| 摘要 |
PURPOSE:To obtain ceramics granules which are truly spherical, are excellent in flowability and can be easily crushed down near to the particle size of the raw material ceramics at the time of molding by adjusting an aq. slurry of ceramics powder to a specific viscosity, then spray-drying the same. CONSTITUTION:The ceramics powder is dispersed into an aq. soln. to prepare the slurry thereof. After the viscosity of this slurry is adjusted to 100-300 centipoise, the slurry is spray-dried. Any methods which generate viscosity by the flocculation effect of the slurry may be adopted for the adjustment of the slurry viscosity and are exemplified usually by a method of adding a flocculating agent to the slurry or a method of adjusting the viscosity by adding a pH adjusting agent in the direction approximate to an equipotential point to eliminate electrostatic repulsion among the particles or the combination methods thereof. The ceramics powder is particularly adequate as the flocculating agent and aluminum sulfate, aluminum chloride and aluminum nitrate are adequate in the case of alumina, alumina-zirconia and zirconia. |
