Metal removal from silicon sawing waste using the electrokinetic method

Review on feasible recycling pathways and technologies of solar photovoltaic modules

“…Tsai et al [34,35] examined the feasibility of adopting the electrokinetic method to remove metal from sawing waste. Exactly how an applied electrical field and its duration affect metal removal efficiency was carefully studied.…”

“…Filtration [23] c-Si ☑ Efficient ☑ Capable of filtering small inclusion particles ☒ Contamination from the filter must be reduced before filtration can be used in industrial practice Centrifugation [24,25] ☑ High purity of recovered silicon ☒ Toxic heavy liquid used ☒ Slow process ☒ Unable to remove submicron SiC particles Phase-transfer separation [26] ☑ High purity and yield of recovered silicon ☑ No toxic heavy liquid used ☑ Efficient and economic Electrophoresis and gravitational settling [28] ☑ High efficiency of Si/Al 2 O 3 separation ☒ Contamination of Al in the recycled silicon Electrical field [27] ☑ High efficiency of Si/SiC separation ☑ No toxic heavy liquid used ☒ Pretreatment of metal impurity removal required Al-Si alloying [29] ☑ Complete removal of SiC ☒ Complicated process Hydrobromination [30] ☑ Recovery high-purity Si without SiC removed first Supercritical water [31] ☑ Recovery of high-purity Si from oily silicon ingot cutting wastes Sedimentation and leaching [32] ☑ Separation of Si and SiC using physical methods ☑ Less-complicated process and easier for industrial application Czochralski mono c-Si process [33] ☑ Low energy consuming ☒ Recovery of mono c-Si ☒ Boron concentration to be lowered for better cell efficiency Electrokinetic separation [34,35] ☑ High removal efficiency of iron fragments in slurry wastes ☑ No use of additive chemicals Hydrometallurgy: oxidation, evaporation, reduction by inorganic reducing agents [36] Thin film (CIGS) ☑ Recovery of high-purity selenium able to be used directly into new solar cells Hydrometallurgy: dissolution, filtration, liquid-liquid extraction, stripping, precipitation electroplating [37] Thin film (CIS) ☑ Recycling of mixed CIS wastes ☑ Use of standard hydrometallurgical processes and chemicals ☑ Recovery of pure indium ☒ Further process refinement needed and metals are separated manually. Glass and metal are sent for recycling.…”

A Revival of Waste: Atmospheric Pressure Nitrogen Plasma Jet Enhanced Jumbo Silicon/Silicon Carbide Composite in Lithium Ion Batteries

“…The active materials were mixed with 10 wt % of carbon black and 15 wt % of sodium alginate. For electrochemical characterizations, the mass loading of the active materials was 0.18−0.25 mg/cm −2 and electrode density was 0.05−0.2 g/cm 3 . The slurry was then casted onto a copper foil by using a cladding process, and the as-prepared electrode was subsequently treated with (N-APPJ).…”

“…1,2 Most cells are produced from silicon (Si) ingots after wafer cutting by wire sawing. 3 However, such processes yield numerous particle wastes including the remains of Si ingots (approximately several hundred nanometers), abraded silicon carbide (SiC) microparticles from cutting wire, and slicing fluid contaminants. 4 In recent years, to reduce the sustained growth of wafer slicing wastes, waste processing has become a major topic in recent years, especially the application of purified wastes.…”

“…Practical solutions are being implemented for resolving green energy problems, and related technologies are entering a vigorous development stage. Demands for photovoltaic cells are growing with the advancements in renewable energy technologies, particularly for solar power industries. , Most cells are produced from silicon (Si) ingots after wafer cutting by wire sawing . However, such processes yield numerous particle wastes including the remains of Si ingots (approximately several hundred nanometers), abraded silicon carbide (SiC) microparticles from cutting wire, and slicing fluid contaminants .…”