EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

Pohang No. 4 Blast furnace, inner volume 5600m3, was relined and blowed in at 8th October 2010. The first failure in copper stave cooling channel was found on 20th. June 2014, 44months after blow-in, in belly. When the copper stave cooling channel in blast furnaces had been damaged in POSCO, cooling plates were installed from the outside of furnace shell to recover cooling function in the past. However, shell crack or hot spoats on the shell was repeated due to insufficient cooling power and refractory. It is decided to replace the old staves to new designed ones whose defects are supplemented, in order to minimize the harmful impact on furnace shell. The new designed copper staves installed from 2 Nov. 2015 in Pohang No. 4 BF to exchange the old ones which have had cooling channel failure. The front refractory brick in the new designed copper stave has been not damaged since it was installed, over 1 year. The new designed cu-stave is designed for distributing stress between refractory brick and stave as well as inter-refractories. It is expected that this innovatively designed cu-stave can prolong the service life of most of Cu-stave BF dramatically.