METHOD FOR MANUFACTURING OPAQUE QUARTZ GLASS, AND OPAQUE ARTICLE MANUFACTURED BY THE METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a pure opaque quartz glass article by which the possibility of contamination in the manufacture process is reduced, and to provide the pure opaque quartz glass article characterized by the resistance against the change of temperature, strength and chemical durability. SOLUTION: A mixture of refined natural quartz granule with Si3N4 powder is charged into a tubular metallic mold 2 rotating around the longitudinal axis 3, successively a counter electrode 8 is introduced into an inner hole 6 from one end of a hollow cylinder 1 and moved continuously along the inside wall 9 of the cylinder to another end of the hollow cylinder 1 to form the molten front face 10 in the hollow cylinder 1, the front face advances toward the outside in the direction of the metallic mold and a boundary between the continuous pore region 11 and the opaque partially molten region 12 is formed. As the result, a region between the inner hole 6 and the inside wall 9 is highly compacted by the high temperature of arc 7 to obtain a molten body 12 having an inner region 15 constituted of a high density transparent quartz glass.