Use of slags from the production of manganese alloys in steelmaking

Abstract

roalloys. One promising direction is the use of manganese slags in steelmaking, particularly in the oxygen-converter conversion of low-manganese pig irons. The addition of such slags in the necessary amounts simultaneously solves the problems of increas- ing the efficiency of oxygen-converter steelmaking and saving manganese ferroalloys. Studies were performed on the use of ladle residues (crests) of slag from the production of silicomanganese at the Nikopol' Ferroalloys Plant to make steels at the Nizhniy Tagil combine, Cherepovets Metallurgical Combine ("Severstal'"), and West Siberian Metallurgical Combine in 160-, 350-, and 300-ton converters from a semifinished product and pig iron with man- ganese contents of 0.02-0.05, 0.15-0.35, and 0.4-0.7%. The blowing rates were 1.9-2.4, 1.4-2.0, and 2.8-4.0 m3/ton.min, respectively. Ladle residues of slag from the production of silicomanganese consist of the alloy silicomanganese (15-25%) and the ferroalloy slag itself (75-85%). The ferroalloy slag contains 16--20% MnO, 8-10% A1203, 4--6% R20 , 3.5-4.5 MgO, 40-50% SiO 2, 10-15% CaO, and 0.7-1.2% S, and it has a melting point of 1250~ The ladle residues contain at least 30% MnOto t.