| 摘要 |
PROBLEM TO BE SOLVED: To provide such refractories for a converter tapping hole consisting of a sleeve fitted to a tapping section of a converter and a block(s) laid on the periphery of the sleeve, in which the oxidation resistance, spalling resistance, dissolution resistance, and wear resistance of the refractories are sufficient to meet the respective requirements and in particular, the service durability of a refractory for the tapping hole sleeve can be improved and accordingly, the frequencies of repair and replacement of the tapping hole sleeve can be reduced and also an improvement in operation rate of the converter can be realized. SOLUTION: A part or all of the refractories consist of spinel-containing formed bodies the production process of each of which comprises: preparing a blend that comprises <50 mass % (excluding zero) of a spinel raw material consisting essentially of magnesia and alumina, <50 mass % (excluding zero) of a magnesia raw material and <=50 mass % (excluding zero) of a carbon raw material; adding 0.1-20 mass % on the outer percentage basis of a binder to the blend; mixing and kneading the resulting mixture; forming the kneaded material into a green body; and drying the green body and thereafter optionally, further firing the dried body in a non-oxidizing atmosphere, to produce the objective formed body; wherein the formed body has a <=15 mass % inevitable impurity content. |
