A Simple Method for the Production of Pure Crystalline Silica from Lemon Grass

Lemon grass is an inexpensive raw material that can be used to produce natural silica. A method using hydrochloric acid (HCl) leaching followed by thermal combustion at 600 °C was developed to produce purified silica from lemon grass. Acid leaching temperatures of 33, 50, 80, and 110 °C were used. The silica content of the lemon grass ash was characterized using X-ray fluorescence (XRF), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) analysis. The shape and texture of the lemon grass ash were studied using SEM. The highest silica content (98.59%) was produced by lemon grass that had been treated at the highest leaching temperature (110 °C). Other elements that were found in the lemon grass ash were magnesium, calcium, potassium, and chlorine. XRD analysis showed that the crystallinity of the silica in treated lemon grass ash increased with increasing leaching temperature. The FTIR analysis confirmed the presence of siloxane and silanol bonds in lemon grass that was calcined at different leaching temperatures.