METHOD FOR ACCELERATING REDUCTION OF MANGANESE ORE IN STEEL MAKING STAGE

摘要

PURPOSE:To incorporate Mn in Mn ore at a high yield into a molten iron by blowing the fine pulverous prereduced Mn ore obtd. by prereducing, embrittling and sieving the Mn ore into the molten iron in a converter from the bottom tuyeres at the time of steel smelting with the converter. CONSTITUTION:The massive Mn ore and coke of 2 to 25% of the weight of the Mn ore, and a carbonaceous reducing agent, such as coal, are charged into the prereducing furnace 1, such as rotary kiln where these materials are heated by a burner 2 to 600 to 1200 deg.C. The strength of the ore lowers and the ore embrittles when the removal rate of oxygen contained in the ore attains a 20 to 50% range; therefore, the ore can easily by pulverized by light grinding. The fine powder sieved to =3mm is blown from the bottom tuyeres 5 of the converter 3 into the molten iron heated to 1430 deg.C. The powder sized =3mm is reground or is added from the upper part into the converter 3. The Mn is reduced and absorbed at a high yield into the molten iron. The Mn is supplied from the Mn ore into the molten iron without using costly ally iron, such as Fe-Mn, by which the molten iron is refined to the high-Mn steel at a low cost.