| 摘要 |
<p>A process and apparatus for spheridizing irregularly shaped minute particles, and the spheres produced thereby, in which a thin carbonaceous coating is applied to the particles in a unique manner, and in a preferred embodiment the particles are then advanced through successive fluidizing beds. The first bed has an inert atmosphere and is maintained at an elevated temperature sufficiently high to allow surface tension to shape the particles into spherical form while in a fluidized condition in the first bed. The spherical particles are then advanced through successive additional beds where they are cooled to an intermediate temperature sufficient to solidify the particles, are subjected to an oxidizing atmosphere which completely removes the coating, and are then further cooled while being maintained in a fluidized condition. The inert gaseous atmosphere within the first bed is continuously withdrawn and recycled through the system.</p> |
