Study On The Behavior Of Ceria In Aluminothermic Reduction Of Blast Furnace Slag

This paper introduces the existence form,research method,formation principle of blast furnace slag and the application of blast furnace slag in the fields of preparing glass-ceramics,treating water pollution,agriculture,producing building materials,high-temperature phase change materials and direct alloying of rare earth.Taking the rare earth blast furnace slag containing Baotou Steel as the research object,the rare earth steel is directly alloyed and smelted to make the rare earth elements enter the steel to achieve the purpose of direct alloying.The six-membered slag system was establishedCaO-SiO₂-Al ₂ O₃-MgO-CaF₂-Ce ₂O ₃using the coexistence theory model.Using Matlab programming and using the downhill method to iteratively calculate the activity of each structural unit.The activity changes in slag with different alkalinity at temperaturesCe ₂ O₃ ranging from 1370°C to 1620?were obtained.When the alkalinity is 1.0,the activity in the blast furnace slagCe₂ O₃ is the highest at a temperature of 1370?,and the maximum is 0.0081.5 g of tin particles,alkalinity is 1.0,1.4,1.7,2.0,2.3.The new blast furnace slag 5 g and the high-purity aluminum 1 g are sequentially placed in a high-temperature tube furnace to raise the temperature to 1550?,and the alkalinity is obtained.The metal in the elevated tin metal is gradually reduced from 4.51 ppm to 1.85 ppm,which is consistent with the theoretical calculation of the six-membered slag activity using the coexistence theory model.The direct alloying experiment was carried out in a 30Kg medium frequency induction furnace.10Kg of pure iron,100g of blast furnace slag and 40g of aluminum powder were added.When 10min,the content of Ce in the molten steel was 3.5ppm,and the reduction rate of Ce was 8.05%.The microscopic process of rare earth elements in the rare earth blast furnace slag of aluminothermic reduction steel is:SiO₂?Al ₉Si?Si?Secondly,the silicon element reduced by Al continues to undergo deoxygenation reduction reactionCaSi₂.10g of reducing agent aluminum was added,and the inclusions in the molten steel were due to inclusions formed by deoxidationAl ₂ O₃ of aluminum and MgO omposite inclusions contained therein.20g of reducing agent aluminum was added,MnS inclusions and MnO inclusions are formed in the molten steel.Mn is oxidized to MnO,Precipitated on the surface of Al ₂ O₃-MgO inclusions,The resulting compositeAl₂ O₃-MgO-MnO inclusions.30g of reducing agent aluminum was added The contents of Al,Ce,and O in the internal spherical inclusions in the molten steel are high,and there are also many internalCe₂ O₃-AlO₃ Composite inclusions wrappedAl ₂ O₃ or CaO.The combined energy of rare earth and oxygen reduced in molten steel is large,Rare earth aluminate CeAlO₃.