Evolution in properties of high alumina castables containing basic zinc carbonate

To improve the properties of high alumina castables containing calcium aluminate cement (CAC) after firing at elevated temperatures, micro-sized basic zinc carbonate (BZC) was introduced as ZnO-based nano fragments into castables. To account for the influence of BZC on the evolution of castable properties, the phase composition and microstructure of castable matrices were examined with X-ray diffraction and scanning electron microscopy equipped with energy dispersive spectroscopy, respectively. Properties of castables having BZC were compared with those with Zn(OH) 2 . Results show that strength of castables added with BZC after firing at both medium temperatures and 1550 °C was improved. The volume stability and hot modulus of rupture at 1550 °C of fired castables containing BZC were also enhanced.