2002 Volume 9 Issue 296 Pages 17-22
30 mol%CaCO3-70 mol%Ca (OH) 2 mixed powder which is coated with a chelate compound of aluminum corresponding to 0-0.1 mass%AL2O3 was sintered at 1500°C for 2 hours to prepared calcia ceramics of 3-5 mm particle size. The open porosity of the 0.1 mass%AL2O3-containing calcia ceramics was lower than that of fused calcia. Fraction of residual CaO in the 0.1 mass%AL2O3-contained calcia was 90% and 45%. respectively, after dipping in water at room temperature and 85°C for 24 h, while that in the fused calcia was 56% and 3%, respectively. Hydration resistance of calcia ceramics containing small amount of AL2O3 was better than that of fused calcia. It was considered that the higher hydration resistance of the 0.1 mass%AL2O3-containing calcia ceramics was attributed to the lower open porosity.