Method for preparing hydrogen fluoride and coproducing white carbon black with silicon tetrafluoride

The invention discloses a method for preparing hydrogen fluoride and coproducing white carbon black with silicon tetrafluoride, comprising the following steps: letting crude silicon tetrafluoride as byproduct from a phosphate fertilizer be subject to dedusting and dehumidification, then reacting with steam with the reacting dose for hydrolysis at the temperature of 200-800 DEG C, carrying out gas-solid separation on the obtained products to respectively obtain hydrogen fluoride and white carbon black. According to the invention, the low grade silicon tetrafluoride as byproduct of fluorine resources is used for preparing high purity absolute hydrogen fluoride and coproducing gas phase white carbon black, thus a novel method for producing gas phase white carbon black is developed, a novel technology of preparing gas phase white carbon black at low temperature is realized, the energy consumption in the preparation is reduced, the raw material is easily available, the price is low, the utilization rate of the raw material is low, and a cost advantage is achieved compared with traditional production method of absolute hydrogen fluoride. The invention can create good economical benefits, and bring huge environmental benefits and social benefits, belonging to a clean production process.