| 摘要 |
In a process for manufacture of dense, amorphous quartz glass granulate by production of a porous granulate from amorphous SiO2 powder and vitrification of the granulate, a porous SiO2 granulate is exposed to a fuel gas flame and is finely dispersed, heated and vitrified therein. The fuel gas flame is more flexible as concerns adjustment of the temperature than in known processes. It is in particular possible to set higher temperatures. The granulate can be exposed to very high sintering temperatures in the fuel gas flame without sintering into agglomerates. At the same time, heat resistance problems of sintering containers such as furnaces and melting pots are avoided. In addition, contamination of the SiO2 granulate by contact with the walls of sintering or vitrifying containers is eliminated. The process makes it possible to economically produce a highly pure and dense quartz glass granulate.
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