| 摘要 |
PROBLEM TO BE SOLVED: To prevent the bottlenecking as well as the clogging of an inner hole in an economical, relatively easy and stable manner without using any mechanical method such as injection of the inert gas, without promoting the low melting point or erosion by the reaction of the aggregate in the refractory with alumina in steel. SOLUTION: In a nozzle 1, a surface layer part 2 of an inner hole has the mineral composition consisting of, by weight, 65-90% agalmatolite mainly consisting of pyrophilite (Al2 O3 .4SiO2 .H2 O), and 10-35% graphite, the binding agent is added to the mixture, and the mixture is kneaded, formed, and sintered in the non-oxidizing atmosphere. Bottlenecking as well as clogging caused by the non-metallic inclusion such as alumina can be suppressed without generating degradation of the structure of the refractory, and the stable operation can be performed. |
