Patent ID: 8915097

Claim:
A method for producing a silica container, the method for producing a silica container comprised of a silica as its main component and having a rotational symmetry, comprising at least: a step of forming a powder mixture by adding at least any one of an Al compound and a powdered compound capable of becoming a crystal nucleating agent for crystallization of a silica glass, into a first powdered raw material comprising silica particles, a step of forming a preliminarily molded article, wherein the powder mixture is fed to an inner wall of an outer frame having a rotational symmetry and aspiration holes arranged in the inner wall while rotating the outer frame thereby preliminarily molding the powder mixture to an intended shape in accordance with the inner wall of the outer frame, a step of forming a silica substrate, wherein the preliminarily molded article is degassed by aspiration from outside the preliminarily molded article through the aspiration holes formed in the outer frame and at the same time heated from inside the preliminarily molded article by a discharge-heat melting method thereby forming an outer part of the preliminarily molded article adjacent to the inner wall of the outer frame into a sintered body while forming an inner part of the preliminarily molded article, opposite the outer part of the preliminarily molded article, into 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 comprised of crystalline silica and 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 by a discharge-heat melting method.