Production of Silica from Rice husk

Rice husk (RH) is an agricultural waste, which is easily available in the market and Silica (SiO2) is the most abundant material in the earth's crust. This paper addresses the production of silica from the rice husk. The Rice husk ash (RHA) is obtained by burning of rice husk in a muffle furnace at a temperature of 500, 600 and 700 0 C, which is bio-organic Silica (SiO2) and has high pozzolanic activity. The temperature and the time duration for the combustion process are optimized. X-ray Fluorescence (XRF) analysis is carried out to determine the chemical composition of rice husk and that of the rice husk ash. The formed rice husk ash is treated with Sodium hydroxide (NaOH) and Hydrochloric acid (HCl) to produce silica. The obtained silica is used for the various applications like automotive industry, cosmetic industry, etc. The compound of silica like Sodium silicate (NaSiO3) is used for water treatment, concrete treatment, cement production, etc. The brief explanation for the process is given below.