Means to cope with the higher alumina burden in the blast furnace

ABSTRACT

The stability of the blast furnace (BF) process depends on the quality of raw materials charged into the BF. Apart from various process variables, slag viscosity and slag fluidity are key parameters that require due attention for the stable BF operation. The varying Al₂O₃ content in slag increases the viscosity of slag and thus hinders the separation of slag from hot metal during the casting process. This leads to the deterioration of hot metal quality because of the entrapment of slag during the slag–metal interfacial reaction. In this work, an attempt is made to utilize the high alumina content raw materials and to reduce the Al₂O₃ content in the final slag. The high alumina content in slag increases the liquidus temperature and viscosity of slag and causes an adverse effect on BF operations. To countermeasure the effect of alumina, slag volume is increased and basicity along with MgO was increased. It has been demonstrated that MgO addition as a flux is effective for compensating the effect of a high alumina burden. By increasing the MgO in slag, fluidity was maintained to ensure easy separation of slag from hot metal.

KEYWORDS:

• Blast furnace
• burden
• high alumina
• viscosity
• fluidity
• slag
• casting

Acknowledgements

We would like to acknowledge the entire blast furnace operation and technology group of Tata Steel Jamshedpur, India, for extending their operational knowledge and making the process data from the furnace available for present insight. We are also grateful to the Automation Division & IT Shikhar, Jamshedpur, Tata Steel for providing us an opportunity to carry out the above work.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Ashish Agrawal http://orcid.org/0000-0002-5550-0147