EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

Based on the investigation results of carbon brick damage of 4BF at Baosteel, this paper discussed the viewpoint that maintaining a stable solidified iron layer(protecting layer) on hot surface of carbon brick is the key for prolong campaign life of hearth and expounded the importance of ensuring higher heat transfer effect of carbon brick construction system. The paper expatiated the operation and maintaining measures to control rising hearth sidewall temperature and erosion of large size blast furnaces at Baosteel, such as improving permeability of deadman and decreasing circuiting flow density of hot metal in hearth by increasing blast energy or lower PCI operation; prolong length of the tapholes; carbon slurry grouting at taphole area, and so on. Key words large blast furnace; hearth; solidified iron layer on the hearth sidewall; operation and maintaining measures to prolong campaign life of hearth