Authors : Hidetoshi Miyazaki, Tetsuya Sugihara, Yuki Makinose, Michiko Egawa and Makoto Handa
Abstract: Rice husk was fired at 400~1000°C under air flow and a white color rice husk ash was obtained. IR spectral data confirmed the absence of water (-OH group) and organics in the rice husk ash obtained after firing at low-temperatures (<700°C). XRD spectra revealed that the rice husk ash obtained at <700°C was amorphous and that the rice husk ash fired at 1000°C crystallized to the cristobalite phase. The rice husk ashes fired at 400 and 700°C were treated with ion-exchanged water at 80°C. Potassium and phosphorus were removed from these rice husk ashes by the hot water treatment, after which the potassium content in these rice husk ashes (fired at 400 and 700°C) decreased from 5% (before treatment) to 1.5% (after treatment). Summarizing, it was demonstrated that the silica in rice husk can be obtained in high purity by the above-described series of treatments.
Hidetoshi Miyazaki, Tetsuya Sugihara, Yuki Makinose, Michiko Egawa and Makoto Handa, 2021. Designing of Synthesizing High Purity Silica by Decarbonization of Rice Husks by Air Flow Firing and Subsequently Hot Water Treatment of the Resulting Rice Husk Ash. Journal of Engineering and Applied Sciences, 16: 182-185.