| 摘要 |
PURPOSE:To obtain a refractory for preliminarily treating molten pig-iron having excellent melting loss resistance and spalling resistance, standing use of an ultra-high temperature in the vicinity of a pig-iron receiving port close to an air or oxygen lance of a mixer car by blending a magnesia raw material or magnesia.calcia raw material (hereinafter abbreviated as magnesia raw material) with silicon carbide and a carbon material in a specific ratio. CONSTITUTION:60-95wt.% of magnesia raw material is blended with 3-30wt.% of silicon carbide and 2-30wt.% of a carbon material, kneaded and molded by a friction press, etc. The molded material is heat-treated at about 300 deg.C for about 10 hours to give an unburned refractory. For example, fused magnesia clinker is used as the magnesia raw material and magnesia clinker as the magnesia.calcia raw material. The carbon material contributes to corrosion resistance and spalling resistance by hardly wetting slag and, for example, both graphite and pitch are used. Silicon carbide has effects of suppressing oxidation of the carbon material, especially oxidation at an ultra-high temperature under exposure to an oxygen gas and exhibiting high corrosion resistance and high spalling resistance of the carbon material. |
