Production process for synthesizing hexafluoroethane by hydrogen fluoride catalytic fluorination method

The invention discloses a production process for synthesizing hexafluoroethane by a hydrogen fluoride catalytic fluorination method, and relates to the technical field of chemical processing. The preparation method comprises the following steps: purifying a mixed material of by-products R115 and R125 from an R125 device, wherein the purified mixed material is used as a raw material, and comprises90-95% of R115 and 5-10% of R125; and carrying out fluorination catalytic reaction with HF in a reaction kettle under a certain pressure and temperature condition to obtain first mixed gas, wherein the main chemical reaction is as follows: C2F5Cl+HF->C2F6+HCl, the reaction temperature is 350-550 DEG C, and the reaction pressure is 0.3-0.9 Mpa. According to the invention, by adopting the technicalscheme, the purified mixed material of chloropentafluoroethane and pentafluoroethane (the content of R115 is 90-95%) and anhydrous hydrogen fluoride are used as raw materials, and a gas-phase materialis subjected to catalytic