Reduction of nickel sulfide stones in glass
US5725628A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1996 |
| Grant date | Mar 10, 1998 |
| Priority date | — |
| Expiry date | Aug 5, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C3/087
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention is a method of preventing the formation of nickel sulfide stones in soda-lime-silica glass. Nickel compounds are often added as colorants or enter the glass batch as an impurity from raw materials. It involves mixing batch raw materials together, melting and refining them to form a molten glass, the improvement comprising the step of reducing the formation of nickel sulfide stones by adding to the batch materials 0.01-2.0 wt. % of an oxygen containing manganese compound calculated as manganese dioxide. The manganese compound may be a manganese oxide or salts of permanganic acid such as sodium or potassium permanganate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.