REDUCTION OF POWDERY OXIDE ORES TO METAL

PURPOSE:To produce molten metal at a low cost without using costly electric power and hard coking coal by using a reducing gas generated during melt reduction for prereduction of powder ore contg. metallic oxides. CONSTITUTION:Granular and small granular metallic oxides are supplied into a prereducing furnace 2. The high temp. generated gas generated in a vertical melt reduction furnace 3 is introduced into a prereduction furnace 2, where the metallic oxides are dried, heated and prereduced. The prereduced ore is blown through tuyeres 8, 8' together with preheating air into the furnace 3. Further, a flux and a reducing agent are charged therein. While the prereduced ore blown into the furnace is heated and melted in the high temp. region formed in the furnace 3 and drops in the lower part of the furnace 3, it is reduced and molten metal and molten slag are formed, whereby refining is effected. In this way, the prereduced ore is reduced satisfactorily.