METHOD OF CONVERSION OF VANADIUM IRON IN CONVERTER Russian patent published in 1999 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method includes charging into converter of metal scrap, pouring of vanadium iron, additive in form of slag-forming materials of lime-containing and magnesium-containing materials in amount required for obtaining slag basicity (CaO+MgO)/SiO₂ of, at least, 2.8, blowing of melt with oxygen through lance; discharge of metal melt into ladle upon completion of blowing with separation from metal of vanadium slag; deoxidation and alloying of metal melt with vanadium by supplying into ladle of vanadium-containing slag; finishing and correction of metal chemical composition in furnace-ladle to produce steel microalloyed with vanadium. Metal scrap amounts up to 10-30%-of iron charge weight. Lime-containing and magnesium-containing materials are added into converter with CaO: MgO ratio of 1: (0.2-0.7), respectively, to obtain slag basicity within 2.8-4.0. Upon completion of blowing with oxygen, lime- vanadium slag is produced which in amount of 2-4% of metal volume in ladle supplied to ladle after metal discharge in capacity of vanadium-containing slag for deoxidation and alloying of metal melt with vanadium. After finishing operation in furnace-ladle, metal is subjected to degassing in vacuumizer. Lime- and magnesium-containing materials are added into converter during the first half of blowing with oxygen of metal melt. Content of magnesium oxide in charge is regulated depending on content of vanadium in iron by the following empirical formula Q(MgO)=B(5.3)/Viron-0.9), where Q(MgO) is amount of MgO in charge kg/t of iron; B is slag basicity equalling 2.8-4.0; 0.8 > V(iron)> 0.2 is content of vanadium in iron, %. One part of lime- vanadium slag produced in converter is used at stage of production of vanadium iron in amount of 30-60 kg/t of iron. EFFECT: higher yield of vanadium recovered into commercial slag (higher degree of vanadium recovery into slag) and slag quality characterized by ratio (V)/(Fe) and concentration of V₂O₅, with simultaneous production of steel microalloyed with vanadium, considerably increased stability of converter lining. 4 cl, 2 tbl