PRODUCTION OF WATER GLASS FROM RICE HUSK ASH
Project no. 1332 · Status: Kapanmış · 2016
Summary
In recent years, both environmental and economic factors have been considered and the number of studies to obtain high value-added products from natural resources has increased. Rice husk is one of the natural resources that can be used as raw material in the production of many silicon-based products due to its high silicon content. During the processing of rice, which is the second most produced grain in the world, approximately 20% of the rice is exposed to silicon-rich husk. Some of the exposed husk can be used in animal feed and some of it as cement additive. However, due to its low density and high quantity, it creates the problem of disposal as agricultural waste. Rice husk ash is obtained by burning the husks in order to overcome this problem partially and also to benefit from the high thermal value of the husk. Silica and carbon-rich rice husk ash is obtained by burning away some elements from the structure. Although the energy released by combustion has been utilized, a new waste is faced since ash constitutes about 20% of the burned husk. For this reason, it is important to develop innovative methods for producing high value-added silicon and carbon-based products by making use of the rich silicon and carbon content of rice husk ash. Therefore, the project aimed to produce sodium silicate and silica particles from rice husk ash, an agricultural waste. Sodium silicate or commercially known water glass are complex solutions formed by dispersing silicate anions and polymeric silicate beads in water. Because of its different structural properties, sodium silicate is used extensively in chemical production, water treatment, detergent, textile, cement, paint, paper, ceramics and mining industries. For this purpose, sodium silicate was obtained as a result of a number of chemical processes applied to the rice husk ash obtained from İpsala-Edirne region. The effects of process variables (type of solvent, ratio of solvent to rice husk ash, process time) during the chemical processes applied on the structural properties of the obtained product were examined parametrically. At the end of the parametric studies, it was tried to determine the most suitable conditions for obtaining the desired properties for the target application area. The sodium silicates obtained were then used as the raw materials for the production of silica particles.