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;
• 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.

A silicon dioxide granulate I, comprising:

• a chlorine content of less than 200 ppm;
• and
• an aluminium content of less than 200 ppb;
• wherein the ppb and ppm are each based on the total weight of the silicon dioxide granulate I.

A process for preparing a silicon dioxide granulate I comprising:

• providing a silicon dioxide powder;
• providing a liquid;
• mixing the silicon dioxide powder with the liquid to obtain a slurry;
• and
• granulating the slurry to obtain the silicon dioxide granulate I.

A silicon dioxide granulate II comprising:

• a chlorine content of less than 500 ppm;
• and
• an aluminium content of less than 200 ppb,
• wherein the ppb and ppm are based on the total weight of the silicon dioxide granulate II in each case.