Industrial method for producing silicon-free hydrogen fluoride

The invention provides an industrial method for producing silicon-free hydrogen fluoride, which includes the following steps: (A) placing aluminum in a first reactor and increasing the temperature to 700-1050 DEG C, adding one or a mixture of more than one of potassium fluotitanate, potassium fluoborate and potassium fluozirconate to the first reactor, stirring the components for 0.5-4 h, allowing the components to stand for 2-4 h and withdrawing a molten liquid on the upper layer to obtain potassium cryolite; (B) according to ratio, adding a certain amount of concentrated sulfuric acid in a second reactor, and adding the potassium cryolite to the second reactor, stirring the components for 0.5-3 h, and controlling reaction temperature to be 200-300 DEG C, allowing the components to stand for 3-4 h, and collecting escaped gas to obtain the silicon-free hydrogen fluoride. In the method, firstly the potassium cryolite is prepared through special steps and then is reacted wit the concentrated sulfuric acid to ob