| 摘要 |
<p>An α-alumina powder is produced by granulating at least one starting material selected from among transition alumina and alumina compounds and firing the obtained granules in a gaseous atmosphere containing a hydrogen halide, a gaseous atmosphere containing a halogen, or an atmosphere containing a mixture of a halogen gas with steam and at least one halogen compound selected from among at least 0.1 vol.% of hydrogen halide gases and halogen gases. It is possible to produce an α-alumina powder having controlled granular form and diameter and a narrow grain size distribution and containing little aggregated granules at a high firing efficiency by granulating the powdery starting material to increase the bulk density and firing the granules in the presence of a halogen.</p> |
