Corrosion behavior of carbon composite brick in high alumina slags

The corrosion behavior of carbon composite brick used in blast furnace hearth by CaO-SiO2-MgO-Al2O3-Cr2O3-based slag with and without B2O3 at different rotation speeds and temperatures was investigated in this work. The radius decrement of the brick increased with the increase of rotation speed, temperature and content of B2O3 in slag. Furthermore, the square of the radius decrement of brick changed linearly with the immersion time, indicating that the dissolution of the brick into slag may be controlled by the mass diffusion step. A slag penetration layer or product layer may be firstly formed during the corrosion process of carbon composite brick in slags, and then the components of brick dissolved into the molten slag by diffusing through this layer. The corrosion of the carbon composite brick by B2O3-containing slag is much severer than that by slag without B2O3 due to the lower viscosity and melting temperature of B2O3-containing slag.