METHOD OF BLAST-FURNACE SMELTING Russian patent published in 2001 - IPC

FIELD: ferrous metallurgy, particularly, methods of blast-furnace smelting of conversion pig iron. SUBSTANCE: method includes charging of burden iron-ore part including up to 30% of nonfluxed pellets containing oxides of titanium, fluxes, coke into blast furnace through its tip; heating, reduction and smelting of burden,; discharge of pig iron and slag.; determination of silicon (Si) weight fraction in ready pig iron. Nonfluxed pellets additionally contain oxides of vanadium, and they are charged into zone found at distance of 0.25 furnace top radius from periphery and blast- furnace axis. In final slag, weight fractions of titanium oxides (TiO₂) and vanadium oxides (V₂O₅) are determined and weight fraction of silicon (Si) in ready pig iron depending on weight fractions of titanium oxides (TiO₂) and vanadium oxides (V₂O₅) is controlled in slag: Si=(0.6-1.0)-(0.07- 0.08)xTiO₂+V₂O₅, where (0.6-1.0) is weight fraction of silicon in ready pig iron, wt.%, with absent titanium and vanadium oxides in final slag; (0.07- 0.08) is reduction if silicon weight fraction in pig iron with increased total fraction of (TiO₂+V₂O₅) in slag by 1% wt. %. EFFECT: higher productivity of blast furnaces and reduced content of sulfur in pig iron. 2 tbl