Basic Study Of Vanadium Titano-magnetite With Carbothermal Sodium Reduction Process

Vanadium titanium magnetite concentrate is an important source of titanium resources in china,most vanadium titanium magnetite concentrate is smelting by blast furnace or non-blast furnace,but titanium resources can not be effective used.In recent years,sodium-treatment is an effective solution to solve this problem,which have been focus.But it also has a series of problems,such as long process flow,high energy consumption,product quality and the smelting process is difficult smooth.In this paper,according to the problems of the sodium-treatment process,the carbothermal sodium-treament of vanadium titanium magnetite concentrate process was presented by alkali fusion.The titanium,aluminum and silicon oxides is changed into the sodium salt respectively by adding alkali fusion agent.In this processing method for vanadium titanium magnetite concentrate,the pyrometallurgy unites with hydrometallurgical.The good separation of slag and iron was realized by adding alkali fusion agent,the vanadium pig and the sodium modified titanium slag was obtained in the pyrometallurgy stage,then the sodium modified titanium slag can be used by hydrometallurgical.The comprehensive utilizing of vanadium titanomagnetite was realized at lower temperature.The alkali fusion agent is NaOH in this paper.The thermodynamics analysis and experimentation of carbothermal reduction process,high basicity on the melting process,high Na/Si on the melting was studied for vanadium titanium magnetite concentrate.The phase composition of the metallized pellets and slag was observed by XRD.The results demonstrate:(1)The higher metallization rate of the metallized pellet with NaOH can be obtained at lower reduction temperature than the metallized pellet without NaOH.When the temperature is 1150?,Na/Si=5.0,C/O=1.4,30 min,the metallization rate of metallized pellet can reach 93.17%.It was found that titanium,aluminum and silicon oxides had been changed into the sodium salt respectively in the metallized pellet by using XRD.(2)The smelting separation of the metallized pellet with NaOH can be realized at lower temperature than the metallized pellet with CaO.When 1350?,Na/Si=5.0,40 min,a good slag-iron separation was obtained and the iron recovery ratio reaches 93.15%.A bad slag-iron separation was obtained with CaO,when 1450?,R=1.0,40 min.When the temperature is 1550?,the smelting separation for the metallized pellet with CaO was realized,the iron recovery ratio reaches 93.1%.This results show that the smelting separation temperature can be reduced with NaOH.(3)The characteristics of titanium slag adding CaO was analyzed using XRD,the high melting substances(CaTiO3)was found.The sodium slats of titanium,aluminum and silicon can be obtained by adding NaOH.This sodium modify slag can be the raw material of hydrometallurgical stage.(4)By studying the thermodynamics and experimentation of alkali fusion of vanadium titanium magnetite concentrate,the technology parameters was determined.Under the condition of the prereduction temperature of 1150?,the prereduction time of 30 min and the smelting temperature of 1380?,the smelting time of 40 min,the iron recovery ratio can reach 95.76%,V recovery ratio is 75.1% for the carbon bearing pellet(Na/Si=5.0,C/O=1.4).It was demonstrated feasibly that the comprehensive utilization of vanadium titanomagnetite can be realized at lower temperature.