A process for preparing solid slag granules from a molten slag composition comprises: (a) providing the molten slag composition; (b) converting the molten slag composition into the solid slag granules in a dispersion apparatus; and (c) sorting the solid slag granules by shape in a separator to produce a plurality of fractions having different sphericities. Granular slag products comprise one or more fractions of solid slag granules produced by the process, and include proppants, roofing granules, catalyst supports, which may be porous or non-porous, and coated or uncoated.