System Assessment of Carbon Dioxide Used as Gas Oxidant and Coolant in Vanadium-Extraction Converter

Study on Final Equilibrium State and Process of CO2 Reacting with Fe–C Melt

“…The constraint conditions are given subsequently. Equations [6] through [9] represent the matter conservation of oxygen, carbon, and iron in the system; the molar amount of each component is non-negative.…”

“…Table I gives an overview of the applications of CO 2 in steelmaking processes and the results that have been obtained from the former research. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] The theoretical basis for achieving the preceding effects is that CO 2 exhibits weak oxidation, which occurs through the reaction CO 2 + [C] = 2CO. The reaction characteristics mainly include the endothermic effect that reduces the temperature of the fire point zone and controls the heating rate of molten steel, generating nearly twice the amount of gas to improve the stirring intensity in the furnace, and selective oxidation of carbon and other valuable elements under different pressures and liquid steel compositions.…”

Change of burden layer reduction process after injecting CO2 into the tuyere of a blast furnace

“…The metallurgical industry is a major producer of CO 2, 9,10 in order to utilise part of the generated CO 2 for itself, metallurgical workers propose to use CO 2 as a resource for their own industry. At present, the process of using CO 2 as a resource in steelmaking is becoming mature, including the application of CO 2 in converter, 11–14 electric furnace, 15 refining 16,17 and the treatment of steel slag. 18,19 But the process of using CO 2 as a resource in the blast furnace is less studied.…”

Oxidation Mechanism During Pyrometallurgical Vanadium Extraction Process Using CO2-Containing Gas

“…2 However, some typical problems need to be overcome for blowing pure O 2 gas into the hot metal; for example, O 2 as a strong oxidizer can cause overheating and consume extra solid coolants. 3 According to the industry process, the temperature rises quickly at the initial oxidation stage, and coolants such as cold bonded pellets, pig iron, and iron ore are added into the converter to lower the bath temperature at this juncture. Therefore, it is difficult to control the bath temperature accurately using this method, and the impurity elements such as phosphorus, sulfur, and silicon can also accelerate the burden of subsequent steelmaking processes in practical production.…”

“…8,10,11 This technology has also been successfully applied to the electric arc furnace, 12 ladle furnace, 13 and Rheinstahl-Heraeus furnace 14 processes. In our previous work, 3,15 vanadium extraction with mixed CO 2 -O 2 injection has proven to be an effective way for vanadium extraction, in which CO 2 was used as a gas coolant to replace the solid coolants. CO 2 , compared with O 2 , is a relatively weaker oxidant and oxidation of hot metal by CO 2 is endothermic, so the oxygen potential and temperature can be adjusted by partial replacement of O 2 by CO 2 in the injected gas, 3,15,16 which can be applied to facilitate the efficiency of the vanadium extraction.…”