| 摘要 |
PURPOSE:To prevent slaking during the production of a crucible and to obtain a high quality melt in a high yield even in case of a high m.p. metal such as a Ti family metal or an alloy thereof by adding a molding assistant to high purity calcium carbonate powder or granules, kneading and molding them and calcining the molded body. CONSTITUTION:This crucible is obtd. by adding a molding assistant to high purity calcium carbonate powder or granules, kneading and molding them and calcining the molded body at 1,700-1,800 deg.C. The high purity calcium carbonate contains >=99.9% CaCO3. The molding assistant is used according to the adopted molding method. In case of vacuum molding, about 1-2% stearic acid and about 2-4% paraffin are added to the powder. In case of cold or hot hydraulic molding, about 1-2% stearic acid and about 3-5% paraffin are added to the granules. A proper amt. of water is further added in both the cases. |
