Pyrolysis method of fluosilicate

The invention relates to a pyrolysis method of fluosilicate, and belongs to the technical field of fluorine chemical industry. The pyrolysis method comprises the following steps: mixing fluosilicate and alkali metal fluoride according to a molar ratio of 1: (0.5-4), granulating to obtain composite particles, and then performing static pyrolysis on the composite particles to prepare SiF4, the particle size of the composite particles is smaller than 10 mm. The fluosilicate and the alkali metal fluoride are mixed and granulated, the alkali metal fluoride and the fluosilicate can realize trace solid solution at high temperature, the melting point of the fluosilicate is improved, the alkali metal fluoride is uniformly distributed around the fluosilicate particles in the mixed granulation, and the melting point of the alkali metal fluoride is higher than that of the fluosilicate. The fluosilicate particles reaching the melting point can be blocked by alkali metal fluoride, local melting is prevented, and the pyroly