Heraeus Quarzglas Gmbh & Co Kg

Heraeus Conamic UK Limited

Eduard Visnow

Boris Gromann

Ian George Sayce

Matthias Söhn

Fabian Schildt

Michael Schindler

Matthias SÖHN

In a method of manufacturing a tube of quartz glass by molding a hollow cylinder having a wall thickness of at least 20 mm, the cylinder is continuously fed under rotation about a rotational axis into a heating zone at a relative feed rate V, softened and radially expanded under the effect of a gas pressure. A tube strand is continuously formed and is withdrawn at a withdrawal rate V. In order to mold thick-walled initial hollow cylinders of quartz glass into tubes with larger diameter, the gas pressure is used as an actuating variable of a diameter regulation for the tube outer diameter or for a geometrical correlated parameter thereof, and in a pressure build-up phase the gas pressure is gradually increased from a lower initial value to a higher final value, and that the following applies to the ratio of Vand V:V=V±0.2·V.

Quartz glass tube and method of manufacturing the same

Described is a process for the refinement of a quartz powder, comprising the step of separating microparticles of refractory minerals, in particular minerals containing rare earth metal compounds, from the quartz powder by an elutriation step.

Purification of quartz powders by removal of microparticles of refractory materials

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Hanau, Germany

Eduard Visnow