processes for the production of titania particles and for the preparation of a catalyst product, uses of controlled nucleation, controlled flocculation, controlled drying and particles of titania, titania, and catalyst product

摘要

The invention provides a process for producing titania particles with a desired morphology. The process comprises providing a titania sun and then drying the sun to provide dried titania particles. The process is characterized in that the morphology of the dried titania particles is controlled by applying one or more of the following criteria: (a) the titania sun is produced from a thio2 containing slurry obtained using a precipitation step in a sulphate process wherein the size of micelles formed during precipitation is controlled; (b) the titania sun is produced from a thio2 containing slurry and the ph of the slurry is controlled to affect the extent to which the titania sun is flocculated; (c) the titania sun is produced from a slurry containing thio2 and the titania isoelectric point is adjusted to affect the extent to which the titania sun is flocculated; (d) the titania sun is dried by the application of heat and the temperature used during the drying step is controlled.