The precursor for nano-sized magnesia was prepared by using Mg(NO3)2·6H2O as raw material, the hydrolysis product of hexamethylene tetramine as precipitating reagent and water as reaction media, and with the polymer (PEG) and DMF as protection reagents for particles. Nano-sized magnesia was prepared by calcining the precursor at 873 K after being dehydrated by freeze centrifugation and vacuum drying at a constant temperature. The formation process and structure of MgO nanocrystallites were investigated by means of TG-DTA, FTIR, TEM, XRD and BET. The results showed that the crystal belonged to cubic system and the average size was 3.1 nm and the specific surface area was 229 m2·g-1.
