| 摘要 |
PURPOSE:To obtain a high-strength calcined beta''-alumina compact with a low ionic conduction resistivity by mixing and pulverizing a water-soluble alkali raw material seed and alumina raw material under wet conditions, then adding a specific amount of beta''-alumina seed crystals having specified properties thereto, spray-drying and granulating the resultant mixture, forming and calcining the produced granule. CONSTITUTION:A water-soluble alkali raw material seed (e.g. sodium hydroxide) and an alumina raw material (e.g. alpha-Al2O3) are mixed and pulverized using water. Alumina seed crystals, containing a crystal phase consisting essentially of beta''-alumina and having >=1 to <=9mum average grain diameter in an amount of >=2 to <=45wt.% are added and mixed with the resultant powder. The prepared mixture is then spray-dried, granulated, formed into a desired shape and calcined to afford a sintered beta''-alumina compact. Thereby, formation ratio of the beta''-alumina is improved to reduce the ionic conduction resistivity and improve strength of the crystal substance. As a result, the sintered compact suitable as an electrolyte for sodium-sulfur batteries is obtained. |
