Investigation on lining erosion and stave damage of large blast furnaces at WISCO

Investigation and analysis on stave erosion of BF No.1, No.6 and No.7 in WISCO were carried out during their intermediate relining. The survey found that damaged cooling staves were mainly located at the joints between the hearth and the bosh. In addition, spheroidal graphite cast iron staves in the middle and lower parts of the shaft were also seriously damaged. Cooling staves located in other areas were essentially undamaged. Due to good heat transfer performance, copper cooling staves were applied in the high heat load area of the BF. As a result, they provide the requirements for long campaign life. The research showed that structural design at the junction between the hearth and the bosh was the main factor that caused severe breakage of the cooling staves. Based on these findings, a new design of connecting structure between the hearth and bosh was proposed and adopted by WISCO during intermediate relining. With this new design, the stave damage problem was successfully solved and the campaign life of blast furnaces at WISCO has been significantly extended.