| 摘要 |
PURPOSE: To enable a stable tapping for a long time, by which wear resistance under high temperature is improved, a property difficult to be cracked is manifested, and enlargement of the tap hole during the use is small. CONSTITUTION: A tap hole of a blast furnace is composed of a refractory material which has the composition consisting of, by weight, 20-90% silicon carbide, 5-50% alumina, and 5-30% mullite, and a cylindrical refractory which contains >=90% of SiC, Al2 O3 and SiO2 in total and whose porosity is <=15% is fitted thereto. This constitution allows the safe operation, the continuous tapping operation and the longer service life. The improvements in the aspects of the working and cost and that of the quality of the molten steel are attained. |
