Development of Recovery System for Extracting Silicon Carbide from Photovoltaic Industry Abrasive Slurry

Abstract

Silicon carbide (SiC) is widely employed as an abrasive material in aqueous media for sawing silicon ingot into individual wafers in photovoltaic industry. After a series of cutting, grinding and polishing operation, a mixture of substances (Cutting fluid, SiC, Si and small amount of magnetic metal) is produced as a form of slurry. The used SiC can be preferably recovered and reused for another application, rather than disposed of as waste. In this study, a pilot scale system (25 kg/h) is developed to extract SiC from photovoltaic industry abrasive slurry. The recovery system is composed of physical and chemical separation processes to remove silicon particles and magnetic materials which are dispersed in the slurry. X-ray diffraction analysis showed that purified powder is in the 6H-SiC structure and powder consists only of silicon carbide and has no residual silicon. It might be applied again in silicon ingot cutting or for other purposes which require this kind of ceramic material.

Sustainable ceramics derived from solid wastes: a review

“…Both powders are mixed with a stoichiometric ratio of SiC and then pressed using a uniaxial hot-pressed at 180°C by applying [216] have used shungite (amorphous coal) and steel plant wastes, respectively, to fabricate SiC. Additionally, some studies are found that the recovering of SiC from photovoltaic industry waste [217,218] and Si wafer cutting slurry [219][220][221][222] through different filtration processes like flotation, applied electrical field, hydrocyclone separation, and alkali-acid treatment.…”