| 摘要 |
PURPOSE:To refine a low phosphorus steel by preliminarily refining hot iron in a converter type dephosporization furnace; increasing the FeO content of slag; and sufficiently mixing the hot iron with the molten slag at a specific temp. with stirring to carry out decarburization and dephosphorization. CONSTITUTION:Hot iron is charged into a bottom blowing converter type dephosphorization furnace and subjected to oxygen blowing in the presence of slag with the ratio of CaO/SiO2=1.2-2.6 to carry out desiliconization and decarburization to about 2.8%. The blowing is then stopped, and an iron type coolant is charged into the furnace to regulate the FeO content of the slag to 10-30%. While adjusting the temp. of the hot iron to 1280-1450 deg.C, a non-oxidizing gas is blown from a nozzle at the furnace bottom. The hot iron and the molten slag are violently stirred with the blown gas, whereby the iron is decarburized with the FeO in the slag, and at the same time, P is oxidized and fixed in the slag as lime phosphate. Thus, a low phosphorus steel is manufactured easily. |
