Damage investigation of WISCO No.1 blast furnace hearth and mechanism of carbon brick erosion
XIAO Zhi-xin1, LI Xiang-wei2, CHEN Xu-heng3, WANG Wei3
1. Institue of Ironmaking Technology, R&D Center of Baosteel Central Research Institute(Qingshan), Wuhan 430080, Hubei, China; 2. Ironmaking Plant, Wuhan Iron and Steel Co., Ltd., Wuhan 430080, Hubei, China; 3. School of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan 430080, Hubei, China
Abstract：It is of great significance to guide the operation of blast furnace and prolong service life of blast furnace by mastering erosion state of WISCO No.1 blast furnace hearth and clarifying destruction process of carbon brick and its erosion mechanism. The damage of WISCO No.1 blast furnace hearth was investigated by drilling core samples. Erosion characteristics of residual carbon bricks in the blast furnace hearth was studied by chemical analysis, optical microscopy and scanning electron microscopy. The results show that the overall erosion of WISCO No.1 blast furnace hearth is in the shape of "pot bottom", and the erosion near the taphole area is more serious than that in the non-taphole area. Down from the center line of the blast furnace taphole, the length of intact layer in residual carbon brick gradually becomes shorter, and the length of broken layer gradually becomes longer. The harmful element potassium is present in the form of silica-aluminates, zinc and sodium are present in the form of oxides, and lead is present in the form of sulfides in carbon bricks. Along the radial direction of furnace hearth, the bulk density of residual carbon bricks increases first and then decreases, and reaches the maximum in the enrichment area of harmful elements. The main reasons for the destruction of carbon brick structure are thermal stress, enrichment of harmful elements and iron penetration.
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2023, Vol. 33 
