Activity Calculation Of Ion Molecule Coexistence Theoretical And Viscosity Measurement In Converter Slag

With the development of society and economy,the requirements of different industries for steel quality are constantly improving.Low cost and high efficiency purification smelting of converter has become one of the key control links of high quality steel manufacturing process."Steelmaking is slag smelting",It is of great significance to study the metallurgical properties of slag forming process of converter slag for the optimization of converter smelting process,especially for the optimization control of coupling reaction such as dephosphorization and decarbonization,so as to ensure stable and efficient clean production.Due to the high FeO content in converter slag,there are few reports on the properties of slag viscosity and component activity.In this paper,the viscosity of CaO-SiO₂-MgO-Al₂O₃-MnO-FeO slag system is measured.At the same time,the activity of each component in CaO-SiO₂-FeO-P₂O₅ and CaO-MgO-SiO₂-FeO-P₂O₅ slag system was calculated by using the theoretical model of ion molecule coexistence.Based on the basic composition of the slag,15 groups of six element CaO-SiO₂-MgO-Al₂O₃-MnO-FeO system slag were designed,and the influence of many factors on the viscosity of the slag was measured.Under different isothermal conditions,the viscosity of slag decreases with the increase of FeO content,while the viscous activation energy of slag decreases.When FeO content is constant,the viscosity of slag increases with the increase of basicity.At the same temperature,the increase of basicity will lead to the increase of viscosity.At 1673k,when the basicity reaches 1.8,only the slag system with 18%FeO content can obtain the viscosity data,which can not be measured due to the excessive viscosity.At 1623k,when the alkalinity reaches 1.5,the FeO content is 12%,and the viscosity is too large to measure.When FeO content is constant,the melting temperature increases with the increase of basicity.When the basicity is constant,the melting temperature decreases with the increase of FeO mass fraction.The models of CaO-SiO₂-FeO-P₂O₅ and CaO-MgO-SiO₂-FeO-P₂O₅ of converter dephosphorization slag system are established by using the theoretical model of ion molecule coexistence.The results are analyzed and obtained as follows:（1）for two kinds of slag systems,the activity of simple component increases with the increase of its mass fraction;（2）for two kinds of slag systems,the activity of Cao increases with the increase of basicity,while the activity of SiO₂ decreases;（3）in the CaO-SiO₂-FeO-P₂O₅ slag system,when the FeO content is less than 16%,the 2CaO·SiO₂ activity increases with the increase of FeO content,and when the FeO content is greater than 16%,the 2CaO·SiO₂ activity decreases with the increase of FeO content.Before the alkalinity increased to 1.5,the activity of 2CaO·SiO₂ increased with the increase of alkalinity,while the activity of 2CaO·SiO₂ decreased with the increase of alkalinity;（4）in CaO-SiO₂-MgO-Al₂O₃-MnO-FeO slag system,with the increase of basicity,the activity of P₂O₅ will show a fuzzy rising trend;with the increase of basicity,the activity of 3CaO·P₂O₅ will gradually increase and then decrease,and the maximum value is 0.00104 when r=1.6;in silicate compounds,the activities of CaO·SiO₂ and 2CaO·SiO₂ are the largest,and with the increase of basicity,the activity of 2CaO·SiO₂ will first increase When the FeO content increased,the FeO activity increased,the Cao activity decreased,and the P₂O₅ activity fluctuated violently,showing an overall upward trend;with the FeO content increased,the activities of 2CaO·SiO₂ and 3CaO·P₂O₅ decreased.