Method of making immersion nozzle and long stopper for continuous casting of steel

A method of making an immersion nozzle or a long stopper, which consists essentially of 3 to 15% by weight of a binder capable of forming a carbon bond upon burning to decompose the binder in a reducing atmosphere, 48 to 82% by weight of zircon sand, 10 to 35% by weight of natural flake graphite and 1 to 8% of silicon containing at least 90% silicon and having a particle diameter of not more than 74 microns, said process comprising the steps of kneading the binder with the zircon sand, graphite and silicon, molding the kneaded mixture in an isostatic press at a pressure of 500 to 1500 kg/cm.sup.2, burning the molded product in a reducing atmosphere at a temperature of 900.degree. to 1200 .degree. C and applying a glassy coating to the outer surface of the burned product.