Extracting And Characterizing Silica Particles Drom Rice Husk Ash: Applying Silica In Cosmetic Product.

Abstract

Rice Husk (RH), a plentiful agricultural byproduct containing abundant amorphous silica, finds wide-ranging utility in diverse industrial goods. Nevertheless, impurities present in RHs pose challenges in the extraction process, necessitating precise experimental conditions to attain maximum output with tailored properties for designated applications. This study involves the production of Rice Husk Ash (RHA) from RH through acid leaching, followed by silica gel extraction from RHA via controlled pyrolysis at three distinct temperatures (600°C, 700°C, and 800°C). Subsequently, the pyrolyzed RHA is desiccated and pulverized to obtain silica and determine the yield. The characterization of silica is carried out utilizing UV-Vis Spectroscopy, Fourier-transform infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). UV-Vis Spectroscopy is employed to ascertain the silica concentration in sodium metasilicate solution based on the color evolution of the Ammonium Molybdate Method. SEM examination reveals the non-homogeneity of silica particle sizes in the range of 5–120 µm with an average diameter size of 25.12 µm. The optimal conditions entail a temperature of 700°C, pre-treatment of RH with 30% HCl, and the production of silica gel at pH 6, which exhibits enhanced stability, transparency, and thickness compared to silica gel formed at varying pH levels. Furthermore, the highest yield recorded was 90.58% silica derived from RH.