Experimental Study On Developing Carbonization Slag Agent Using Scrap Carbon Block In Aluminum Reduction Cell

As a solid waste in the electrolytic aluminum industry process,scrap carbon blocksin aluminum electrolytic cells have important recycling and reuse value because of their high carbon content.However,the vast majority of aluminum plants currently have low levels of recycling of these scrap carbon blocks.At the same time,in the process of smelting iron and steel products,the carbon content in liquid steel often requires carbon addition due to operating problems such as oxygen decarburization in the smelting process and the carbon content does not reach the expected requirements.The carbon content of scrap carbon blocks is high.The scrap carbon block from the aluminum electrolytic cell can be used to prepare the carbon-removing raw materials for carbon steelmaking.At the same time,they contain components that reduce the melting point of the smelting slag,and they also have slag-removing capability in the process of carbon steel smelting and smelting.It have the double effects and turn waste into treasure.It is of great theoretical significance and practical value to develop an experimental study on the use of scrap carbon in aluminum electrolytic cells to develop a slag-retaining agent.By analyzing the basic characteristics of the components,phases,and structures of used carbon blocks in aluminum reduction cells,basic data are provided for the use of scrap carbon blocks in aluminum reduction cells as a carbonization slag agent;tests are carried out in the medium frequency induction furnace to control carbon addition and slagging.The effect of particle size,recarburization temperature and other factors on the effect of slag was studied.By using the quadratic regression orthogonal design method,the melting temperature,meltingspeed and viscosity of the refining slag of different formulations were determined.Among the scrap carbon blocks,the anode carbon block contains 96at% carbon,and the cathode carbon block contains about 49at% carbon.The spent cathode carbon block is graphitized to a greater extent than the anode carbon block.When the ratio of waste cathode carbon block to waste anode carbon block is 3:1,when adding scrap carbon blocks with a particle size of 3.4mm or less at the bottom of the furnace,the absorption rate of molten steel is the highest,and the effect of carbon addition is best.The best recarburization temperature is near the equilibrium temperature,and the molten steel is stirred to promote the carbon addition.Taking the amount of used cathode carbon blocks added,the amount of used anode carbon blocks added,and the slag system alkalinity as the reference factors,the ratio of waste cathode carbon blocks to spent anode carbon blocks in the slag series and the alkalinity of the slag series were determined to determine the slag line.Melting point and viscosity of the melting point.The basicity has the greatest influence on the melting temperature of the slag system,followed by the content of the spent cathode carbon block,and finally the content of the waste anode carbon block.The content of waste cathode carbon block has the greatest influence on the viscosity of the slag system,followed by the waste anode carbon block content,and finally the basicity.When the basicity is 4,the waste cathode carbon block content is 30%,and the waste anode carbon block content is 10%,the melting point and viscosity of the slag system are low,and the fluidity of the slag is effectively improved.