Research On The Influence Factors Of Vanadium Oxidation In Vanadium-containing Hot Metal By Blowing CO₂-O₂ Mixed Gas

As the main component of greenhouse gases,the large amount of emissions of CO₂,which results in the greenhouse effect of the earth,has seriously affected the the living environment and health of human beings.Metallurgical industry is an energy intensive industry.Coal is its main combustion energy and carbon source,and a lot of carbon dioxide is emitted from blast furnaces and coke ovens.Reducing carbon dioxide emissions is an urgent problem to be solved.The technique to extract vanadium during converter steelmaking process is to blow pure O₂ to oxidize vanadium in molten iron into slag.The main difficulty of the process is to control the pool temperature below the carbon vanadium transformation temperature.CO₂ is a weak oxidizer,Using CO₂ instead of part of the O₂ of converter vanadium extraction,restrain the temperature rise of the molten pool.Therefore,research on the influence factors of vanadium oxidation in vanadium-containing hot metal by blowing CO₂-O₂ mixed gas has important theoretical and practical significance for the establishment of a new process of vanadium extraction and the reduction of CO₂ emission as well as environmental protection.In this paper,the effects of CO₂ ratio,injection temperature,injection flow rate and phase injection on the molten iron in the mixed gas are studied,and the effects of adding calcium carbonate on the phase composition and physical properties of vanadium slag are studied.The conclusions drawed by the paper are belowed:?1?Under the conditions of this experiment,changing the proportion of CO₂ in the blowing gas CO₂-O₂ have great influence on the oxidation of vanadium and carbon in molten iron.In this study,the comprehensive effect of extracting vanadium from vanadium is the best when the ratio of CO₂ is 10%and the flow rate is 1.714 L/?min·kg?.?2?Under the conditions of this experiment,changging the blowing temperature of the mixed gas CO₂-O₂ on the vanadium containing iron will affect the oxidation rate of vanadium.When the blowing temperature is 1300-1360°C it can meet the requirement of the extraction of vanadium.?3?The use of subsection combined injection mode can effectively exert the effect of CO₂ inhibition on the temperature rise of the bath,which is beneficial to the extraction of vanadium and carbon conservation.Under the conditions of this experiment,the initial injection of CO₂ is CO₂-O₂ of 10%and the injection CO₂ in the middle and late stages is15%of CO₂-O₂,the oxidation rate of vanadium is 95.14%.?4?Under the experimental conditions,the diopside?CaMgSi₂O₆?and tricalcium phosphate?Ca₃?PO₄?₂?was formed in the vanadium slag on the basis of vanadium iron spinel,titanium spinel,and fayalite after adding calcium carbonate.The melting temperature of vanadium slag is reduced by 42°C,which helps improve the flowability of vanadium slag and promotes the slag-gold interfacial reaction.