Study On Molten Steel Desulphurization Dephosphorization By Effect Of Synthetic Refining Slags

This paper carried out the research on the dephosphorization and desul-phurization of molten steel systematically according to synthetic refining slags.The project carried out thermal simulation experiment according to some performance properties of refining in laboratory and analysed the crucial factors that affects dephosphorization and desulphurization. according to the melt thermodynamics and kinetics theory,in vertue of the orthogonal design. AdoptedCaO(BaO)-Al2O3-MgO-CaF2 slags for simultaneous desulphurization and dephosphorization and try to adopt aluminium powder and the lime slags to carry out desulphurization experiment.Analysed the restriction factors that affects desulphurization and dephosphorization from the kinetics theory.The CaO-Al₂O₃-MgO-CaF₂ slags for desulphurization and dephosphorization experiment result show that deep desulphurization must go on under the prerequisite of deep deoxidation; If initial content of sulphur, phosphorus is high,so desulphurization and dephosphorization efficiency is high; The increase of sulphur and phosphorus distribution coefficient with the increase of optical basicity.In the slags including BaO, BaO and CaO was gone on reasonable match that can get higher desulphurization and dephosphorization rate; added to CaF₂ that has reduced the viscosity of the slags,raised liquidity,is helpful to increase reaction rate; basicity is 10 ～19%, optical basicity is 0.87 ⁰.9,Al₂O₃ is 9 ～13%,CaF₂ is 16～18%,BaO is 15～20%,desulphurization rate and dephosphorization rate are higher.The aluminium powder and lime slags is for deep desulphurization, synthetic slags composition is simple,gain ideal desulphurization effect and reduced cost. It can be known that high temperature is helpful for desulph-urization,low temperature is helpful for dephosphorization according to analysing the influence on reaction rate of desulphurization and dephosphorization in molten slags.the restricted link that affects reaction rate is the course of mass transfer about sulphur and phosphorus in slags and steel.