| 摘要 |
PURPOSE:To produce a high purity mullite sintered body at a low cost by adding an Al compd. to artificial kaolinite and sintering them. CONSTITUTION:Artificial kaolinite having <1mum average particle size, consisting of Al2O3, SiO2 and <=0.3wt.% impurities and contg. <=5wt.% free SiO2 besides amorphous SiO2 is wet-mixed with an Al compd. giving Al2O3 of 99.8wt.% purity after ignition, e.g. the oxide, hydroxide, carbonate, nitrate or chloride of Al in a ratio giving millite (3Al2O3.2SiO2) and the mixture is freed of the water by calcination, pulverized and wet-mixed with an org. binder. The resulting uniform slurry is dried and molded into a prescribed shape and this molded body is sintered at >=1,400 deg.C. A high purity mullite sintered body can be produced at a low cost. |
