Homogeneous quartz glass from pyrogenic silicon dioxide granulate

A process for the preparation of a quartz glass body comprising pyrogenic silicon dioxide, comprising:

• providing a silicon dioxide granulate comprising:
• providing a pyrogenic silicon dioxide powder;
• and
• processing the silicon dioxide powder to obtain a silicon dioxide granulate, wherein the silicon dioxide granulate has a greater particle diameter than the silicon dioxide powder;
• making a glass melt out of the silicon dioxide granulate in an oven;
• making a quartz glass body out of at least part of the glass melt;
• wherein the quartz glass body comprises:
• an OH content of less than 10 ppm;
• a chlorine content of less than 60 ppm;
• and
• an aluminium content of less than 200 ppb;
• wherein the ppb and ppm are each based on the total weight of the quartz glass body.

A quartz glass body containing pyrogenic silicon dioxide, wherein the quartz glass body comprises:

• an OH content of less than 10 ppm;
• a chlorine content of less than 60 ppm;
• and
• an aluminium content of less than 200 ppb;
• wherein the ppb and ppm are each based on the total weight of the quartz glass body.