Effect of micro-sized hydromagnesite addition on the properties of calcium aluminate cement-bonded castables

摘要

To assess the viability of micro-sized hydromagnesite as a precursor in refractory castables bonded with calcium aluminate cement, the volumetric stability and thermo-mechanical properties of high-alumina castables containing different micro-sized hydromagnesite amounts (0-1.6 wt%) after firing at 1550 degrees C were investigated. Phase composition and microstructure evolution in fired castable matrices with different micro-sized hydromagnesite contents were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Dimensional stability, hot modulus of rupture and thermal shock resistance of castables were improved by adding micro-sized hydromagnesite. The microstructure evolution in castable matrix added with micro-sized hydromagnesite was discussed to understand the mechanism of enhanced volume stability and thermo-mechanical properties.