| 摘要 |
PURPOSE:To easily produce a low P and extremely low S molten iron at casting floor by providing desiliconizing stage, desulfurizing stage and dephosphorizing stage at the time of treating by blowing powdery material by gas into the molten iron in the casting floor trough and specifying slag-off operation at each stage. CONSTITUTION:At a first stage, desiliconizing agent is blown through a lance nozzle, set above the molten iron or submerged into the molten iron in the molten iron trough on the casting bed of a blast furnace to mainly execute the desiliconization. Next, after desulfurizing by blowing desulfurizing agent at a second stage, dephosphorizing agent is blown at a third stage to mainly execute the dephosphorization. And, after treating the desiliconization in the first stage, the slag-off is executed and after treating the sulfurization in the second stage, the slag is flowed together with the molten iron in the third stage and after treating the dephosphorization in the third stage, the slags are mixed to execute the slag-off operation. Or, after treating the desiliconization in the first stage, the slag is flowed to the second stage and the third stage together with the molten iron and after treating the third stage, the slags are mixed and slag-off operation may be executed.
|
