Patent ID: 6197073
Filing Date: 2001-03-06
Classification: B01J,C01B,C01F,C01P

Abstract:
A process for producing substantially spherical aluminum oxide beads, comprising the steps of:(a) passing an acidic sol based on aluminum oxide or an acidic suspension based on aluminum oxide having a viscosity of 10 to 500 mPa's through a vibrating annular nozzle plate so as to form falling hydrosol droplets,wherein the nozzle plate is vibrated at a frequency of 10 Hz to 20,000 Hz, and has at least ten droplet nozzles,(b) laterally blowing ammonia gas against the falling droplets so that the surfaces of the falling droplets are substantially evenly gelled in a substantially spherical shape,wherein the ammonia gas is carried through a narrow pipe which is laterally directed at the falling droplets and positioned a distance below the opening of said droplet nozzles;(c) allowing the falling droplets to drop into an aqueous ammonia solution and coagulate to form substantially spherical beads;(d) collecting the beads from the aqueous ammonia solution; and(e) converting the collected beads to aluminum oxide.