Abstract: Disclosed are a method of coating a granular material comprising steps of: dropping a granular material from an upper portion in a draft disposed in a coating apparatus; spraying the granular material during falling with a coating solution containing a film-forming material dissolved in a solvent in the draft; drying the granular material sprayed with the coating solution by a drying gas flowing upwardly from a lower portion to an upper portion in the draft; and carrying the dropped granular material to an upper portion in the coating apparatus, and a coating apparatus for coating a surface of a granular material with a coating solution while dropping the granular material, comprising a guide for guiding the granular material, coating solution spray nozzles disposed inside a draft and a means for supplying a drying gas upwardly from a lower portion to an upper portion to the granular material falling in the draft.

Abstract: A process for purifying carbon black which contains solid impurities by removing the solid impurities thererom, which process comprises suspending said carbon black uniformly in water to obtain a carbon black aqueous slurry and subjecting the slurry to sieving treatment by an ultrasonic vibration sieving apparatus.