摘要 |
A magnesium aluminate spinel-bonded refractory can be formed which does not exhibit undue expansion (due to the reaction of magnesia and alumina to form magnesium aluminate spinel) between the raw, compacted state and the fired, ceramically bonded state when fired to a temperature of 1400 DEG C if a very finely divided alumina with dense particles is used. More specifically, the alumina used has an average particle size of less than 5, preferably less than 2, microns, and a specific surface of less than 30 m<2>/g, preferably about 5 m<2>/g (i.e., the small crystallites or particles are dense and do not have a high surface area, as do finely divided active aluminas). |