Thermodynamic Analysis On Oxidations Of Ti And V In Hot Metal Containing Vanadium

There is a lot of magnetite which contains vanadium and titanium in China, resourcesof vanadium, titanium element in the industry have a very important strategic. Now toextract V2O5in the vanadium slag, firstly to get the molten iron which contains vanadiumthrough the blast furnace, the magnetite which contains vanadium and titanium is smelted,then through the oxidation of vanadium slag in converter, and lastly using hydrometallurgyto get it. That is the main pattern to utilize the magnetite. This process ignores theextraction of titanium element. And the quality of vanadium slag will be effected by oxides.Based on the thermodynamic theory, the oxidation of various elements in V-containing hotmetal was analyzed. The favorable thermodynamic conditions of Vanadium, titaniumoxide were obtained. The transformation temperature of the carbon and vanadium iscalculated. The best of the vanadium extraction temperature and existence form of maincomponents in vanadium slag were got. And the calculation on every element in vanadiumbearing hot metal changes with O2、CO2、FeO content by using FactSage was made, therelationship between basic slag system of vanadium slag and equilibrium was studied asfollows:(1)Based on the mechanism analysis of the oxidation reaction of various elements invanadium bearing hot metal, the thermodynamic conditions of vanadium oxidation wasobtained. The lower reaction temperature of molten bath was good for vanadium oxidation.The more silicon content of hot metal composition,the less conducive to vanadiumoxidation. The theoretical calculations of the transition temperature of vanadium oxidationwas also made. The result was that the best vanadium oxidation temperature was1380℃.And the existing form of vanadium, titanium, manganese, silicon in vanadium slag isV2O3、TiO2、MnO、SiO2。(2)Through the FactSage equilibrium calculation, when the O2is2%(1.399L)、CO2is14%(7.143L)、FeO is2%, the titanium oxidation became equilibrium, The oxidationrate of titanium was87.36%、89.47%、86.84%. Meanwhile the Vanadium had not begun to oxidation, it was good to get the titanium slag. In the actual operation of the process,CO2was easier to control the selective oxidation of vanadium and titanium, which was thebest oxidant. then skimmed the titanium slag, and continued to add oxidant, to make thevanadium oxidation reaction reached equilibrium. According to the vanadium oxidationrate was the same, by comparison of oxidizing agent, the least amount of FeO wasobtained. And vanadium oxidation rate is higher as89.28%.(3) According to the study on the basic slag system of vanadium slag:FeO-SiO2-TiO2(V2O3) pseudo four component phase diagram, the calculations and analysis on thetwo component phase diagram, FeO-SiO2、FeO-TiO2、SiO2-TiO2phase diagram weremade, and the transition point temperature、the structure of compounds were found toconsistent with the calculations. It was demonstrated that the phase diagram calculationwas accuracy and reliability. Through the calculation of the FeO-SiO2-TiO2(V2O3) phasediagram’s isothermal section, the Vanadium slag isothermal section which in thetemperature is1300℃、1350℃、1400℃were obtained. By the calculation of FeO-SiO2-TiO2ternary phase diagrams, the solid area was more in1300℃, Only when the content ofSiO2was15%-40%, and the content of FeO was40%-85%, the liquid phase appeared.When the temperature was rised to1350℃, the liquid region was increased, and theexistence of FeSiO4was liquid phase. When the temperature was1400℃, the FeO whichnear the FeO vertex turned into liquid phase. By studied the pseudo quarternary phasediagram which added V2O3, all the liquid region joined the ferric vanadate.