ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 35, Number 4
JKCSEZ 35(4)
August 20, 1991 

In order to synthesize high-purity alpha alumina fine powder, the aluminum hydroxide and ammonium aluminum sulfate(alum) precursor were prepared from natural alumino-silicate(halloysite). The thermal decomposition mechenism for both precursors was elucidated by DTA/TG, XRD and IR analysis. The microstructure, specific surface area and purity of α-Al2O3 were characterized by SEM, and BET analysis. The particle size of α-Al2O3 was determined to be φ = 0.1∼0.5 μm. However, the specific surface area for the alum derived α-Al2O3(89.0 m2/g) was extremely higher than that for the aluminum hydroxide derived one(7.3 m2/g).