In order to better study the application of CO2 in the vanadium extraction process of a combined blowing converter, the simulation experiment of combined injection was carried out under laboratory conditions by changing the injection ratio of CO2 and O2 at the initial injection temperature of 1:10, 2:10 and 3:10 (the flow rate of O2 is 600 ml/min and the flow rate of CO2 varies proportionally according to the flow rate of O2). The oxidation of carbon and vanadium in the molten pool and the thermal effect of molten pool under different bottom blowing flow rates were studied. The experimental result shows that with the increase of bottom blowing strength, vanadium-extraction and carbon conservation can be improved. If the flow rate of CO2 increases by 10%, the temperature of molten pool decreases by about 5–7 °C and the heat from molten pool decreases by about 1.3857–2.0214 kJ. © 2020, The Minerals, Metals & Materials Society.

Through thermal simulation experiment and SEM analysis, limestone dissolution in a steelmaking slag was studied. The results showed that the dissolution rate of limestone is 5.4 times greater than lime under the same conditions in slag, the dissolution rate of limestone in slag increases rapidly with the increase of stirring gas flux. The rapid dissolution of limestone in the slag can be explained on two sides. Limestone decomposition and dissolution happens simultaneously, the newly generated lime participates in slagging in its highest activity. On the other hand, CO2 from limestone decomposition not only strengthen the mixing strength of the molten pool, but also helps to remove the high melting point 2CaO·SiO2 product. © 2017 Trans Tech Publications, Switzerland.

A review of resource application and development of carbon dioxide in the ferrous metallurgy process is presented. Study on resource utilization of CO 2 in the steelmaking process is significant to the reduction of CO 2 emissions and coping with global warming. Based on the resource application of carbon dioxide in the whole process of ferrous metallurgy, the paper introduces the development and application of carbon dioxide in the sintering, BF, Converter, secondary refining, Continuous Casting and smelting process of stainless steel in recent years. According to the domestic and foreign research and application status, the paper analyzes the feasibility and metallurgical effects of the application of carbon dioxide in the ferrous metallurgy process. The paper mainly introduces some new techniques: flue gas circulating sintering, blowing CO 2 through Blast Furnace tuyere and CO 2 as a pulverized coal carrier gas, top and bottom blowing CO 2 in the converter, Ladle Furnace and Electric arc Furnace bottom blowing CO 2 , CO 2 as Continuous Casting shielding gas, CO 2 for stainless steel smelting, and CO 2 circulation combustion. CO 2 has a very broad application prospect in iron and steel metallurgy process, and the quantity of CO 2 utilization is expected to 100k/ton steel. It will effectively facilitate the progress of metallurgical technology, strongly promote energy conservation of metallurgical industry, and contribute to sustainable development.

During the production of Medium-Low Carbon Ferrochromium (M-LCFeCr) or Medium-Low Carbon Ferromanganese (M-LCFeMn) in converter process with introduction of oxygen, the oxidation reactions of main and tramp elements by oxygen are all exothermic reactions, hence lead to energy surplus in the production process. Essentially there are three practical strategies to deal with energy surplus: Dilute the surplus energy by adding coolants. Remove the surplus energy by blowing inert gases (like argon). Neutralize the surplus energy by injecting part CO2. The first method is used frequently nowadays, but the additional coolants including silicochromium and M-LCFeCr are costly and cause the temperature variation in a wide margin. The second way is not cost effective to remove small amount of heat by introducing the expensive argon. The last method could be moderate and worth to study. CO2 introduction is aimed to realize controlling the bath temperature flexibly because C+CO2=2CO is an endothermic reaction, enhancing the yield of Cr (Mn) because of its weaker oxidation ability, prolonging the life time of the converter lining because of less thermal shock. However, those advantages need to be proved by theoretical and experimental work. The heat and material balance calculation can provide a theoretical basis for the production practice with introduction of CO2 in converter process. The authors pay attention to this aspect with the aim to optimize the amount of CO2 and the materials requirements. The optimal ratio of CO2 and O2 for producing M-LCFeCr and M-LCFeMn with different carbon content has been determined. © Proceeding of the 14th International Ferroalloys Congress: Energy Efficiency and Environmental Friendliness are the Future of the Global Ferroalloy Industry, INFACON 2015. All rights reserved.