Mica melt crystallization behavior

    People in order to synthesize large crystals of pure mica , mica always want to melt crystallization from start to finish this whole process only precipitate a crystalline phase . But the truth is far from it , because the melt crystallization behavior of its composition, the heating process , the size and shape of the container as well as the synthesis of other factors. Noda Japanese scholars findings indicate Inayoshi melt fluorphlogopite theoretical component is initially precipitates magnesium olivine , with lower melt temperature , forsterite again dissolved into the melt , and then precipitated mica crystals. The results of this study concluded with the United States Bureau of Mines Hatch , who is the same . The excess , if any, exist in the melt MgF2 , it is not the beginning of the forsterite crystal phase , but the mica. Since then, Noda et al Inayoshi further study the effects of heat on the melt crystallization process behavior . That the melt can cause excessive heating of the melt , such as severe cold , then the precipitated crystals are almost all particulate attapulgite , but the sample was again placed under a relatively low temperature (1250 ℃) for 2h , the particulate attapulgite Stone showed a decreasing trend , and re- precipitation of mica crystals. They think will happen then melt the following reaction :
   2KMg3 AISi3 010 F2 - '2 KAISi2 06 +2 (Mg2.Si04.MgF2)
    Thus, the cooling rate of the melt can not be too fast, otherwise it will lead to the formation of large olivine crystals or grains humite . They also confirmed that the fluorine content of the melt in a little excess mica crystallization is advantageous.