Synthesis of Silica Materials from the Slurry Waste
In solar energy industry, large amount of slurry wastes were produced during the wafer dicing process. The slurry waste contains silicon, silicon carbide and cutting oil. In this study, silicon in the slurry waste was treated with sodium hydroxide to produce a liquid mixture of the sodium silicate. The residue of the reaction was silicon carbide. The liquid mixture was separated to be a sodium silicate solution and used as a silica precursor for producing the silica powder and a hydrophobic silica aerogel by using the sol-gel method. The products were characterized by Fourier transformation infrared spectroscopy (FTIR) and powder X-ray diffraction (pXRD). Experimental results show that the characteristics of the products produced from the slurry waste are similar to that obtained by using the pure sodium silicate solution. It indicates that the wafer dicing slurry waste has a high potential to be a resource for other industries.
Z. Y. Shen et al., "Synthesis of Silica Materials from the Slurry Waste", Key Engineering Materials, Vol. 765, pp. 79-82, 2018