JP2013519624A5 - - Google Patents

Claims (16)

A quartz glass crucible for pulling a single crystal by forming a particle layer (12; 14) in a molten mold (1) and sintering or melting the particle layer (12; 14) under the formation of a quartz glass crucible. In the production method, at least a part of the particle layer (12; 14) is produced from silica glass granules, and the production is performed by the following method steps:
(A) a step of mechanically compacting silica powder using a roll briquetting method under the formation of a compression molded body having a substantially uniform spheroid morphology; and (b) the compression molded body. Alternatively, the method includes the step of thermally consolidating the fragments of the compression molded body into silica glass granules.   The method according to claim 1, wherein the compression molded body has an average equivalent diameter in the range of 1 to 5 mm. Individual compression-molded body has an average volume in the range of 1 to 100 mm ^3, Method according to claim 1 or 2. 4. A method according to any one of claims 1 to 3, wherein the individual compression molded bodies have an average density in the range of 0.6 to 1.3 g / cm < ³ >.   The method according to any one of claims 1 to 4, wherein the compression molded body is crushed before sintering or melting.   The method according to claim 5, wherein the compacted body is crushed prior to thermal consolidation in method step (b). Disintegrated compressed molded body is formed of SiO ₂ granules having a bulk density of within the limits excessive electrical 0.45 g / cm ^3, claim 5 or 6 method described.   The method according to any one of claims 1 to 7, wherein the compression molded body or the fragments of the compression molded body are treated in a chlorine-containing atmosphere before the thermal consolidation according to method step (b).   The thermal compaction of the compression molded body or debris of the compression molded body from method step (b) to silica glass granules under an atmosphere containing at least 30% by volume of helium and / or 0.5 bar or more The process according to any one of claims 1 to 8, which is carried out under a reduced pressure below.   The method according to any one of claims 1 to 9, wherein silica glass granule particles made of hydrogen-doped quartz glass are used.   Silica glass granules thermally compacted by method step (b) are applied as an outer particle layer on the inner wall of the molten mold and sintered to provide a crucible inner wall exterior from at least partially opaque quartz glass. 11. A method according to any one of claims 1 to 10, wherein the method is layered.   Silica glass granules thermally compacted by method step (b) are applied as an intermediate particle layer on the outer particle layer and sintered to form a crucible inner wall intermediate layer or at least partially opaque quartz The method according to claim 1, wherein the inner layer of the inner wall of the crucible is made of glass.   The silica glass granules thermally consolidated by method step (b) are subjected to an arc during sintering or melting, melted therein and transparent on the inner wall of the crucible-shaped substrate from quartz glass. The method according to any one of claims 1 to 12, wherein the collision is performed under formation of an inner wall of a crucible inner wall from quartz glass.   Silica glass granules thermally compacted by method step (b) are applied as an internal particle layer onto the inner wall of a crucible-shaped substrate and melted on the substrate to obtain a crucible from transparent quartz glass. The method according to claim 1, wherein the inner wall is an inner layer.   15. The method of claim 14, wherein a porous crucible-shaped substrate from silica glass granules is used, and the inner particle layer is sintered to the inner wall of the crucible wall under the application of reduced pressure.   16. A process according to any one of the preceding claims, wherein silica glass granule particles are used whose diameter shows a deviation of at most 10% from the nominal diameter.