| 摘要 |
<p>1302223 Al 2 O 3 -CR 2 O 3 spheres UNIVERSAL OIL PRODUCTS CO 1 June 1970 [12 June 1969] 26278/70 Heading B1E [Also in Division C1] Al 2 O 3 -Cr 2 O 3 spheres are produced by (a) forming a Cr 2 O 3 sol by dissolving CrO 3 in HCl using .2-2 moles HCl per mole CrO 3 , and treating with a reducing agent, (b) forming an Al 2 O 3 sol by dissolving Al in aqueous HCl and/or AlCl 3 , (c) mixing the sols together with a substance which decomposes to give NH 3 , and dispersing the mixture as droplets in a hot oil bath, (d) aging the gel spheres at elevated temperature to decompose residual NH 3 precursor, and (e) washing, drying, and calcining the spheres. The reducing agent may be HCHO, CH 3 CHO, C 2 H 5 CHO, n- or iso- (C 3 H 7 CHO, HCOOH, CH 3 COOH, (COOH) 2 , or N 2 H 4 . The sol mixture preferably has an atomic ratio of metal to Cl of 1-2 and contains 8-20 wt. % metal. The NH 3 precursor may be hexamethylenetetraamine. The oil bath may be at 49-104‹C. Aging may be effected at 49-260‹C and 40-150 psig in the hot oil bath. Optionally followed by an NH 4 OH age. The washing water may contain NH 4 OH and/or NH 4 NO 3 . Drying may be effected at 93-316‹C and calcining at 427-760‹C. The spheres may contain 10-90% Cr 2 O 3 .</p> |
