叶蜡石及蜡石质釉面砖坯焙烧过程物相变化的X射线研究

An XRD Study of Phase Changes during Firing of Pyrophyllite and Pyrophyllitic Tile Bodies

利用ｘ射线衍射分析对叶蜡石及蜡石质釉面砖坯在不同温度下焙烧的物相变化进行了研究。结果表明叶蜡石约在６００℃脱去羟基后晶体结构基本不变，直到１０５０℃分解。两类坯体焙烧后最终物相都是莫来石、方英石、石英及玻璃质。出于蜡石质釉面砖坯配料中存在含Ｋ_２Ｏ的伊利石等杂质，使叶蜡石晶体破坏，新矿物莫来石，方英石的生成温度较低。

Phase changes of pyrophyllite and pyrophyllitie tile bodies firing of different temperatures have been studied by using XRD.Pyrophyllites are dehydroxyllated at about 600℃ and their crystal structures keep almost unchanged until 1050℃.The final phases in both tile bodies are mullite,cristobalite,quartz and glass.However,the new minerals such as mullite and cristobalite form at a lower temperature in pyrophyllitie tile than in pyrophyllite tile body due to the existence of K_2O-bcaring illitc and other impurities in the pyrophyllitic tile bodies.