Preserving Copper Staves and Extending Blast Furnace Campaign Life
The failure of copper staves principally from abrasion wear can lead to an early reline at great cost to the blast furnace owner. Maintaining a robust protective accretion on the copper stave hot face is well known to protect the stave from abrasion related wear. Controlling the process conditions to achieve such a stable accretion is difficult due to the variable conditions within the blast furnace and a lack of reliable information on the accretion thickness. Hatch developed the Low Frequency Pulse Ultrasonic (LFPU) technology to address this situation and accurately measure both stave and accretion thickness insitu while the blast furnace is operating. Working from our long experience in the non-ferrous industries, Hatch developed a unique copper ‘finger’ cooler that can be installed into a damaged copper stave to restore cooling performance. Early measurement of the copper stave wear using the LFPU technology and the timely implementation of finger coolers can extend the copper stave service life in a predictable manner. Details of these two technologies are presented, and combined with a stable blast furnace operation these powerful tools can enable the industry to proactively extend the campaign life of copper stave cooled blast furnaces.