Improvement in hydration resistance of CaO granules based on CaO-TiO2, CaO-ZrO2 and CaO-V2O5 systems

In this paper, CaO granules were prepared, using the slaked lime as the raw material as well as ZrO2, TiO2, and V2O5 as additives, respectively. The influence of different additives on the sintering properties, microstructure and hydration resistance of CaO granules was investigated. The results indicated that the introduction of additives could obviously promote the densification and the hydration resistance of the specimens. Especially, the sintering mechanisms of the specimens with different additives were studied. For the specimens with ZrO2 and TiO2 as additives, the in-situ formed CaZrO3 and Ca3Ti2O7 between grain boundaries promoted the densification to enhance the properties of the granules. However, the adding of V2O5 generated a coating on the surfaces of CaO granules which contributed to the best hydration resistance.