| 摘要 |
A refractory brick having durability equal to alumina-magnesia castable materials, which is especially suitable for a ladle for steel making is provided. A refractory brick prepared by using an alumina raw material and a magnesia raw material containing 90 % by mass or more of a fine powder of not more than 0.5 mm, press molding and then heat treating at 100 °C or higher and not higher than 1,150 °C, the refractory brick containing Al 2 O 3 and MgO in a total sum of 90 % by mass or more, from 4 to 16 % by mass of MgO, from 0.5 to 5 % by mass of SiO 2 , and Na 2 O and K 2 O in a total sum of from 0.3 to 2 % by mass, with the remainder being inevitable impurities and Al 2 O 3 . |
