The performance of micropore carbon and its performance at other furnaces was investigated. The study provided insight into the classic hearth failure mechanisms and enabled further development of hearth design. Micropore carbon was developed by adding alumina and silicon to increase resistance to dissolution and to reduce pore size. This was done to reduce localized erosion and embrittlement. The hearth condition at blast furnace revealed various types of cracking and the extensive presence of a deteriorated zone.