Study On Slag Properties Of Vanadium-titanium Magnetite Smelting And Vanadium Distribution Behavior Between Slag And Iron

Vanadium-titanium magnetite is the main resource for extracting iron and vanadium.The advantages of the“blast furnace-converter”method are that the processing technology is mature,and the vanadium extraction efficiency is high.It is the main method for using vanadium-titanium magnetite.Compared with Panzhihua vanadium-titanium magnetite and Chengde vanadium-titanium magnetite,Yangxian vanadium-titanium magnetite has lower TiO₂ content and higher V₂O₅ content.The properties of slag and the distribution ratio of vanadium can directly determine the recovery rate of V₂O₅.Studying the properties of slag and the distribution ratio of vanadium is the prerequisite for efficient utilization of Yangxian vanadium-titanium magnetite.There are few studies on low-titanium blast furnace slag system in Yangxian vanadium-titanium magnetite.Based on the blast furnace smelting process,this paper simulates the reduction of vanadium-titanium magnetite in Yangxian and carbon-saturated molten iron,and systematically studies the fluidity,thermodynamic and dynamic behavior of vanadium distribution.The main contents are as follows:When the TiO₂ content increased from 9%to 17%,the slag viscosity decreased from 2.298Pa·S to 2.161Pa·S at the 1533?,the melting temperature was reduced from1645.36K to 1594.54K,and the activation energy was from 115.27 kJ·mol^-1 reduced to100.86 kJ·mol^-1.[TiO₄]-tetrahedron enters the slag melt and combines with the O-Si-O ionic bond to form a Si-O-Ti unit,which reduces the viscosity of the slag.TiO₂ leads to the increase of simple polymerization structures Q⁰ and Q¹ in the slag melt and the decrease of complex polymerization structures Q² and Q³,the increase of simple silicate structural units and the decrease of the degree of polymerization of the melt.It is clear that the degree of difficulty of carbon reduction is V₂O₅<SiO₂<TiO₂.The equilibrium time of the vanadium reduction is 150min.The vanadium distribution ratio L_V increases with temperature,alkalinity,and V₂O₅ content,TiO₂ content and Al₂O₃content.MgO had a small effect on the vanadium distribution ratio.The calculation formula for?_?V2O5?obtained by multiple linear regression is?_V2O5=-345.865+7.9485?%V₂O₅?+1.8432?%Al₂O₃?+0.3657?%TiO₂?+0.3197?%MgO?+0.1619T+55.9413R,the correlation coefficient is 0.9521.The vanadium reduction rate R_V gradually increases with the increase of temperature,alkalinity,V₂O₅ content,TiO₂ content,Al₂O₃ content and MgO content.It is calculated that ln[?%V₂O₅?-?%V₂O₅?_e]has a clear linear relationship with the reduction time t.The reduction of V₂O₅ in the slag sample is a first-order reaction.The control steps is the diffusion of V₂O₅ in the slag and V in the molten iron,and the apparent activation energy is 53.60kJ·mol^-1.