CO2 injection improves the high-temperature performances of Cr-bearing vanadia-titania magnetite smelting in blast furnace. Issue 43 (January 2021)

• Record Type: Journal Article
• Authors: Song, Hanlin; Zhang, Jinpeng; Cheng, Gongjin; Yang, Songtao; Xue, Xiangxin
• Is Part Of: Journal of CO₂ utilization. Issue 43(2021)
• Publication Date: 2021-01
• Subjects: CO2 injection -- Cr-bearing vanadia-titania magnetite -- Blast furnace -- High-temperature performances -- Energy savings and CO2 emissions reduction; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2020.101363
• Languages: English
• ISSNs: 2212-9820

Abstract

Highlights: CO2 can be used in vanadia-titania magnetite ironmaking. CO2 injection helps to reduce coke consumption and CO2 emissions. CO2 improves the softening-melting-dripping performances to be better. CO2 injection helps to reduce the generation of titanium carbonitride. Abstract: The effects of CO2 injection on the high-temperature metallurgical performance of Cr-bearing vanadia-titania magnetite (CVTM) in blast furnace (BF) smelting were investigated. The dry air or O2 -enriched air is not necessarily suitable for any blast furnace production, and CO2 -containing high-temperature energy-carried gas (CHEG) also can be an alternative injection gas with lower cost and pollution. This kind of CHEG can be blast furnace gas, basic oxygen furnace gas, coke oven gas, sintering gas and rotary kiln gas and so on, which contained high sensible heat and CO2, H2 and CO. Injecting CHEG into the blast furnace can replace air injection to achieve the heat balance in the cohesive zone and raceway. The calculated boundary injection ratio of CO2 is approximately 15.3%, and the experimental optimal CO2 injection ratio is about 10∼20%. CO2 injection benefits the blast furnace operation, the permeability of cohesive zone, recovery ratio of Cr and V. With increasing injected content of CO2, the temperature range of softening zone [T40 -T4 ] and melting-dripping zone [Td -Ts ] decrease almost 20℃, and the dripping ratio increases from 62.36% to 69.76%, the recovery of V increases from 32.75% to 47.96%, and the recovery of Cr increases from 42.35% to 64.41%. The CO2 injection affects the melting temperature of the high-titanium slags to be higher and the maximum temperature difference can reach 45℃, which is beneficial to the slag stability and separation of slag-iron and restrain the over-deduction of titania to TiN upon the slag-coke interface with lower N2 .