| 摘要 |
PURPOSE:To obtain the calcination mold with which the shrinkage at the time of a high-temp. molding is adequately compensated by calcining and holding a cured mold which is formed by mixing metal oxide aggregate, metal oxide expanding material and binder and using the mixture as a molding material, thereby forming an oxide having a spinel structure. CONSTITUTION:The mold material is obtd. by mixing the metal oxide aggregate, the metal oxide expanding material which consists of at least one set of any of the metal oxides expressed by formulas AxOy and BmOn (A, B are metal element) and is adjusted in grain size to <=80mu and the binder. A kneading agent is added to this mold material and the material is cast and invested into a desired mold and is cured. The cured mold is calcined and held at <=1300 deg.C to form the oxide having the spinel structure expressed by AB2O4 in the mold at 5 to 85wt.% of the entire part of the calcination mold and to generate a volume expansion, by which the desired calcination mold is obtd. The reason for adjusting the above-mentioned grain size to <=80mu lies in that the formation of the spinel is nonuniform and the deformation of the mold is liable, to arise if the grain size exceeds 80mu. Further, the reason for defining the above-mentioned temp. conditions to <=1300 deg.C lies in that the excess formation of the spinel arises and is liable to cause the collapse of the mold if the temp. exceeds 1300 deg.C. |
