Abstract: Procedures have been developed which may yield spherical type bismuth oxych-loride particles with narrow size distribution by forced hydrolysis of bismuth nitrate solutions at elevated temperature. The particle size and shape characteristics in each precipitation region were investigated by electron microscopy. The presence of sur-factants during the precipitation and aging processes has a marked effect on the properties of the sols resulted.

Key words: Monodispersion, Bismuth oxychloride