Research On The Kinetic Of Vanadium Oxidation In Vanadium-Containing Hot Metal By Blowing CO₂-O₂ Mixed Gas

CO₂ emissions leads to "greenhouse effect", seriously deteriorating our living environment in the past several decades. Countries all over the world are actively carrying out research on CO₂ emission reduction and utilization, and many achievements have been made in the application of CO₂ in biological, chemical and other fields. Iron and steel industry produces a large of CO₂, On one hand,a lot of work on reducing CO₂ emissions has already been conducted; on the other hand many researchers focused on the CO₂ in metallurgical process,such as hot metal protection, protection technology ba slag splashing. It is of great significance in environmental protection and reducing consumption. With the property of the element in the CO₂ of metal melt oxidation, the parts of the O₂ for vanadium oxide were replaced, it’s make the CO₂ emissions from steel production process, to get part of the recycling and reduce its CO₂ emissions. It is a new direction of CO₂ application in metallurgical industry. Therefore, this work focuses on using CO₂-O₂ mixed gas to various elements in vanadium containing molten iron, so as to provide theoretical basis for the application of CO₂ in the process of extracting vanadium, which has important theoretical and practical significance.In this paper, the experimental study on the oxidation of vanadium containing molten iron by pure CO₂ and CO₂-O₂ mixed gas was carried out. Combined theoretical analysis with experimental results, the principle and rule of the oxidation reactions of CO₂, and CO₂-O₂ mixed gas with various elements were studied. The double film theory model were used to analyze the oxidation kinetics of [V] in liquid iron, so as to obtain the effect mechanism of CO₂-O₂ mixed gas on the velocity and limitation of [V] oxidation, providing a theoretical basis for the application of CO₂ in the process of extracting vanadium in a converter. The following results were obtained.（1） The reaction orders of CO₂ with [V] in liquid iron was two.The [V] oxidation rate was controlled by the concentration of CO₂ and [V]. The reaction activation energy Ea was 77872.25 J/mol, A was e0.9 / t·wt; The reaction of CO₂-O₂ with [V] is an apparent first-order reaction when CO₂ content below 25%.The [V] oxidation rate was controlled by the concentration of [V].（2） The oxidation of [V] by CO₂ is mainly carried out in two steps.（3） To remove vanadium but keep carbon in molten iron has the best result when CO₂ is 15%; CO₂ content exceeds 15%, CO₂ reacts with various elements in molten iron.（4） A liquid-liquid model was established to describe the oxidation of [V] in molten iron using the mixed CO₂-O₂ gas. Combined with experimental get [V] oxidation rate is controlled by concentration of [V]. The apparent rate constant isK′= 6.3*10-3⁸.7*10-3s-1.The experimental results are in good agreement with the calculated valuesusing the established model in this paper. Iron liquid initial [Si], [Ti] content in the rise of the oxidation of [C], [V] has strong inhibition and the initial [C] content in liquid iron smaller effect on the oxidation of [V].