METHOD FOR PRODUCING GLASSES, GLASS CERAMICS AND THE USE OF SAME

摘要

A method for producing bubble-free glasses is provided, in which a glass mixture that is arsenic-free, antimony-free and tin-free with the exception of any unavoidable raw material impurities and at least one sulfate compound as a refining agent are used. The glass mixture and refining agent are melted and primarily refined in a first region of a melting tank, an average melting temperature (T1) is set at T1>1580° C. and an average melt residence time (t1) is set at t1>2 hours. A secondary refinement is carried out in a second region, an average melting temperature (T2) is set at T2>1660° C. and an average melt residence time (t2) is set at t2>1 hour, and the proportion of the SO3 resulting from decomposition of the sulfate is reduced to less than 0.002 wt. %.

主权项

1. A method for producing glasses, comprising:
using a glass batch that is free of arsenic, antimony, and tin except for unavoidable raw-material impurities; using at least one sulfate compound as refining agent; melting and primarily refining the glass batch and the refining agent in a first region of a furnace melting tank, wherein in the first region, an average melting temperature T1 is set at T1>1580° C. and an average residence time of the melt t1 is set at t1>2 hours; secondarily refining the glass batch and the refining agent in a second region of the melting tank, wherein in the second region, an average melting temperature T2 is set at T2>1660° C., and an average residence time t2 of the melt is set at t2>1 hour, and wherein the proportion of the SO3 forming due to the decomposition of the sulfate compound is decreased to less than 0.002 wt. % at the latest during the conducting of the secondary refining; and high-temperature refining the glass batch and the refining agent after the secondary refining.