Process and apparatus for preparing monodispersed, spherical, non-agglomerated metal oxide particles having a size below one micron

A process for preparing spherical, submicronic, monodispersed, and non-agglomerated particles of metal oxides by reacting with steam a gaseous stream containing an aerosol of liquid particles of a hydrolyzable metal compound of a metal selected from the class consisting of titanium, aluminum, zirconium, chromium, vanadium, gallium and iron, characterized in that into a duct, in which flows an inert gas stream containing vapors of said hydrolyzable metal compound, there is fed through a nozzle a cold inert gas stream, the temperatures and flow rates of the two gaseous streams being such as to establish in the duct a temperature lower than the condensation temperature of the said metal compound;

• the mixed gaseous streams having a turbulent flow in the duct with a Reynolds number equal to or higher than 1,800;
• and at the duct outlet, the aerosol of the said metal compound liquid particles, which has formed in the duct, is reacted with steam, wherefore solid particles of hydrated oxide of said metal form, which are then calcined to the corresponding metal oxide.