Analysis of titanium distribution behaviour in vanadium-containing titanomagnetite smelting blast furnace

ABSTRACT

The operating data of a commercial vanadium-containing titanomagnetite smelting blast furnace (BF) have been examined over a period of one year. The liquidus temperatures and viscosities of a large number of slags were calculated by using the software Multi-Phase Equilibrium. The results show that both the slag liquidus temperature and hot metal temperature of the BF were 60 K lower than that of conventional BF operation, while both slags had similar viscosity. The correlations between the Ti distribution of hot metal and slag and the operating temperature, and hot metal and slag chemistry were analysed. Ti distribution ratio increases with increasing temperature and carbon content in hot metal. The Ti distribution calculated based on a slag/hot metal equilibrium model gave reasonably good agreement with plant measurements. This suggests that the slag and hot metal phases were close to equilibrium in the furnace hearth. A sensitivity analysis showed that temperature and C content has a significant influence on the Ti distribution ratio. The effect of slag chemistry on the Ti distribution is insignificant. Lowering of the operating temperature and carbon in hot metal can help reducing the Ti distribution into the hot metal, hence reducing the formation of Ti(C,N).

RÉSUMÉ

On a examiné sur une période d’une année les données d’opération d’un haut-fourneau (HF) commercial de fusion de titanomagnétite contenant du vanadium. On a calculé les températures de liquidus et de viscosités d’un grand nombre de scories en utilisant le logiciel Multi-Phase Equilibrium. Les résultats montrent que la température de liquidus de la scorie et la température du métal chaud du HF étaient toutes deux inférieures de 60 K à celle du HF conventionnel, alors que les deux scories avaient une viscosité similaire. On a analysé les corrélations entre la distribution de Ti dans le métal chaud et la scorie et la température d’opération, et entre la chimie du métal chaud et de la scorie. Le rapport de distribution du Ti augmente avec l’augmentation de la température et de la teneur en carbone du métal chaud. La distribution de Ti calculée sur la base d’un modèle d’équilibre scorie/métal chaud donnait un assez bon accord avec les mesures en usine. Ceci suggère que les phases de scorie et de métal chaud étaient près de l’équilibre dans le creuset du four. Une analyse de sensitivité a montré que la température et la teneur en C avaient une influence significative sur le rapport de distribution du Ti. L’effet de la chimie de la scorie sur la distribution du Ti est insignifiant. L’abaissement de la température d’opération et du carbone dans le métal chaud peut aider à réduire la distribution de Ti dans le métal chaud, diminuant ainsi la formation de Ti(C,N).

KEYWORDS:

• Blast furnace
• titanium distribution ratio
• MPE
• viscosity
• liquidus temperature
• thermodynamic modelling

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Ke-xin Jiao is a lecturer at the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing. His interests include blast furnace campaign life, blast furnace slag and Hot metal properties.

Chun-lin Chen is a professor at CSIRO Mineral Resources, His interests include Sintering mechanism and Thermodynamic simulation.

Jian-liang Zhang is a professor at the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing. His interests include ironmaking and coke making.

Zheng-Jian Liu is a vice professor at the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing. His interests include sinter and pellet.

Gang-wei Wang is a lecturer at the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing. His interests include injection coal and coke.

Wenpeng Wang is an engineer at Chengde Iron and Steel group. His interests include blast furnace campaign life.

Qiujun Shao is a post doctor at the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing. His interests include coke and blast furnace campaign life.

Additional information

Funding

This work was financially supported by the National Science Foundation for Young Scientists of China (51704019), Major Science and Technology Program for Water Pollution Control and Treatment (2017ZX07402001), supported by the Fundamental Research Funds for the Central Universities (FRF-BD-17-010A) and (FRF-TP-17-040A1).