TOP-BLOWING LANCE FOR REFINING MOLTEN METAL, AND BLOWING METHOD FOR MOLTEN METAL

PROBLEM TO BE SOLVED: To provide a top-blowing lance which increases a secondary combustion rate and efficiently transfers generated secondary combustion heat to the molten metal, when oxidation-refining the molten metal by blowing an oxygen-containing gas through the top-blowing lance. SOLUTION: The top-blowing lance 1 has respectively the same number of three or more Laval nozzles 4 for diagonally and vertically jetting an oxygen-containing gas downward, and three or more straight nozzles 8 for diagonally and vertically jetting the oxygen-containing gas downward alternately and circumferentially placed at the top; and is used for the purpose of oxidation-refining the molten metal by supplying the oxygen-containing gas toward the molten metal through these nozzles. The Laval nozzle and the straight nozzle have respectively such inclination angles of (θ1) and (θ2) as to satisfy the following expression: θ2-θ1>10°. COPYRIGHT: (C)2007,JPO&INPIT