| 摘要 |
PROBLEM TO BE SOLVED: To suppress oversintering of a structure, to improve a spalling resistance and to remarkably improve a service life of an immersion lance by blending CaO, fumed silica and alumina superfine powder to an Al2 O3 -SiO2 material low cement castable using an alumina cement as a binding agent. SOLUTION: A low cement castable is composed of 60wt.% Al2 O3 and 40wt.% SiO2 . 0.4-0.8wt.% CaO, <=3wt.% fumed silica having 0.1μm average grain size and 0.5-5wt.% alumina superfine powder having 2.5μm average grain size are added to the above castable. A total content of the silica and the alumina having <=10μm grain size is <=5wt.%. A blending example is that 2wt.% alumina cement having 28wt.% CaO content, 2wt.% fumed silica and 2wt.% alumina superfine powder are blended to the Al2 O3 -SiO2 low cement castable whose basic formulation is 40wt.% chamotte, 30wt.% alumina and 30wt.% alumina fine powder. |
