| 摘要 |
<p>PURPOSE:To dephosphorize a molten iron with a smaller amt. of a dephosphorizing material by blowing a flux for dephosphorization by gaseous N2 from a bottom blowing tuyere and adjusting the stirring force to be applied to the molten iron from the initial period to the end period of the dephosphorization at the time of blowing the oxygen in the presence of basic molten slag and subjecting the molten iron to a dephosphorization treatment. CONSTITUTION:The molten iron 2 is put into a converter 1 having the bottom blowing tuyere 4 and a top blowing lance 7 and inexpensive steel scrap 3 is added to the molten iron and is melted. A mixture composed of lumped CaO, CaF2 and iron ore is charged as a slag forming material for dephosphorization from a tank 6 into this molten iron to form the molten slag for dephosphorization. The powder of the above- mentioned slag forming agent for dephosphorization in a blow tank 5 is simultaneously blown by gaseous N2 form the bottom blowing tuyere 4 and gaseous oxygen is brown from the lance 7 to maintain the stirring force epsilon defined by formula I in the molten iron at 1.2 to 10kw/t in the initial period of dephosphorization and at 0.5 to 1.1kw/t in the end period of dephosphorization, by which the molten iron is dephosphorized with the lessened use of the dephosphorizing agent essentially consisting of the CaO.</p> |
