GR1003305B - Pyro-metallurgical method for the reduction of oxygen containingferronickel ores with selective use of an additive reducing agent, metal or metals in combination or a combination of alloys thereof to the metallurgical mixture and addition to the reduced. - Google Patents

Abstract

To the nickel-containing iron ore, rich or poor in iron, is added, together with the necessary carbon, a selected metal M or alloy of metals, preferably an iron alloy, FeM in a quantity corresponding to, and suitable for reduction of, the theoretical percentage of nickel contained in the slag and at least 10-20% of the theoretical percentage of iron trioxide which is likewise contained in the slag. The above metallurgical mixture, having been wetted with a solution of crude oil and liquid glass, is led into a vacuum mixer for better mixing of the reducing agents with the ore. It is then fed into a revolving furnace I,2 where selective reduction of the iron trioxide to the level of the first oxide of iron is carried out, the product exiting with 1% +- 20% carbon and a temperature of 950-1050 degree C. To the above product from the revolving furnace II, 2 is added pre-reduced iron ore or nickel-containing iron ore rich in iron with the suitable chemical composition and necessary percentage, according to the type of ore to be processed. Finally, the above mixture is fed, hot, into the electric smelting furnace III, 2 where it is produced and where due to the difference in specific gravity, the metallic iron-nickel is separated from the floating slag. The steady operation of the smelting furnace and the suitable chemical composition of the slag on one hand, and, on the other, the strongly exothermic reaction of the nickel oxide with the metallic reducing agent M or FeM, give slags low in nickel.