Sinterability of Calcium Oxide Prepared by Heating Mixture of Calcium Carbonate and Calcium Hydroxide

Abstract

Sinterability of CaO prepared from Al₂O₃ coated CaCO3-Ca (OH) 2 powder was investigated in order to clarify effect of Ca (OH) 2 and small amount of Al2O3 content.The CaCO₃-Ca (OH) ₂ mixed powders were coated with a chelate compound of aluminum corresponding to 0-0.1mass%Al₂O₃. The CIP'ed compacts of the powders were sintered at a rate of 300°C·h^-1 up to 1500°C in air and held at 1500°C for 2h to prepare CaO ceramics. The bulk density and fine structure for the CaO ceramics were measured in process of sintering. The bulk density for the CaO ceramics prepared from CaCO₃-Ca (OH) ₂ mixed powder was higher than that from CaCO₃ powder at the temperature above 800°C. The bulk density of the CaO ceramics was slightly increased with increase of Al₂O₃ content, while the CaO grain size was greatly increased with Al₂O₃ content.