摘要
To obtain CaO clinker with high density, low po- rosity, and good hydration resistance, the effect of the La2 03 content on physical properties, such as sintering property and hydration resistance of CaO clinker was re- searched in this paper. Apparent porosity and bulk density were measured by Archimedes principle with kerosene as the medium. Two methods were used to test hydration resistance of CaO clinker. One was carried out in a hu- midity cabinet at 20℃ with 90% of relative humidity. Another was the boiling method. SEM and EDS charac- terization analyses of CaO clinker were pe.rformed to observe the microstructural information and the hydration mechanism was put forward. The results show that： （1） the specimen with 0.79 mass% of La2O3 addition has lower apparent porosity, and higher bulk density; （2） the hydration mass gain of CaO clinker with 0.79 mass% La2O3 addition is lower, which is less than 1% after 20 days ; （3） La2O3 mainly distributes in the grain boundary, attd a small amount of La203 dissolves in grains. The average grain size of CaO specimens with 0.79 mass% La2O3 addition sintered at 1 450℃, 1 550℃, and 1 650℃, is 44. 5 μm, 48. 6 μm, and 63. 5 μm , respectively; （4） solid solution is formed due to the similar ionic radius of La^3＋ and Ca^2＋, which promotes the sintering of CaO clinker and improves the hy- dration resistance simultaneously.
To obtain CaO clinker with high density, low po- rosity, and good hydration resistance, the effect of the La2 03 content on physical properties, such as sintering property and hydration resistance of CaO clinker was re- searched in this paper. Apparent porosity and bulk density were measured by Archimedes principle with kerosene as the medium. Two methods were used to test hydration resistance of CaO clinker. One was carried out in a hu- midity cabinet at 20℃ with 90% of relative humidity. Another was the boiling method. SEM and EDS charac- terization analyses of CaO clinker were pe.rformed to observe the microstructural information and the hydration mechanism was put forward. The results show that： （1） the specimen with 0.79 mass% of La2O3 addition has lower apparent porosity, and higher bulk density; （2） the hydration mass gain of CaO clinker with 0.79 mass% La2O3 addition is lower, which is less than 1% after 20 days ; （3） La2O3 mainly distributes in the grain boundary, attd a small amount of La203 dissolves in grains. The average grain size of CaO specimens with 0.79 mass% La2O3 addition sintered at 1 450℃, 1 550℃, and 1 650℃, is 44. 5 μm, 48. 6 μm, and 63. 5 μm , respectively; （4） solid solution is formed due to the similar ionic radius of La^3＋ and Ca^2＋, which promotes the sintering of CaO clinker and improves the hy- dration resistance simultaneously.
