The temperature, pressure, physical and chemical changes, strength, and severity of working conditions experienced by the furnace lining at each height in the blast furnace are different, and the mechanism and condition of lining damage are also different. Therefore, the selection of refractory materials is also significantly different.

Working conditions of refractory materials for blast furnace lining

The working temperature of each part of the blast furnace is 1450-1800 ℃ in the bottom and hearth area, 400-1600 ℃ in the belly and waist area, and 600-800 ℃ in the upper part of the furnace body.

The masonry of each part of the blast furnace is subjected to mechanical effects such as friction and impact of the descending burden, erosion and wear of the dust contained in the rising gas, erosion of alkali metal oxide vapor, carbon deposition during gas decomposition during combustion at 400-600 ℃, chemical erosion of molten metal and slag, and infiltration of high-temperature molten iron and lead.

Therefore, the overall technical requirements for refractory bricks used in blast furnaces are: good volume stability at high temperatures, high mechanical strength, good stress resistance, dense structure, low porosity, good slag resistance, and low iron oxide content.