Hollow inorganic spheres and methods for making such spheres

摘要

Novel hollow inorganic spheres are prepared by (1) tumbling together a mixture comprising (a) solidifiable liquid globules that comprise a fugitive organic binder material and a source of volatile void-forming agent and (b) a mass of free-flowing inorganic sinterable parting agent particles that are at least partially absorbed into the globules during the tumbling action; (2) providing conditions under which hollow spheres form in which the sphere walls contain the sinterable particles; and (3) firing the spheres to remove the binder material and sinter the parting agent particles to form shape-retaining spheres having sintered inorganic walls.