| 摘要 |
PURPOSE:To obtain a spherical ceramic granule excellent in fluidity, capable of breaking down into the size nearly same as that of the ceramic particle and uniformly and densely molding and almost free from a recessed part generated by sinking by adding a betaine type surfactant into a slurry-like suspending solution made by blending a binder and a medium with a powdery raw material followed by spray-drying. CONSTITUTION:The oxide or carbonate of an alkali earth metal element, yttria and the oxide of a rare earth element are added as a firing assistant into the main component of the powdery ceramic raw material having 0.5-3mum particle diameter and, furthermore, 0.05-0.15wt.% betaine type surfactant (Existing Chemical Substance No 2-1291) is added by using water as the medium and is mixed by a ball mil. Next, 2-8 pts.wt. binder per 100 pts.wt. powdery ceramic raw material is mixed therewith and stirred. The suspended solution is 0.1-3.0 Pa in yield value and controlled to 8.5-9.5 in pH. The conc. of the suspended solution is preferably 10-55% by volume ratio. The granule of 20-250mum particle diameter is obtained by spray-drying the suspended solution. |
