EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

During initial blow-in of the blast furnace the hearth refractory system could experience high temperatures. Over time, skull formation on the hot face of refractory results in temperature reduction within the hearth refractory. Such temperature fluctuation may generate undesirable refractory cracking and/or gap formation, particularly around ramming mixture. These flaws could increase the thermal resistance of refractory system; thus, reducing the efficiency of hearth cooling system. The higher temperatures in the hearth refractory accelerate the refractory erosion and limit the hearth campaign life. This paper presents a novel tool for assessing the impact of temperature fluctuation on the structural integrity of hearth refractory. Using this tool, locations of potential refractory damages during blow-in and blow-down of the furnace can be identified and mitigated during design stage. This tool can also be utilized in order to explain the hearth refractory wear in existing furnaces.