| 摘要 |
PROBLEM TO BE SOLVED: To obtain excellent durability by constituting the innermost side wall of a regular shaped refractory using magnesia material and chrome matter- containing material as indispensable refractory materials and alumina material if required, molded, heat-treated at a specified temp. and being made to a specified porosity. SOLUTION: A refractory composition is prepared by using 25-90wt.% (hereafter %) magnesia material and chrome matter-containing material as indispensable components, and incorporating 2-25% alumina material containing >=90% Al2 O3 if required, and compounding to have >=90% of the total quantity of refractory materials in the sum of three materials. A binder (if required) is added to the refractory composition, kneaded and molded and the molding is heat-treated at <=1000 deg.C, thus the regular shaped refractory having <=15vol.% porosity is obtained. Subsequently the innermost side wall of the furnace is constituted by using the regular shaped refractory, and dry type monolithic refractories are charged between the regular shaped refractory and a furnace main body and filled under direct vibrations, thus the induction furnace is obtained. |
