Preparation of quartz glass bodies from silicon dioxide granulate

A process for the preparation of a quartz glass body comprising:

• providing a silicon dioxide granulate comprising:
• providing a silicon dioxide powder;
• and
• processing the silicon dioxide powder to obtain a silicon dioxide granulate, wherein the silicon dioxide granulate has a greater particle size than the silicon dioxide powder and such that the silicon dioxide granulate is open-pored;
• wherein the silicon dioxide granulate has a particle size distribution D50 of 160 μm or greater in order to avoid crust formation and has a particle size distribution D50 of 290 μm or less in order to avoid gas bubble formation;
• making a glass melt out of the silicon dioxide granulate in an oven, wherein the oven comprises a melting crucible;
• and
• making a quartz glass body out of at least part of the glass melt;
• wherein the melting crucible comprises at least one inlet and at least one outlet;
• and
• wherein at least part of the glass melt is taken from the outlet of the melting crucible.