Al-CaO Composite Deoxidation Process

With the progress of social science and technology,the requirements for the quality of steel in industries such as industry and agriculture are increasing day by day.The phosphorus,sulfur and other impurities in the molten steel and Al2O3 inclusions,all affect the performance of steel.Removal of Al2O3 inclusions is the key technology of clean steel production.Using Al / CaO composite deoxidizer to deoxidize the molten steel and generate low melting point inclusions is beneficial to the floating of Al2O3 inclusions,reducing the content of Al2O3 inclusions in the steel and reducing the nodulation of the continuous casting inlet.By adjusting the ratio of Al and CaO,Al2O3 inclusions can be more transformed into low melting point calcium aluminate,reduce the content of Al2O3 inclusions in the molten steel,which will help to improve the quality of steel and casting conditions.In this paper,180 t ladle as the research object to establish a hydraulic model,by changing the ladle bottom blowing position and the amount of air blowing,the use of PIV technology and high-speed video camera to determine the speed of inclusions in molten steel floating speed,Gas conditions on the mixing time of the molten steel to determine the oxygen ladle is most conducive to floating inclusions blowing position and the amount of blowing air.The experimental results show that when the distance from the center is 0.5R and the blowing volume is 0.08m3 / h,the gas stirring efficiency is the best,and the particle floating speed is also the fastest,which is most conducive to the floating removal of inclusions.In this paper,the high temperature silicon-molybdenum furnace was used to carry out the thermal experiments to study the formation of low-melting-point Al / CaO compounds by changing the proportion of Al and CaO,using scanning electron microscopy to analyze the non-metallic inclusions in the sample morphology.The chemical composition of inclusions were analyzed to explore the formation of inclusions.The experimental results show that with the addition of CaO,the number of irregular shaped inclusions in the molten steel is less and less,the number of spherical inclusions is significantly increased,and the size of inclusions is also reduced.When Al,CaO addition ratio of 1: 1.75 ~ 1: 2.5,the molten steel produced calcium aluminate inclusions.Calcium aluminate low melting temperature,high stability,can improve the quality of the furnace and steel refining,shortening the smelting cycle,reduce production costs.