| 摘要 |
PURPOSE:To efficiently execute preliminary refining such as desiliconization, dephosphorization, etc. of a molten iron by measuring the content of Si of the molten iron to be tapped from a blast furnace and adding a desiliconizing agent or dephosphorizing agent together with a carrier gas into the molten iron in a tapping spout according to the measured value thereof. CONSTITUTION:The content of Si in the molten iron 9 which flows down in the tapping spout 7 is measured by an Si measuring instrument 4 in the stage of receiving the molten iron 9 tapped from the blast furnace 6 into a torpedo 8, etc. The desiliconizing agent is added by the carrier gas to the down stream part of the tapping spout 7 by opening a feeding valve 1-1 of a desiliconizing agent tank 1 and opening a valve 1-2 of a carrier gas supply pipe 1-3 if the measured content of Si is >=0.20%. The dephosphorizing agent is added into the molten iron flow in the spout 7 by opening a feeding valve 2-1 of a dephsophorizing agent tank 2 and opening a valve 2-2 of the pipe 1-3 if the measured value of Si is <=0.2%. The preliminary refining such as desiliconization and dephosphorization of the molten iron is efficiently executed according to the content of Si in the molten iron. |
