The installation of PV modules was 97.9GW and the accumulation volume of PV device was 500GW in 2018 According to the research, the accumulation of waste modules will reach to 8600 tons in 2030 as the result of the life expectancy of PV modules. Moreover, Crystalline-Silicon solar panels account for 90% of the waste. This study recycles photovoltaic solar cells by leaching and extraction. According to the analyst, Silicon cells content 90% of Si, 0.7% of Ag, and 9.3% of Al. Silicon cells were leached by 4M nitric acid at 80°C for 4 hours then 3M sodium hydroxide at 70°C for 3 hours, and the leaching efficiency were 99.7% of Ag, and 99.9% of Al, respectively. Leaching process separated Silicon from others metal. Na-Cyanex 272 in kerosene was employed to separate Al from Ag. The efficiency of extraction is 96%. After the process of extraction, 1M hydrochloride acid was employed to strip Al from the organic solvent. The efficiency of stripping is 99.9%. After extraction process, Ag was remained in the aqueous phase and precipitated to AgCl. In conclusion, this study shows the optimal parameters of the leaching steps, extraction steps, precipitation and vaccum concentration to get the product. The recovery of Si and Ag were 99.5% and 98% respectively.
50 billion cubic meters of brine every year creates ecological hazards to the environment. In order to reuse brine efficiently, rubidium and cesium were recovered in this experiment. On the other hand, the main impurities which were needed to be eliminated in brine were lithium, sodium, potassium, calcium, and magnesium. In the procedure, seawater was distilled and evaporated first to turn into simulated brine. Perchloric acid was then added into simulated brine to precipitate potassium perchlorate which could reduce the influence of potassium in the extraction procedure. After that, t-BAMBP and ammonia were separately used as extractant and stripping agent in the extraction and stripping procedures to get rubidium hydroxide solutions and cesium hydroxide solutions. Subsequently, they reacted with ammonium carbonate to get rubidium carbonate and cesium carbonate. In a nutshell, this study shows the optimal parameters of pH value to precipitate potassium perchlorate. Besides, pH value in the system, the concentration of t-BAMBP and ammonia, organic phase/aqueous phase ratio (O/A ratio), reaction time, and reaction temperature in solvent extraction step were investigated to get high purities of rubidium carbonate and cesium carbonate.
With the dramatic increase of photovoltaic (PV) module installation in solar energy-based industries, the methods for recovering waste solar generators should be emphasized as the backup of the PV market for environmental protection. Crystalline-silicon accounts for most of the worldwide PV market and it contains valuable materials such as high purity of silicon (Si), silver (Ag), copper (Cu), tin (Sn), and lead (Pb). This study can provide an efficient recycling process for valuable materials resourced from waste crystalline-silicon PV module, including Si in the PV cell, and Ag, Cu, Pb, Sn, in PV ribbon. As tempered glass and Ethylene Vinyl Acetate (EVA) resin were removed, the module was separated into two materials, PV ribbon and PV cell. For PV cell purification, Si with purity at 99.84% was recovered by removing impurities such as aluminum (Al) and Ag by two-step leaching and dissolving the impurities. For PV ribbon recovering, purified metal or metal oxide was obtained through the processes of leaching/polishing, extraction, and chemical precipitation. In the polishing process, 99.5% of copper wire was collected. The purities of final products are 99.7% for CuO, 99.47% for PbO, 99.68% for SnO2, and 98.85% for Ag respectively.
With rapidly increasing production and installation, recycling of PV modules has become the main issue. In this study, we developed the application to recover the tempered glass from panels and remove Ethylene-vinyl acetate (EVA) from PV cells. The processes divided into two parts, organic solvents soaking and thermal treatment. In the organic solvents process, this study soaked PV modules into organic solvents to dissolve EVA resin and recover tempered glass. In the thermal treatment, this study removed EVA resin remaining on the PV cell. This study can comprehensively recover tempered glass and remove 99.97% EVA resin from PV cell. Moreover, it can contribute to not only subsequent leaching processes but also the environment and humankind health.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.