The Research On Application Of The Rice Husk Ash

Rice husk ash and lees ash were studied in this paper. Experiments were carried out to obtain the influence of temperatures, burning time and furnace typies on the specific surface area.By comparing with the rice husk ashes obtained under different conditions, the optimum conditions of producing rice husk ash with large specific surface area were determined, which included combustion temperature and burning time. By examining rice husk ash obtained under different conditions by SEM, it was found that the rick husk ash obtained at 600℃had classical netword structure and large specific surface area, and the rick husk ash obtained at 700℃still had the classical network structure However specific surface area is significantly decreased. By observating the photos of SEM, it was observed that the rice husk ash cross-section is composed of many porous films in connective forms packed tightly by countless SiO₂ particles, pore size is in nano-scale, the result is in fine accordance with thao of specific surface area test. The nano-scale SiO₂ particles and nano-scale pores packed by SiO₂ are the fundamental causes for the high specific surface area of rice husk ash. The experiments of different specific surface area of rice husk ash replacing cement additives verified the strength effect of the large surface area ash materials on the cement. At the same time, the strength effects of different blending amount (5%, 10%, and 20%) were compared in the work. The blending amount of 10% had the best effect was obtained.The influences of different temperatures and furnace types on the components of lees and specific surface area were studied in the next experiment. The low heat-sensitivity (the variation degree of the specific surface area with temperature change) of lees was verified. By testing the specific surface area and cemet strength, it was proved that lees ash had the large specific surface area and it can be used as additives for cemet. The feasibility of preration of additives for cemet by low temperature combusting lees using fluidized bed was demonstrated.