PURPOSE: To provide a carbon-containing unburned refractory brick improved in oxidation resistance, corrosion resistance to melted steel, etc., by blending a carbon colloidal silica mixture having a specific composition with a refractory raw material consisting essentially of alumina at prescribed amount.
CONSTITUTION: 10-70wt.% (expressed in terms of solid content) colloidal silica is added to a carbon raw material (e.g. carbon black) and water content of the mixture is controlled to afford a carbon-colloidal silica mixture. Then the carbon-colloidal silica mixture is blended with a refractory raw material consisting essentially of alumina at an amount of 2-10wt.% and the blend is kneaded with a binder (e.g. phenol resin) and the kneaded material is formed into a desired shape to provide a carbon-containing unburned refractory brick. A carbon-alumina sol mixture obtained by adding 10-70wt.% (expressed in terms of solid content) alumina sol to carbon can be used instead of the above- mentioned carbon-colloidal silica mixture.
KASUYA HIROTAKA
SAKAGUCHI MASAYUKI
KAWAKAMI TATSUO
