Abstract:Adding titanium containing burden to the blast furnace is one of the measures to protect the furnace hearth. The mechanism of protecting the furnace is not yet clear, and the effectiveness of use varies greatly. Titaniumbearing material use for a long time will also bring some adverse effects on the blast furnace operation. Therefore, the protection mechanism and the failure reason of titaniumbearing material were discussed. The reasonable range of TiO2 content in slag, TiC precipitation temperature in molten iron and the corresponding titanium content were systematically investigated by thermodynamic calculation method so as to guide the production practice and provide a theoretical basis for the operation parameters selection of titaniumbearing material protection for blast furnace operators. The results show that titaniumbearing material protection is mainly achieved by the dual action of reducing the flow rate of molten iron and promoting the formation of composite protective layer of carbon brick. To achieve better protective effect, it is necessary to eliminate the air gap of the hearth sidewall to ensure the integrity of the heat transfer system. Under the current calculation conditions, the TiO2 mass fraction in blast furnace slag, the TiC precipitation temperature in molten iron, and the titanium mass fraction in molten iron are controlled within the range of 1.5%-3.0%, 1300-1400℃, and 0.064%-0.11%, respectively, which can effectively protect the furnace and reduce its adverse effects.
NIU Qun,ZOU Zhongping,ZHAO Yunjian,WANG Gang.
Problems and discussion on blast furnace protection with titaniumbearing material[J]. Journal of Iron and Steel Research, 2023, 35(7): 851-860 https://doi.org/10.13228/j.boyuan.issn1001-0963.20220282