Measurement of the Volume Expansion of SiC Refractories Induced by Molten Salts Corrosion

摘要

Silicon carbide refractories are used successfully in municipal solid waste-to-energy facilities (WtE). The corrosion of Silicon Carbide (SiC) refractories with oxide bonding by molten salts was reproduced at the laboratory scale with environment conditions close to those present in incinerator plants in order to describe the corrosion mechanisms. The experimental corrosion agreed quite well with the corrosion of "post mortem" SiC-based tiles. Corrosion induces the formation of parawollastonite (CaSiO_3), grown from SiC aggregates, in the porosity. The volume expansion due to the phase change was measured by means of a coordinate measuring machine (CMM). Around 1.5% volume expansion was observed when the sample was corroded by molten salts against 0.0.5% for the uncorroded sample. This paper reports the corrosion mechanisms of SiC refractories with oxide bonding and the induced volume expansion.