| 摘要 |
PURPOSE:To obtain the title stable material having a desired compsn. ratio and hardly undergoing a change by adding water contg. (NH4)2SO4 to a blend of starting materials including alkaline earth metal carbonates and blended in a prescribed compsn. ratio and by mixing and treating them. CONSTITUTION:(NH4)2SO4 having about 99.5% purity is added into water to >=0.2wt.% concn. and the water is added to a blend of starting materials including alkaline earth metal carbonates and blended in a prescribed compsn. ratio. They are wet-mixed with a ball mill or the like to form a slurry and this slurry is dehydrated by filtration or other method, dried and calcined. The starting materials may be powders of BaCO3, SrCO3, CaCO3 and TiO2 each having about 99.5% purity. |
