Preparation of quartz glass powder

Abstract

Abstract PURPOSE:To prepare high-purity quartz glass powder inexpensively, by adding a silicate such as alkali metal silicate, etc. to a mineral acid at a specific pH, precipitating water-containing silicic acid, cleaning, drying and calcining the precipitate. CONSTITUTION:In a raw material powder for preparing a crucible to pull up single crystal of semiconductor, a silicate of an alkali metal or alkaline earth metal is added to a mineral acid at <=1.5pH, to precipitate water-containing silicic acid. Water-glass is advantageously used as the silicate, nitric acid is effective as the mineral acid, the lower limit of its pH is about 0.5, and practically, its concentration is properly about 1-4 normal. The precipitated water- containing silicate is cleaned, dried, and calcined at about 1,100-1,300 deg.C for about 30min-2hr, to give quartz glass powder.

Inventors

• 👤 Akihiro Chuma
• 👤 中馬　明博
• 👤 Akio Yanagisawa
• 👤 柳沢　明男

Bibliographic Details