| abstract |
The present invention provides a method for producing a silica container, wherein the method comprises: a step of forming a powder mixture by adding an Al compound or a crystal nucleating agent into a first powdered raw material (silica particles), a step of preliminarily molding to an intended shape by feeding the powder mixture to an inner wall of an outer frame while rotating the outer frame having aspiration holes, a step of forming a silica substrate, wherein the preliminarily molded article is degassed by aspiration from a peripheral side and at the same time heated from inside the preliminarily molded article at high temperature thereby making a peripheral part of the preliminarily molded article to a sintered body while an inner part to a fused glass body, and a step of forming a transparent silica glass layer on an inner surface of the silica substrate, wherein a second powdered raw material having a higher silica purity than the first powdered raw material is spread from inside the silica substrate and at the same time heated from the inside at high temperature. Accordingly, a method for producing a silica container with a high dimensional precision, a high durability, and suppressed gas release, and with a reduced energy consumption and a low production cost, by using a cheap and relatively low grade powdered silica as a main raw material, is provided. |