Magnesia-carbon refractory compositions for slide gate plates and method of manufacture
US5250479A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 1992 |
| Grant date | Oct 5, 1993 |
| Priority date | — |
| Expiry date | Apr 16, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B35/66
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The invention concerns a fired magnesia-carbon shape having a combination of properties making it especially suitable for slide gate plates, inserts for such plates and for pouring nozzles useful in casting aggressive steels. The fired refractory shape is formed from a batch consisting essentially of, by weight percent, PA0 2 to 8 finely divided graphite (natural or synthetic); PA0 3 to 8 aluminum metal powder; PA0 1 to 5 of finely divided silica and/or a silicon yielding powder; PA0 an effective amount of carbon bond forming resins; PA0 and the balance coarse and fine magnesia grains. The magnesia grains should contain less than about 0.02 weight percent boron oxide. After firing, the shape is characterized by a carbon bonding system including a spinel (magnesia-alumina) phase plus aluminum carbide bonding the magnesia-carbon matrix. The refractory shape is preferably carbon impregnated after firing to further enhance its properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.