| 摘要 |
PURPOSE:To obtain economically a base material for an additive which has extremely less fluctuation in components by grinding raw materials for the additive to specific grain sizes to mix then granulating the mixture, melting the granules in a cupola and cooling and grinding the melt. CONSTITUTION:Raw materials for an additive for casting are ground to <=3mm. grain size and are mixed. The granules are melted in a cupola and the melt is cooled and ground. If the raw materials are ground in such a way, the variance in the components of the melt is small and the mixture is obtd. with less variance in the mixing of the raw materials. The granulating property is better and the strength of granulation is higher in the case of granulating the mixture for the purpose of charging the same into a cupola which is an economical melting furnace. Since the CaO base, clay base, etc. in the raw materials act as a binder in the case of granulation, no binders are required in general with the materials having small grain sizes and water glass, colloidal silica, resins, etc. are usable in the case of large grain sizes requiring binders. |
