OXIDATION OF SILICON CARBIDE: INLUENCE ON THERMAL EXPANSION OF SiC CASTABLES USED IN WASTE-TO-ENERGY PLANTS

摘要

This paper reports results concerning the oxidation of silicon carbide of pure SiC powder (98% of SiC) and the oxidation of two silicon carbide castables containing 60% and 85% of SiC, respectively. The studied castables are used in waste-to-energy plants (WTE). The investigated temperature range (800-1200°C) corresponds to typical service conditions in WTE.Thanks to thermogravimetric and thermal expansion tests, kinetics of oxidation of the powder of SiC and of the castables have been investigated. According to these tests, several important points have been underlined. Firstly, the oxidation of SiC has a high influence on the thermal expansion and on weight gain of SiC castables. Secondly, the grain size distribution of SiC within castable is a key point according to the evolution of thermal expansion.