Patent ID: 8919151

Claim:
A process for producing glass raw material granules, comprising: adding boric acid to at least one of or a glass raw material powder and an alkaline solution having a pH of at least 9; and mixing the glass raw material powder together with the alkaline solution after the addition of boric acid to obtain a glass raw material powder mixture; and granulating the glass raw material powder mixture to form the glass raw material granules; wherein the mixing and granulating are conducted by tumbling granulation; wherein the glass raw material powder is a borosilicate glass, comprising as represented by mass percentage based on oxides SiO 2 : from 40 to 85 mass %, Al 2 O 3 : from 1 to 22 mass %, B 2 O 3 : from 2 to 20 mass %, MgO: from 0 to 8 mass %, CaO: from 0 to 14.5 mass %, SrO: from 0 to 24 mass %, BaO: from 0 to 30 mass %, and R 2 O: from 0 to 10 mass % wherein R is an alkali metal.