CHARGE FOR FERRONIOBIUM EXTRAFURNACE SMELTING AND METHOD OF FERRONIOBIUM EXTRAFURNACE SMELTING Russian patent published in 2002 - IPC

FIELD: metallurgy. SUBSTANCE: invention relates to production of ferroalloys with niobium by aluminothermic process. Charge has components in the following ratio, wt.-%: technical niobium pentoxide, 39-48; iron scale, 20-27; aluminum powder, 21-24 and lime, 8-13. Method involves the following stages: by-step loading and melting charge in sloping hearth, pouring off smelting products into ingot mold. Initially, 68-79 wt.-% of iron scale of its total amount is melted in mixture with aluminum powder and lime taken in the ratio = 1:(0.22-0.28):(0.27-0.37), respectively. Then technical niobium pentoxide is loaded and melted with 69-76 wt.-% of aluminum powder of total amount of latter in charge followed by loading and melting the rest amount of iron scale, aluminum powder and lime taken in their ratio = 1:(0.31-0.38): (0.82-0.88), respectively. Invention provides to decrease the total mass of charge and slag melt, decrease slag amount. EFFECT: decreased energy consumption in metallurgic process carrying out, decreased ecology hazard of technogenic exhausts and cost for their utilization. 4 cl, 1 tbl, 4 ex