Effects of Fluorides on Mullitization of SiO2-Al2O3 System,Korean Kaolin

초록

Kaolin without any addition of fluorides began to be transformed into the mullite at 1100 C. Mullite peaks were disernible in the X-ray diffraction patterns of the specimens which contained fluorids equivalent to about 2 wt % fluorine,and which were sintered at 1050 C. Experiments showed that mullite could be formed at 950 C from kaolin mixed with 3.4% fluorine. The orders of acceleraters for mullitization were as follows; (1)NA2SiF6 (2)NaF (3)AlF3 (4)KF (5)NH4F (6)MgF2 (7)CaF2.