Brief description of the hardening of titanium oxide powdery

摘要

1426925 Hardening powdered titania BRITISH STEEL CORP (CHEMICALS) Ltd 4 June 1974 [4 June 1973] 26484/73 Heading ON A method of hardening pigment -grade powdered titania consisting of anatase or rutile comprises thoroughly dispersing the powder in water, removing the excess water, drying and calcining. The hardened titania is suitable as a catalyst support, particularly for catalysts used in the oxidation of orthoxylene to phthalic anhydride. -The dispersion of the powdered titania may be aided by adding surfactants or water-soluble organic compounds, e.g. acetone, acetic acid, methyl alcohol, ethyl alcohol, propanol, n-butanol or 2-butanol or highly polar inorganic compounds, e.g. HCl, HNO 3 , H 3 PO 4 , NaOH or NaNO 3 which assist the dispersion. The excess water may be removed from the titania by filtration or by adding flocoulants to the dispersion. The material is then dried, e.g. by heating at between 70‹ and 120‹C. and then dried paste is calcined at between 700‹ and 900‹ C., preferably 800‹ to 850‹ C. If rutile TiO 2 is employed rather than anatase the lower limit for calcination may be 650‹ C.