| 摘要 |
PROBLEM TO BE SOLVED: To enable drying at a low-temperature, to secure an excellent temperature characteristics in a temperature range to a high temperature, corrosion resistance and heat spalling resistance, by mixing a refractory composition consisting essentially of magnesia and chromia with specific amounts of chromium carbide powder and chromium oxide powder having controlled particle diameters. SOLUTION: A refractory composition consisting essentially of a magnesia raw material and a chromia raw material is mixed with 0.4-3.3 wt.% of chromium carbide powder having <=10 μm particle diameters and 2-10 wt.% of chromium oxide powder having 10 μm particle diameters and >=95% purity. The mixture of the composition is pressurized by a friction press, an oil press, a rubber press, etc., and molded. The drying is carried out at 100-500 deg.C. The baking is performed at about 1,700-1,750 deg.C since the mixture is made into such a state as to be readily sintered. Consequently a dense refractory having a low porosity is stably obtained without the great change of a production process. |
