| 摘要 |
PURPOSE:To provide a casting mold which has excellent deflection strength and is free from deformation and crack by casting pressure by adding water to a mixture composed of gypsum, hydrate of magnesium sulfate and refractories to prepare a slurry, subjecting the molding to injection molding with pressure in a mold to form a molding and drying the molding in twt stages. CONSTITUTION:Gypsium and hydrate of magnesium sulfate, for example, 7- hydrate are mixed to <=3:7 by weight. Water is added to the mixture composed thereof to prepare a slurry. The slurry is injection-molded in a mold under the pressure exerted thereto to form a molding having the shape of a casting mold. Such molding is subjected to primary drying at >=120 deg.C and further to secondary drying at >=200 deg.C. |
