WANG ZhuMei , LI YueMing , SHEN ZongYang , CHENG Yue , ZUO JianLin
(Jingdezhen Ceramic Institute,Key Laboratory of Advanced Ceramics of Jiangxi Province Jingdezhen Jiangxi 333001, China)
Abstract: Clay specimens were collected from Jinyinshan in Bijie, Guizhou, then ball-milled and screened through an 80-mesh sieve for analysis. The chemical composition, mineral composition, physicochemical properties and microstructure of the clay were characterized by XRF, XRD, DTA-TG, FE-SEM and TEM. Its various processing properties were also investigated. The results indicate that the main mineral composition of the clay includes muscovite (27.69wt%), kaolinite (33.12wt%), quartz (35.31wt%) and brookite (0.91wt%). It is of typical laminar structure. The clay shows very good plasticity, low cation exchange capacity, high liquidity, less thixotropy, small drying shrinkage and high drying strength. Due to its low contents of alkaline metal oxides and alkaline earth metal oxides (4.73wt%), the clay is sintered at a relatively high temperature (1250℃~1300℃). And also, its relatively high Fe2O3 (1.66wt%) and TiO2 (0.23wt%) contents lead to low firing whiteness, which is only 41.12% when sintered at 1250℃.
Key words: clay minerals; muscovite; kaolinite; processing properties; Guizhou