Preparation and Characterization of High Purity Silica Obtained from Rice Husks

Abstract

Although SiO2 is produced mostly from mineral sources like quartz, it has recently been obtained from lignocellulosic natural resources, such as rice husk (hull). Several methods for extracting silica (SiO2) from rice husks are available in the literature. These methods are based essentially on heat treatment and/or extraction. This study represents a thorough account of heat treatment and acid-base extraction, to obtain silica from rice husks with a high purity and to eliminate other inorganic impurities. Rice husks, considered to be a potential silica source, were pretreated with various acids, base and water and then thermally degraded in a fixed bed reactor under an inert gas atmosphere (N2). The materials produced in these conditions were characterized by BraunerEmmett-Teller analysis, for surface area and pore volume, by Fourier transform infrared spectroscopy, powder X-ray diffraction, X-ray fluorescence, and scanning electron microscopy.

Preparing Nanosilica Particles from Rice Husk Using Precipitation Method

“…Silicon is a crystalline semi-metal that is covered about 30% of the Earth's crust, it is so widespread but difficult to find it as a pure state in nature, the only stable form of silicon at naturals conditions is silicon dioxide (1). Silica is commonly named of silicon dioxide where it plays an important role in industries as raw material or enhanced them, such as the cement industry, glass, bottles and crockery, enamel, paints, ceramics, electronics, industrial tire, and even cosmetics.…”