Method for processing glass fiber waste

A process for comminuting glass fibers from waste glass-based fibrous materials, comprising the process steps of

• a) coarsely comminuting the glass fibers to obtain coarsely comminuted glass fibers;
• and
• b) finely comminuting said coarsely comminuted glass fibers with a granular additive having a d50 value within a range of from 0.1 to 5.0 mm as an aggregate to obtain finely comminuted glass fibers, the mixing ratio of glass fibers to additive being from 25/75 to 95/05 by weight,
• wherein the additive is selected from the group of quartz sand, lime, burnt lime, dolomite, burnt dolomite, blast furnace slag, Al2O3, aluminum hydroxide, albite, orthoclase, anorthite, boric acid, boron oxide, alkali and alkaline earth borates, and mixtures thereof and
• wherein the additive remains in a mixture with the finely comminuted glass fibers.