TY - JOUR T1 - 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 AU - Miyazaki, Hidetoshi AU - Sugihara, Tetsuya AU - Makinose, Yuki AU - Egawa, Michiko AU - Handa, Makoto JO - Journal of Engineering and Applied Sciences VL - 16 IS - 5 SP - 182 EP - 185 PY - 2021 DA - 2001/08/19 SN - 1816-949x DO - jeasci.2021.182.185 UR - https://makhillpublications.co/view-article.php?doi=jeasci.2021.182.185 KW - Rice husk KW -silica KW -purify KW -potassium AB - 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. ER -