SURFACE-TREATED GRAPHITE AND CARBON INDETERMINATE REFRACTORY BY USING THE SAME

PROBLEM TO BE SOLVED: To obtain a surface-treated graphite excellent in oxidation resistance and strength, and usable as an indeterminate refractory by fixing super fine powders of an oxide and a nonoxide on the surface of a graphite powder by using a binder. SOLUTION: A binder is diluted with a solvent, and super fine powders of an oxide and a nonoxide are added thereto and stirred therewith to provide a slurry having good fluidity. The obtained slurry is coated on the surface of a graphite powder by adding dropwise or spraying, and the product is dried to fix the super fine powder on the surface of the graphite to provide the objective surface-treated graphite powder. Alumina, magnesia, zirconia, silica or the like is used as the oxide, and silicon carbide, silicone nitride, aluminum nitride, boron carbide or the like is used as the nonoxide. A phenol resin, a tar pitch or the like is used as the binder, and ethanol, methanol or the like is used as the solvent. The ratio of the liquid binder to the solvent is about 1:(3-10) expressed in terms of weight, and the percentage of the liquid binder in the surface-treated graphite powder is about 1-3 wt.%.