Process for making glass with agglomerated refining agents
US4313747A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 16, 1980 |
| Grant date | Feb 2, 1982 |
| Priority date | — |
| Expiry date | May 16, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C1/004
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Refining agents comprising intimate mixtures of finely-divided sulfates and reducing agents are added to vitrifiable charges of glassmaking raw materials prior to melting the raw materials so that, when the charge is melted, the refining agent will evolve bubbles of sulfur dioxide gas which will remove smaller bubbles of other gases from the molten glass as these bubbles rise to the surface of the molten glass. The metal sulfates and reducing agents (preferably carbon) employed in the refining agent have a particle size of less than about 0.1 mm and are formed into homogeneous agglomerates having a size of about 1 to 5 mm. The glassmaking raw materials are also finely-divided and may be used in this form or may be formed into agglomerates of about the same size as, or containing the agglomerated refining agent. The relative amounts of reducing agent to sulfur in the refining agent is such that at least one-fourth of the sulfate present will be reduced to the sulfide form, and the amount of refining agent employed is such that the amount of added sulfur expressed as SO.sub.3 is at least 0.05% by weight of the glass to be obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.