Smelting iron ores without forming deposits on furnace walls - by using mixt. of different iron ores in furnace charge, esp. haematite and magnetite

摘要

To prevent deposits on the walls of blast furnaces, rotary drum furnaces, or other smelting plant, the charge is made from a mixt. of different iron ores so it has a very low tendency to form deposits during the smelting operation. The charge pref. consists of a mixt. of haematite ore (I) and magnetite ore(II). To obtain the ore mixt. (I, II), part of ore (I) may be pre-reduced to form a ore of type(II); or part of ore(II) may be oxidised to form an ore of type(I). Alternatively a mixt. may be used of ores in which the Fe is in the same oxidn. state but the ores possess a different physical structure and/or different amts. of FeO, CaO, MgO, Al2O3 and/or similar cpds. The invention also prevents the formation of "scaffolds" in blast furnaces.