| 摘要 |
PURPOSE:To prevent the degradation in the spalling resistance of the refractory bricks around tuyeres by inserting small diameter pipes around the bottom tuyeres and supplying liquid carbon sources from said pipes during oxygen blowing or after the end of the blowing in a bottom blown converter using gaseous CO2 as a gas for protecting the tuyeres. CONSTITUTION:In performing steel making-refining by oxygen blowing with a bottom blown converter, gaseous oxygen is blown from the inside pipe 4A of a tuyere 4 and gaseous CO2 from the outside pipe 4B as a protecting gas for the tuyere 4, whereby molten iron is oxidized and refined to molten steel. Here, 10-20% carbon contained for the purpose of improving spalling resistance in refractory bricks 2 is oxidized by CO2 after the decarburization of the C in the molten steel and since this degrades the spalling resistance, liquid carbon sources such as tar, molasses and the like are fed from small diameter steel pipes 5 of 1-4mm. diameters buried around the tuyeres 4 during oxygen blowing or after the blowing, whereby the consumed carbon contents in the refractory bricks 2 are replenished and the spalling resistance of the refractory bricks is prevented rom degrading. |
