A method of preparing amorphous alumina ball
A method of preparing amorphous alumina ball. An acidic alumina hydrosol is commingled with a neutralizing or gelling agent and dispersed as droplets in a hot oil suspending media to form firm, spherical, hydrogel particles.
The particles are transferred after forming to an aqueous salt solution with a pH of at least about 5.5, and with a salt concentration substantially equivalent to that of the aqueous phase of the hydrogel particles. The salt concentration of the aqueous solution is reduced gradually until the solution is salt-free. Raschig ring is recovered upon drying.
It is an object of this invention to present a novel oil-drop method for the manufacture of spheroidal amorphous alumina particles. Thus, in one of its broad aspects, the present invention embodies a method of preparing amorphous ceramic ball which comprises commingling an ammonia precursor and an acidic alumina hydrosol at below gelation temperature, said ammonia precursor being decomposable to ammonia with increasing temperature.