Structure characteristics and partial relining investigation of a compound hearth

Structure characteristics of compound hearth with self-baking carbon block and ceramic brickwork were examined for the No.7 BF at Anshan Iron and Steel Company, and some weakness on the hearth design were discussed in detail. Analyses of the investigation results about the blowing out for partial relining after five year service reveal that chief causes of the looseness and brittleness of the carbon block at some local areas from first to third layers under the BF's tuyers are respectively that temperature is not high enough to bring about the graphitization of the carbon block, that alkalic metals entering the carbon block causes a chemical erosion and that the looseness and brittleness are intensified by water sprayed cooling after the blowing out.