| 摘要 |
A dispersion of aluminium metahydroxide is either caused to gel, or the particles are electrophoretically separated as a precipitate from the dispersion. The gel or the precipitate is dried and comminuted to give grains. The grains are, directly or after a preceding calcination, heated rapidly to a temperature above 1200 DEG C and then further heated to a sintering temperature in the range from 1200 to 1700 DEG C. The resulting grains of sintered high-purity alumina have a high density, hardness, strength, fracture toughness and a high chemical resistance and wear resistance. They can be used as abrasives or refractories. <IMAGE> |
