Cast copper cooling staves have been newly developed to prolong blast furnace campaign life. Mathematical analysis by using the finite element method was carried out to investigate the thermal and mechanical characteristics of both the conventional cast iron and cast copper cooling staves. These calculation results showed that temperature of cast copper cooling staves was lower than that of cast iron cooling staves due to the higher thermal conductivity and the temperature distribution of cast copper cooling staves became uniform. As a result, thermal stress of cast copper cooling staves, caused by temperature difference, was much lower than that of the cast iron type.
According to approval examination of test staves at actual blast furnace, heat flux through the copper staves was estimated the same level as the cast iron staves by the help of formation of slag accretion layer on the surface of the staves. It became clear that there was no difference between rolled and cast copper staves in practical use although thermal conductivity of cast copper was slightly lower than that of rolled copper. Therefore, it was favorable to use cast copper staves from the viewpoints of the easiness of manufacturing and economical reason.
In the case of high rate injection of pulverized coal, peripheral gas flow tends to be intensified at the lower part of blast furnace. It was considered that cast copper staves were particularly effective for long life campaign in such a high heat load condition.
