The Development Of High Effective Desulphurizer For Ladle Slags Infiltration

With the increasingly strict requirement of users on the sulfur content in steel,the theory and technology of clean steel deep desulfurization has been the focus of some research.To produce ultra-low sulfur clean steel,it couldn't be achieved only by secondary refining,but by controlling the sulfur content during each smelting process, and it must according to the sulfur content of different steel type to choose the proper refining process.This paper under the enhanced desulfurizer to improve the performance of slag infiltration desulfurization process,developed a new type of desulfurizer.Through experiments on resistance furnace,we investigated the reaction mechanism in the ultra-low-sulfur-steel,and analyzed the key factors on elective desulphurization.This investigation provides the theatrical direction for the production of new ultra-low-sulfur-steels.This paper deals with sintering technology and desulphurization ability of new refining slag of 12CaO·7Al₂O₃,which has been opened up by foreign country in past two years,and investigated desulphurization ability of less-fluoride premelted slag. According to some diferent trial procedures,we did the thermodynamic balance trials and desulphurization tirals,and got the conclusions as follows.The calcium aluminate premelted slag has lower melting temperature and better fluidity in refining temperature on the base of low melting point phase 12CaO·7Al₂O₃.Because of high basicity and Al₂O₃ content,the slag system has high desulphurization ability,its desulphurization ability is highly improved by adding a lot of lime in course of refining process,especially it fits to Al-deoxidization steel desulphurization. The premelted slag containing CaC₂ or BaO has satisfied the requirement of less-fluoride or free-fluoride,and which is harmless to the environment.The desulphurizer has the good desulphurization capability.Furthermore,the desulphurizer which has the high desulphurization speed could satisfy the requirement of high production rhythm in practice and its fit for the slag infiltration of ultra-lowsulfur-steels.The desulphurized slags which we researched has wide resource and low cost,its easy to storage and transport.