ON THE WALL EROSION OF THE BLAST FURNACE
Koretaka Kodama, Kazumi Miyatake, Naoto Nakamura, Masashi Kase
Recently the life of a blast furnace has a tendency to be decided by the damage of wall bricks at the shaft. Higashida No. 5 blast furnace in Yawata Steel Works was one of these examples, too. This furnace had been operated for about seven years, and during the campaign the shaft-wall-brick had expanded and forced the charging assembly upwards about 1m. Consequently it was obliged to be blown out. In the dismantling work of the furnce the state of erosion and the changes of physical and chemical properties of bricks were investigated. And the structural changes of bricks were investigated with micro-photographs. The result of this investigation showed to a certatin extent the mechanism of brick degradation by alkalis, CO, Zn, Pb etc. in furnace gas penetrating through its pores, and the following counter-measures were devised.
1. Use of bricks of compact structure.
2. Shell-type construction with many cooling plates.
3. Limitmg the use of raw material containing large amount of alkalis, Zn, Pb etc.