9. Scaffolding

The damage caused by accretion to the blast furnace is very serious. It is because that the accretion on higher part of stack is difficult to remove by smelting and generally it is necessary to stop the smelting to remove it by explosion, which needs to open holes on the sealed furnace body in general situation and sometimes needs to remove the cooling staves and lining. This is not only the loss of production, but also a serious damage to furnace body. Although the accretion in the middle and lower parts of the stack can be flushed away, the loss and destructiveness are also amazing. There was a 300 m³ small blast furnace, for the treatment of removing accretion, more than 1000 t of coke and 200 t fluorite were consumed in 20 days before and after and the output loss was more than 2000 t [1]. There was also a blast furnace, due to the late discovery of the accretion, the blast furnace was abnormal for a long time, and the loss was very much. Therefore, the prevention of accretion is really the primary task of blast furnace operators.