| 摘要 |
PROBLEM TO BE SOLVED: To obtain a closing material having excellent high-early-strength properties and corrosion resistance, capable of controlling roughness phenomenon of tapping by uniformly dispersing pitch powder into a phenolic resin to give a binder composition and mixing the composition with a refractory raw material. SOLUTION: A coal-based pitch or a petroleum-based pitch may be cited as a pitch to be mixed with a phenolic resin. The fixed carbon ratio of the pitch is >=35% and its softening point is >=250 deg.C and <=350 deg.C. The amount of the pitch added is >=5 wt.% and <=30 wt.% in the binder composition. In order to uniformly disperse the pitch into the phenolic resin, for example, the resin is mixed with pitch powder in a stainless steel container by a biaxial mixer for about 10-15 minutes. A refractory aggregate such as alumina, etc., a carbonaceous raw material such as coke, etc., or a fire clay such as kaolin, etc., can be used as the refractory raw material. Preferably the amount of the binder composition to be mixed with the refractory raw material is preferably >= about 10% and <= about 40%. |
