Occurrence State and Behavior of Carbon Brick Brittle in a Large Dissected Blast Furnace Hearth. Issue 11 (6th August 2021)

• Record Type: Journal Article
• Authors: Guo, Ziyu; Zhang, Jianliang; Jiao, Kexin; Zong, Yanbing; Wang, Zhongyi
• Is Part Of: Steel research international. Volume 92:Issue 11(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-08-06
• Subjects: blast furnaces -- carbon bricks -- disappearing mechanisms -- erosion mechanisms -- harmful elements; Steel -- Periodicals; Steel -- Metallurgy -- Periodicals; 669.142
• DOI: 10.1002/srin.202100273
• Languages: English
• ISSNs: 1611-3683

Abstract

Abstract : The thickness of the carbon bricks is one of the important factors of the longevity of the blast furnace. Herein, a large number of brittle carbon bricks in the hearth sidewall and the continuous rectangle‐shape floating refractory in residual iron are found during the blast furnace hearth dissection. The occurrence state of the carbon brick is characterized through chemical analysis, X‐ray diffraction (XRD), and scanning electron microscope (SEM)–energy‐dispersive X‐ray spectroscopy (EDS). The contents of K, Na, Cl, Zn, and Fe in brittle carbon bricks are relatively high, and a large number of large‐scale Al2 O3 phases and nepheline appear in the floating carbon brick. It indicates that K, Na, Cl, Zn, and Fe are major causes for the serious erosion of the carbon brick, and the floating carbon brick may come from brittle carbon bricks on the sidewall. In addition, the source of Al2 O3 and the consumption pathway of SiO2 and ZnO in floating refractory in residual iron are analyzed. Finally, the disappearing mechanism of carbon brick is proposed, which is that the carbon bricks floated up to the tuyere and burnt. Abstract : Based on the brittle carbon brick in the hearth sidewall and floating refractory in residual iron during the blast furnace dissection, the occurrence state of the hearth carbon bricks is characterized by chemical analysis, X‐ray diffraction (XRD), and scanning electron microscope (SEM)–energy‐dispersive X‐ray spectroscopy (EDS). The erosion and disappearing mechanism of the carbon bricks are proposed.