Abstract: An artificial coarse-grain aggregate with particle size of 1-5 mm is prepared by adding alumina particulates as an agent for preventing molten iron erosion, metallic silicon particulates as a pore-size reducing agent, and organic binder to flake graphite with high thermal conductivity or to artificial graphite with particle size of 1 mm or less or to a mixture of both types of graphite, and then by kneading, molding, baking, crushing, and screening. By compounding the coarse-grain aggregate thus manufactured instead of the conventional coarse-grain aggregate of calcined anthracite, artificial graphite, or flake graphite to manufacture carbon refractories, large-sized carbon refractories for blast furnaces, with high thermal conductivity and resistance to molten iron, may be manufactured at high yields. In result, the obtained carbon refractories are favorable as lining material for the basin parts of blast furnaces.