화학공학소재연구정보센터
Energy Sources, Vol.19, No.9, 1005-1025, 1997
Agglomeration characteristics of alumina sand rice husk ash mixtures at elevated temperatures
The agglomeration characteristics of alumina sand-rice husk ash mixtures were investigated at various levels of temperature (750, 850, 900, 950, and 1000 degrees C) and ash content (0.0, 5.0, 10.0, 15.0, 20.0, and 25.0%) using light microscopy, scanning electron microscopy, and energy dispersive X-ray analysis techniques. The scanning electron microscopy and X-ray analysis were also used for the identification of the rice husk and elemental makeup of lice husk ash. There was no indication of melting at all the levels of temperature and ash content studied. However weak and friable agglomerates were obsen,ed at 950 and 1000 degrees C. The stnccture of the particles was not altered and bonding by surface diffusion may be a possible mechanism for the fomzation of the weak friable agglomerates. Physical entrapment by minute whiskers at the surface of lice husk ash may also be a factor. The use of alumina sand as an inert fZuidizable material in fluidized bed systems will prevent the formation of these easily breakable sauctures because ofparticle friction caused by miting and f7uidization. Thus these friable stiuctures are not expected to cause any problem during the normal operation offZuidized bed gasification systems that are normally operated at temperatures in the range of 700-800 degrees C.