Experimental Study on Preparation of Amorphous SiO2 by Fluidized Bed Combstion of Rice Husk

Rice husk ash contains SiO2 with a mass fraction of 87%-97%. Through controlled combustion under suitable conditions, SiO2 in rice husk ash will be amorphous, with high activity and rich porosity, which can be applied to construction, silicon preparation and adsorption industries.Thus it is necessary to study the effects of combustion parameters on the quality of RHA. Compared to conventional boiler furnace, the fluidized bed combustor has a lower combustion temperature and a longer residence time, which is suitable for the production of high quality amorphous rice husk ash. In this thesis, the effects of fluidized bed combustion parameters on the quality of RHA will be studied to provide guidance for amorphous SiO2 preparation by combustion control in boiler. On the existing 15kw bench-scale fluidized bed system, experiments were made to study the effects of fluidized bed combustion parameters on the quality of RHA. The rice husk combustion curve was comprehensively depicted, and the rice husk ash was analyzed by BET analysis, XRD scanning and thermogravimetric analysis. Therefore, the casual relationship between rice husk combustion process and RHA quality was evaluated comprehensively.