Dissection Investigation of Forming Process of Titanium Compounds Layer in the Blast Furnace Hearth

• Published in: ISIJ International Vol. 60; no. 11; pp. 2385 - 2391
• Main Authors: Gao, Kai, Jiao, Kexin, Zhang, Jianliang, Zhang, Lei, Wang, Cui, Gong, Weimin, Zheng, Jingxian, Zhang, Haibin
• Format: Journal Article
• Language: English
• Published: The Iron and Steel Institute of Japan 15.11.2020
• Subjects: acid attack; boundary migration; hearth; ironmaking; Ti(C; titanium compounds layer
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.ISIJINT-2020-146

In this paper, titanium compounds samples were obtained by dissecting the blast furnace for which protected the hearth by adding titanium ores for a long time, and the formation process of the titanium protective layer in the blast furnace was deduced. It was found that Ti(C, N) precipitated in the molten iron initially, and then grew up in the slag by grain boundary migration between grains. Finally, Ti(C, N) grains consolidated with slag and iron to form a protective layer. Furthermore, the 3D morphology of the precipitated phase of Ti(C, N) was also observed by the acid attack method, found that the Ti(C, N) grains mainly in the form of the layered structure and stepped rectangular structure. Besides, the internal of the Ti(C, N) grains was not dense packing. The above results can provide an in-depth understanding of furnace protection with titanium ores.