| 摘要 |
PURPOSE: To produce a magnesia based non-fired brick excellent in resistance to slag penetration and suitable to a ladle, etc., by compounding in a prescribed amount two kinds of alumina based superfine powders having different grain diameter into a magnesium based refractory material and bonding with a binder. CONSTITUTION: (A) 85-97wt.% magnesium based refractory material (e.g. sintered magnesia), (B) 10-2wt.% alumina based superfine powder having <=10μm grain diameter and (C) 5-1wt.% alumina based superfine powder having <=1μm grain diameter are mixed. Then, the obtained composition is bonded preferably with an inorg. binder (e.g. phosphate) to obtain the magnesia based non-fired brick. In this way, a contact area with the A component is enlarged by adding C component, and a spinel forming reaction is generated at a vicinity of a working surface from more early time, and the penetration of the slag to a deep part due to the modification is suppressed. And, since B component is used jointly, the spinel forming reaction is delayed and continued for a long term, and as such a result, a suppressing function of slag penetration is continued for a long term. |
