.90 T - Top And Bottom Blowing Converter 08al Steel Metallurgical Effect Analysis

Based on the top and bottom blowing converter,top–bottom combined blowing converter process integrates the advantages and overcomes the disadvantages of them.At present,it has become the main steelmaking process in the world.In the past 30 years ,the practice shows that the top–bottom combined blowing converter process can make the reaction between molten steel and slag at the end point of blowing approach to the balance, decrease the oxidizability of molten steel and slag at the end point of blowing,increase the capability of dephosphorization and dedesulfurization , yield good economic returns,etc.Based on consulting the extensive literatures and summarizing the study on the top–bottom combined blowing converter process at home and abroad, through sampling from production field ,analyzing the composition of molten steel and slag at the end point of blowing, testing the final slag's melting point in the lab and so on ,the metallurgical effect of 08Al steel has been studied in 90t top-bottom combined blowing converter.The main conclusions are drawn as follows: The effects of desulfurization and dephosphorization are the best when the final slag's basicity is about 4.5.The molten steel is over oxidized severely at the end point of blowing and the FeO content of final slag is excessive.With the increase of the FeO content, the melting point reduce obviously.When the MgO content less than 11%, the melting point decrease with the increase of the MgO content,when the MgO content exceed 11%, the melting point enhance with the increase of the MgO content ,the MgO content of final slag is satisfied with the demand of slag splashing in substance.According to the researches,in order to improve the metallurgical effect of 08Al steel in 90t top-bottom combined blowing converter under the current conditions,it is necessary to reduce the FeO content of final slag,control the final slag's basicity approach to 4.5 and assure the MgO content exceed 11% to slag splashing.Moreover we can take some measures to reduce the FeO content of final slag: decrease the reblowing times likely, mend the model of the bottom blowing intensity and the control in oxygen lance height,reduce the tapping temperature properly and add in some coke powder .