FIELD: ferrous metallurgy, particularly, devices for refining liquid steels and methods of liquid steel refining in the course of treatment for making ox extra low-carbon steel. SUBSTANCE: plant has device for circulating vacuum treatment designed for remelting of liquid steel and including vacuum chamber and submersible inlet and outlet pipes through one of which metal is supplied to chamber and through other, it is withdrawn from chamber. Located in side wall of circulating vacuum treatment device are many injection lances. Each lance consists of internal and external tubes. Internal tube is narrowed to form gas jet at supersonic velocity. Blown through external tube is cooling gas for cooling internal tube. Method of refining of liquid steel regulates beginning of blowing of oxygen or oxygen-containing gas by reaction jets at supersonic velocity in direction of surface of liquid steel in vacuum chamber when measured internal pressure in vacuum chamber amounts to 150 mbar. Gas is blown at least 3 min or until completion of decarbonization. EFFECT: easy removal of carbon from liquid steel, prevented drop of liquid steel temperature and ensured stable operation of plant. 26 cl, 16 dwg, 7 ex
