| 摘要 |
PROBLEM TO BE SOLVED: To provide highly plastic alumina particles exhibiting an excellent plastic property as a raw material for ceramics by forming alumina hydrate coating films on the surfaces of alumina particles. SOLUTION: The alumina particles each preferably has a fine hexagonal plate-like shape, a particle size of <=15 μm and a thickness of <=1 μm. The highly plastic alumina particles are produced by dissolving a soluble Al salt, such as aluminum sulfate, in pure water, adding alumina particles to the solution, stirring the mixture, dropwisely adding an alkali aqueous solution to the obtained slurry until giving about slurry pH 7, centrifuging the coating-treated slurry, washing, drying and pulverizing the obtained particles, and subsequently calcining the pulverized particles. The content of the alumina hydrate is preferably 5-10 wt.% based on the alumina. The calcination of the alumina particles after the coating of the surfaces is carried out for obtaining a large surface area, preferably at a treating temperature of 300-700 deg.C. |
