxide (as an eco-friendly and sustainable solvent) supported by ultrasonic treatment to break van der Waals' bonding between spherical Al microparticles that compose the Al paste layer, thus liberating Al in microparticle suspension form with particle size ∼3 μm, recovery rate >98%. After that, leaching by nitric acid and other eco-friendly reagents (Sodium Chloride, Ammonia solution and glucose syrup) assisted by ultrasonic treatment was used to dissolve Ag and later precipitate it in form of nanoparticles with avg. size 30 nm, yield >92%. Finally, etching using paste containing phosphoric acid was done to remove anti-reflection coating and purify the Si substrate with final recovery rate >99%. SEM-EDS, XRD, FTIR, and TEM were used for analysis of extracted materials as well as changes in the solvent. Investigation was also concerned with determining economic/global warming impacts of the technology.