Method for producing quartz glass crucible and quartz glass crucible for melting optical glass

摘要

PROBLEM TO BE SOLVED: To provide a quartz glass crucible in which natural silica powder containing a predetermined amount of Al component and Ca component is used as a raw material of a quartz glass crucible, and the quartz glass is appropriately crystallized to prevent the crucible from being deformed and cracked. Provided is a method for producing an opaque quartz glass crucible with low devitrification, which can be suppressed, and the quartz glass crucible. SOLUTION: A rotating molding die is loaded with a raw material silica powder having a molar concentration ratio (Al/Ca) calculated from an Al concentration and a Ca concentration determined by a chemical purity analysis of 15 or more, and the molding step 1 is performed. And a step 2 of inserting an arc electrode into the molding die and arc melting the raw material silica powder layer deposited on the inner surface of the molding die to vitrify the silica glass crucible. A quartz glass crucible for melting optical glass, having an Al concentration of 55 wtppm or more and 100 wtppm or less, a Ca concentration of 1.2 wtppm or more and 9.5 wtppm or less, and a molar concentration ratio (Al/Ca) of 15 or more. [Selection diagram] None