| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide molding sand which has high heat resistance, is excellent in low expansibility and low friability, is applicable to the casting of a large cast steel article having high pouring temperature, is excellent in reusability of sand, and has high production yield, and can be produced inexpensively; and to provide a method for producing the molding sand. <P>SOLUTION: Molding sand has chemical components of, 50-85 wt.% Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>, 5-40 wt.% MgO, >0 to ≤20 wt.% SiO<SB POS="POST">2</SB>, wherein the total of the weight percentage of Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>, MgO and SiO<SB POS="POST">2</SB>is ≤100 wt.%, wherein the molding sand includes a molten spherical substance having as one kind of crystal construction, single spinel or composite of spinel with any one of alumina, mullite, cordierite and sapphirine, and wherein the molten spherical substance has a particle size distribution of 30-3,000 μm. <P>COPYRIGHT: (C)2013,JPO&INPIT |
