In order to produce small composite granules having binary components of CaCO3 and SIC powders, experiments were carried out by the simultaneous operation of granulation, grinding, and separation in a single continuous rotating conical vessel with grinding media. To characterize these composite granules, SiC agglomerates contained in a granule were separated by chemical methods, and the size distributions of granules and SiC agglomerates were measured by an image analyzer through a microscope. The structure of a composite granule was characterized by comparing the size of a composite, granule with that of SiC agglomerates in the granule. It was found that composite structures of the granules could be classified into six kinds of structural models, and that the composite structure depended on the size of the granules and the volume fraction of the SiC component in the granule.