US Patent 9290400 Granules and process for their production

To provide granules which are to be used as raw material for aluminosilicate glass and which are capable of reducing formation of fine powder during the production thereof, and a process for their production. Granules of a glass raw material mixture comprising at least silica sand and aluminum oxide, which are to be used for production of glass, characterized in that when the granules in such a state that the water content is at most 2 mass % are subjected to screening using a sieve having 1 mm openings, D50 representing the volume cumulative median diameter in the particle size distribution curve of particles passed through the sieve, is from 350 to 5,000 μm, and in the particle size distribution curve of water-insoluble components in the granules, the proportion of particles exceeding 50 μm in diameter is at most 6 vol %, and D90 representing the 90% volume cumulative particle diameter from the smaller particle size side is at most 45 μm.