Study On Group Activity And Balance Prediction Of Titanium Dioxide Slag

The activity data is kind of basic and important thermodynamic properties for the component in metal and slag melt, especially for the application of the metallurgical process. Based on the molecular interaction volume model (MIVM) and its pseudo-multicomponent approach, the activities of the metal and slag melt containing titanium are predicted in this study. And the equilibrium distribution coefficients of Ti between slags and iron are also investigated during the metallurgical process of V-Ti magnetite in blast furnace. This will provide basic thermodynamics data and bring a theory foundation for the metallurgical process of V-Ti resources.Activities data of binary system is essential to the study of thermodynamic and phase equilibrium for multi-component system. The formulas of calculating activities from binary phase diagram was raised by Zhou Guozhi. For this algorithm is based on the endpoint value of binary phase diagrams as the initial value, it does not apply to the incomplete phase diagram which lack of endpoint value, however, the incomplete phase diagrams in the partial composition generated by experimental determination are widespread. Therefore, the formulas of Zhou are improved in this work. The calculation results of binary system of Bi-In, Al-Cd, CaO-SiO2 and MnO-TiO2 are in good agreement with corresponding experimental data which the deviations are less than 30%. This indicates that the improved algorithm is reliable and efficient to calculate activities of alloy and slag system from binary phase diagrams in the partial composition concentration. Based on the reliability of improved algorithm, this study calculate the activities of MgO-TiO2, Al2O3-TiO2,SiO2-TiO2 and CaO-TiO2 system lacking of the experimental data and bring the thermodynamic data for the lasting research on multicomponent slag system.The component activities of FeO-MnO-SiO2, FeO-MnO-TiO2 and MnO-SiO2-TiO2 in slag systems are predicted by pseudo-multicomponent approach of MIVM and the Coexistence Theory Model. The results show that the MIVM could predict the thermodynamic properties stability and accurately. The activity of MnO and FeO in Al2O3-FeO-MnO-SiO2 and TiO2 in Al2O3-CaO-MgO-SiO2-TiO2 are predicted by MIVM and the results are in reasonable agreement with experimental data. changing patterns about activity of TiO2 in quintuple system are investigated which are consistent with the experimental.Based on the molecular interaction volume model, the activities of Mn and Si in Fe-C-Mn and Fe-C-Si melts, respectively, are predicted and compared with Wagner Interaction Parameter Formalism, the Unified Interaction Parameter Formalism and the Interaction Parameter Approach, respectively. The results show that the MIVM are more accurate than other models after the comparing with experimental. The equal activity curves of each component at 1873K in Fe-C-Ti system are calculated and drawn by MIVM, and the changing patterns about the activity coefficient of Ti in carbon-saturated Fe-Csat-Si-Ti melts are obtained. Finally, the equilibrium distribution coefficients of Ti between blast furnace slags CaO-MgO-Al2O3-SiO2-TiO2 and carbon-saturated iron are estimated by using present model. Furthermore, the effects of carbonic oxide partial pressure, basicity of slag and temperature on the equilibrium distribution coefficients of Ti are investigated, and this will create a theoretical accountability for controlling the reduction of TiO2.