Effect of Carbon Aggregates on the Properties of Carbon Refractories for a Blast Furnace

The effect of carbon aggregates on the carbon refractory properties for a blast furnace was studied with X-ray diffraction (XRD), scanning electron microscopy (SEM), an energy-dispersive X-ray, mercury porosimetry, a resistivity instrument, and a laser thermal conductivity meter. The results showed that the microporous structure of a sample was determined by the amount of β-SiC whiskers. The thermal conductivity was controlled by the thermal conductivity of the corresponding carbon aggregate, and the alkali and molten-iron attack was decided mainly by the pore and the graphitization degree of aggregate, respectively. For samples using calcined anthracites as aggregates, the microporous structure became worse, the thermal conductivity increased, and the molten-iron as well as the alkali attack became more severe with an increase in the anthracite calcining temperature. For all samples, microcrystalline graphite possessed the best microporous structure and the least alkali and molten-iron attack, whereas the graphite electrode scraps had the highest thermal conductivity and the most severe alkali and molten-iron attack.