苏州高岭土在不同温度下的结构与性能

The Structure and Property of Suzhou Kaolin at Different Temperature

采用XRD、IR、TG/DSC、SEM检测苏州高岭土在100℃～1300℃不同温度下的煅烧产物,分析其结构及形态变化,并测试白度及吸油值。实验结果表明:随着煅烧温度的升高,苏州高岭土先从结晶有序的高岭石转化成无定型的偏高岭石,然后重新结晶,转化成莫来石。其形态先由片状和管状变成颗粒状团聚体,之后少部分变成针状短柱状的莫来石。随着煅烧温度的升高,白度先略有降低,然后一直上升,至1000℃～1300℃,白度基本恒定,吸油值先增大后减小。在800℃～900℃,白度达90%,吸油值最高,为78.3g/100g,该温度煅烧高岭土可用作造纸涂料或高级电缆填料用的有机改性高岭土原料。

Suzhou calcined kaolin samples at different temperature of 100-1300℃ were test by XRD, IR, TG/DSC and SEM to study their structures. The whiteness and the oil absorded value were test to analysis their property. The results showed that Suzhou kaolin was first transformed from crystal kaolinite to unformed metakaolinite and later to mullite by recrystallization with the temperature rising. Its shape was changed from sheet and pipe-like to grain reunite, and later to a few pin-like mullite. The whiteness was kept invariableness at 1000-1300℃ after a little down at low temperatures. The oil absorbed value was first rise and later down with the temperature rising. The whiteness is 90% and the highest oil absorbed value is 78.3g/100g at 800℃. The kaolin calcined at this temperature can be used as paper coating and as the start material of organic modification of excellent cable filling