| 摘要 |
PURPOSE:To provide a titled casting mold compsn. which has a long pot life and is commonly usable with an acid curable org. casting mold as facing sand by consisting the same of molding sand, an aq. soln. of aluminum-iron double salt of phosphoric acid having an adequate molar ratio of Al and Fe and iron oxide. CONSTITUTION:A casting mold compsn. consists of molding sand, an aq. soln. of aluminum-iron double salt of phosphoric acid having a 95:5-10:90 molar ratio of Al and Fe and iron oxide. The compsn. has a good collapsing property, has high dimensional accuracy, permits reutilization of used sand and is commonly usable with an acid curable org. casting mold as facing sand. Stability can be improved by changing the molar ratio of Al and Fe in the above-mentioned range and adjusting the curing rate over a wide range. The above-mentioned aq. soln. of aluminum-iron double salt of phosphoric acid is preferably added at about 0.6- 10wt% by the weight of the molding sand. The iron oxide acting as a hardener is usable usually in about 20-60% range of the aq. soln. of aluminum-iron double salt of phosphoric acid. |
