| abstract |
A process for producing titania-silica mixed crystal particles having a high bulk density and comprising titanium oxide as the main component and silicon oxide as a subsidiary component, the process comprising decomposing a gaseous titanium halide and a gaseous silicon halide, each heated at 600øC, or more in the presence of oxygen or water vapor heated at 600øC or more, heating the obtained powder at 300 to 600øC to decrease the concentration of raw material-originated hydrogen halide in the powder to 1 mass% or less, and then subjecting the powder to a treatment of dissociating the aggregated or steric structure. |