叶蜡石加热相变及其演化特征

Heating Phase Transformation and Evolutionary Characteristics of Pyrophyllite

通过对叶蜡石20～1 300℃热处理产物进行系统的差热分析、X射线衍射分析和红外光谱分析等的研究,发现叶蜡石加热相变过程具有明显的阶段性.根据主要物相及其变化和组合特征,可以将叶蜡石的加热相变过程分为4个阶段,即叶蜡石阶段(室温～660℃)、偏叶蜡石阶段(660～1 100℃)、不定形SiO2 与莫来石形成阶段(1 100～1 200℃)、莫来石与方石英共存阶段(≥1 300℃).

The characteristics of heating phase transformation of pyrophyllite during 20～1 300℃ are studied by DTA analysis, X-ray diffraction analysis and IR spectra analysis. The results show that the phase transformation of pyrophyllite occurs stage by stage during heating. According to the major phase and their assemblage, four stages can be devided, i.e., the pyrophyllite stage(indoor temperature660℃),pyrophyllite anhydride stage(6601 100℃),amorphous SiO_(2) and mullite crystallite forming stage(1 1001 200℃), and coexistence stage of mullite and cristoblite(≥1 300℃).