贵州毕节毛家屯粘土的理化及工艺性能研究

Physico-Chemical and Processing Properties of Maojiatun Clay from Bijie City of Guizhou Province

从矿山采集具有代表性的粘土，球磨并过80目筛备用。利用X射线荧光光谱仪（XRF）、X射线衍射仪（XRD）、综合热分析仪（DTA—TG）、场发射扫描电子显微镜（FE—SEM）和透射电子显微镜（TEM）对粘土的化学成分、矿物组成、理化性质和微观形貌进行了表征，并详细考察了其多项工艺性能指标。研究结果表明：该粘土的主要矿物组成为高岭石（32．17wt.％）、伊利石（49．03wt．％）、蒙脱石（8．53wt．％）、石英（6．72wt．％）和锐钛矿（3．36wt．％），呈典型的片层状结构。该矿物原料可塑性非常好，阳离子交换容量很高，流动性较小，触变性较大，干燥收缩很大，干燥强度较低。由于该粘土矿物中碱金属和碱土金属总含量不高（4．02wt．％），因此烧结温度较高（烧结温度范围为1250℃-1300℃），并且其含有较多的Fe2O3（1．34wt．％）和TiO2（3．36wt．％），导致烧成（1250℃）白度较低，仅为34．84％。

The representative clay samples were collected from Maojiatun in Bijie city of Guizhou province, then ball-milled and screened with an 80-mesh sieve for analysis. The chemical composition, mineral composition, physico-chemical properties and microstructure of these samples were characterized by XRF, XRD, DTA-TG, FE-SEM and TEM. Their processing properties were investigated. The results indicate that the main mineral components of the clay are kaolinite （32.17wt. %）, illite （49.03wt. %）, montmorillonite （8.53wt. %）, quartz （6.72wt. %） and anatase （3.36wt. %）. In typical sheeting or layered structure, it shows very good plasticity, high cation exchange capacity value, less liquidity, high thixotropy, large drying shrinkage and low drying strength. Due to its low content of alkali and alkaline earth metal oxides （4.02wt. %）, it＇s sintered at a relatively high temperature （1250℃~1300℃. And also, its relatively high content of Fe2O3 （1.34wt. %） and TiO2 （3.36wt. %） leads to low firing whiteness, which is only 34.84% when sintered at 1250℃.