Final Conclusion on the Thermal Effects of Kaolinite
Before setting out to a conclusion of the critical analysis of structural transformation of kaolinite as described in Chaps. 19–25, it is important to recapitulate the past and present scenario on thermal decomposition of it. Kaolin at high temperature finally transforms to yield stable mullite phase and β-cristobalite as per the prediction of equilibrium phase diagram of the SiO2-Al2O3 system. Many investigations explained the fundamentals of the breakdown of kaolinite and the subsequent recrystallization of it to mullite. Although intermediate steps of reaction have been extensively studied the interpretations are full of controversies. It is reviewed that even with the application of many recent experimental techniques to resolve one of the most interesting crystallo–chemical problems of K-M reaction series, a few areas are yet to be solved or there is absence of general agreement on various issues.