Analysis of erosion mechanism for carbon bricks in blast furnace
CUI Yuan-yuan1, YANG Bin1, ZHONG Kai1, SHAO Jun-ning2
1. Iron and Steel Technology Department, Research Institute of Technology, Shougang Group Co., Ltd., Beijing 100043, China; 2. Manufacturing Department, Beijing Shougang Co., Ltd., Qian'an 064404, Hebei, China
Abstract:Two years after the opening of Shougang Qiangang No.2 blast furnace, the abnormal rise of water temperature occurred in the hearth, and it has been forced to add titanium to protect the furnace and control the smelting strength for a long time. The corrosion of carbon bricks is the key to exploring the corrosion of hearth. Through the chemical composition analysis, SEM and EDS, the abnormal erosion state and mechanism of carbon bricks in hearth of No.2 blast furnace were studied. The results showed that the carbon bricks in elephant foot area below the No.13 tuyere were mainly eroded by elements Fe, K and S, and the erosion depth of Fe was the deepest. In addition to the erosion of elements Fe, K and S, the carbon bricks in elephant foot area below the No.20 tuyere were also eroded seriously by Zn, but the erosion depth of Zn was less than that of Fe, K and S. The carbon bricks in the taphole area were mainly eroded by Zn and S, and a gas leakage phenomenon was near the carbon brick in the taphole area. There were cracks on the surface of carbon brick, elements at where were mainly Zn and S. There were uneven mixing in the core of carbon bricks, which would inevitably cause cracks in the carbon brick with temperature and pressure changing.