Use of waste or by-products from different industries and the agricultural sector has received increasing attention in the scientific, technology, ecological, economic and social spheres in recent years. Rice husk (RH) is a by-product of rice milling and rice husk ash (RHA) is generated by combustion in a separate boiler. Both RH and RHA are abundantly accessible in rice growing countries such as China, India, Brazil, the USA, and Southeast Asia. RH has therefore been recycled by burning it for energy production. This generates RHA, which contains a huge quantity (85-95%) of amorphous silica. Over the past two decades, RHA has been used extensively in numerous fields for manufacturing of different silicates, zeolites, catalysts, nanocomposite, cement, lightweight construction materials, insulators, and adsorbents. This paper presents a comprehensive overview on the processing of nano-silica from RH/RHA. It tries at the same time, to present a critical review of the application of RHA as an ingredient for the production of various ceramic materials, e.g. refractory, glass, whiteware, oxide and non-oxide ceramics, silica aerogel and SiO 2 /C composites. In summary, amorphous silica derived from RHA or RH provides a potential alternative to conventional silica sources (e.g. quartz) for the manufacture of value-added ceramics for practical applications.
The aim of the study was to investigate the effect of amorphous silica on the phase formation and study the physical characteristics of forsterite refractory prepared from quartz and MgO powder. Various samples were subjected to sintering temperature around 1100 • C and development of forsterite phase was characterized using Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The result indicate that the addition of rice husk ash (RHA) significantly affect the formation of forsterite phase. As the amount of RHA increased, it led to a better reaction between amorphous silica and periclase, later that will transform into forsterite phase at a temperature around 1100 • C. Formation of forsterite resulted in decrease of density, porosity, and thermal conductivity, while the opposite was observed for Cold Crushing Strength. Formation of forsterite phase was identified by XRD analysis of the sample. Based on the characteristics, the samples were considered as an insulator and of the potential use as refractory devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.