Study On Interfacial Reaction Mechanism Between MgO Saturated Vanadium Slag And Converter Lining Based On Slag Splashing

Furnace life is a comprehensive technical and economic index to measure the production level of converter.Slag splashing is the most important and universal technology to improve the furnace life of converter.The duplex process of converter is the main technology for vanadium extraction from vanadium titanomagnetite.Due to the distinct differences between vanadium slag（Feo-SiO₂-V₂O₃-TiO₂）and steel slag（CaO-SiO₂-FeO）,they have essential differences in the erosion of basic furnace lining and the physical and chemical laws of slag splashing furnace protection.Therefore,the mature slag splashing furnace protection technology applied in steelmaking converter cannot be simply transplanted to vanadium extraction converter.Therefore,it is urgent to strengthen the basic research of slag splashing for vanadium extraction converter.In this paper,the saturated solubility of MgO in vanadium slag and its influencing factors were studied by combining the calculation based on the ionic molecular coexistence theory and the dissolution equilibrium experiment.The saturated solubility of MgO in Feo-SiO₂-V₂O₃ slag system is positively correlated with the content of V₂O₃,and negatively correlated with the FeO/SiO₂ ratio.The solubility of MgO increased with the increase of TiO₂ and Al₂O₃ content,but decreased with the increase of MnO content.With 40 ^oC temperature increase,MgO style solubility increases by 0.5%.The corrosion rate of MgO-C material in vanadium slag and its influencing factors were studied by using the dynamic dissolution experiment system,the dissolution kinetics equation of MgO-C refractory in vanadium slag saturated with MgO was established and the corresponding kinetic parameters were calculated,and the restrictive link of MgO-C refractory dissolved in vanadium slag saturated with MgO was defined.The corrosion rate of MgO-C refractory in vanadium slag decreased with the increase of MgO and V₂O₃ content,increased with the increase of FeO/SiO₂ ratio,and increased with the increase of experimental temperature and rotation speed.The dissolution and activation energy of MgO-C refractory in MgO-saturated vanadium slag is 179.44KJ/mol,which belongs to the scope of diffusion control.The expression of J-factor derived from the calculation also verifies this viewpoint.By analyzing the microstructure and composition of the samples after the dynamic dissolution test,the evolution of the interface between MgO-C and vanadium slag was studied.It is found that there is an obvious transition layer at the reaction interface.TiO₂,MnO and Al₂O₃ in the slag will aggravate the corrosion damage of MgO-C material.The corrosion mechanism is that Fe²⁺in slag penetrates into the original layer along the gaps and cracks of mgo-c material resistant samples.By increasing the viscosity of slag,MgO can reduce the mass transfer coefficient of Fe²⁺and MgO-C samples,and at the same time reduce the dissolution driving force of MgO particles in the samples,so as to improve the erosion of the samples.