8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

Copper stave has been widely applied in large blast furnaces especially whose inner volume exceed 2000m3 due to high cooling capacity. In the past years, cooper staves suffered damages in some blast furnace, dwindling the campaign life of blast furnace. For this problem, the damage mechanism of the cooling stave was studied by analyzing the chemical composition, thermal conductivity, metallographic tissue and microstructure in this paper. It was found that the main reason for the damage of the cooling stave was not the cooling stave itself but its working condition. Firstly, the poor quality of the coke and the large furnace angle promoted the development of the marginal airflow, which intensified the erosion of refractory materials, resulting in a large area of slag crust fall-off and the damage of the cooling water pipe. After the remedy, the cooling capacity of the cooling stave was still reduced. And the temperature was easy to rise, especially when the temperature reached 370℃,the hydrogen embrittlement happened. Those two reasons led to the rapid decrease of the ability of adhering slag. Finally, the erosion of marginal airflow caused the damage of cooling stave.