METHOD OF SMELTING STEEL IN CONVERTER Russian patent published in 1997 - IPC

FIELD: steelmaking. SUBSTANCE: invention relates to smelting steel in combined-blast converter. The latter is charged with scrap and then filled with liquid cast iron. Smelt is blasted from above with oxygen and from below, through bottom lances, with carbon dioxide, nitrogen, or argon. In the beginning of smelting, bottom nitrogen or argon blasting lasts $$$ min, this time being determined from expression: $$$ = (1000- 5000)/A:t where A is a portion of liquid cast iron in charge, t temperature of liquid cast iron in C, and (1000-5000) empirical coefficient taking into account oxygen blast intensity and percentage of silicon in cast iron, min C. Time $$$ run out, carbon dioxide is blasted through bottom lances. EFFECT: increased stability of process and increased percentage of smelting with bottom blasting. 1 tbl