Application Of Improved Molecular Interaction Volume Model In Molten Iron And Slag And Matte

Metallurgical melts are substances that participate in metallurgical reactions by pyrometallurgy,including alloy melts,molten slag,molten matte and molten salt.The study of melt activity has important theoretical significance for understanding metal smelting.In the process of iron and steel smelting,the study of melt thermodynamics with phosphorus and sulfur plays an important role in desulfurization and dephosphorization.Based on the Modified molecular interaction volume model(M-MIVM),the thermodynamic activities of the components in the nonmetallic alloy melts and complex slag systems involved in the smelting process of iron and steel have been fitted and predicted.In this paper,the total mean relative errors of thermodynamic activities of 15 carbon-containing binary systems,15 silicon-containing binary systems,8 phosphorus-containing binary systems and 6 sulfur-containing binary systems were calculated as 16.89%,20.96%,14.55% and 9.34%,respectively.Based on M-MIVM in non-metallic(C,Si,P,S,etc.)in liquid alloy thermodynamics binary showed good stability,and satisfactory effect,the C-Cr-Fe,C-Fe-Mn,C-Fe-Si,C-Mn-Si and C-Fe-Mn-Si containing carbon,such as system forecast,and compared with experimental value,the total average relative error is 18.67%,among them to C-Cr-Fe system in predict the average relative error was 59.55% in group C(Wagner 120.5%,UIPF 140.86%);The average relative errors of Al in Al-Fe-Si and Al-Ni-Si systems were 1.09% and 8.01% respectively.In the prediction of Fe-Cr-P and Fe-Mn-P in phosphorus-containing system,the mean relative errors of Fe-Cr-P and Fe-Mn-P were 14.22%,21% and 16.14%,respectively,and 22.46%,15.06% and 57.82%,respectively,indicating that M-MIVM has a poor effect in the application of non-metal component phosphorus and needs to be improved.Based on the good application of M-MIVM in strongly negative deviation system and asymmetric system,M-MIVM is applied to the calculation of slag activity.Throughverifiability fitting of 22 conventional binary slag,the total average relative error is 11.53%,which is good.In MnO-FeO-SiO₂,the average relative error between the predicted values of MnO and FeO and the experimental values was 5.82% and 0.97%,respectively.In CaO-FeO-SiO₂,the average relative errors between the predicted and experimental values of components FeO and SiO₂ were 15.05% and 176.53%,respectively.In Ca O-Al₂O₃-SiO₂,the average relative error between the predicted values of component CaO and SiO₂ and the experimental values was 31.91% and 96.66%,respectively.The average relative error between the predicted values of Ca O and SiO₂ in CaO-MgO-SiO₂ and the experimental values was 36% and 39%,respectively.The average relative error between the predicted value and the experimental value of component Mn O in CaO-MnO-SiO₂ is 24.8%.The average relative error between the predicted value of component MnO in CaO-MnO-MgO-SiO₂ and the experimental value was 20.46%.The average relative error between the predicted value of component MgO in CaO-FeO-MgO-SiO₂ and the experimental value was 65.57%,respectively.The average relative error between the predicted and experimental values of component FeO in CaO-FeO-MgO-P₂O₅-SiO₂ was 33.28 %.On this basis,the five binary phosphorous slag has carried on the fitting,get five binary system of the total average relative error is only 7.95%,of which the total average relative error is only 7.02% P₂O₅,effect is good,Based on this,the component activity of Ca O-Fe O-P₂O₅ and FeO-MgO-P₂O₅ containing phosphorus slag is directly predicted,which can be used as the reference data to calculate the distribution coefficient of phosphorus between slag and metal.Based on the good application of M-MIVM in strong negative deviation system and asymmetric system,M-MIVM is applied to the calculation of sulfonium activity.Through the fitting of 9 binary matte,the total average relative errors of M-MIVM-1,M-MIVM-2 and MIVM pseudo-multivariate method are 13.23%,14.18% and 17.2% respectively,which are better.The activity of each component in Cu₂S-FeS-PbS and Cu₂S-FeS-SnS was predicted,and the total average relative error between the predicted value and the experimental value was 12.53%,16.88% and 18.17%,respectively.The results above will provide valuable thermodynamic data for iron and steel smelting process.