| 摘要 |
PURPOSE:To stably maintain secondary combustion ratio to high and to prevent reoxidization of molten metal by specifying ratio of molten slag thickness in a furnace and dent depth on the slag formed with top blowing oxygen. CONSTITUTION:By top-blowing the oxygen gas to raw materials of ore, carbonic material, etc., charged in the smelting reduction furnace 1, the carbonic material is burnt, to reduce iron oxide. Then, the ratio Ls/Ls0 of the molten slag thickness Ls0 in the furnace and the dent depth Ls of the slag formed with the top blowing oxygen 8 is set to <=0.7. The maintenance of this setting value is executed by controlling height of the top blowing lance 5. By this method, the high efficient smelting reduction is executed, so that the dent depth Ls of the molten slag does not reach to the molten metal 2. |
