METHOD OF SMELTING CAST IRON IN BLAST FURNACE Russian patent published in 1998 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method consists in charging iron-ore materials, coke, and flux into furnace, blowing in hot oxygen- enriched air-blast into hearth, and periodically charging material containing free silica and carbon, specifically schungite with fineness 10-100 mm containing silica and carbon at ratio (1.25-2.4):1 and in amounts 30-60 kg/t per each 1% silicon in cast iron. Schungite is charged in distinct portions with periodicity 0.3 to 2.6 h^-1. Presence of fine silica and carbon in close contact with each other facilitates reduction of silicon. EFFECT: reduced coke consumption and increased constancy of cast iron makeup.