| 摘要 |
1,257,043. Silica bead supports. FARBENFABRIKEN BAYER A.G. 1 May, 1969 [12 June, 1968], No. 22196/69. Heading B1E. [Also in Division C1] Porous, bead-like catalyst supports containing predominantly silica are prepared by the process of (a) forming an aqueous silica sol of specific area of 150 to 400 m<SP>2</SP>/g (B.E.T.); (b) forming a suspension in this sol of solid material comprising a silica filler of specific surface area of 20 to 200 m<SP>2</SP>/g (B.E.T.) in quantities of 20 to 60% by weight and an argillaceous mineral selected from kaolinite, montmorillonite and attapulgite in quantities of 5 to 30% by weight, the quantities specified being for the calculated composition of the suspension, related to dry substance; (c) mixing the suspension with 0.1 to 3% by weight of hydrated magnesium oxide; (d) dividing the now gellable mixture into drops of the required size and gelling in a water-immiscible liquid; and (e) separating the granules followed by drying and calcining at 500 to 1000‹C for at least 10 minutes. The supports may be impregnated with solutions of catalytically active metal salts, e.g. vanadium salts and/or with mineral acids, e.g. phosphoric acid. The supports are suitable for use in either fixed bed or fluidised processes. When a V 2 O 5 containing catalyst is used for sulphur dioxide oxidation, the catalyst is pre-sulphated with SO 2 before use. The silica filler may contain some CaO and Al 2 O 3 . |
