Preparation of CaO aggregates by granulation method: effects of aluminate ester impregnation on its hydration resistance and thermal shock resistance

Abstract

Calcium oxide refractories exhibited stable high-temperature properties and used for smelting ultra-pure high-temperature alloys. CaO aggreates are an important component in the preparation of CaO refractories. This work focuses on the preparation of CaO aggreates by granulation method based on the decomposition of aluminates coupling agents impregnated CaCO₃.The hydration resistance, mechanical properties, and thermal shock resistance of the CaO aggreates are analyzed. The main objective of this research is to introduce alumina into CaO aggreates through impregnation, to obtain CaO aggreates with enhanced hydration resistance and good thermal shock stability. The results indicated that the CaO aggreates impregnated with the coupling agent exhibit significantly improved hydration resistance and compressive strength. It was found that the introduction of alumina promoted liquid–phase heating, facilitated the growth of CaO grains, and increased the heating density of the aggreates. The thermal shock resistance of CaO aggreates was improved obviously through this preparation process.