Experimental Study On 12CaO·7Al₂O₃ Base Refining Slag Of Desulfurizaiton And Removal Inclusion

With the progress of the clean steel smelting technique,the requirement increase of the steel with ultralow sulphur content,desulphurization in the secondary refining process with fine refining stags has become a focal problem concerned all over the world.The main purpose is how to choose proper refining slag in accordance to different facility of second refining.According with the study of desulphurization dynamics and thermodynamics, With summarizing research work of the predecessor,through experiments on resistance furnace,there study sintering technology and desulphurization ability and removal non-metallic inclusion ability of refining slag of 12CaO·7Al₂O₃ in ladle furnace.With theoretical analysis,this paper deals with desulphurization ability of free-fluoride refining slag of 12CaO·7Al₂O₃-BaO-MgO-Li₂O-SiO₂.Under the experimental conditions,12CaO·7Al₂O₃ premelted refining slag has high desulphurization ability,the initial sulfur content in steel was in the range of 0.030%～0.031%,the final sulfur content in steel was decreased to the range of 0.016%～0.023%,and the desulpurizaiton ratio was in the range of 23.33%～48.391%.Free-fluoride refining slag of 12CaO·7Al₂O₃-SiO₂-BaO-Li₂O-MgO has perfect desulphurization ability.Under the experimental conditions,the initial sulfur content in steel was 0.030%,the final sulfur content in steel was decreased to 0.006%,and the desulpurizaiton ratio was 80.00%. Under theoretical analysis,the optimal slag composition attained from the experiment was 12CaO·7Al₂O₃(%)/SiO₂(%) 9～10,(BaO%) 15%～20%,(MgO%) 4%,(Li₂O%) 3%.12CaO·7Al₂O₃ base free-fluoride refining slag in ladle furnace has satisfied the requirement of free-fluoride,and which is harmless to the environment.Which we researched has wide resource and low weathering for furnace firebrick lining,its easy to process and transport.12CaO·7Al₂O₃ free-fluoride refining slag high content of CaO and Al₂O₃,can absorb a large number of aluminum deoxidation product of-Al₂O₃,and Al₂O₃ inclusions adsorbed,the composition will not cause substantial fluctuations in refining slag. Comparison of aluminum for deoxidation of steel.