水洗高岭土活化特性及评价方法

Activation Characteristics and Evaluation of Water-Washed Kaolin

采用钙吸收值、氢氧化钙吸收峰和抗压强度对热活化偏高岭土活性进行评价,并结合原位高温XRD分析了两种水洗高岭土的热活化过程。试验结果表明:钙吸收值与抗压强度值呈正相关,钙吸收值与氢氧化钙吸收峰面积呈负相关;相同温度热活化的茂名水洗高岭土的活性高于热活化的北海水洗高岭土,且均在650℃时活性最大;在热活化过程中结晶度高的水洗高岭土(001)与(002)晶面更容易被破坏。

The activity of thermally activated metakaolin is evaluated by calcium absorption value,calcium hydroxide absorption peak and compressive strength,and the thermal activation processes of two kinds of water-washed kaolin were analyzed by in-situ high temperature XRD.The results show that the calcium absorption value is positively correlated with the compressive strength,and the calcium absorption value is negatively correlated with the area of the XRD peak of calcium hydroxide.When calcined at the same temperature,the pozzolanic activity of thermally activated kaolin in Maoming(KM)is higher than that of kaolin in Beihai(KB),and both obtained the highest pozzolanic activity at 650℃.The lattice plane(001)and(002)of water-washed kaolin with high crystallinity is easier destroyed than the water-washed kaolin with poor crystallinity during the thermal activation processes.