Properties and microstructures of blast furnace carbon refractories with Al additions

Abstract

The effect of Al additions on the properties and microstructures of carbon refractories for blast furnaces was evaluated in terms of phase and microstructure evolutions as a function of the coking temperature. The formation and evolution of Al₄C₃, AlN and SiC crystalline phases in the matrix contribute to the excellent properties of such materials, namely high thermal conductivity and low mean pore diameter of open pores. The experimental results indicate that about 2–4 wt-%Al plus about 4–6 wt-%Si additions at ～1300°C were optimum for the manufacture of carbon refractories.