Patent ID: 11952303
Assignee: HERAEUS QUARZGLAS GMBH & CO. KG
Field: Measurement (Instruments)
Classification: CPC C  B  G  H  Y | IPC B  C  G  H

Claim 0:
1. A process for the preparation of a quartz glass body comprising:
providing a silicon dioxide granulate, wherein this provision comprises:
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, wherein the processing of the silicon dioxide powder comprises one of spray granulation, centrifugal pulverisation, fluidized bed granulation and roll granulation and wherein the BET surface area of the silicon dioxide granulate is in a range from 25-35 m2/g and wherein the silicon dioxide granulate has a particle size distribution D10 in the range from 50 to 150 μm and D50 in the range from 150 to 300 μm;

continuously making a glass melt out of the silicon dioxide granulate in a continuous melting process; and
making a quartz glass body out of at least part of the glass melt;, wherein processing the silicon dioxide powder to obtain a silicon dioxide granulate includes adding elemental silicon in order to limit the OH content of the quartz glass body in the continuous melting process to less than 500 ppm.